A Phase 1/2 Study of Galinpepimut-S in Combination With Pembrolizumab (MK 3475) in Patients With Selected Advanced Cancers
Phase: PHASE1
Conditions: Acute Myelogenous Leukemia, Ovarian Cancer, Colorectal Cancer, Triple-negative Breast Cancer, Small-cell Lung Cancer
Sponsor: Sellas Life Sciences Group

CLINICAL STUDY PROTOCOL SLS17-201/ MK3475-770 
IND # 18730 
 
CLINICALTRIALS.GOV IDENTIFIER:  
NCT03761914 
 
 
 
A PHASE 1/2 STUDY OF GALINPEPIMUT-S IN COMBINATION WITH 
PEMBROLIZUMAB (MK-3475) IN PATIENTS WITH SELECTED 
ADVANCED CANCERS 
 
PROTOCOL NUMBER SLS17-201/MK3475-770 
 
PROTOCOL v1.1 
AMENDMENT 1.0 
 

Sponsor: 
SELLAS Life Sciences Group, Inc. 
15 West 38th Street; 10th Floor 
New York, NY 10018 
United States of America 
 
 
Telephone:  +1-917-438-4352 
FAX:           +1-917-634-3413 
 
Medical Monitor: 
 
Nicholas J. Sarlis, MD, PhD 
Email: nsarlis@sellaslife.com 
 
Clinical Research 
Organization: 
 
Cancer Insight, LLC 
1422 E Grayson; 3rd Floor 
San Antonio, TX 78208 
United States of America 
 
 
Date of Original Protocol:  
8 January 2018 (original protocol) 
Date of Protocol v1.1 
(Amendment 1.0): 
 
12 April 2019 
 
CONFIDENTIAL  
All financial and nonfinancial support for this study will be provided by SELLAS Life 
Sciences Group. The concepts and information contained in this document or generated 
during the study are considered proprietary and may not be disclosed in whole or in part 
without the expressed, written consent of SELLAS Life Sciences Group. 
 The study will be conducted according to the International Council on Harmonisation 
harmonised tripartite guideline E6(R2): Good Clinical Practice (ICH GCP). 
 

SELLAS Life Sciences Group 
Galinpepimut-S 
Protocol: SLS17-201/MK3475-770 Protocol v1.1 (Amendment 1.0) 
12 April 2019 
 
Protocol Approval – Sponsor Signatory 
 
Study Title 
A Phase 1/2 Study of Galinpepimut-S in Combination with 
Pembrolizumab (MK-3475) in Patients with Selected Advanced 
Cancers 
Protocol Number 
SLS17-201/MK3475-770 
Protocol Date 
08 January 2018 (original) 
Date of Protocol v1.1 
(Amendment 1.0)  
12 April 2019 
 
Protocol v1.1 (Amendment 1.0) accepted and approved by: 
Chief Medical Officer and Study Medical Monitor 
SELLAS Life Sciences Group, Inc. 
Nicholas Sarlis, MD, PhD, FACP 
Chief Medical Officer 
SELLAS Life Sciences Group, Inc. 
 
15 West 38th Street; 10th Floor 
New York, NY 10018 
 
United States of America 
 

SELLAS Life Sciences Group 
Galinpepimut-S 
Protocol: SLS17-201/MK3475-770 Protocol v1.1 (Amendment 1.0) 
12 April 2019 
 
 
 
 
12 April 2019 
Signature 
 
Date 

SELLAS Life Sciences Group 
Galinpepimut-S 
Protocol: SLS17-201/MK3475-770 Protocol v1.1 (Amendment 1.0) 
12 April 2019 
 
Protocol Approval –Study Master Principal/Coordinating Investigators 
Study Title 
A Phase 1/2 Study of Galinpepimut-S in Combination with 
Pembrolizumab in Patients with Selected Advanced Cancers 
Protocol Number 
SLS17-201/ MK3475-770 
Protocol Date 
08 January 2018 (original) 
Date of Protocol v1.1 
(Amendment 1.0)  
12 April 2019 
Protocol accepted and approved by: 
Co-Principal/Coordinating Investigators 
United States 
Co-PI #1  
Richard T. Maziarz, MD 
Medical Director, 
Adult Blood and Marrow Stem Cell Transplant & Cellular Therapy Program 
Professor of Medicine  
Knight Cancer Institute 
Oregon Health and Science University (OHSU) 
3181 SW. Sam Jackson Park Road 
Portland, OR 97239 
USA 
 
<On file> 
 
12 April 2019 
Signature 
 
Date 
 
Co-PI #2  
Roisin O’Cearbhaill, MB BCh, BAO 
Assistant Attending Physician 
Gynecologic Medical Oncology Service 

SELLAS Life Sciences Group 
Galinpepimut-S 
Protocol: SLS17-201/MK3475-770 Protocol v1.1 (Amendment 1.0) 
12 April 2019 
 
Department of Medicine 
Memorial Sloan-Kettering Cancer Center 
1275 York Avenue  
New York, NY 10065 
USA 
 
<On file> 
 
12 April 2019 
Signature 
 
Date 

SELLAS Life Sciences Group 
Galinpepimut-S 
Protocol: SLS17-201/MK3475-770 Protocol v1.1 (Amendment 1.0) 
12 April 2019 
 
Declaration of Investigator* 
 
I have read and understood all sections of the protocol entitled “A Phase 1/2 Study of 
Galinpepimut-S in Combination with Pembrolizumab (MK-3475) in Patients with Selected 
Cancers”, Protocol v1.1 (Amendment 1.0), and the accompanying investigator’s brochures, 
version 2.0, dated 08 June 2017 for galinpepimut-S and edition 16, dated 29 June 2018 for 
pembrolizumab. 
I agree to supervise all aspects of the protocol and to conduct the clinical investigation in 
accordance with the Final Protocol v1.1, Amendment 1.0, dated 12 April 2019, the 
International Council on Harmonisation harmonised tripartite guideline E6(R2): Good 
Clinical Practice (ICH GCP) and all applicable government regulations. I will not make 
changes to the protocol before consulting with SELLAS Life Sciences Group or implement 
protocol changes without independent ethics committee approval except to eliminate an 
immediate risk to patients. I agree to administer study treatment only to patients under my 
personal supervision or the supervision of a subinvestigator. 
I will not supply the investigational drug to any person not authorized to receive it. I will 
protect patient confidentiality and patient identity will not be disclosed to third parties or 
appear in any study reports or publications. 
I will not disclose information regarding this clinical investigation or publish results of the 
investigation without authorization from SELLAS Life Sciences Group.  
<Signature > 
 
<DD/MM/YYYY> 
Signature of Principal Investigator*  
 
Date 
<Name> 
 
 
Printed Name of Principal Investigator* 
 
 
 
*: Declaration Form for Individual Participating Clinical Site P.I.’s 

SELLAS Life Sciences Group 
Galinpepimut-S 
Protocol: SLS17-201/MK3475-770 Protocol v1.1 (Amendment 1.0) 
12 April 2019 
 
 

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List of Tables ........................................................................................................................... 17 
List of Figures .......................................................................................................................... 18 
Protocol Synopsis .................................................................................................................... 20 
List of Abbreviations ............................................................................................................... 58 
1 
Introduction ...................................................................................................................... 68 
1.1 
Galinpepimut-S Background .................................................................................. 68 
1.1.2. Galinpepimut-S Clinical Studies ............................................................................ 73 
1.1.2.1. Phase 1 Clinical Experience with Galinpepimut-S (Study 06-085) .................... 73 
1.1.2.2.2. Study MCC-15025 (AML Patients) ................................................................. 84 
1.1.2.2.3.  Study 15-247 (Ovarian Cancer Patients) ........................................................ 87 
1.2 
Pembrolizumab Background .................................................................................. 91 
1.2.1. General ................................................................................................................... 91 
1.2.2. Pharmaceutical and Therapeutic Background ........................................................ 91 
1.2.3. Pre-clinical and Clinical Trials .............................................................................. 92 
1.2.4. Justification for Pembrolizumab Dose ................................................................... 93 
1.3. Study Rationale ......................................................................................................... 94 
1.3.1. General ................................................................................................................... 94 
1.3.1.1.  Rationale for Galinpepimut-S and Pembrolizumab Combination Therapy ....... 95 
1.3.1.2.  Rationale for Selection of Indications ................................................................ 98 
1.3.1.2.1.   Metastatic Colorectal Cancer (Third/Fourth line) .......................................... 98 
1.3.1.2.2.   Ovarian Cancer (Second/Third line) ............................................................ 100 

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1.3.1.2.3.   Small Cell Lung Cancer (Second Line) ....................................................... 101 
1.3.1.2.4.   Breast Cancer (Triple Negative; Second Line) ............................................ 102 
1.3.1.2.5.   Acute Myelogenous Leukemia (AML) ........................................................ 103 
2 
Study Objectives ............................................................................................................ 107 
2.1 
Primary Objective ................................................................................................. 107 
2.2 
Secondary Objectives ........................................................................................... 108 
2.3 
Exploratory Objectives ......................................................................................... 108 
3 
Investigational Plan ........................................................................................................ 110 
3.1 
Study Design ......................................................................................................... 110 
3.1.1. Overall Treatment Investigational Administration Schedule ............................... 110 
3.1.2.  
Rationale of Study Design ............................................................................ 114 
4.0. Patient Selection and Withdrawal Criteria ..................................................................... 116 
4.1. Selection of Study Population ................................................................................. 116 
4.1.1. Inclusion Criteria .................................................................................................. 116 
4.1.2. Exclusion Criteria ................................................................................................. 124 
4.2. Withdrawal of Patients from the Study ................................................................ 129 
4.2.1. 
Reasons for Withdrawal/Discontinuation .............................................. 129 
4.2.2. 
Handling of Withdrawals ...................................................................... 131 
4.2.3. 
Replacements ......................................................................................... 132 
5. 
Study Treatments ........................................................................................................... 133 
5.1. Method of Assigning Patients to Treatment ......................................................... 133 
5.2. Treatments Administered ..................................................................................... 133 

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5.2.1. 
Galinpepimut-S ...................................................................................... 133 
5.2.2. 
Montanide ISA 51 VG ........................................................................... 134 
5.2.3. 
Sargramostim (GM-CSF) ...................................................................... 135 
5.2.4. 
Pembrolizumab ...................................................................................... 135 
5.3. Identity of Investigational Drug Product .............................................................. 137 
5.3.1. 
Galinpepimut-S ...................................................................................... 137 
5.3.2. 
Montanide ISA 51 VG ........................................................................... 139 
5.3.3. 
Sargramostim (GM-CSF) ...................................................................... 140 
5.3.4. 
Pembrolizumab ...................................................................................... 140 
5.3.5. 
Overall Treatment Schedule .................................................................. 140 
5.3.6. 
Toxicities ............................................................................................... 141 
5.3.6.1. Dose-Limiting Toxicities ....................................................................... 144 
5.3.6.2. AML-Specific Dose-Limiting Toxicities .............................................. 149 
5.3.6.3. Dose Modification and Toxicity Management Guidelines for 
Pembrolizumab ...................................................................................... 153 
5.3.7. 
Toxicity Management of Injection-reactions Related to Galinpepimut-S
 ............................................................................................................... 161 
5.3.8. 
Definition of an Overdose of Investigational Agents for This Protocol 162 
5.3.9. 
Toxicity Management of Known/Expected AEs Associated with the 
Continuing Use of Hypomethylating Agents (HMAs) in Patients 
Enrolled in the AML Arm ..................................................................... 163 
5.3.9.1.   Toxicity Profile and Dose Modifications for Azacitidine (AML Patients) 
(Vidaza® US Prescribing Information; Appendix 12.1) ........................ 163 
5.3.9.2.   Toxicity Profile and Dose Modifications for Decitabine (AML Patients) 
(Dacogen® US Prescribing Information; Appendix 12.2) ..................... 165 
5.4. Management of Clinical Supplies ......................................................................... 166 

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5.4.1. 
Study Drug Packaging and Storage ....................................................... 166 
5.4.2. 
Test Article Accountability ................................................................... 167 
5.4.3. 
Other Supplies ....................................................................................... 168 
5.4.4. 
Blinding ................................................................................................. 168 
5.4.5. 
Breaking the Blind ................................................................................. 168 
5.5. Treatment Compliance ......................................................................................... 168 
5.6. Prior and Concomitant Therapy ........................................................................... 168 
5.7. Rescue Medications and Supportive Care ............................................................ 170 
5.7.1. 
Supportive Care Guidelines for Pembrolizumab ................................... 170 
5.8. Diet/Activity/Other Considerations ...................................................................... 171 
6. Study Assessments and Procedures ................................................................................... 173 
6.1. Study Visits ........................................................................................................... 185 
6.1.1. 
Screening Period and Enrollment .......................................................... 185 
6.1.2. 
Open-Label Treatment Period ............................................................... 185 
6.1.3. 
End of Treatment/Early Termination Visit ............................................ 185 
6.1.4. 
Safety Follow-up Period ........................................................................ 185 
6.1.5. 
Relapse Visit .......................................................................................... 186 
6.1.6. 
Unscheduled Visits ................................................................................ 187 
6.2. Efficacy Assessments ........................................................................................... 187 
6.3. Exploratory Assessments ...................................................................................... 188 
6.4. Safety Assessments ............................................................................................... 191 
6.4.1. 
Adverse Events ...................................................................................... 191 
6.4.1.1. Definitions of Adverse Events ............................................................... 191 
6.4.1.2. Eliciting and Documenting Adverse Events .......................................... 192 

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6.4.1.3. Reporting Adverse Events ..................................................................... 193 
6.4.1.4. Assessment of Severity .......................................................................... 195 
6.4.1.5. Assessment of Causality ........................................................................ 196 
6.4.1.6. Exceptions ............................................................................................. 197 
6.4.1.7. Follow-Up of Patients Reporting Adverse Events ................................ 197 
6.4.1.8. Events of Clinical Interest ..................................................................... 198 
6.5. Safety Monitoring Committee .............................................................................. 199 
6.6. Pregnancy in Partners of Male Patients ................................................................ 199 
6.7. Laboratory Analyses ............................................................................................. 199 
6.8. Tumor Imaging and Assessment of Disease ......................................................... 201 
6.8.1. 
Initial Tumor Imaging ........................................................................... 202 
6.8.2. 
Tumor Imaging During the Study ......................................................... 203 
6.8.3. 
End of Treatment and Follow-up Tumor Imaging ................................ 203 
6.8.4. 
RECIST 1.1 Assessment of Disease ...................................................... 204 
6.8.5. 
iRECIST Assessment of Disease ........................................................... 204 
7. 
Statistical and Analytical Plan ....................................................................................... 209 
7.1. Primary Efficacy Endpoints .................................................................................. 209 
7.2. Secondary Efficacy Endpoints .............................................................................. 209 
7.3. Exploratory Endpoints .......................................................................................... 209 
7.4. Sample Size Calculations ..................................................................................... 209 
7.5. Analysis Sets ......................................................................................................... 211 
7.5.1. 
Prior Therapies ...................................................................................... 212 
7.6. Statistical Analysis Methodology ......................................................................... 213 
7.6.1. 
Analysis of Primary Efficacy Endpoint ................................................. 213 

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7.6.2. 
Analysis of Secondary Efficacy Endpoints ........................................... 214 
7.6.3. 
Analyses of Exploratory Endpoint ........................................................ 214 
7.6.4. 
Safety Analyses ..................................................................................... 214 
7.6.4.1. Adverse Events ...................................................................................... 215 
7.6.4.2. Laboratory Test Results ......................................................................... 215 
7.6.4.3. 12-Lead Electrocardiogram Results ...................................................... 216 
7.6.4.4. Physical Examination ............................................................................ 216 
7.6.4.5. Vital Signs ............................................................................................. 216 
7.6.4.6. Eastern Cooperative Group Performance Status ................................... 216 
7.6.5. 
Interim Analyses .................................................................................... 216 
7.6.6. 
Go/No-Go and Futility Monitoring Guidelines ..................................... 217 
7.7. Data Quality Assurance ........................................................................................ 219 
7.7.1. 
Data Management .................................................................................. 219 
8. 
Ethics .............................................................................................................................. 221 
8.1. Independent Ethics Committee or Institutional Review Board ............................ 221 
8.2. Ethical Conduct of the Study ................................................................................ 221 
8.3. Patient Information and Consent .......................................................................... 222 
9. 
Investigator’s Obligations .............................................................................................. 223 
9.1. Confidentiality ...................................................................................................... 223 
9.2. Financial Disclosure and Obligations ................................................................... 224 
9.3. Investigator Documentation ................................................................................. 224 
9.4. Study Conduct ...................................................................................................... 225 
9.5. Adherence to Protocol .......................................................................................... 225 

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9.6. Adverse Events and Study Report Requirements ................................................. 225 
9.7. Investigator’s Final Report ................................................................................... 226 
9.8. Records Retention ................................................................................................. 226 
9.9. Publications .......................................................................................................... 227 
10. Study Management and Monitoring ............................................................... 228 
10.1. External Data Monitoring Committee ......................................................... 228 
10.2. Monitoring of the Study .............................................................................. 228 
10.2.1. Inspection of Records ............................................................................... 229 
10.3. Management of Protocol Amendments and Deviations ....................................... 229 
10.3.1. Modification of the Protocol ..................................................................... 229 
10.3.2. Protocol Deviations .................................................................................. 230 
10.4 Study Termination .................................................................................................. 230 
10.5. First Interpretable Results (FIR) Report ............................................................... 231 
10.6. Final Complete Clinical Study Report (CSR) ....................................................... 231 
11. Reference List .................................................................................................................. 232 
12. Appendices ...................................................................................................................... 258 
12.1 Appendix 1. Azacitidine (Vidaza®) US Prescribing Information .......................... 258 
12.2. Appendix 2. Decitabine (Dacogen®) US Prescribing Information ....................... 258 
12.3. Appendix 3. WT1 IHC Assessment and Documentation Form ............................ 258 
12.4.  Appendix 4. Eastern Cooperative Group Performance Status ............................. 261 
12.5.  Appendix 5. Revised Recommendations of The International Working Group for 
Diagnosis, Standardization of Response Criteria, Treatment Outcomes, and 
Reporting Standards for Therapeutic Trials in Acute Myeloid Leukemia .... 262 

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List of Tables 
 
Table 1 
Definition of Adequate Organ Function ........................................................ 121 
Table 2 
Treatment for Pembrolizumab ....................................................................... 135 
Table 3 
Description of Investigational Products ........................................................ 137 
Table 4 
Structural Formula of Galinpepimut-S .......................................................... 138 
Table 5 
Dose Modification and Toxicity Management Guidelines for Immune-related 
AEs Associated with Pembrolizumab ........................................................... 154 
Table 6 
Pembrolizumab Infusion Reaction Dose Modification and Treatment 
Guidelines ...................................................................................................... 158 
Table 7 
Pembrolizumab Product Description……………………………………….167 
Table 8 
Schedule of Assessments…………………………………………………...174 
Table 9 
Laboratory Analyses………………………………………………………..200 
Table 10 
Imaging and Treatment After First Radiological Evidence of Progressive 
Disease……………………………………………………………………...205 
Table 11 
Statistical Design Performance for CRC or OvC Cohorts of 20 Patients…..209 
Table 12 
Statistical Design Performance for SCLC Cohort of 20 Patients…………..210 
Table 13 
Statistical Design Performance for TNBC and AML Cohorts of 15 
Patients……………………………………………………………………..210 

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Table 14 
Decision Criteria for a Stop or Go Decision in Each Cohort at the Planned 
Sample Size…………………………………………………………………216 
 
List of Figures 
Figure 1 
Kaplan-Meier Plot for Overall Survival by Disease Group ............................ 75 
Figure 2 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median Disease-Free 
Survival ............................................................................................................ 79 
Figure 3 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median Overall 
Survival ............................................................................................................ 79 
Figure 4 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median EFS from First 
Galinpepimut-S Administration ...................................................................... 80 
Figure 5 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median Overall 
Survival from First Galinpepimut-S Administration ....................................... 80 
Figure 6 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median Disease-Free 
Survival of Patients < 60 Years of Age ........................................................... 81 
Figure 7 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median Overall 
Survival of Patients < 60 Years of Age ........................................................... 81 
Figure 8 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median Disease-Free 
Survival of Patients ≥ 60 Years of Age ........................................................... 82 
Figure 9 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median Overall 
Survival of Patients ≥ 60 Years of Age ........................................................... 82 

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Figure 10 
Study MCC-15025 (AML Patients in CR2): Kaplan-Meier Plot for Median 
Overall Survival in Galinpepimut-S-treated Patients who Received >2 
Vaccine Inoculations (N=10) versus Contemporaneously Treated Historical 
Matched Controls (N=15) ................................................................................ 86 
Figure 11 
Study 15-247 (Ovarian Cancer Patients): Kaplan-Meier Plot for Median 
Progression-Free Survival Showing the Landmark 1-year PFS Rate in the ITT 
Population  ....................................................................................................... 90 
Figure 12 
Study Design………………………………………………………………..114 
Figure 13 
Overall Treatment Administration Schedule……………………………….141 
Figure 14 
Imaging and Treatment for Clinically Stable Patients Treated with 
Pembrolizumab after First Radiologic Evidence of PD Assessed by 
Investigator…………………………………………………………………207 
 
 

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Protocol Synopsis 

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Protocol Number: 
SLS17-201/MK3475-770 
Title: 
A Phase 1/2 Study of Galinpepimut-S in Combination with 
Pembrolizumab (MK-3475) in Patients with Selected Advanced 
Cancers 
Protocol version 
Study Amendment # 
1.1 
1.0 
Sponsor: 
SELLAS Life Sciences Group, Inc. 
15 West 38th Street; 10th Floor 
New York, NY 10018 
United States of America 
 
 
Telephone:  +1-917-438-4352 
FAX:           +1-917-634-3413 
Study Phase: 
1/2 
Study Sites: 
Up to 20 centers in the United States.  
Indication: 
Colorectal (third or fourth line), ovarian (second or third line), 
small cell lung cancer (second line), breast cancer (triple 
negative; second line), acute myelogenous leukemia (unable to 
attain deeper response than partial on hypomethylators and who 
are not eligible for allogeneic hematopoietic stem cell 
transplant). For all the solid tumor indications, the highest 
citable number of lines of the therapy above is the maximum 
allowed for eligibility, i.e., patients who have received 
subsequent lines of therapy are ineligible. 

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Rationale: 
There is clearly an unmet need for novel and effective therapy to 
improve responses and prolong disease 
remission/progression-free intervals already achieved with 
checkpoint blockade monotherapy (Farkona et al, 2016). The 
objectives of this proposed clinical study are: (i). to explore 
clinical outcomes (safety and potentially promising activity) in 
tumors using a combination of agents that improve immune-
mediated anticancer effects, namely pembrolizumab and 
galinpepimut-S, and (ii). to maximize the chances of detecting a 
clinically meaningful efficacy signal in comparison to historical 
monotherapy data (with pembrolizumab alone) for further 
validation in larger, randomized trials.   
To meet these objectives, the current design of a Phase 1/2 
open-label, non-comparative, multicenter, multi-arm clinical 
study was chosen, as it has been used successfully in similar 
studies before (Menis et al, 2014; Toulmonde et al, 2018; 
Goldberg et al, 2016), and therefore considered as highly 
suitable for this trial. 
The rationale behind this clinical study consist of 2 parts: a 
general strategy and a specific approach choosing Wilms 
Tumor-1 (WT1) protein as a direct immunization target and the 
selection of specific tumors for inclusion. Up to 5 tumor types 
will be included: colorectal cancer (CRC), ovarian cancer 
(OvC), small cell lung cancer (SCLC), triple-negative breast 
cancer (TNBC), and acute myeloid leukemia (AML). 
Immune activation, suggested by the presence of infiltrating 
cytotoxic T cells in tumors, as well as eventual maintenance of a 
long-term proimmune status against the  

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tumor via memory T cells, have shown be associated with a 
better prognosis across a wide variety of malignancies (Reeves 
et al, 2017; Wölfl M et al, 2014). Therapies blocking 
programmed death receptor-1 (PD-1), such anti-PD-1 
monoclonal antibodies, have shown the ability to reduce 
inhibitory immune signals within the tumor microenvironment 
(TME), thus allowing cytotoxic T cells to infiltrate the tumor 
and cause tumor regression in an expanding group of human 
malignancies, leading to a series of regulatory approvals and 
clinical usage on a global scale (Interkofer et al, 2013; Kyi et al, 
2014; Spranger et al, 2016). These advances notwithstanding, 
there is significant room for improvement in the depth, 
frequency, and duration of antitumor responses with anti-PD1 
agents. This provides a strong rationale for developing strategies 
to prime a host (cancer patient) with tumor-specific cytotoxic T 
cells targeted to specific tumor antigens via host administration 
while increasing the likelihood of significantly amplifying such 
a specific response with an anti-PD1 therapy (in this case, 
pembrolizumab), as well as prolong the duration of such a 
response (Perez-Gracia, et al, 2014) by both mitigation of 
tolerance and via induction of memory T cells [Marzo et al, 
2000]). Thus, combining innovative, highly tolerable actively 
immunizing agents, such as peptide vaccines against well-
validated high-antigenicity tumor targets, with anti-PD-1 
products, such as pembrolizumab (Keytruda®) represents a 
highly attractive strategy, which deserves assessment in the 
clinical setting (Parchment et al, 2016; Drake CG, 2012).  
The Wilms Tumor-1 (WT1) protein, the WT1 oncogene 
product, was first identified in childhood renal tumors, but has 

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been found to be overexpressed in a high proportion of solid and 
hematological malignancies, while its expression is substantially 
void in most healthy adult tissues (Wagner et al, 2014). Each 
WT1 protein isoform has different DNA binding and 
transcriptional activities, and can positively or negatively 
regulate various genes involved in cellular proliferation, 
differentiation, apoptosis, organ development, and sex 
determination (Haber et al, 1991). Although originally described 
as a tumor suppressor gene, the WT1 proteins appear to be 
involved in tumorigenesis as a bona fide oncogene (Keilhoz et 
al, 2005; Lindstedt, et al, 2014). As WT1 is a transcription factor 
and is not expressed intact in the cell membrane, it has not been 
able to be targeted (druggable) with either small molecules or 
monoclonal antibodies (Toska et al, 2014). Nonetheless, the 
protein is processed by the proteasome in tumors and the 
derived peptides are presented in a major histocompatibility 
complex (MHC)-dependent manner on the cell surface. 
Furthermore, WT1 peptide fragments when administered as 
direct immunogens (vaccines) are also taken up by antigen-
presenting cells (APCs) and processed by the 
immunoproteasome for MHC-dependent presentation (Jiagirdar 
et al, 2016; Asemissen et al, 2006; Müller et al, 2003). Thus, 
WT1 is a highly attractive target for immunotherapy (Oka et al, 
2002; Oka et al, 2007). WT1 was ranked as the top cancer 
antigen by a working group organized by the National Cancer 
Institute (NCI) in 2009 (Cheever, et al, 2009). The strong 
expression of WT1 protein in assorted cancers, coupled with its 
proposed mechanism of antigenicity and induction of immune 
responses (both CD4 and CD8 [Chapuis et al, 2013; Dao et al, 

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2016; Tyler et al, 2013; Tyler and Koehne, 2013; Fujiki et al, 
2008; Krug et al; 2010]); after direct immunization against WT1 
in patients with assorted cancers), makes it a rational candidate 
for the development of specific immunotherapies, such as 
peptide vaccines (Van Driesshe et al, 2012; Oka and Sugiyama, 
2010; Oka et al, 2009; Dao and Seheinbert, 2008). 
Galinpepimut-S is a directly immunizing therapy (a vaccine-like 
proprietary mixture of carefully selected heteroclitic and native 
WT1 peptide fragments) proven to produce WT1-specific 
T-lymphocytes in patients that could target a patient’s cancer 
(Gomez-Nunez et al, 2006; Pinilla-Ibarz et al, 2006; Bleakley 
and Ridell, 2011; May et al, 2007; Brayer and Pinilla-Ibarz, 
2013). Additionally, galinpepimut-S monotherapy has 
previously shown promising clinical activity in both pilot and 
Phase 2 studies in patients with AML, malignant pleural 
mesothelioma (MPM), high-risk multiple myeloma, and ovarian 
cancer (OvC) in a minimal residual disease (MRD) setting 
(Maslak et al, 2010; Krug et al 2010; Brayer et al, 2015; Maslak 
et al, 2016; Maslak et al, 2018; Zauderer et al, 2016; Zauderer et 
al, (iMig), 2016; Zauderer et al, 2017; Koehne et al 2017; 
http://e-materials.com/ebmt2017/#/presentation/16745; 
https://learningcenter.ehaweb.org/eha/2017/22nd/181028/guenth
er.koehne.wt1.heteroclitic.epitope.immunization.following.autol
ogous.html; Koehne et al, 2018; O’Cearbhaill et al, 2018; 
Tsuboi et al, 2012). Galinpepimut-S is generally well tolerated. 
(SELLAS, Data on file; Brayer et al, 2015; Zauderer et al, 2017; 
Maslak PG et al, 2018; Koehne et al, 2017; O’Cearbhaill et al, 
2018; Galinpepimut-S Investigator Brochure v2.0, 08 June 
2017). 

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Therefore, combining galinpepimut-S with the checkpoint 
inhibitor pembrolizumab, which beneficially and profoundly 
alters the TME (among other potent immunostimulatory effects 
in the host), is hypothesized to increase the proportion of 
patients who develop an immune response against their cancer 
and potentially improve their clinical outcome over 
pembrolizumab monotherapy, without the burden of additional 
toxicities in macroscopically measurable malignancies.   
In this clinical trial, for each chosen tumor type to be studied, 
we will investigate whether galinpepimut-S administered 
concomitantly with granulocyte-macrophage colony-stimulating 
factor (GM-CSF) and the well-characterized adjuvant 
Montanide (van Doorn et al, 2016; Montanide IB 2015; 
Aucouturier et al, 2002; Aucouturier et al, 2001; Tovey and 
Lallemand, 2010) can be safely administered with 
pembrolizumab. We postulate that galinpepimut-S will induce a 
WT1-specific immune response, which will be associated with 
enhancement of the efficacy of anti-PD1 monotherapy when 
considered in the context of historical controls, as assessed by 
overall response rate (ORR), as well as duration of response 
(DOR), and well as exploratory endpoints including WT1-
specific immune response dynamics and overall survival (OS), 
will be investigated. If this pilot study meets the primary 
efficacy endpoint of ORR for a given tumor type, a randomized 
Phase 2 trial would be warranted in that tumor type.  
The tumor types selected for this trial (CRC, OvC, SCLC, 
TNBC, and AML) have been documented to commonly express 
WT1, and this trial will select patients whose tumors are positive 

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for WT1 expression. The choice of these tumor types was based 
on specific features of each malignancy. 
Colorectal cancer (CRC): WT1 expression has been documented 
to be expressed in between 70 to 90% of patients with CRC 
(Miyata et al, 2007; Oji et al, 2003; Bejrananda et al, 2011). 
Patients with microsatellite-stable (MSS) tumor genetics make 
up between 80 to 90% of cases (Naboush et al, 2017; Diaz and 
Le, 2015).  Patients will have microsatellite (MS) instability 
(MSI) status tested in their primary tumors and will be classified 
as MSI-high (H) and -low (L) (Pawlik et al, 2004; Morán et al, 
2010; Supek and Lerner, 2015; Goldstein et al, 2014). The focus 
will be on MSI-low tumors, but no entry selection will be 
applied based on this tumor feature. In several clinical trials in 
MSI-L CRC, anti-PD-1 agents have shown to induce 0 to 5% 
ORR (Link and Overman, 2016; 
http://www.targetedonc.com/publications/targeted-therapies-
cancer/2017/2017-february/immune-checkpoint-inhibitors-in-
crc; Boland and Ma, 2017; Myint and Goel, 2017; Overman et 
al, 2016; Segal et al, 2016; Bendell et al, 2016; Overman et al, 
2016; Andre et al, 2017). This is in contrast to the significant 
activity of PD1 blockade in MSI-H CRC, the basis for the recent 
Food and Drug Administration (FDA) approval of 
pembrolizumab in MSI-H cancers (including CRC) 
(https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncem
ents/ucm560167.htm). Only those CRC patients with MSI-L and 
MSS will be included in the efficacy analyses. 
Ovarian cancer (OvC): WT1 expression is highly prevalent in 
OvC (Dupont et al, 2004). The degree of expression is high 
enough that pathologists routinely use IHC stains for WT1 with 

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a standardized convention for describing its expression to help 
distinguish epithelial ovarian cancers from other 
ovarian/fallopian tumors (Al-Hussaini et al, 2004). WT1 is a 
particularly sensitive and specific marker for serous ovarian 
cancer (Acs, et al, 2004). 
Small-cell lung cancer (SCLC): WT1 expression has not been 
studied in SCLC as extensively as in non-SCLC (NSCLC), 
mainly due to the relative rarity of the former. Nonetheless, 
WT1 positivity is higher (40 to 83%) in SCLC versus NSCLC 
(Babiak et al, 2014; Menssen et al, 2000; Oji et al, 2002; Wang 
et al, 2013). The activity of anti-PD1 agents in SCLC in the 
second line of therapy is reflected in ORR values of about 33 to 
37% (Ott et al, 2016; Hellman et al, 2016; Antonia et al, 2016; 
Riess et al, 2016). 
Triple-negative breast cancer (TNBC): Although WT1 
expression occurs in 70 to 80% of patients with basal-type 
breast cancer, in specimens from TNBC (Provenzano et al, 
2016; Domfeh et al, 2008), WT1 expression is approximately 8 
to 15%. Nonetheless, this value may represent low sensitivity of 
currently used, commercially available anti-WT1 monoclonal 
antibodies used for IHC (Ichinohasama 2010). Additionally, 
WT1 has been found to be focally amplified in a significant 
proportion of TNBCs and hence is still a valid 
immuno-oncology target, despite its low abundance observed 
(Craig et al, 2012).  
Acute myeloid leukemia (AML): WT1 is strongly and 
prevalently (90 to 95% of cases) expressed in AML blasts both 
in the peripheral blood (PB) and bone marrow (BM) (Inoue et 
al, 1998; Hosen et al, 2002; Keilholz et al, 2005; Cilloni et al 

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2009; Menssen et al, 1995; Inoue et al, 1997). It is also 
expressed in leukemic stem cells (LSCs) (Saito et al 1997; Yong 
et al, 2008). WT1 expression is reliable enough to be used as a 
marker of MRD in AML (as a molecular marker of 
relapse/response) (Alonso-Dominguez et al, 2012; Messina et al, 
2014; Ogawa et al, 2003; Candoni et al, 2009; Hämäläinen et al, 
2008; Mulé et al, 2016) and is typically included in MRD 
diagnostic multi-gene panels (Buccisano et al, 2017).  To date, 
anti-PD1 therapies have shown modest activity in relapsed AML 
(second line) in combination with hypomethylating agents 
(Lichtenegger et al, 2017; Haroun et al, 2017) as reflected in 
ORR values of up to 34% in that setting (Daver et al, 2016; 
Daver et al, 2017; Nagler et al, 2017; Krupka et al, 2016; Sehgal 
et al, 2015; http://www.targetedonc.com/publications/targeted-
therapies-cancer/2017/2017-february/immune-checkpoint-
approaches-in-aml-and-mds-a-next-frontier; Chien et al, 2018; 
Daver et al, 2018).  
Objectives: 
Primary Objectives: 
• To evaluate the safety and tolerability of galinpepimut-S 
in combination with pembrolizumab in patients with 
selected advanced cancers  
• To evaluate the anti-tumor activity of the combination of 
galinpepimut-S and pembrolizumab as defined by 
Response Criteria in Solid Tumors (RECIST) 1.1 and 
Immune-related Response Criteria in Solid Tumors 
(iRECIST) to determine if the activity seen, as measured 
by ORR, is sufficiently promising to evaluate the 
combination in future clinical studies. For AML patients: 
to study the possibility of achieving morphologic 

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complete response (CR; including CR with incomplete 
recovery of blood counts or platelets [CRi/CRp]).  
Hypothesis for the Primary Objectives: Combining 
galinpepimut-S with pembrolizumab could increase the 
clinical benefit of pembrolizumab monotherapy 
(Seledstov et al, 2015; Kleponis et al, 2015) as assessed 
by improved ORR values versus historical controls for 
each individual tumor type tested. This would constitute 
a “positive efficacy signal” (as relevant to each particular 
tumor type tested) and warrant broader future clinical 
investigations. Further, the combination will not increase 
the burden of toxicities and will have an overall 
similar/comparable adverse event (AE) profile as 
pembrolizumab monotherapy. 
(N.B.: The a priori statistical assumptions and threshold 
criteria supporting the definition of a positive signal are 
described in detail in Section 7.6.). 
Secondary Objectives: 
• To evaluate the clinical benefit of galinpepimut-S in 
combination with pembrolizumab in patients with 
selected advanced cancers through the analysis of time to 
response (TTR), time to next treatment, and duration of 
response (DOR)  
Hypothesis for the Secondary Objectives: Galinpepimut-S in 
combination with pembrolizumab could increase the clinical 
benefit of pembrolizumab monotherapy upon parameters other 
than ORR, such as TTR, time to next treatment, and DOR. In 

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case of a positive efficacy signal, such effects could be 
correlated with effects on ORR (vs. historical controls).  
Exploratory Objectives: 
• To further characterize the immunogenicity profile of 
galinpepimut-S when administered in this combination, 
i.e., its ability to generate WT1-specific immunocyte 
responses through analyses of WT1-specific CD8 and 
CD4 cells in PB, as well as WT1-specific memory CD8 
T cells, myeloid-derived suppressor cells [MDSC], and 
T-regulatory cells (Treg) in PB  
• To gauge the general immunodynamics effects upon 
non-antigen-specific lymphocyte immunophenotypic 
subtypes will be studied in PB via flow cytometry 
• To assess the effects of the combination on defined 
biomarkers of immune checkpoint activity in the tumors 
(or bone marrow for AML patients) and their 
surrounding microenvironment (pharmacodynamics 
specific to pembrolizumab) 
• To assess the association between selected biomarker 
readouts and clinical efficacy measures at specific 
time-points, using pre-treatment and on-treatment tumor 
biopsies 
• To assess OS and progression-free survival (PFS) 
• To assess the rate of achievement of MRD negativity 
(for patients in the AML arm only).  
Hypothesis for Exploratory Objectives: Combining 
galinpepimut-S with pembrolizumab could lead to the 
development of a robust WT1-specific immune response 

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against patients’ cancers, and potentially improve the 
abundance and functionality of the hosts’ immunocytes 
within the TME (versus pembrolizumab monotherapy) 
(Duraiswamy et al, 2013). Positive correlative analyses (as 
relevant to a particular tumor type) between immune and 
clinical outcomes would provide a mechanism of action 
(MOA) framework to inform the design of future larger, 
randomized clinical studies in that tumor type. 
Overall Study Design: 
This is a Phase 1/2, open-label, non-comparative, multicenter, 
multi-arm study of galinpepimut-S in combination with 
pembrolizumab in patients with selected advanced cancers. This 
study will assess efficacy and safety of galinpepimut-S and 
pembrolizumab on various tumor types. Patients will be 
followed long-term for OS and safety.  
The general principles regarding the schedule of administration 
of the investigational therapies will be as follows:  
Overall Treatment Investigational Administration Schedule 
The first 2 galinpepimut-S injections will initially be 
administered as monotherapy every 3 weeks (Week 0 and 
Week 3). Thereafter, galinpepimut-S will be co-administered 
with pembrolizumab every 3 weeks for 4 additional 
administrations (for the galinpepimut-S initial immunization 
induction phase series; weeks 6-15) to coincide with the per 
label pembrolizumab dosing frequency. After that, there will be 
one un-paired administration of pembrolizumab (week 18), and 
then galinpepimut-S will be resumed on an every 3-week 
schedule for 6 additional doses (early immune booster phase; 
weeks 21-36). At the end of this phase, there will be a 12-week 
interval where 3 unpaired administrations of pembrolizumab 

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will occur (weeks 39-45), and then galinpepimut-S will be 
resumed on an every 12-week schedule for 4 additional doses 
(late immune booster phase; weeks 48-84). After 84 weeks, 
continuing non-progressed patients will be treated with 
pembrolizumab alone up until week 111. 
Galinpepimut-S will be administered 30-60 minutes after the 
completion of IV infusion of pembrolizumab on Day 1 of each 
cycle during which the 2 drugs are being co-administered. 
Pembrolizumab will be administered at a dose of 200 mg 
intravenously every 3 weeks on Day 1 of each cycle (3-week 
cycles) starting on Study Week 6 and continuing for up to 
2 years thereafter (Study Week 111).  
To monitor for any adverse reactions, specifically for systemic 
anaphylaxis type reactions against either GM-CSF or 
galinpepimut-S, patients will remain in the clinic for 
approximately 30 minutes following each GM-CSF or 
galinpepimut-S injection.  
Safety assessments will be conducted at every visit. The end of 
treatment (EOT) visit will occur 30 days after the last injection.  
Specifically for patients in the AML arm, the timing of the 
administration of the investigational therapies (pembrolizumab 
and galinpepimut-S) with respect to administration of 
hypomethylating agents (HMAs) will be as follows: 
• AML patients on cycles #1 – 4 of HMA on-label 
therapy (treated according to standard clinical care) 
will be pre-screened to gauge potentially eligibility for 
the study.  
• If restaging bone marrow biopsy immediately after the 
completion of cycle #4 of HMA therapy demonstrates 

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morphological partial response (PR), then such 
patients become eligible for the study and can initiate 
investigational therapy (pembrolizumab and 
galinpepimut-S), as long as the latter commences 
prior to the initiation of cycle #5 of the HMA. 
• Reasonable efforts will be made by the Contracted 
Research Organization (CRO), Cancer Insight, LLC,  
at actively enrolling clinical sites to initiate 
investigational therapy within 14 +/7 days from the 
completion of cycle #4 of HMA therapy, to ensure 
relative homogeneity in the initiation timing 
relationship between the two therapeutic modalities, 
i.e., HMA and investigational therapy. 
Furthermore, for clarification purposes, each cycle of therapy in 
patients in the AML arm will be defined by the frequency of 
administration of the study investigational agents 
(pembrolizumab and galinpepimut- S), i.e., 3 weeks. This 
clarification is important, because: 
a. patients in the AML arm will continue their HMA therapy 
throughout the administration of study investigational agents 
and  
b. the timing of initiation between HMA cycle #5 and that of the 
first administration of investigational therapies are de-linked. 
Number of Patients 
Approximately up to 90 patients will be enrolled in the study. 
The planned number of patients within each tumor-specific 
cohort is as follows:  CRC (N = 20), OvC (N = 20), SCLC (N = 
20), TNBC (N = 15), and AML (N = 15). 

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Summary of Subject 
Key Eligibility Criteria: 
For inclusion in the study, patients will be: 
• Male or female ≥ 18 years of age at the time of signing 
the informed consent form, have histologically or 
cytologically-confirmed advanced or metastatic solid 
tumors (CRC, OvC, SCLC, or TNBC) or AML with best 
response of “partial response” (PR) after 4 cycles of 
HMA therapy (per European LeukemiaNet [ELN] 
criteria). All tumor types will also meet their additional 
cohort-specific requirements (see Section 4.1. below). 
• Specifically for patients in the AML arm, the following 
subject subgroups are eligible: 
§ Frontline (1st line) patients treated with HMAs since 
their initial AML diagnosis  
§ Patients who have required cytoreductive 
therapy with hydroxyurea or leukapheresis at 
the time of their initial AML diagnosis, and 
who subsequently seamlessly transitioned to 
HMA therapy 
§ Subjects who have experienced induction early 
failure after initial therapy with 1 - 2 cycles of a 
standard chemotherapy (“7+3” and similar 
regimens) and subsequently immediately treated 
with HMAs  
as long as such patients have achieved PR as their best 
observable response after 4 cycles of HMA therapy (per 
European LeukemiaNet [ELN] criteria). 
• At the time of screening for study entry, patients’ tumor 
material (or bone marrow [BM] for AML) will be tested 
for WT1 expression via immunohistochemistry (IHC) as 
follows: in the solid tumor arms, in both their initial 

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primary tumor and recent biopsy of metastatic disease, 
whereas in the AML arm in leukemic blasts (either in the 
BM or PB) at the time of initial diagnosis. .  
• At the time of screening for study entry, patients in the 
solid tumor arms should have measurable disease based 
on RECIST 1.1 criteria, whereas in the AML arm should 
have evidence of morphologic partial response (decrease 
of BM blast percentage to 5% to 25% and decrease of 
pretreatment BM blast percentage by > 50%) but 
absence of extramedullary disease, as defined initially by 
the AML Working Group Criteria (Cheson et al, 2003) 
and also quoted in the more recent ELN criteria (Döhner 
et al, 2010). In both arms, tumor/leukemic blast burden 
will be  determined by a local site investigator 
(physician) upon clinical and imaging/BM morphologic 
assessment..  
• Adequate organ function as defined in Table 1 and 
Eastern Cooperative Oncology Group (ECOG) 
performance status of 0 or 1. 
For a full list of eligibility criteria, refer to Sections .   

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Treatments: 
Patients will be administered a fixed dose of the following 
treatments: 
• Galinpepimut-S: 4 WT1 derived synthetic analog 
peptides (galinpepimut-S) emulsified with the adjuvant 
Montanide for a total injection volume of 1 mL. 
• Pembrolizumab: 200 mg 
Patients will be administered subcutaneous (SC) sargramostim 
(from here on referred to as GM-CSF) at the site of the planned 
galinpepimut-S injection 2 days before (Day –2) and the day of 
(Day 1) each galinpepimut-S administration. 
The overall treatment administration schedule is shown in the 
figure below: 
Refer to Section 5 for more details on treatment. 

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Dose-limiting Toxicities 
All toxicities will be graded using NCI CTCAE Version 5.0 
(published in November 2017), as per the following link:. 
https://ctep.cancer.gov/protocolDevelopment/electronic_applicati
ons/docs/CTCAE_v5_Q uick_Reference_5x7.pdf. 
The dose-limiting toxicity (DLT) window of observation will 
be: 
For patients in the solid tumor arms: at least one (1) cycle 
following the co-administration of galinpepimut-S in 
combination with pembrolizumab. 
For patients in the AML arm: at least 8 weeks following the 
first administration of pembrolizumab 
N.B.: this DLT assessment time window at the beginning 
of the study was chosen considering that (i). the 
treatment regimen in AML subjects includes the 
administration of HMA treatment (with cycle duration of 
at least 4 weeks), along with investigational therapy 
(pembrolizumab and galinpepimut-S), and (ii). the 
timing of administration of the two sets of modalities is 
not linked, so that an adequate time interval to capture 
potential toxicities is secured. 
A DLT is judged by the investigator to be possibly, probably, or 
definitely related to study drug administration.  
 
 
 
For patients in the solid tumor arms:  
Missing > 25% of the doses as a result of drug-related AE(s) 
during the period from first administration of galinpepimut-S 

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and up until the completion of the first cycle of the co- 
administration of galinpepimut-S in combination with 
pembrolizumab, drug-related AE(s) which caused patient to 
discontinue treatment during Cycle 1, or Grade 5 toxicity, will 
be considered DLTs. 
DLTs will also be defined as most Grade 4 nonhematologic 
toxicities (not laboratory) or hematologic toxicity lasting 
≥ 7 days except thrombocytopenia, most nonhematologic AEs ≥ 
Grade 3 in severity, febrile neutropenia (FN) Grade 3 or Grade 
4: missing >25% of pembrolizumab doses as a result of drug-
related AE(s) during the first cycle, thrombocytopenia < 
25,000/mm3  and meeting specific criteria, including a life-
threatening bleeding event, or prolonged delay (> 2 weeks) in 
initiating the second cycle of of co- administration of 
galinpepimut-S in combination with pembrolizumab due to 
treatment-related toxicity. Details for DLTs are provided in 
Section 5.3.6.1. 
Staggered Early Enrollment: 
To minimize exposing subjects to the risk of potential unknown 
acute and subacute toxicities of combining pembrolizumab with 
galinpepimut-S, the inter-dosing interval in-between the first 
consecutive three (3) subjects to be enrolled in this study arm 
will be one (1) week following the administration of the first 
dose of pembrolizumab in these patients. 
DLT assessment and actions (unless stopping rules apply): 
Initially up to 6 patients will be enrolled across all active solid 
tumor cohorts (colorectal, ovarian, small cell lung cancer, breast 
cancer).  If 2 or fewer patients of these first 6 patients have 
DLTs, enrollment can continue for up to another 6 patients 

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across these arms with no dose adjustments made. If DLTs are 
observed in more than 2 patients of the first 6, the time interval 
between galinpepimut-S doses for the inoculation following the 
one associated with the DLT will be doubled. For example, if 
galinpepimut-S was given on a Q3W schedule before the DLT 
occurred, it should be given Q6W for the immediately 
subsequent administration after the dosing event associated with 
the DLT, while keeping the pembrolizumab dose and frequency 
stable.  In the next 6 patients (patients 7 to 12), if again, 2 or 
fewer of these patients have DLTs observed, enrollment can 
continue. If DLTs are observed in more than 2 of patients 7 to 
12, the time interval between galinpepimut-S doses for the 
inoculation following the one associated with the DLT will be 
doubled, while keeping the pembrolizumab dose and frequency 
stable. If DLTs are observed in more than 2 patients of the first 
6 (patients 1 to 6) and again in more than 2 patients of the next 6 
(patients 7 to 12), the time interval between galinpepimut-S 
doses will be doubled for two (2) inoculations following the one 
associated with the DLT. For example, if galinpepimut-S was 
given on a Q3W schedule before the DLT occurred, it should be 
given Q6W for the 2 immediately subsequent administrations 
after the dosing event associated with the DLT, while keeping 
the pembrolizumab dose and frequency stable.  
 
Should a given patient experience any of the above DLTs at any 
time after the completion of the first cycle of co-administration 
of galinpepimut-S in combination with pembrolizumab, the 
frequency of administration of galinpepimut-S will be reduced 
by 50% for the next cycle, but pembrolizumab will continue as 

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scheduled. If another DLT occurs in that next cycle, the 
frequency of administration of galinpepimut-S will be reduced 
by 50% for the subsequent 2 cycles, but pembrolizumab will 
continue as scheduled. If a DLT occurs after these dose 
modifications in subsequent cycles, the patient will be 
discontinued from the study. 
The above dose density modifications in response to DLTs is 
further summarized in the bulleted list of actions below: 
• 
First DLT à skip the next GPS inoculation (scheduled 
for the next cycle, i.e., 3 wks ahead) and administer GPS 
6 wks ahead (i.e., ‘spread out’) once thereafter, i.e. for 
1 additional cycle à DLT resolution à Return to per 
protocol schedule of GPS administration  
• 
Second DLT (after reverting to the per protocol 
schedule) à skip the next GPS inoculation (scheduled 
for the next cycle, i.e., 3 wks ahead) and administer GPS 
6 wks ahead (i.e., ‘spread out’) twice thereafter, i.e. for 
2 additional cycles à DLT resolution à Return to per 
protocol schedule of GPS administration  
• Third DLT (occurring either after reverting to the per 
protocol schedule or during the ‘spread out’ schedule to 
manage the 2nd DLT above) à Discontinue patient from 
study. 
N.B.: In all above modifications of the dose density of 
galinpepimut-S, as all intervals (in weeks) between 2 successive 
GPS administrations are multiples of three (3) by design, 
following these rules, co-administration with pembrolizumab is 
always secured. 

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Stopping Rules: 
• Development of any SAEs at least “possibly 
attributable” to the study agent(s) in 2 out of the first 6 
patients in the study. In this case, the upper 90% one-
sided CI bound for 2 patients with SAEs within 6 
patients would be 66.7%, consistent with an excessive 
rate of toxicity. 
• The fraction of patients experiencing an SAE at least 
“possibly attributable” to the study agent(s) exceeds 
1/3, at any time during study implementation beyond 
the first 6 patients. 
• Death at least “possibly attributable” to the 
study agent(s) within 30 days after the 
administration of the investigational treatment 
(GPS plus pembrolizumab). 
 
If the study is stopped due to activation of the above rules, the 
safety data will be examined by the sponsor in consultation with 
investigators in order to determine how to proceed or whether to 
discontinue the study at large. 
For patients in the AML arm:DLTs will be defined by 
toxicities observed in the first 8 weeks from study entry, as 
follows: 
a. Missing > 25% of the doses as a result of drug related AE 
during cycle 1 and/or 2 

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b. Drug-related AE which causes patient to discontinue 
treatment during cycle 1 and/or 2 
- Grade 5 toxicity 
- Grade 4 non-hematological toxicity (other than laboratory 
abnormality) 
- Grade 3 non-hematological toxicity (other than laboratory 
abnormality; exception: fatigue, nausea, emesis, diarrhea, 
rash, infection, fever, or bleeding unless the event lasts more 
than 3 days despite optimal care) 
- Grade 3 and 4 non-hematological lab abnormality, if any of 
the following occurs: 
• Medical intervention is required 
• Abnormality persists > 1 week 
• Abnormality results in drug-induced liver injury 
• Any treatment-related toxicity that causes a greater than 
3-week delay in initiation of cycle 2 and/or 3 
• Development of an immune-related AE resulting in 
withholding of pembrolizumab and initiation of steroids, 
for example, grade 2 or higher colitis/diarrhea, grade 2 or 
higher pneumonitis, grade 2 or higher transaminitis, any 
grade myocarditis (complete list currently shown in 
Table 5) 
Any other toxicities in the AML arm will not be considered 
dose-limiting. Details for AML DLTs are provided in Section 
5.3.6.2. 

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Staggered Early Enrollment: 
To minimize exposing subjects to the risk of potential unknown 
acute and subacute toxicities of combining HMA with the 
investigational therapy (pembrolizumab and galinpepimut-S) in 
the AML arm, the inter-dosing interval between the first two (2) 
subjects to be enrolled in this study arm will be 12 weeks. 
DLT assessment and actions (unless stopping rules apply): 
AML-specific DLTs will be considered separately from all other 
patients. Initially up to 6 patients will be enrolled in the AML 
cohort. If 2 or fewer patients of these first 6 patients have DLTs, 
enrollment can continue for up to another 6 patients in the AML 
arm with no dose adjustments made. If DLTs are observed in 
more than 2 patients of the first 6, the time interval between 
galinpepimut-S doses will be doubled for the inoculation 
following the one associated with the DLT, but pembrolizumab 
will continue as scheduled. 
In the next 6 patients (patients 7 to 12), if again, 2 or fewer of 
these patients have DLTs observed, enrollment can continue. If 
DLTs are observed in more than 2 of patients 7 to 12, If DLTs 
are observed in more than 2 of patients 7 to 12, the time interval 
between galinpepimut-S doses will be doubled for the 
inoculation following the one associated with the DLT, but 
pembrolizumab will continue as scheduled.  
If DLTs are observed in more than 2 patients of the first 6 
(patients 1 to 6) and again in more than 2 patients of the next 6 
(patients 7 to 12), the time interval between galinpepimut-S 
doses will be doubled for two (2) inoculations following the one 
associated with the DLT, but pembrolizumab will continue as 
scheduled. For example, if galinpepimut-S was given on a Q3W 

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schedule before the DLT occurred, it should be given Q6W for 
the 2 immediately subsequent administrations after the dosing 
event associated with the DLT, while keeping the 
pembrolizumab dose and frequency stable. 
 
Should a given patient experience any of the above DLTs at any 
time after the completion of the second cycle of co- 
administration of galinpepimut-S in combination with 
pembrolizumab, the frequency of administration of 
galinpepimut-S will be reduced by 50% for the next cycle, but 
pembrolizumab will continue as scheduled. If another DLT 
occurs in that next cycle, the frequency of administration of 
galinpepimut-S will be reduced by 50% for the subsequent 2 
cycles, but pembrolizumab will continue as scheduled. If a DLT 
occurs after these dose modifications in subsequent cycles, the 
patient will be discontinued from the study. 
The above dose density modifications in response to DLTs is 
further summarized in the bulleted list of actions below: 
• 
First DLT à skip the next GPS inoculation (scheduled 
for the next cycle, i.e., 3 wks ahead) and administer GPS 
6 wks ahead (i.e., ‘spread out’) once thereafter, i.e. for 
1 additional cycle à DLT resolution à Return to per 
protocol schedule of GPS administration  
• 
Second DLT (after reverting to the per protocol 
schedule) à skip the next GPS inoculation (scheduled 
for the next cycle, i.e., 3 wks ahead) and administer GPS 
6 wks ahead (i.e., ‘spread out’) twice thereafter, i.e. for 

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2 additional cycles à DLT resolution à Return to per 
protocol schedule of GPS administration  
• Third DLT (occurring either after reverting to the per 
protocol schedule or during the ‘spread out’ schedule to 
manage the 2nd DLT above) à Discontinue patient from 
study. 
N.B.: In all above modifications of the dose density of 
galinpepimut-S, as all intervals (in weeks) between 2 successive 
GPS administrations are multiples of three (3) by design, 
following these rules, co-administration with pembrolizumab is 
always secured. 
 
Stopping rules: 
• Development of any SAEs at least “possibly 
attributable” to the study agent(s) in 2 out of the first 6 
patients in the study. In this case, the upper 90% one-
sided CI bound for 2 patients with SAEs within 6 
patients would be 66.7%, consistent with an excessive 
rate of toxicity. 
• The fraction of patients experiencing an SAE at least 
“possibly attributable” to the study agent(s) exceeds 
1/3, at any time during study implementation beyond 
the first 6 patients. 
• Death at least “possibly attributable” to the 
study investigational agent(s) within 30 days 
after the administration of the investigational 
treatment (GPS plus pembrolizumab) 
• Development of grade 3 or higher colitis/diarrhea, 

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grade 3 or higher pneumonitis, grade 3 or higher 
nephritis, grade 3 or higher transaminitis, or any grade 
myocarditis in 2 out of the first 6 patients in the AML 
arm of the study. In this case, the upper 90% one-
sided CI bound for 2 patients with SAEs within 6 
patients would be 66.7%, consistent with an excessive 
rate of toxicity. 
• The fraction of patients experiencing grade 3 or 
higher colitis/diarrhea, grade 3 or higher 
pneumonitis, grade 3 or higher nephritis, grade 3 or 
higher transaminitis, or any grade myocarditis 
exceeds 40%, at any time during study 
implementation beyond the first 6 patients in the 
AML arm. 
If the study is stopped due to activation of the above rules, the 
safety data will be examined by the Sponsor in consultation with 
investigators in order to determine how to proceed or whether to 
discontinue the study at large. 
Note: Dose modifications for HMA-related (known/expected) 
toxicities -for either azacitidine or decitabine- in AML patients 
will be based on the respective US Prescribing Information for 
these products. These documents are included as Appendices 
12.1 and 12.2. 
 
 

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Procedures 
After signing the informed consent, patients will enter the 28-
day Screening period. At the baseline visit (Day −2), all 
pretreatment screening procedures/assessments must be 
completed, review of inclusion/exclusion criteria (including 
specific tumor histologic type verification, [e.g., TNBC]), and 
review of laboratory and tissue pathology results confirmed 
prior to enrollment and the first GM-CSF injection. 
Patients will then enter the open-label treatment period which is 
approximately 111 weeks (777 days; 2.13 years) in duration; the 
last galinpepimut-S administration would occur at 84 weeks 
(day 588 days; 1.61 years). 
Patients will be treated until progression, death, unacceptable 
toxicity (including activation of the stopping rules in either the 
solid tumor arms or the AML arm), or completion of 2 years of 
therapy with pembrolizumab, whichever occurs first. 
A safety follow-up period will occur 30 days after the last 
administration of study drug. A follow-up phone call for serious 
adverse events will occur 90 days after the last dose of 
pembrolizumab or 30 days following cessation of study 
treatment if the patient begins new anticancer therapy, 
whichever is earlier. If the patient initiates new anticancer 
therapy, this must be reported by the investigator. 
For a full list of study procedures, including the timing of each 
procedure, please refer to Section  and the Schedule of 
Assessments in Table 8.  

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Estimated Study 
Duration: 
Maximum study treatment duration is approximately 111 weeks 
(777 days; 2.13 years), during which the last galinpepimut-S 
administration would occur at 84 weeks (day 588 days; 
1.61 years) – all time measurements assume t-zero the date of 
first galinpepimut-S administration, except specifically for 
safety, t-zero assumes the date of first GM-CSF administration 
(day -2 of the entire protocol schedule).  
Efficacy Assessments: 
Signal response for each a priori statistically defined clinical 
outcome (ORR per RECIST 1.1) for all solid tumor types or 
other appropriate instrument scales, such as attainment of 
morphologic CR in AML patients. In addition to RECIST 1.1, 
all scans will be read according to iRECIST immune response 
consensus guideline (Seymour et al, 2017) to ensure that 
patients are not discontinued from therapy due to the 
phenomenon of tumor “pseudoprogression”, and clinical 
decisions will be based on iRECIST (Hodi et al, 2016).  
Exploratory 
Assessments: 
ORR per iRECIST in patients in the solid tumor arms and the 
frequency (rate) of achievement of MRD negativity in patients 
in the AML arm will be evaluated as exploratory endpoints.  
All patients enrolled in the study will be followed and assessed 
for PFS and OS, according to the intent-to-treat (ITT) principle. 
Specifically for OS, patients who complete the protocol-
specified study treatment period or patients who discontinue 
early will enter an off treatment follow-up period to assess OS, 
with regular assessments every 3 months until study closure 
(defined as up to 2 years and 6 weeks, i.e., 111 weeks after the 
first galinpepimut-S administration given to the last patient 

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enrolled into the study, which corresponds to 2 years after the 
first injection of pembrolizumab).  
This study will also assess the effect of the study treatment on 
readouts of immunologic tests in PB samples, as well as 
presence and density of immune cell infiltrates within the tumor 
stroma (or BM in AML patients) using at least one post-therapy 
tumor biopsy (and comparing the findings with those at 
baseline, i.e., prior to initiation of treatment). Details are 
provided in Section 6.3. 
Safety Assessments: 
At each galinpepimut-S administration visit the investigator will 
review concomitant medications, AEs, ECOG performance 
status score, vital signs (including body temperature, systolic 
and diastolic blood pressure [BP], heart rate, and respiratory 
rate; and weight). All blood samples will be collected before 
galinpepimut-S and/or pembrolizumab administration (Day 1 of 
each cycle). Blood samples for complete blood count (CBC) 
with differential and platelet count and serum chemistry, will 
also be collected prior to the administration of GM-CSF at Day -
2 of each cycle whereby galinpepimut-S is also co-administered. 
In addition to the blood samples collected for safety, blood 
samples will be collected for exploratory investigations on 
immune reactivity against the tumor. 
Safety assessments will be conducted at every visit. The EOT 
visit will occur 30 days after the last pembrolizumab injection. 
A follow-up phone call for serious adverse events (SAEs) will 
occur 90 days after the last dose of pembrolizumab or 30 days 
following cessation of study treatment if the patient begins new 
anticancer therapy, whichever is earlier.  

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Toxicity will be graded in accordance with CTCAE v5.0 
developed by the NCI 
(https://ctep.cancer.gov/protocolDevelopment/electronic_applica
tions/docs/CTCAE_v5_Quick_Reference_5x7.pdf). 
Details regarding mitigation steps if AEs occur during drug 
administration (e.g., injection site reactions [ISRs]) post- 
galinpepimut-S SC administration (when administered as 
monotherapy during the first 2 administrations, as well as 
subsequently, i.e., in combination with pembrolizumab IV 
infusion), as well as infusion related reactions (IRR) to 
pembrolizumab IV (when given in combination with 
galinpepimut-S SC) are included in Section 5.3.6. 
Statistical 
Considerations: 
Sample Size: Approximately 90 patients will be enrolled in the 
study. The planned number of patients within each tumor-
specific cohort is as follows:  CRC (N = 20), OvC (N = 20), 
SCLC (N = 20), TNBC (N = 15), and AML (N = 15). This study 
uses a Bayesian monitoring approach to guide decision-making 
using data on the primary efficacy endpoint (ORR for patients in 
the solid tumor arms and rate of achievement of CR/CRi/CRp in 
patients in the AML arm) within each tumor-specific cohort. If 
the data provide high confidence that the true ORR (or 
CR/CRi/CRp rate for AML) exceeds a minimal clinically 
meaningful level or threshold, then the results would support 
continued development (a “Go” decision) for that cohort. If the 
data suggest that the true ORR (or CR/CRi/CRp rate for AML) 
is unlikely to meet the desired level of clinical activity, then the 
results would support a decision to halt further continuation of 
accrual (a “Stop” decision) for that cohort. This approach is 

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based on the decision-making framework of Lalonde et al, 2007 
and Frewer et al, 2016.  
For each tumor type test, the minimal clinically meaningful 
level of any given ORR (or CR/CRi/CRp rate for AML) 
value/result is defined by the “lower reference value” (LRV), 
and the desired level of clinical activity is defined by the “target 
value” (TV). The LRV and TV for each tumor type are 
determined by a synthesis of medical opinion, evidence from the 
literature, or data from other compounds being developed in the 
same area. These values are as follows: CRC LRV=10%, 
TV=20%; OvC LRV=10%, TV=20%; SCLC LRV=30%, 
TV=40%; TNBC LRV=15%, TV=25%; AML LRV=15%, 
TV=25%. 
Enrollment in a cohort may be stopped for futility prior to 
reaching the planned sample size if there is a high predicted 
probability of a Stop decision at the planned sample size. 
Enrollment in a cohort may be increased with approximately 10 
additional patients beyond the planned sample size if the 
sponsor determines that further data is needed to clarify the 
safety or efficacy signals for a Go/No-Go decision. 
Based on the performance characteristics computed and 
described in the statistical section of the protocol, the sample 
sizes are adequate to address the study’s objectives. No formal 
statistical power calculations to determine sample size were 
performed. 
Statistical Methods: 
Analysis Sets 
• The full analysis set (FAS) comprises all patients who 
are assigned to receive study treatment as per the 
intent-to-treat (ITT) principle, regardless of whether or 

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not they subsequently go on to receive study treatment or 
whether they deviate from the protocol in any major 
way. 
• The modified intent-to-treat (mITT) set comprises all 
patients who are assigned to receive study treatment and 
have at least 1 post-baseline efficacy assessment 
(RECIST 1.1), even if they deviate from the protocol in 
any major way. The mITT will also include any patient 
that goes off study treatment because of clinical 
progression prior to the first scheduled per-protocol scan. 
• The safety analysis set comprises all patients who 
receive any amount of study drug. 
• The per-protocol set (PPS) comprises all patients who 
are assigned to receive study treatment, receive at least 
1 injection of study treatment, have at least 1 
post-baseline efficacy assessment (RECIST 1.1), and do 
not deviate from the protocol in any major way 
All efficacy analyses will be based on the FAS and will also be 
conducted on the mITT set and PPS for exploratory purposes. 
The study’s primary objective will be judged on the basis of the 
analysis of ORR. For CRC patients, only those with MSS and 
MSI-L will be included in the primary efficacy analysis. The 
safety analyses will be based on the safety analysis set and will 
group patients according to treatment actually received. 
Secondary and exploratory efficacy analyses will be performed 
on the FAS as well as on the mITT set and PPS for exploratory 
purposes. 
Analysis of Primary Efficacy Endpoint: For each tumor-
specific cohort, a Bayesian approach with non-informative 

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Jeffreys prior beta distribution with parameters a = 0.5 and 
b = 0.5 will be used to estimate the ORR (or CR/CRi/CRp rate 
in AML) and its 95% credible interval based on the posterior 
distribution.  
At the time of analysis, within each tumor-specific cohort, the 
prior distribution will be updated with all available data from the 
evaluable patients to obtain the posterior distribution of the true 
ORR. The posterior probabilities that ORR (or CR/CRi/CRp rate 
in AML) exceeds TV and LRV will be reported for each cohort. 
A high posterior probability that ORR > LRV will support a 
“Go” decision to continue development in the cohort, and a low 
posterior probability that ORR > TV will support a “Stop” 
decision to halt development in the cohort. A “Consider” 
decision results if neither a Stop nor a Go decision can be made. 
The specific criteria for making a Stop, Consider, or Go decision 
within each tumor-specific cohort are derived using the 
following acceptable risks: 
• 10% false stop risk: maximum acceptable probability 
that ORR > TV given that a Stop decision is made. 
• 20% false go risk: maximum acceptable probability that 
ORR ≤ LRV given that a Go decision is made 
Before reaching the planned sample size in a cohort, the 
posterior probabilities will be updated continuously after each 
patient (or group of patients) and will be used to determine, 
within each cohort, the predictive probability of eventually 
reaching a Stop decision at the planned sample size. If this 
predictive probability is ≥ 80%, then enrollment in that cohort 
may be stopped early for futility. 

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Stop/Go and futility decision criteria are non-binding and may 
be regarded as guidance and information to be integrated with a 
full medical review of safety and efficacy data observed at the 
time of analysis in determining the next course of action. No 
tests of statistical significance are planned.  
CRC  
Given a sample size of 20 patients in the CRC (third/fourth line) 
group, where TV = 20% and LRV = 10%, the decision criteria 
are as follows: Go if ≥ 4 responses observed (20%); Stop if ≤ 1 
responses observed (5%). With these criteria, there is a 59% 
probability of a Go decision and 7% probability of a Stop 
decision if the true ORR is 20%, and there is a 13% probability 
of a Go decision and 39% probability of a Stop decision if the 
true ORR is 10%. 
OvC  
The same sample size, TV, LRV, decision criteria, and 
probability statements as the CRC group apply. 
SCLC 
Given a sample size of 20 patients in SCLC group, where 
TV = 40% and LRV = 30%, the decision criteria are as follows: 
Go if ≥ 8 responses observed (40%); Stop if ≤ 5 responses 
observed (20%). With these criteria, there is a 58% probability 
of a Go decision and 13% probability of a Stop decision if the 
true ORR is 40%, and there is a 23% probability of a Go 
decision and 42% probability of a Stop decision if the true ORR 
is 30%.  
TNBC 
Given a sample size of 15 patients in the triple negative breast 
cancer group, where TV=25% and LRV=15%, the decision 

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criteria are as follows: Go if ≥ 4 responses observed (27%); Stop 
if ≤ 1 responses observed (7%). With these criteria, there is a 
54% probability of a Go decision and 8% probability of a Stop 
decision if the true ORR is 25%, and there is a 18% probability 
of a Go decision and 32% probability of a Stop decision if the 
true ORR is 15%. 
AML 
The same sample size, TV, LRV, decision criteria, and 
probability statements as the TNBC group apply. 
General Considerations 
Data will be summarized and/or analyzed by cohort. Safety and 
demographic data will be summarized using standard tabulations 
and listings. Continuous variables will be summarized using 
descriptive statistics such as mean, standard deviation, median, 
minimum value, and maximum value. Continuous variables may 
be summarized by a clinically relevant discretization, as 
appropriate. Categorical variables will be summarized using 
frequency counts and percentages. Time-to-event data will be 
summarized using the Kaplan-Meier method. All time to event 
endpoints are measured from day of enrollment (Day-2 
pretreatment baseline visit). Where appropriate, 95% confidence 
intervals around point estimates will be presented, and estimates 
of the median and other quantiles, as well as individual time 
points (e.g., 3-month, 6-month, and 12-month rates), will be 
produced. Data will be provided in data listings. 
Objective response rate will be reported with category counts, 
percentage and 95% confidence interval. Duration of response 
(DOR), TTR, and OS will be evaluated using Kaplan-Meier 
estimates and curves will be generated based on these estimates.  

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Date of Protocol 
Amendment: 
12 April 2019 

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List of Abbreviations 

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Abbreviation 
Definition 
aa 
amino acids 
AE 
AGO-OVAR 
adverse event 
Arbeitsgemeinschaft Gynaekologische Onkologie - Studiengruppe 
Ovarialkarzinom 
allo-SCT 
allogenic (hematopoietic) stem cell transplant 
ALT 
alanine aminotransferase 
AML 
acute myeloid leukemia 
ANC 
absolute neutrophil count 
APC 
antigen-presenting cell 
APL 
acute promyelocytic leukemia 
aPTT 
activated partial thromboplastin time 
AST 
aspartate aminotransferase 
AUC 
area under the concentration curve 
BCG 
Bacillus Calmette–Guérin 
BICR 
Blinded Independent Central Review 
BM 
bone marrow 
BP 
blood pressure 
CBC 
complete blood count 
CBFB/MYH11 
core-binding factor beta subunit/myosin heavy chain-11 
cDNA 
complementary deoxyribonucleic acid 
CFR 
Code of Federal Regulations 
Cmax 
maximum observed concentration 
CML 
chronic myeloid leukemia 

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Abbreviation 
Definition 
CNS 
central nervous system 
CR 
complete remission, complete response (AML) 
 
CR1 
first complete remission (AML) 
CR2 
second complete remission (AML) 
CRC 
colorectal cancer 
CrCl 
creatinine clearance 
CRi 
CR with incomplete recovery of blood counts (AML) (encompasses  
the definition of CRp) 
CRi/CRp 
CR with incomplete recovery of blood counts or platelets (AML) 
CRO 
clinical research organization 
CRp 
CR with incomplete recovery of blood platelets (AML) 
CT 
computed tomography 
CTCAE 
Common Terminology Criteria for Adverse Events 
CTL 
cytotoxic T-lymphocyte 
CV 
coefficient of variation 
DFS 
disease free survival 
DILI 
drug-induced liver injury 
DLT 
dose-limiting toxicity 
DMC 
data monitoring committee 
DNA 
deoxyribonucleic acid 
DOR 
duration of response  
DTH 
delayed-type hypersensitivity testing 

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Abbreviation 
Definition 
ECG 
electrocardiogram 
ECI 
Events of Clinical Interest 
eCRF 
electronic case report form 
ECOG 
Eastern Cooperative Oncology Group 
EDC 
electronic data capture 
EDTA 
ethylene diamine tetra-acetic acid 
EFS 
event free survival 
ELISPOT 
enzyme-linked immunospot 
ELN 
European LeukemiaNet 
EOT 
end-of-treatment 
ES-SCLC 
extensive stage small cell lung cancer 
FAS 
full analysis set 
FDA 
FIR 
Food and Drug Administration 
First Interpretable Results 
FISH 
fluorescence in situ hybridization 
FN 
febrile neutropenia 
FT3 
free triiodothyronine 
FT4 
free thyroxine 
GBM 
gBRCA mut 
glioblastoma multiforme 
germline BRCA mutations 
GCP 
Good Clinical Practice 
G-CSF 
granulocyte colony-stimulating factor 
GFR 
glomerular filtration rate 

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Abbreviation 
Definition 
GM-CSF 
GOG 
GPS 
H 
HBsAg 
granulocyte-macrophage colony-stimulating factor 
Gynecologic Oncology Group (US) 
galinpepimut-S 
hour 
hepatitis B surface antigen 
HCV RNA 
hepatitis C RNA 
HER2 
human epidermal growth factor receptor 2 
HIPAA 
Health Insurance Portability and Accountability Act 
HIV 
human immunodeficiency virus 
HLA 
human leukocyte antigen 
HMA 
hypomethylating agent 
HSCT 
hematopoietic stem cell transplant 
IB 
Investigator’s Brochure 
ICF 
informed consent form 
ICH 
International Council on Harmonisation 
iCPD 
iRECIST confirmed progressive disease 
ICS 
intracellular cytokine staining 
ICU 
IDH1 
intensive care unit 
isocitric dehydrogenase-1 
IEC 
independent ethics committee 
IHC 
immunohistochemical 
ILD 
Interstitial lung disease 

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Abbreviation 
Definition 
INR 
IR 
International Normalized Ratio 
immune response 
irAE 
immune-related adverse event 
IRB 
Institutional Review Board 
iRECIST 
Immune-related Response Evaluation Criteria In Solid Tumors 
IRR 
infusion related reaction 
IRS 
immuno-reactive score 
ISR 
injection site reaction 
ITT 
intent-to-treat 
IV 
intravenous 
IWRS 
interactive web response system 
LFS 
leukemia-free survival 
LRV 
lower reference value 
LSC 
leukemic stem cell 
mAb 
monoclonal antibody 
MCC 
Moffitt Cancer Center 
MDS 
myelodysplastic syndrome 
MedDRA 
Medical Dictionary for Regulatory Activities 
MDSC 
Myeloid-derived suppressor cell 
MHC 
major histocompatibility complex 
mITT 
modified intent-to-treat 
MK-3475 
pembrolizumab 
MM 
multiple myeloma 

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Abbreviation 
Definition 
MOA 
mechanism of action 
MPM 
malignant pleural mesothelioma 
MRD 
minimal residual disease 
MRI 
magnetic resonance imaging 
MRK 
Merck & Co., Inc., Kenilworth, N.J., USA (known as MSD outside 
the United States and Canada) 
MS 
microsatellite 
MSI 
microsatellite instability 
MSKCC 
Memorial Sloan-Kettering Cancer Center 
MSS 
microsatellite stable 
NCI 
National Cancer Institute 
NCI CTCAE 
National Cancer Institute Common Toxicity Criteria for Adverse 
Events 
NIH 
National Institutes of Health 
NSAID 
non-steroidal anti-inflammatory drug 
NSCLC 
non-small cell lung cancer 
NYHA 
New York Heart Association 
ORR 
overall response rate 
OS 
overall survival 
OvC 
PARP 
ovarian cancer 
poly-ADP ribose polymerase 
PB 
peripheral blood 
PCR 
polymerase chain reaction 

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Abbreviation 
Definition 
PD 
progressive disease 
PD-1 
programmed cell death receptor 1 
PFS 
progression-free survival 
PK 
pharmacokinetics 
PD-L1 
ligand to PD-1 receptor 
PML-RAR-a 
promyelocytic leukemia-retinoic acid receptor alpha 
PPS 
per-protocol set 
PR 
partial response 
PT 
Prothrombin time 
PTT 
Partial thromboplastin time 
Q2W 
every 2 weeks  
Q3W 
RBC 
every 3 weeks  
red blood cell 
RECIST 
Response Evaluation Criteria In Solid Tumors 
RT-PCR 
reverse transcription polymerase chain reaction 
SAE 
serious adverse event 
SAF 
safety analysis set 
SAP 
statistical analysis plan 
SC 
subcutaneous 
SCLC 
small cell lung cancer 
SCT 
stem cell transplant 
SD 
standard deviation 
SIM 
Site Imaging Manual 

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Abbreviation 
Definition 
SUSAR 
suspected unexpected serious adverse reaction 
SWFI 
sterile water for injection 
T1/2 
terminal elimination phase half-life 
T1DM 
Type 1 diabetes mellitus 
T3 
triiodothyronine 
TAA 
tumor-associated antigens 
TAM 
tumor-associated macrophage 
TBX 
tumoral biopsy samples 
TEAE 
treatment-emergent adverse event 
Tmax 
time at which the highest drug concentration occurs 
TME 
tumor microenvironment 
TNBC 
triple-negative breast cancer  
TRAE 
treatment related adverse events 
Treg 
T-regulatory cell 
TSH 
thyroid stimulating hormone 
TTR 
time to response  
TV 
target value  
ULN 
upper limit of normal  
US 
United States 
USP 
WBC 
United State Pharmacopeia 
white blood cell 
WOCBP 
woman of childbearing potential 
WT1 
Wilms tumor gene 

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1 
Introduction 
1.1 
Galinpepimut-S Background 
1.1.1. Preclinical and Pharmacological Background 
The Wilms Tumor-1 (WT1) protein, the WT1 oncogene product, was first identified in 
childhood renal tumors, but has been found to be overexpressed in a high proportion of solid 
and hematological malignancies, while its expression is substantially void in most healthy 
adult tissues (Wagner et al, 2014). WT1 was originally identified by complementary 
deoxyribonucleic acid (cDNA) mapping to a region of chromosome 11p13. The WT1 cDNA 
encodes a protein of 575 amino acids (aa) in length, containing 4 Kruppel zinc fingers and 
exhibiting a complex pattern of alternative splicing, resulting in 4 different transcription 
factors (Haber et al, 1990; Hohenstein et al, 2016). Each WT1 protein isoform has different 
deoxyribonucleic acid (DNA) binding and transcriptional activities, and can positively or 
negatively regulate various genes involved in cellular proliferation, differentiation, apoptosis, 
organ development, and sex determination (Haber et al, 1991). WT1 is normally expressed in 
tissues of the mesodermal origin during embryogenesis, including the kidney, gonads, heart, 
mesothelium, and spleen (Oji et al, 1999; Sharnhorst et al, 1999). In normal adult human 
tissues, WT1 expression is limited to very low levels in the nuclei of normal CD34+ 
hematopoietic stem cells, myoepithelial progenitor cells, renal podocytes, injured 
myocardium, and some cells in the testis and ovary (Mundlos et al, 1993; Buckler et al, 1991; 
Fraizer et al, 1995). Although originally described as a tumor suppressor gene, the WT1 
proteins appear to be involved in tumorigenesis as a bona fide oncogene (Keilhoz et al, 2005; 
Lindstedt, et al, 2014).  
As WT1 is a transcription factor and is not expressed intact in the cell membrane, it has not 
been able to be targeted (druggable) with either small molecules or monoclonal antibodies 
(Toska et al, 2014). Nonetheless, the protein is processed by the proteasome in tumors and 
the derived peptides are presented in a major histocompatibility complex (MHC)-dependent 
manner on the cell surface. Furthermore, WT1 peptide fragments when administered as direct 

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immunogens (vaccines) are also taken up by antigen-presenting cells (APCs) and processed 
by the immunoproteasome for MHC-dependent presentation (Jiagirdar et al, 2016; 
Asemissen et al, 2006; Müller et al, 2003). The above features render WT1 a highly attractive 
target for immunotherapy (Oka et al, 2002; Oka et al, 2007). WT1 was ranked as the top 
cancer antigen by a working group organized by the National Cancer Institute (NCI) in 2009 
(Cheever, et al, 2009). The strong expression of WT1 protein in assorted cancers, coupled 
with its proposed mechanism of antigenicity and induction of immune responses (both CD4 
and CD8 [Chapuis et al, 2013; Dao et al, 2016; Tyler et al, 2013; Tyler and Koehne, 2013; 
Fujiki et al, 2008; Krug et al; 2010]; after direct immunization against WT1 in patients with 
assorted cancers), makes it a rational candidate for the development of specific 
immunotherapies, such as peptide vaccines (Van Driessche et al, 2012; Oka and Sugiyama, 
2010; Oka et al 2009; Dao and Seheinbert, 2008). The WT1 antigen is one of the most 
widely expressed cancer antigens in multiple malignancies. It has been ranked by the NCI – 
National Institutes of Health (NIH) - as the top priority among cancer antigens for 
immunotherapy (Cheever MA, et al 2009). WT1 is overexpressed in numerous hematological 
malignancies, including acute myeloid leukemia (AML), chronic myeloid leukemia (CML), 
and multiple myeloma (MM), as well as in many solid malignancies such as malignant 
pleural mesothelioma (MPM), gastrointestinal cancers, i.e., colorectal cancer (CRC), 
glioblastoma multiforme (GBM), triple-negative breast cancer (TNBC), ovarian cancer 
(OvC), small-cell lung cancer (SCLC); all in all WT1 is expressed in at least 50% of tumor 
pathology specimens in up to 25 assorted malignancies (Oji Y et al, 2003; Bejrananda T et al, 
2010-2011; Inoue K, et al, 1997; Nakatsuka S-I et al, 2006; Provenzano E, et al, 2016; Narita 
M et al, 2010; Di Stasi A et al, 2015; Tyler EM and Koehne G. 2013; Babiak A et al, 2014; 
Menssen HDet al,  2000; Oji Yet al, 2016; Nakahara Y et al, 2004; Van Driessche Aet al, 
2005).  
Despite WT1’s broad expression in assorted malignancies, due to its nature - an intracellular 
transcription factor localized in the cell nucleus, and as mentioned earlier- it has been ‘un- 
druggable’ via standard pharmacology approaches, such as small molecules or surface-acting 
macromolecules (such as monoclonal antibodies). Thus, immunotherapy approaches, such as 

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direct immunizers (such as peptide-based vaccines) emerged as an attractive pathway to 
therapeutically target this key protein (Brayer and Pinilla-Ibarz, 2013; Schwartz J et al, 2003; 
Oka Y et al, 2006; Van Driessche A et al, 2012). Because WT1 protein is a self-antigen, 
breaking tolerance is a potential problem for an effective treatment. When developing 
potential treatment candidates, a strategy in use at Memorial Sloan-Kettering Cancer Center 
(MSKCC) to circumvent the poor immunogenicity and potential tolerance of tumor-
associated peptides is to design synthetic analog peptides that will be more immunogenic. 
Such peptide analogues could generate an immune response that not only recognizes the 
immunizing epitopes, but also cross-reacts with the original native peptides; this is known as 
a heteroclitic response. By using computer prediction analysis, a large number of synthetic 
peptides derived from WT1 protein sequences were designed in which single or double aa 
substitutions were introduced into the peptides at key human leukocyte antigen 
(HLA)-A*A0201 binding positions (Pinilla-Ibarz et al, 2006; Gomez-Nunez M et al, 2006). 
Peptides predicted to bind with high affinity to HLA-A*A0201 molecules were directly 
assayed for their ability to stabilize major histocompatibility complex class I A0201 
molecules on the surface of antigen-transporting-deficient T2 cell lines. The new synthetic 
peptides stabilized major histocompatibility complex class I A0201 molecules better than 
native sequences. Avidly binding peptides were then assayed in an antigen-specific T-cell 
expansion in vitro system for the ability to elicit HLA-restricted, peptide-specific cytotoxic 
T-lymphocyte (CTL) responses using purified T cells from healthy donors. The synthetic 
analog peptides generated more effective immune responses than the native peptides. In 
addition, CD8+ T-cells stimulated with the new synthetic peptides displayed heteroclitic 
features and cross reacted with the native WT1 peptides and also were able to mediate 
peptide-specific cytotoxicity. Importantly, T-cells stimulated with the new synthetic peptides 
cross-reacted with the native WT1 peptide sequence and were able to destroy HLA-matched 
CML blasts (Pinilla-Ibarz J et al, 2000;). This validates the expression and possibility of 
killing tumors in this system. Other groups have validated the same native sequence in use as 
a target (Mailänder et al, 2004). 

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Synthetic peptides with longer WT1 sequences were also designed by modifying previously 
identified WT1 peptide segments and adding flanking aa segments. These peptides are 
capable of stimulating a CD4+ response, which is necessary for inducing long-term T-cell 
memory. They can induce a peptide-specific CD4+ response that can recognize 
WT1-positive tumor cells in multiple HLA-DRB1 settings. Using cross-priming experiments, 
it was shown that the WT1 peptide is presented on the surface of mesothelioma tumor cells 
and could be recognized by the T-cells stimulated by the individual WT1-DR peptides (May 
et al, 2007). 
In order to broaden immunogenicity over a range of HLA subtypes, 4 WT1-derived peptides 
were chosen to combine into a mixture to be used as a direct immunizer. The current 
candidate product, now known as galinpepimut-S, contains 1 WT1 heteroclitic peptide to 
stimulate CD8 responses (WT1-A1), 2 longer WT1 native peptides to stimulate CD4 
responses (WT1-427 long and WT1-331 long) and 1 longer heteroclitic peptide that could 
stimulate both CD4 and CD8 cells (WT1-122A1 long). Galinpepimut-S, along with the 
immunological adjuvant Montanide™ with granulocyte-macrophage colony-stimulating 
factor (GM-CSF) pre-stimulation was then taken into human trials, initially in AML and 
mesothelioma, and subsequently in other indications (multiple myeloma and ovarian cancer). 
With regard to the use of GM-CSF as an immune adjuvant and to establish the paucity of any 
confounding immunologic and/or clinical effects thereof when co-administered with 
galinpepimut-S, the following information is of relevance: Firstly, GM-CSF has been 
recognized as an activator of the first step in adaptive immunity responses to antigens, 
especially peptide vaccines over the last 25 years (Caux et al, 1996). Pre-stimulation of host 
macrophages/monocytes and other antigen-presenting cells (APCs) is absolutely required for 
the induction immune responses against moieties of relatively low antigenic potential (such 
as tumor-associated antigens, or TAAs) presented through the MHC Class I and II systems 
(Mach et al, 2000; Olatunde et al, 2018). This is true for oligopeptide fragments of the WT1 
protein, including those within the galinpepimut-S tetravalent mixture. In essence, in order 
for most peptide vaccines to induce immunogenicity – leading to CD8+ and/or CD4+ 

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lymphocyte activation, which is the prerequisite for the emergence of an immunologically 
mediated antitumor clinical effect, they need to be co-administered with an immune adjuvant. 
In a wide variety of such vaccines, including galinpepimut-S, one of the most commonly 
used (and more widely studied) adjuvant for this purpose is GM-CSF. Secondly, several 
clinical and immunobiological studies have shown lack of consistent effect of GM-CSF 
monotherapy, i.e., when this adjuvant is administered by itself and in the absence of another 
tumor-directed immunotherapy, with regard to GM-CSF’s ability to induce or maintain 
antigen-specific T- and B-cell immune responses and clinical effect in patients with various 
malignancies (O’Day et al, 2009; Greter et al, 2012; Lawson et al, 2015). Indeed, although 
GM-CSF monotherapy in cancer patients has been shown to exert various modulatory effects 
in the number/frequency and activation level of dendritic cells (DCs) and other immunocytes, 
none of these cell subpopulations have even been consistently shown to be specifically 
directed to/reactive against tumor-associated antigens. This is especially true when GM-CSF 
is used in small doses (such as that used in this study, 70 µg per administration - rather than 
the per-label dose of 250 µg per administration) (Parmiani et al, 2007).  Of note, in an earlier 
phase 2b, double-blinded, randomized, controlled clinical study of galinpepimut-S (plus GM-
CSF) versus GM-CSF alone given in the maintenance setting after frontline debulking 
multimodality therapy in patients with malignant pleural mesothelioma, no WT1 (antigen)-
specific T-cell (CD8 or CD4) immune responses were observed in the control arm. Further, 
the clinical outcome (as measured by overall survival since randomization) in the control arm 
was comparable to that reported in patients who relapsed during follow up for the natural 
history of their disease (Zauderer et al, 2017). Therefore, when all the above is taken into 
consideration, GM-CSF alone appears to be inactive with regard to antigen-specific 
immunogenicity and antitumor effect. 
1.1.1.2.  Justification for Galinpepimut-S Dose 
A dose of 200 μg for each WT1 peptide within the galinpepimut-S mixture (total weight of 
all 4 peptides per inoculation being equal to 800 μg) was chosen because it is within the 
range of safe and active doses used in other WT1-based treatments. Peptide vaccines have 

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generated immune and clinical responses within a wide range of doses (100 to 2000 μg 
injected) without clear evidence of dose response relationships. Higher doses have the 
theoretical possibility of stimulating lower affinity T-cell receptors on T cells and reducing 
the response. 
1.1.2. Galinpepimut-S Clinical Studies1.1.2.1. Phase 1 Clinical Experience 
with Galinpepimut-S (Study 06-085) 
The MSKCC conducted a single institution, open-label, single arm Phase 1 study (#06-085)  
in patients with AML, non-small cell lung cancer (NSCLC), or mesothelioma to determine 
the safety and immunogenicity of treatment with galinpepimut-S (Krug et al, 2010; Maslak et 
al, 2010; ClinicalTrials.gov identifier: NCT00398138). Patients with myelodysplastic 
syndrome (MDS) were eligible to enroll in this study; however, none were treated. In this 
study, all HLA subtypes were eligible. Patients with AML were ≥ 65 years of age and had 
previously completed induction chemotherapy, achieved clinical remission, and completed 
postremission therapy, or completed induction chemotherapy, achieved clinical remission, 
and had no plans for further postremission therapy. AML patients had documented WT1-
positive disease as demonstrated by WT1 protein on a pretreatment bone marrow (BM) 
biopsy or detectable disease with real-time quantitative reverse transcription polymerase 
chain reaction (RT-PCR). Mesothelioma patients were required to have malignant pleural 
mesothelioma or peritoneal mesothelioma, unresectable or relapsed disease, and had to have 
received no more than 1 prior pemetrexed-containing chemotherapy regimen. Patients with 
NSCLC were either stage III or IV and had completed initial treatment with surgery and/or 
chemotherapy and/or radiation therapy. Both mesothelioma and NSCLC patients were 
required to have neoplasms that showed immunohistochemical (IHC) staining for WT1 in 
greater than 10% of cells. Patients were stratified according to disease type: AML (Myeloid 
Group) versus NSCLC or mesothelioma (Thoracic Group). Results from the myeloid group 
are presented in the following sections. Results from the thoracic group can be found in the 
Galinpepimut-S Investigator Brochure v2.0, June 2017. 

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Galinpepimut-S as a pharmaceutical preparation is a multicomponent direct immunogen 
mixture, consisting of the 4 WT1 peptides defining the galinpepimut-S drug substance 
suspended in Montanide adjuvant. Sargramostim (hereafter referred to as GM-CSF) was 
administered at the injection site before each treatment. Treatment was administered on 
Weeks 0, 4, 6, 8, 10, and 12 for a total of 6 injections. Patients who had a clinical, molecular, 
or immunologic response and did not have disease progression were able to receive up to 6 
additional administrations administered approximately 1 administration every month for 6 
months. 
Ten patients were enrolled in the AML arm. Seven patients (70.0%) prematurely 
discontinued; the most frequently reported primary reason for discontinuing active treatment 
was progressive disease/disease relapse (4 patients). The remaining patients discontinued to 
the following reasons: 1 patient due to excessive toxicity, 1 patient due to another 
complicating disease, and 1 due to other reasons. The median age of patients was 67 years 
(range: 24 to 78 years). Seven patients (70.0%) were male and 3 patients (30.0%) were 
female. 
In the myeloid group, all 10 patients received at least 1 administration with WT1 peptide. 
Eight patients (80.0%) received ≥6 administrations, and 5 patients (50.0%) received > 8 
administrations. The total exposure to WT1 peptide ranged from 28 to 295 days, with a 
median of 144.5 days. 
With regard to safety, in the myeloid group, hyperglycemia (10 patients; 100.0%) was the 
most common treatment-emergent adverse event (TEAE), followed by platelet count 
(8 patients; 80.0%); hemoglobin and white blood cell disorder (6 patients each; 60.0%); and 
hepatic enzyme abnormal, white blood cell analysis, and hypernatremia (5 patients each; 
50.0%). Eight study treatment-related TEAEs were reported in 3 patients (30.0%) and were 
mild (all were ≤ Grade 2). The study treatment-related TEAEs were edema peripheral, 
erythema multiforme, injection site extravasation, platelet count, pruritus, white blood cell 
disorder, and white blood cell analysis. No serious TEAEs were reported in the myeloid 
group. 

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Four patients (40.0%) in the myeloid group were known to be alive with no progression of 
disease at the time of last contact and 6 patients (60.0%) died. The median overall survival 
(OS) in the myeloid group was 31 months (2.6 years; see Figure 1). One patient who received 
7 treatments with galinpepimut-S was still alive as of Month 54.3 (4.5 years); another patient 
who received 8 treatments with galinpepimut-S was still alive as of Month 78.2 (6.5 years). 
Another patient, after completion of at least 12 treatments, had no progression of disease at 
the time of her death, on Month 54.6 (4.6 years). 
Figure 1 
Kaplan-Meier Plot for Overall Survival by Disease Group 
 
The results from the myeloid arm of this Phase 1 study were superior to published AML 
outcome data (Ries et al, 2007; Appelbaum et al, 2006; Deschler and Lübbert 2006). Age 
appears to be a major determinant in patient outcomes, with the oldest populations deriving 
little benefit from many of the dose-intensive therapies introduced in the last few years. 
Appelbaum et al (2006) reported a median OS of 18.8 months in patients younger than 
56 years of age, 9.0 months in patients 56 to 65 years of age, and 6.9 months in patients 66 to 
Overall Survival (%)
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75 years of age (Appelbaum et al, 2006). The median age of AML patients treated in the 
Phase 1 pilot study was 67 years of age; therefore, the outcomes for this study’s AML group 
compare favorably with published data from Appelbaum et al where the youngest cohorts 
had the best outcomes. Though caution needs to be exercised in interpreting these results as 
there may be a bias regarding patient selection and reduced sample size in the study group, 
the results were intriguing enough to warrant further study in a larger clinical study 
examining the role of galinpepimut-S administration as a viable treatment for AML in 
complete remission status. Hence, additional Phase 2 studies were undertaken at the 
MSKCC. 
1.1.2.2. Phase 2 Clinical Experience with Galinpepimut-SFour additional studies with 
galinpepimut-S were initiated at the MSKCC (A Phase 2 study in AML and acute 
lymphoblastic leukemia, a Phase 2 study in MPM, a Phase 1/2 pilot study in patients with 
multiple myeloma (MM), and a Phase 1/pilot study in ovarian cancer [OvC]). One additional 
Phase 1/2/pilot study was performed at the Moffitt Cancer Center (MCC) in patients with 
AML. Results from the Phase 1 and Phase 2 studies in AML and Phase 1/pilot study in OvC 
are discussed in the following section, as they are pertinent to 2 of the arms in the present 
study, while results from the other 2 studies (in MPM and MM) can be found in the 
galinpepimut-S investigator’s brochure (IB). While not all primary endpoint data for all 
above studies have been reached, their preliminary results extend the observations from the 
the earlier trials and form the basis to investigate galinpepimut-S efficacy in randomized 
Phase 3 clinical trials of galinpepimut-S (given in the maintenance setting) in both AML and 
MPM after initial debulking therapy. 
1.1.2.2.1. Study 10-143 (AML Patients)This open-label, Phase 2 trial (Maslak et al, 2018; 
ClinicalTrials.gov identifier: NCT01266083) evaluated the safety and efficacy (as measured 
by OS at 3 years) of galinpepimut-S used as postremission therapy in patients in complete 
remission (CR) from leukemia. In addition, this study assessed disease-free survival at 
3 years, immunologic responses (as measured by CD4+ T-cell proliferation, CD3+ T-cell 
interferon-g release, and WT1 peptide tetramer staining), and any effect the galinpepimut-S 

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had on minimal residual disease (MRD) (as measured by RT-PCR for WT1 transcript). 
Eligible patients were ≥18 years of age, had a morphological confirmation of a diagnosis of 
AML or acute lymphoblastic leukemia, and had achieved CR (within 2 years of first 
treatment administration) after completing induction therapy and any planned post-remission 
therapy. In addition, eligible patients could not be candidates for allogeneic stem cell 
transplantation. Potential patients who were ≥ 60 years of age, who achieved CR (within 2 
years of first treatment administration) and in whom no further postremission chemotherapy 
was planned were eligible for enrollment. Eligible patients had documented WT1-positive 
disease, defined as the detectable presence of any WT1 transcript via RT-PCR on a BM 
performed at the MSKCC within 4 weeks before the administration of the first dose of 
treatment. At least 4 weeks must have elapsed between the patient's last chemotherapy or 
radiation treatment and the first administration. In this trial, patients were administered the 
treatment, prepared as an emulsion of galinpepimut-S and Montanide, every 2 weeks for a 
total of 6 administrations. Those who were clinically stable and without disease recurrence 
could continue with up to 6 more treatments administered approximately every month. All 
patients receive sargramostim (GM-CSF, 70 µg) administered subcutaneously 2 days prior to 
each treatment as well as on the actual day of each administration to prestimulate the 
injection site. 
The data cut-off date for the disposition, demographic, and safety information was 
22 May 2015; the data cut-off date for patient survival was 30 October 2015. As of the data 
cut-off date, 22 patients had been enrolled. No additional patients were enrolled, as the study 
has been closed to enrollment.  
A total of 22 patients (7 men and 15 women) were enrolled on the study, were treated, and 
were evaluable for response. The median age was 64 years (range 25 to 76 years). Fifty 
percent (11 of 22) of study patients had a normal karyotype. 
Of the 22 patients enrolled, 14 (64%) received the planned 6 galinpepimut-S administrations 
and 10 (46%) completed all 12 galinpepimut-S administrations. Overall, 15 (68%) patients 
relapsed: 10 while receiving treatment, 4 after the entire series of 12 galinpepimut-S 

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administrations, and 1 patient 13 months following discontinuation of therapy secondary to a 
delayed- type hypersensitivity reaction. Four of the 15 patients relapsed after 1 galinpepimut-
S administration, likely an insufficient amount of time to induce an immune response. Ten 
relapsed patients died due to complications from progressive leukemia. Five of the 
15 relapsed patients underwent hematopoetic stems cell transplant (HSCT) following 
successful re-induction chemotherapy. Three of these patients remained alive without 
evidence of recurrent disease, ranging from 11 to 31 months post-HSCT. There was no 
statistically significant difference in either relapse rate or OS in patients who were treated 
prior to spending 8 months in first complete remission (CR1) compared with those treated at 
or after this timepoint. 
From first galinpepimut-S administrations, 19 of 22 (86%) patients were evaluable for 
survival at 3 years, and 9 of these 19 (47%) evaluable patients were alive for ≥3 years. 
Consequently, the study met its prespecified endpoint of ≥34% OS at 3 years.   
From CR1, the median disease-free survival (DFS) was 16.9 months (Figure 2). The median 
OS from diagnosis (Figure 3) was not reached but is poised to reach or exceed 67.6 months 
(5.6 years by log-rank analysis). The median event free survival (EFS) from the time of first 
galinpepimut-S administration was 9.4 months, while the median OS from the time of 
administration has not been reached (Figure 4 and Figure 5). The probabilities of EFS at 6 
and 9 months post galinpepimut-S administration were 64% (CI: 40%, 80%) and 54% (CI: 
32%, 72%), respectively. Likewise, the probabilities of OS at 6 and 9 months post 
galinpepimut-S administration were 100% (CI: 100%, 100%) and 77% (CI: 54%, 90%), 
respectively. 
For patients <60 years of age (n=9), neither the median DFS nor OS times were reached 
(Figure 6 and Figure 7). However, for patients in the older cohort (age >60; n=13), median 
DFS from CR1 was 10.8 months and median OS time post- diagnosis was 35.8 months 
(Figure 8 and Figure 9). Likewise, from first galinpepimut-S treatment, median EFS and OS 
times in the older cohort were 7.8 and 30.2 months, respectively. Lastly, landmark EFS in the 
older cohort at 6 and 9 months post first galinpepimut-S treatment were 54% (CI: 25%, 76%) 

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and 46% (CI: 19%,70%), respectively, while OS 6 and 9 months post first galinpepimut-S 
were 100% (CI: 100%,100%) and 62% (CI: 31%,82%). 
Figure 2 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median 
Disease-Free Survival 
 
Figure 3 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median 
Overall Survival 
 
 

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Figure 4 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median EFS 
from First Galinpepimut-S Administration 
 
Figure 5 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median 
Overall Survival from First Galinpepimut-S Administration 
 

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Figure 6 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median 
Disease-Free Survival of Patients < 60 Years of Age 
 
Figure 7 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median 
Overall Survival of Patients < 60 Years of Age 
 

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Figure 8 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median 
Disease-Free Survival of Patients ≥ 60 Years of Age 
 
Figure 9 
Study 10-143 (AML Patients): Kaplan-Meier Plot for Median 
Overall Survival of Patients ≥ 60 Years of Age 
 
Galinpepimut-S administration was generally well tolerated and the toxicity profile is 
consistent with other WT1 vaccine-adjuvant combinations (Oka, et al, 2004; Keilholz et al, 
2009; Rezvani et al, 2008; Rezvani et al, 2011; Uttenthal et al, 2014).  The montanide 
adjuvant is a known irritant (van Doorn et al, 2015) and many of the most frequent toxicities 
consisted of mild to moderate local reactions and inflammation: injection site reaction (46%), 
fatigue (32%), skin induration (32%), and injection site pruritus (27%). These toxicities were 
self-limited and responded to local supportive measures and analgesics. Several transient 
occurrences of decreased white blood cell, neutrophil, lymphocyte, and platelet counts were 
noted and these resolved, often on the same day of testing, and resulted in no significant 

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infectious complications or supportive transfusions. None of the patients developed 
significant hepatic or renal insufficiency and no episodes of systemic anaphylaxis were 
observed.  
Overall, galinpepimut-S in this population of AML patients was safe and well tolerated, with 
a majority of TEAEs being of mild or moderate severity (150/244, 61.5%). There were no 
reported deaths and a majority of Grade 3/4 TEAEs were unrelated to study treatment. The 
majority of injection site reactions, skin induration, and pruritus were easily managed with 
supportive care. Two patients discontinued therapy due to probable hypersensitivity reactions 
that were believed to be related to study treatment. One patient developed 2 episodes of a 
maculopapular rash (Grade 1) and then developed, on a separate occasion, an episode of 
flushing (Grade 3) immediately following the second study treatment administration. The 
patient remained hemodynamically stable and developed no signs of anaphylaxis but, given 
the severity of the episode, he discontinued further treatment. The patient subsequently 
relapsed and died from complications of recurrent AML 29 months after discontinuing 
galinpepimut-S treatment. The second patient developed bone pain, dyspnea, flushing, and 
non-cardiac chest pain (Grade 3) leading to hospitalization immediately following the fourth 
administration. The patient responded to standard supportive measures and the symptoms 
resolved the same day without further incident. The patient recovered without sequelae and 
remains alive as of the last study follow-up (approximately 36 months after discontinuing 
galinpepimut-S).  
Although this is a relatively small study (22 patients), several clinical observations regarding 
the potential for therapeutic efficacy can be made.  The study met its pre-specified endpoint 
of ≥34% actual OS rate at 3 years. The actual OS rate of 47.4% at 3 years post 
galinpepimut-S administration exceeded historical published data of 20-25% by 2.4-1.9-fold 
(or 240% to 190%), respectively. In addition, 11 of the 22 (50%) patients were alive at the 
time of their last assessment. Nine of these remained in CR1, while 3 relapsed during or 
following galinpepimut-S administration and were successfully salvaged with HSCT. The 
median DFS from CR1 was 16.9 months, with the median OS not reached, but poised to be at 

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least 67.6 months. These survival outcomes are higher than published results for similar 
patients treated with conventional post-remission therapies and compare favorably to subsets 
of patients treated with HSCT (Lowenberg et al, 2009; Fernandez et al, 2009; Kolitz et al, 
2010; Nand et al, 2013; Dombret et al, 2015; McClune et al, 2010; Saber et al, 2012; Walter 
et al, 2010; Yanada et al, 2007).  
However, there are several potential caveats in interpreting the results of this study with 
regard to therapeutic efficacy. The study population is relatively heterogeneous with several 
different prognostic groups contained within the data set which could skew outcomes (Rollig 
et al, 2011). The patients enrolled in this study may represent those with the best possible 
response in that not only were they able to achieve CR1, they remained in CR1 for a median 
of 8 months prior to treatment with galinpepimut-S. The immunologic correlates provide 
information regarding biologic effect but are not surrogates for clinical response. Several 
patients did not exhibit an immune response, yet still did well. We do not know if the patients 
that were negative were false negatives, as the assays are not sensitive, nor directed at most 
relevant key epitopes, nor are all technical issues regarding testing of this type resolved to 
date (Butterfield, 2015).  
Despite these potentially confounding factors, this study supports the continued investigation 
of galinpepimut-S as a strategy for AML postremission therapy. Galinpepimut-S can be 
administered on an outpatient basis with minimal toxicity in most patients. This cohort of 
patients appears to do well compared with historical outcome data and the immunologic 
correlates which have been used in this study show the generation of an immune response in 
most tested patients. 
1.1.2.2.2. Study MCC-15025 (AML Patients) 
Galinpepimut-S was studied at the same dose, schedule, and overall manner of administration 
as in the previously discussed studies has been used in only 1 other known study in patients 
with AML. In 2015, Brayer et al published the findings of a study conducted at the 
Moffitt Cancer Center (MCC) that enrolled patients with either WT1-positive AML in CR1 

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or second complete remission (CR2), or MDS following at least 1 prior line of therapy 
(Brayer et al, 2015; ClinicalTrials.gov identifier: NCT00665002). Patients enrolled in the 
study received galinpepimut-S, along with GM-CSF on Days -2 and 0 of each galinpepimut-
S dose. Patients received 6 bi-weekly galinpepimut-S administrations, and continued monthly 
until they had received 12 doses in total or showed evidence of disease relapse. Patients were 
evaluated for overall survival and progression free survival (PFS) from the time of the last 
remission, and immune response was evaluated by delayed-type hypersensitivity testing 
(DTH) and T cell interferon-g enzyme-linked immunospot (ELISPOT) assay at specific 
intervals. The key findings of this study pertain to the subgroup of patients with AML who 
successfully achieved CR2 after 2nd line standard antileukemic therapy, and more 
specifically a cohort of 10 patients who received >2 galinpepimut-S inoculations and 
therefore had adequate exposure to the vaccine so that they could become immunized. The 
clinical outcomes (PFS and OS) in these patients were compared to post-hoc matched, 
contemporaneously treated patients with AML in CR2 status, a cohort that was used for 
‘historical’ controls in the comparison.In more detail, a total of sixteen (16) patients (2 with 
refractory MDS and 14 with AML [4 in first CR and 10 in second CR]) were enrolled in the 
study. Five of the 14 AML patients had a prior diagnosis of MDS or myeloproliferative 
neoplasm. Nine of the 14 AML patients and both of the MDS patients exhibited a normal 
karyotype on cytogenetic analysis of the BM. Of the 5 AML patients with abnormal 
karyotype at baseline, 3 had complex karyotype, 1 contained a t (15;17) translocation not 
involving the classic promyelocytic leukemia-retinoic acid receptor alpha (PML-RAR-a) 
translocation, and 1 contained a core-binding factor beta subunit-myosin heavy chain 11 
(CBFB/MYH11) (inversion 16) translocation (Brayer et al, 2015). The median age of 
patients was 74 years. Of the 16 patients, 9 completed the planned 6 galinpepimut-S doses, 
and 6 continued for up to 6 additional doses. Of the 14 patients with AML, 10 received >2 
inoculations of galinpepimut-S and were eligible for formal PFS and OS endpoint analysis. 
Out of these 10, 4 completed a total of 12 galinpepimut-S doses while  all other AML 
patients discontinued this agent due to disease progression. Of the 2 patients with MDS, 1 
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The remaining patient received 4 galinpepimut-S doses but discontinued due to progressive 
disease with transformation to AML. 
For the patients with AML, the mean time to disease progression (AML relapse) was 8.0 
months and the mean OS from time of CRs was 19.9 months (range 6.6 to 35.2 months). At 
the time of the published study manuscript in 2015, (Brayer, et al, 2015), 11 of the 
14 patients had died and 3 remained alive but with progressive disease. Four of the 
14 patients had sustained responses either equaling or exceeding the time period of their 
initial remission. An ad hoc analysis comparing the outcomes of 10 eligible AML patients in 
CR2 enrolled in the study who received >2 inoculations of galinpepimut-S with those of a 
contemporaneously treated historical matched cohort (n=15) demonstrated a numerical 
difference in median PFS (10.5 months versus 4.3 months; P = 0.19) in patients treated with 
study drug, but demonstrated a statistically significant and clinically meaningful 
improvement in median OS in the same comparison in favor of the active arm (16.3 months 
versus 5.4 months, P = 0.0175). These data are shown in Fig. 10 below: 
Figure 10 Study MCC-15025 (AML Patients in CR2): K-M Plot for Median OS in 
Galinpepimut-S-treated pts who Received >2 Vaccine Inoculations (N=10) 
versus Contemporaneously Treated Historical Matched Controls (N=15) 
Both MDS patients 
remained transfusion-dependent but 1 patient demonstrated a 50% reduction in the need for 
transfusion as compared to the 4 months prior to enrollment. An analysis of the patient’s BM 

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showed an approximately 40% reduction in myeloblast percentage. The second patient 
demonstrated no response while receiving galinpepimut-S treatment but became transfusion-
independent after study completion and had remained so for over 14 months prior to 
publication of the manuscript. 
Four of the 14 AML patients developed a DTH response, while neither of the MDS patients 
did. An interferon-g response by CD4 T cells was observed in 4 patients, with 3 of these 
patients also demonstrating CD8 T-cell-mediated interferon-g responses. 
Galinpepimut-S was well tolerated, with most AEs reported as Grades 1 or 2. There was a 
single Grade 3/4 AE of neutropenia. Six of the 14 patients experienced injection site 
reactions. Two of these patients developed local induration and erythema after completion of 
the protocol; both developed delayed-type hypersensitivity responses. 
Note: As galinpepimut-S is always co-administered with the light oil Montanide in the form 
of an emulsion, as will be the case in this study, specific information about this emulsifying 
agent is provided in the Montanide Investigator Brochure. 
Note: As patients will be administered SC sargramostim (GM-CSF) at the site of the planned 
galinpepimut-S injection 2 days before (Day –2) and the day of (Day 1) each injection of 
galinpepimut-S (emulsified in Montanide), specific information about sargramostim (GM-
CSF) is provided in the US Prescribing Information for Leukine®.  
1.1.2.2.3.  
Study 15-247 (Ovarian Cancer Patients) 
Galinpepimut-S was studied a phase 1 single-arm trial at MSKCC to evaluate its safety and 
immunogenicity in combination with the PD1 inhibitor nivolumab (Opdivo®; Bristol-Myers 
Squibb) in patients with WT1(+) ovarian cancer in second or greater remission after 
successful debulking with standard chemotherapy. The preliminary results were reported in 
2018 (O’Cearbhaill et al, 2018; ClinicalTrials.gov identifier: NCT02737787).  

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Patients were enrolled from June 2016 to July 2017, and received 6 galinpepimut-S 
inoculations over a period of 12 weeks (on weeks 0, 2, 4, 6, 8 and 10). GM-CSF (70 µg) was 
administered 2 days prior to and on the day of each vaccine administration. All galinpepimut-
S inoculations were administered subcutaneously in extremities, with rotation of the injection 
site with each vaccination. Nivolumab at a dose of 3mg/kg per administration was given IV q 
2weeks over 12 weeks. Patients who remained in remission were offered a maintenance 
course of galinpepimut-S at weeks 19, 27, 35, 43. Dose modification was not permitted. 
Treatment was continued until disease progression (assessed by RECIST 1.1) or toxicity 
(assessed by NCI CTCAE v4.03). The primary endpoint is to evaluate the safety of the 
combination. Dose limiting toxicity (DLT) was defined as an adverse event (AE) at least 
possibly related to the galinpepimut-S plus nivolumab combination occurring with 30 days 
from the 1st galinpepimut-S administration, and included (among other criteria) grade 2 
uveitis, grade 3 injection site reaction, grade 3 fever, grade 3 AEs lasting >72 hours, grade 4 
AE’s (with the exception of clinically non-significant lab toxicities) or grade 5 AEs. 
Detection of greater than 2 DLTs among 10 treated patients would have deem the 
combination unsafe, but this was not observed. An exploratory objective was the 
progression-free survival (PFS) landmark rate at 1-year. PFS was measured from the start 
date of the immediately preceding chemotherapy to the date of progression of disease or 
death. 
IgM & IgG antibody (Ab) responses were measured by ELISA against individual WT1 
peptides contained within the galinpepimut-S mixture, as well as full length WT1. Immune 
responders were defined as those with Ab titers going from undetectable to ≥1:40 or ≥8-fold 
increase if such patients had detectable pretreatment levels. WT1-specific CD4+ and CD8+ T 
cell responses were compared to baseline via intracellular cytokine staining flow cytometry 
and values ≥0.6% were considered positive. 
Eleven patients with recurrent serous ovarian cancer in their 2nd or 3rd remission were treated 
on-protocol with the combination of galinpepimut-S and nivolumab. Their baseline 
demographics and disease characteristics were representative of similar cohorts of patients in 

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the published literature - mainly by the Gynecologic Oncology Group (GOG) in the US and 
the Arbeitsgemeinschaft Gynaekologische Onkologie - Studiengruppe Ovarialkarzinom 
(AGO-OVAR) in Germany. The most common treatment-related AEs with the combination 
were injection site reaction (maximum [max] grade 1), arthralgia (max grade 2) and fatigue 
(max grade 2). DLT was observed in one patient, who developed grade 3 panmyositis 
(including cardiac involvement) following the 2nd dose of galinpepimut-S and nivolumab and 
required insertion of a permanent cardiac pacemaker. With regard to immune responses, 
serum levels of antigen-specific IgG, against both individual WT1 peptides within 
galinpepimut-S and the full-length WT1 protein were induced in 86% of evaluable patients 
between week 6 and week 27 following treatment with the combination. Antigen-specific T 
cell responses to individual WT1 peptides were observed between weeks 6-15.  These 
responses were primarily CD4+, with best responses seen against the heteroclitic peptide 
122A1-Long and its corresponding native counterpart 122A-Long, and to a lesser extent 
CD8+, mainly for peptides 427 and 331 in patients with HLA class I allelic types other than 
HLA-A02. 
The landmark PFS rate at 1-year was 64% in the intent-to-treat group as shown in Figure 11 
below. The 1-year PFS rate was 70% for patients who received >2 doses of galinpepimut-S 
and nivolumab.  

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Figure 11 
Study 15-247 (Ovarian Cancer Patients): Kaplan-Meier Plot for 
Median Progression-Free Survival Showing the Landmark 1-year 
PFS Rate in the ITT Population 
 
This Phase 1/Pilot study concluded that administration of the immune-targeted combination 
of the subcutaneously inoculated galinpepimut-S vaccine and the intravenous anti-PD1 agent 
nivolumab to patients with WT1-positive ovarian cancer in second or third remission was 
safe and well tolerated and resulted in high rates of antigen-specific immunization. 
Furthermore, the landmark PFS rate of 70% in patients who received >2 doses of the 
combination (N=9) compares favorably to historic rates that do not exceed approximately 
50% in comparable populations treated with chemotherapy regimens that are currently 
considered standard of care (but without post-chemotherapy maintenance). The findings 
suggested that the combination of galinpepimut-S and anti-PD1 antibodies warrants further 
evaluation in patients with WT1-positive ovarian cancer, and provides strong background 
rationale for the launch of the ovarian cancer arm in the present study. 

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1.2 
Pembrolizumab Background 
1.2.1. General 
Pembrolizumab is a potent humanized immunoglobulin G4 (IgG4) monoclonal antibody 
(mAb) with high specificity of binding to the programmed cell death 1 (PD 1) receptor, thus 
inhibiting its interaction with programmed cell death ligand 1 (PD-L1) and programmed cell 
death ligand 2 (PD-L2). Based on preclinical in vitro data, pembrolizumab has high affinity 
and potent receptor blocking activity for PD 1. Pembrolizumab has an acceptable preclinical 
safety profile and is in clinical development as an intravenous (IV) immunotherapy for 
advanced malignancies. Keytruda® (pembrolizumab) is indicated for the treatment of 
patients across a number of indications. For more details on specific indications refer to the 
Investigator’s Brochure (edition 16.0, dated 29 June 2018). 
Refer to the Pembrolizumab Investigator’s Brochure/approved labeling for detailed 
background information on MK-3475. 
1.2.2. Pharmaceutical and Therapeutic Background 
The importance of intact immune surveillance function in controlling outgrowth of neoplastic 
transformations has been known for decades (Disis, 2010). Accumulating evidence shows a 
correlation between tumor-infiltrating lymphocytes in cancer tissue and favorable prognosis 
in various malignancies. In particular, the presence of CD8+ T-cells and the ratio of CD8+ 
effector T cells/FoxP3+ regulatory T-cells (T-regs) correlates with improved prognosis and 
long-term survival in solid malignancies, such as ovarian, colorectal, and pancreatic cancer; 
hepatocellular carcinoma; malignant melanoma; and renal cell carcinoma. Tumor-infiltrating 
lymphocytes can be expanded ex vivo and reinfused, inducing durable objective tumor 
responses in cancers such as melanoma (Dudley et al, 2005; Hunder et al, 2008). 
The PD-1 receptor-ligand interaction is a major pathway hijacked by tumors to suppress 
immune control. The normal function of PD-1, expressed on the cell surface of activated T 

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cells under healthy conditions, is to down-modulate unwanted or excessive immune 
responses, including autoimmune reactions. PD-1 (encoded by the gene Pdcd1) is an 
immunoglobulin (Ig) superfamily member related to cluster of differentiation 28 (CD28) and 
cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) that has been shown to negatively 
regulate antigen receptor signaling upon engagement of its ligands (PD L1 and/or PD-L2) 
(Greenwald et al, 2005; Okazaki et al, 2001). 
The structure of murine PD-1 has been resolved (Zhang et al, 2004). PD-1 and its family 
members are type I transmembrane glycoproteins containing an Ig-variable–type (IgV type) 
domain responsible for ligand binding and a cytoplasmic tail responsible for the binding of 
signaling molecules. The cytoplasmic tail of PD-1 contains 2 tyrosine-based signaling motifs, 
an immunoreceptor tyrosine-based inhibition motif, and an immunoreceptor tyrosine-based 
switch motif. Following T-cell stimulation, PD-1 recruits the tyrosine phosphatases, SHP-1 
and SHP-2, to the immunoreceptor tyrosine-based switch motif within its cytoplasmic tail, 
leading to the dephosphorylation of effector molecules such as CD3 zeta (CD3ζ), protein 
kinase C-theta (PKCθ), and zeta-chain-associated protein kinase (ZAP70), which are 
involved in the CD3 T-cell signaling cascade (Okazaki et al, 2001; Chemnitz et al, 2004; 
Sheppard et al, 2004; Riley, 2009). The mechanism by which PD-1 down-modulates T cell 
responses is similar to, but distinct from, that of CTLA-4, because both molecules regulate an 
overlapping set of signaling proteins (Parry et al, 2005; Francisco, 2010). As a consequence, 
the PD 1/PD-L1 pathway is an attractive target for therapeutic intervention in the 5 
malignancy types investigated in this study.   
1.2.3. Pre-clinical and Clinical Trials 
Therapeutic studies in mouse models have shown that administration of antibodies blocking 
PD-1/PD-L1 interaction enhances infiltration of tumor-specific CD8+ T cells and ultimately 
leads to tumor rejection, either as a monotherapy or in combination with other treatment 
modalities (Hirano et al, 2005; Blank et al, 2004; Weber, 2010; Strome et al, 2003; Spranger 
et al, 2014; Curran et al, 2010; Pilon-Thomas et al, 2010).  Anti-mouse PD-1 or anti-mouse 

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PD-L1 antibodies have demonstrated antitumor responses in models of squamous cell 
carcinoma, pancreatic carcinoma, melanoma, acute myeloid leukemia and colorectal 
carcinoma (Strome et al, 2003; Curran et al, 2010; Pilon-Thomas et al, 2010; Nomi et al, 
2007; Zhang et al, 2004).  In such studies, tumor infiltration by CD8+ T cells and increased 
IFN-γ, granzyme B and perforin expression were observed, indicating that the mechanism 
underlying the antitumor activity of PD-1 checkpoint inhibition involved local infiltration 
and activation of effector T cell function in vivo (Curran et al, 2010). Experiments have 
confirmed the in vivo efficacy of anti-mouse PD-1 antibody as a monotherapy, as well as in 
combination with chemotherapy, in syngeneic mouse tumor models (see the Pembrolizumab 
Investigator’s Brochure [I.B.]). 
1.2.4. Justification for Pembrolizumab Dose 
The planned dose of pembrolizumab for this study is 200 mg every 3 weeks (Q3W). Based 
on the totality of data generated in the Keytruda development program, 200 mg Q3W is the 
appropriate dose of pembrolizumab for adults across all indications and regardless of tumor 
type. As outlined below, this dose is justified by: 
Clinical data from 8 randomized studies demonstrating flat dose- and exposure-efficacy 
relationships from 2 mg/kg Q3W to 10 mg/kg every 2 weeks (Q2W),  
Clinical data showing meaningful improvement in benefit-risk including overall survival at 
200 mg Q3W across multiple indications, and pharmacology data showing full target 
saturation in both systemic circulation (inferred from pharmacokinetic [PK] data) and tumor 
(inferred from physiologically-based PK [PBPK] analysis) at 200 mg Q3W. 
Among the 8 randomized dose-comparison studies, a total of 2262 participants were enrolled 
with melanoma and non-small cell lung cancer (NSCLC), covering different disease settings 
(treatment naïve, previously treated, PD-L1 enriched, and all-comers) and different treatment 
settings (monotherapy and in combination with chemotherapy). Five studies compared 2 
mg/kg Q3W versus 10 mg/kg Q2W (KN001 Cohort B2, KN001 Cohort D, KN002, KN010, 

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and KN021), and 3 studies compared 10 mg/kg Q3W versus 10 mg/kg Q2W (KN001 Cohort 
B3, KN001 Cohort F2 and KN006). All of these studies demonstrated flat dose- and 
exposure-response relationships across the doses studied representing an approximate 5- to 
7.5-fold difference in exposure. The 2 mg/kg (or 200 mg fixed-dose) Q3W provided similar 
responses to the highest doses studied. Subsequently, flat dose-exposure-response 
relationships were also observed in other tumor types including head and neck cancer, 
bladder cancer, gastric cancer and classical Hodgkin Lymphoma, confirming 200 mg Q3W 
as the appropriate dose independent of the tumor type. These findings are consistent with the 
mechanism of action of pembrolizumab, which acts by interaction with immune cells, and 
not via direct binding to cancer cells. 
Additionally, pharmacology data clearly show target saturation at 200 mg Q3W. First, PK 
data in KN001 evaluating target-mediated drug disposition (TMDD) conclusively 
demonstrated saturation of PD-1 in systemic circulation at doses much lower than 200 mg 
Q3W. Second, a PBPK analysis was conducted to predict tumor PD-1 saturation over a wide 
range of tumor penetration and PD-1 expression. This evaluation concluded that 
pembrolizumab at 200 mg Q3W achieves full PD-1 saturation in both blood and tumor. 
Finally, population PK analysis of pembrolizumab, which characterized the influence of 
body weight and other participant covariates on exposure, has shown that the fixed-dosing 
provides similar control of PK variability as weight-based dosing, with considerable overlap 
in the distribution of exposures from the 200 mg Q3W fixed dose and 2 mg/kg Q3W dose. 
Supported by these PK characteristics and given that fixed-dose has advantages of reduced 
dosing complexity and reduced potential of dosing errors, the 200 mg Q3W fixed-dose was 
selected for evaluation across all pembrolizumab protocols. 
1.3. Study Rationale 
1.3.1. General 
There is clearly an unmet need for novel and effective therapy to improve responses and 
prolong disease remission/progression-free intervals already achieved with checkpoint 

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blockade monotherapy (Farkona et al, 2016). The objectives of the proposed clinical study 
are: (i). to explore clinical outcomes (safety and potentially promising activity) in tumors 
using a combination of agents that improve immune-mediated anticancer effects, namely, 
pembrolizumab and galinpepimut-S, and (ii). to maximize the chances of detecting a 
clinically meaningful efficacy signal in comparison to historical monotherapy data (with 
pembrolizumab alone) for further validation in larger, randomized trials.  
The rationale behind this clinical study consists of 2 parts as detailed below. 
1.3.1.1.  Rationale for Galinpepimut-S and Pembrolizumab Combination 
Therapy 
Immune activation, suggested by the presence of infiltrating cytotoxic T cells in tumors, as 
well as eventual maintenance of a long-term proimmune status against the tumor via memory 
T cells, have shown be associated with a better prognosis across a wide variety of 
malignancies (Reeves et al, 2017; Wölfl M et al, 2014). Therapies blocking programmed 
death receptor 1 (PD-1), such anti-PD-1 monoclonal antibodies, have shown the ability to 
reduce inhibitory immune signals within the tumor microenvironment (TME), thus allowing 
cytotoxic T cells to infiltrate the tumor and cause tumor regression in an expanding group of 
human malignancies, leading to a series of regulatory approvals and clinical usage on a 
global scale (Intlekofer et al, 2013; Kyi et al, 2014; Spranger et al, 2016). These advances 
notwithstanding, there is significant room for improvement in both the depth, frequency, and 
duration of antitumor responses with anti-PD1 agents. This provides a strong rationale for 
developing strategies to prime a host (cancer patient) with tumor-specific cytotoxic T cells 
targeted to specific tumor antigens via host administration while increasing the likelihood of 
significantly amplifying such a specific response with an anti-PD1 therapy (in this case, 
pembrolizumab), as well as prolong the duration of such a response (Perez-Gracia et al, 
2014) by both mitigation of tolerance and via induction of memory T cells (Marzo et al, 
2000). Thus, combining innovative, highly tolerable actively immunizing agents, such as 
peptide treatments against well-validated high-antigenicity tumor targets with anti-PD1 

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products, such as pembrolizumab (Keytruda®), represents a highly attractive strategy, which 
deserves assessment in the clinical setting (Parchment et al, 2016; Drake CG, 2012). 
As mentioned previously, galinpepimut-S is a directly immunizing therapy (a vaccine-like 
proprietary mixture of carefully selected heteroclitic and native WT1 peptide fragments) 
proven to produce WT1-specific T-lymphocytes in patients that could target a patient’s 
cancer (Gomez-Nunez et al, 2006; Pinilla-Ibarz et al, 2006; Bleakley and Ridell, 2011; May 
et al, 2007; Brayer and Pinilla-Ibarz, 2013). Additionally, galinpepimut-S monotherapy has 
previously shown promising clinical activity in both pilot and Phase 2 studies in patients with 
AML, MPM, MM and OvC; all data originating from studying the effects of galinpepimut-S 
in a MRD setting, i.e., in the absence of measurable/macroscopic disease burden (after initial 
debulking of the malignancy), whereby the potential influence of TME factors has been 
mitigated (Maslak et al, 2010; Krug et al, 2010; Brayer et al, 2015; Maslak et al, 2016; 
Maslak et al, 2018; Zauderer et al, 2016; Zauderer et al, (iMig), 2016; Zauderer et al, 2017; 
Koehne et al, 2017;  http://e-materials.com/ebmt2017/#/presentation/16745; 
https://learningcenter.ehaweb.org/eha/2017/22nd/181028/guenther.koehne.wt1.heteroclitic.ep
itope.immunization.following.autologous.html; Koehne et al, 2018; O’Cearbhaill et al, 2018; 
Tsuboi et al; 2012). 
Galinpepimut-S is generally well tolerated. In a total of 122 patients across multiple studies, 
TEAEs either clinical or laboratory-test-related (including those of Grade 3/Grade 4 severity) 
were due to the underlying disease processes or complications thereof. Treatment-related 
adverse events (TRAEs) included injection site reactions, skin induration, and pruritus 
occurred at a frequency of 43.8% to 62.5% across studies, and were Grade 1/Grade 2 in 
severity, consistent with the fact that Montanide (which is co-administered with 
galinpepimut-S) is a known irritant. All TRAEs observed with galinpepimut-S monotherapy 
were manageable and did not lead to study drug discontinuation, with the exception of 
2 patients in the AML Phase 2 study, who discontinued therapy due to probable 
hypersensitivity reactions (not anaphylaxis) (SELLAS, Data on file; Maslak PG et al, 2018; 

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Zauderer et al, 2017; Koehne et al, 2017; O’Cearbhaill et al, 2018; Galinpepimut-S 
Investigator Brochure v2.0, 08 June 2017). 
Therefore, combining galinpepimut-S with the checkpoint inhibitor pembrolizumab, which 
beneficially and profoundly alters the TME (among other potent immunostimulatory effects 
in the host), is hypothesized to increase the proportion of patients who develop an immune 
response against their cancer and potentially improve their clinical outcome over 
pembrolizumab monotherapy, without the burden of additional toxicities in macroscopically 
measurable malignancies.  
In this clinical trial, for each chosen tumor type to be studied, we will investigate whether 
galinpepimut-S administered concomitantly with the well-characterized adjuvant Montanide 
(van Doorn et al, 2016; Montanide IB 2015; Aucouturier et al, 2002; Aucouturier et al, 2001; 
Tovey and Lallemand, 2010) (also with GM-CSF priming at Day -2 and Day 1 of 
galinpepimut-S administration) can be safely administered with pembrolizumab, as well as 
preliminarily assess the degree of efficacy of anti-PD1 monotherapy when considered in the 
context of historical controls, as assessed by overall response rate (ORR). Moreover, we will 
investigate various secondary and exploratory endpoints. For the latter, we postulate that 
galinpepimut-S will induce a WT1-specific immune response, which will be associated with 
enhancement of clinical benefit seen with pembrolizumab monotherapy alone. Additional 
secondary efficacy measures (such as duration of response), as well as exploratory endpoints 
including WT1-specific immune response dynamics, and overall survival, will be 
investigated. If this pilot study meets the primary efficacy endpoint of ORR for a given tumor 
type, a randomized Phase 2 trial would be warranted in that tumor type. 
Finally, as mentioned previously, in Section 1.1.1. (titled: “Preclinical and Pharmacological 
Background” – for galinpepimut-S), it is important to note that GM-CSF alone appears to be 
inactive with regard to antigen-specific immunogenicity and antitumor effect, and, therefore, 
any immunobiological (as assessed by WT1-specific T-cell immune responses) or clinical (as 
measured by ORR – for solid tumors- or CR/CRi/CRp -for AML) synergy between 

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galinpepimut-S and pembrolizumab observed in this study would be solely attributable to the 
co-administration of these 2 experimental agents (and not GM-CSF).  
 
1.3.1.2.  Rationale for Selection of Indications 
The tumor types selected for this trial have been documented to commonly express WT1, and 
this trial will select patients whose tumors are positive for WT1 expression (assessed by 
commercially available IHC methods using standard anti-WT1 antibodies in paraffin-
embedded specimen sections).  
The following [up to 5] tumor types will be included: CRC, OvC, SCLC, TNBC, and AML. 
The choice of these tumor types was based on specific features of each malignancy, as 
detailed below. For all solid tumor indications, the highest citable number of lines of therapy 
listed below is the maximum allowed for eligibility, i.e., patients who have received 
subsequent lines of therapy are ineligible. 
1.3.1.2.1.   Metastatic Colorectal Cancer (Third/Fourth line) 
Colorectal cancer (CRC) is a common disease, diagnosed in nearly 1.4 million people 
worldwide annually (GLOBOCAN 2012).  In the United States, there are nearly 133,000 new 
diagnoses each year (Key Statistics for Colorectal Cancer, 2016). Approximately one-third of 
patients with CRC will develop metastatic disease.  In most of these patients, the disease 
relapses and becomes refractory. The overall prognosis of patients with metastatic CRC has 
improved significantly, with average survival today being 30 months (Formica and Roselli, 
2015), thanks to new research identifying different molecular subtypes of CRC. Although 
some patients with metastatic CRC can be cured, the disease remains incurable in most cases, 
clearly indicating a need for new therapies. 
WT-1 expression has been documented to be expressed in between 70 to 90% of patients 
with CRC (Miyata et al, 2007; Oji et al, 2003; Bejrananda et al, 2011). Patients with 

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microsatellite-stable (MSS) molecular genetics make up between 80 to 90% of all CRC cases 
(Naboush et al, 2017; Diaz and Le, 2015). In this study, patients will have microsatellite 
(MS) instability (MSI) status tested in their primary tumors and will be classified as 
MSI- high (H) and -low (L) (Pawlik et al, 2004; Morán et al, 2010; Supek and Lerner, 2015; 
Goldstein et al, 2014). The focus will be on MSI-low tumors, but no entry selection will be 
applied based on this tumor feature. In several clinical trials in MSI-L CRC, anti-PD-1 agents 
have shown to induce 0 to 5% ORR (Link and Overman, 2016; 
http://www.targetedonc.com/publications/targeted-therapies-cancer/2017/2017- 
february/immune-checkpoint-inhibitors-in-crc; Boland and Ma, 2017; Myint and Goel, 2017; 
Overman et al, 2016; Segal et al, 2016; Bendell et al, 2016; Overman et al, 2016; Andre et al, 
2017). This is in contrast to the significant activity of PD1 blockade in MSI-H CRC, the basis 
for the recent Food and Drug administration (FDA) approval of pembrolizumab in MSI-H 
cancers (including CRC) 
(https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm560167.htm). Only 
those CRC patients with MSS and MSI-H will be included in the efficacy analyses.  
In several clinical trials, anti-PD-1 agents have shown between 0 to 5% ORR in these 
patients. We plan to treat patients with metastatic CRC previously treated with at least 2 lines 
of prior systemic chemotherapy (third/fourth line population) (n = 20). 
Expression of ligand to PD-1 receptor (PD-L1) is associated with poor prognosis in CRC and 
has been shown to promote invasion of CRC cells in vitro. Pembrolizumab is a highly 
selective, humanized monoclonal anti-PD-1 antibody designed to block the interaction 
between PD-1 and its ligands, thereby enhancing antitumor immune activity. Pembrolizumab 
monotherapy has an acceptable safety profile but minimal antitumor activity in patients with 
heavily pretreated PD-L1-positive advanced CRC (Bendel et al, (ESMO); Le et al NEJM; 
http://www.ecco-org.eu/Vienna2015/Scientific-Programme/Abstract-
search?abstractid=21431 [KEYNOTE 028]) showing MSS molecular features. In view of the 
above, there is good rationale to investigator the combination of galinpepimut-S plus 
pembrolizumab in CRC-MSS. 

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1.3.1.2.2.   Ovarian Cancer (Second/Third line) 
OvC is one of the most common gynecologic malignancies and the fifth most frequent cause 
of cancer death in women in the United States. Over 22,000 cases are diagnosed annually, 
and there are an estimated 15,500 deaths per year (Siegel R, et al 2012). The majority of 
patients have widespread disease at presentation (Hoskins WJ, et al 2005). The 5-year 
survival for advanced-stage disease remains less than 30% (Siegel R, et al 2012). Although a 
complete clinical remission following initial chemotherapy can be anticipated for many 
patients, a review of second-look laparotomy when it was often performed as a matter of 
routine care indicates that less than 50% of patients are actually free of disease (Barnhill DR, 
et al, 1984). Furthermore, nearly half of patients with a negative second look procedure 
relapse and require additional treatment (Rubin SC et al, 1988). Many patients will achieve a 
second complete clinical response with additional chemotherapy. However, almost all 
patients will relapse after a short remission interval of 9 to 11 months. (Markman M et al, 
1991). Effective strategies to prolong remission or to prevent relapse are required (Hoskins 
WJ et al, 2005).  
With regard to immunotherapy approaches in OvC, immunization against tumor-associated 
antigens (TAA) lead to emergence of both TAA-specific antibodies and T-cell effectors have 
been shown to provide benefit in OvC models. Antibodies have been noted to curtail early 
tissue invasion (Zhang H et al, 1998). Preclinical models have also demonstrated the 
clearance of circulating tumor cells and the elimination of systemic micrometastasis through 
the use of both passively administered and vaccine-induced antibodies. With regards to T-cell 
effectors, a globally activated immune response has been shown to be associated with 
improved clinical outcome in patients with advanced OvC. Zhang et al showed that the 
presence of tumor infiltrating T cells within tumor cell islets was associated with 
improvement in both progression free and OS (Zhang H et al, 2003). Conversely, the 
infiltration of T- regulatory cells confers a worse prognosis (Curiel TJ et al, 2004).  
OvC patients in second or greater remission confirms them to relapse in a predictable fashion 
(Iasonos A et al, 2012) and, therefore, are candidates for novel immune-based 

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“consolidation” strategies, such as those including checkpoint inhibitors and TAA-directed 
immunizing vaccine-type therapies, like galinpepimut-S, either alone or in combination.  
The strong expression of WT1 protein in OvC coupled with its proposed mechanism of 
action makes it a rational target for immunotherapy. WT1 expression is highly prevalent in 
OvC (Dupont et al, 2004). Indeed, WT1 expression is high enough that pathologists routinely 
use IHC stains for WT1 with a standardized convention for describing expression and 
determining as “positive” or “negative” to help distinguish epithelial ovarian cancers from 
other tumors (Al-Hussaini et al, 2004). WT1 is a particularly sensitive and specific marker 
for serous ovarian cancer (Acs et al, 2004). Ovarian tissue microarrays at MSKCC 
(New York, USA) suggest approximately 80% of serous ovarian cancers express WT1 
(Lim et al, 2016), thus corroborating earlier studies with IHC (Tornos et al, 2005; Köbel et al, 
2009; Karamurzin et al, 2013). 
Overexpression of the PD-1 ligand PD-L1 has been demonstrated in OvC and may hinder an 
effective antitumor immune response 
(http://abstracts.asco.org/199/AbstView_199_184843.html). The activity of anti-PD1 agents 
in recurrent OvC in second and third lines of therapy is reflected in ORR values of 
approximately 15% (Varga et al, 2015; Weiss et al, 2017). In a previous clinical study with 
pembrolizumab with 15.5 months of follow-up, as well as in a review of the existing recent 
literature in the use of PD-1 blockers in OvC, pembrolizumab continued to be well tolerated 
and demonstrated durable antitumor activity in patients with advanced OvC (Mittica et al, 
2016). In view of the above, there is good rationale to investigate the combination of 
galinpepimut-S plus pembrolizumab in OvC.  
1.3.1.2.3.   Small Cell Lung Cancer (Second Line) 
Treatment options for patients with SCLC who progress on platinum-based chemotherapy 
are limited. WT1 expression has not been studied in SCLC as extensively as in NSCLC, 
mainly due to the relative rarity of the former. Nonetheless, WT1 positivity is higher (40 to 
83%) in SCLC versus NSCLC (Babiak et al, 2014; Menssen et al, 2000; Oji et al, 2002; 

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Wang et al, 2013). Therefore, WT1 is an appropriate target for direct TAA-specific 
immunotherapy approaches, such as galinpepimut-S. Pembrolizumab, an anti–PD-1 
monoclonal antibody designed to block the interaction between PD-1 and its ligands PD-L1 
and PD-L2, has shown antitumor activity in multiple advanced malignancies, including 
thoracic tumors such as NSCLC and SCLC 
(http://meetinglibrary.asco.org/record/109650/abstract).  
The median PFS and OS following initial chemotherapy in extensive stage small cell lung 
cancer (ES-SCLC) patients are 2 and 7 months, respectively (Ready, 2015). Maintenance 
therapy with pembrolizumab did not improve PFS in these patients but favorable OS 
suggests that some SCLC patients can benefit from maintenance pembrolizumab (Clinical 
trial information: NCT02359019; http://abstracts.asco.org/199/AbstView_199_183991.html). 
In patients with PD-L1+ SCLC who have progressed on prior platinum-based therapy, 
pembrolizumab is generally well tolerated and has promising antitumor activity. Enrollment 
in the SCLC cohort of KEYNOTE-028 is ongoing (Clinical trial information: 
NCT02054806). The activity of anti-PD1 agents in SCLC in the second line of therapy is 
reflected in ORR values of about 33 to 37% (Ott et al, 2016; Hellman et al, 2016; Antonia et 
al, 2016; Riess et al, 2016). In view of the above, there is good rationale to investigate the 
combination of galinpepimut-S plus pembrolizumab in SCLC.  
1.3.1.2.4.   Breast Cancer (Triple Negative; Second Line) 
While many histologic/genetic variants of breast cancer have effective treatments, to date, 
treatments for TNBC have been minimally effective (Bianchini et al, 2016). Although WT1 
expression occurs in 70 to 80% of patients with basal-type breast cancer, in specimens from 
TNBC (Provenzano et al, 2016; Domfeh et al, 2008), WT1 expression is approximately 8 to 
15%. Nonetheless, this value may represent low sensitivity of currently used, commercially 
available anti-WT1 monoclonal antibodies used for IHC (Ichinohasama, 2010). Additionally, 
WT1 has been found to be focally amplified in a significant proportion of TNBC’s and hence 
is still a valid immuno-oncology target, despite its low abundance observed (Craig et al, 

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2012). Hence, galinpepimut-S could in principle be active in a significant proportion of 
TNBC patients.  
Current anti-PD1 therapies have shown modest monotherapy activity in recurrent TNBC 
(second line), as reflected in ORR values of approximately 18% (Nanda et al, 2016; Hartkopf 
et al, 2016; Migali et al, 2016; Emens et al, 2015; Dirix et al, 2018; Adams et al, 2016; 
Emens et al, 2016; Dua and Tan 2017). In view of the above, there is good rationale to 
investigate the combination of galinpepimut-S plus pembrolizumab in TNBC. 
1.3.1.2.5.   Acute Myelogenous Leukemia (AML) 
AML, a clonal, neoplastic, hematopoietic disorder, is the predominant form of acute 
leukemia in adults. It has an incidence of approximately 2.5 per 100,000 persons and this 
incidence increases with age, with approximately half of patients with newly diagnosed AML 
older than 65 years. While most patients are able to achieve CR using 
anthracycline/cytarabine-based chemotherapy, the benefit associated with standard intensive 
chemotherapy remains debated in older patients, as well as those with medical co-morbidities 
because of excessive toxicity and short response duration. Response rates to conventional 
induction chemotherapy regimens in older patients are around 50%; and median survival is 
usually less than 1 year (Appelbaum et al, 2006; Döhner Het al, 2015). Despite recent 
advances in targeted therapy in certain subgroups of AML patients with predefined molecular 
aberrations (such as FLT3 internal tandem duplication [ITD], isocitric dehydrogenase 1 
[IDH1] mutations, and CD33 expression; summarized in Wei and Tiong, 2017 and Stahl et 
al, 2017) and the advent of a liposomally delivered chemotherapy formulation as well as 
potential future cell-based immunotherapies (Bose P et al, 2017; Sallman and Lancet, 2017; 
Short and Ravandi, 2016; De Kouchkovsky and Abdul-Hay, 2016; Dombret and Gardin, 
2016; Gbolahan et al, 2017), the tolerability of long term/ full-dose administration of such 
agents in the same subgroup of patients (those ≥ 60 years of age and/or those with 
comorbidities) will probably remain a challenge. The DNA methyltransferase inhibitors, 
azacitidine and decitabine are currently extensively used in this type of patients, because of 
their relatively mild side effects (Kaminskas et al, 2005). Both drugs have a complex 

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mechanism of action (MOA) involving epigenetic modification of entire groups of genes, 
thus leading to marked effects on the pattern of gene expression post- therapy (Cruijsen et al, 
2014). These 2 drugs are also called hypomethylating agents (HMAs); some of their effects 
are pro-differentiating, while others lead to cell killing of leukemic blasts, especially those 
AML blasts with unfavorable cytogenetic characteristics (Maurillo, 2012).  
Recent Phase 3 trials have shown the superiority of HMAs when compared with 
conventional care for older AML patients (not eligible for intensive treatment). HMAs are 
FDA-approved and widely used as frontline AML therapy for long-term disease control in 
patients unable to have an allogeneic (allo-) hematopoietic stem cell transplant (HSCT) or as 
a promising strategy to “bridge” allo-HSCT-candidate patients to the potential curative 
treatment of a transplant (Gbolahan et al, 2017; Ustun et al, 2013). The above 
notwithstanding, achievement of CR rates with HMAs in AML remains rather low, ranging 
from 8% to 32% depending on the series. (Gardin and Dombret 2017; Thomas and Le Jeune, 
2017; Yun et al, 2008; Feldman, 2016). Another 10 to 20% of AML patients reach partial 
response (PR), whereas, up to 45 to 50% of patients do not respond to HMAs with either PR 
or CR (Sekeres, 2013). The prognosis of patients who achieve less than CR after at least 4 
cycles of HMA therapy is worse than those able to achieve CR (after 4 cycles), although PR 
can be relatively prolonged in select cases. Of note, HMA interruption should be avoided 
once a sustained response, including PR, has been achieved. With regard to patients who 
continue on HMAs once they reach PR after the first 4 cycles, most prove unable to convert 
this PR into a CR (Müller and Florek, 2014; Malik and Cashen, 2014). Hence, the probabilty 
of such a conversion (i.e,, achievement of CR) in this subpopulation with continuation of 
HMAs alone after the fourth cycle is probably <5% (Cashen et al, 2010; Joeckel and Lübbert, 
2012; Park et al, 2017).  
WT1 is strongly and prevalently (90 to 95% of cases) expressed in AML blasts both in the 
peripheral blood (PB) and BM (Inoue et al, 1998; Hosen et al, 2002; Keilholz et al, 2005; 
Cilloni et al, 2009; Menssen et al, 1995; Inoue et al, 1997). It is also expressed in leukemic 
stem cells (LSCs) (Saito et al, 1997; Yong et al, 2008). WT1 expression is reliable enough to 

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be used as a marker of MRD in AML (as a molecular marker of relapse/response) (Alonso-
Dominguez et al, 2012; Messina et al, 2014; Ogawa et al, 2003; Candoni et al, 2009; 
Hämäläinen et al, 2008; Mulé et al, 2016) and is typically included in MRD diagnostic multi-
gene panels (Buccisano et al, 2017). As noted above, galinpepimut-S has shown activity (as 
assessed by median PFS and median OS since the time of initial diagnosis versus historical 
controls) in AML patients who were able to achieve their CR1 after standard induction 
chemotherapy, as well as 1 to 4 post-CR1 cycles of administration of further ‘consolidation’ 
chemotherapeutic regimen, after the completion of which they received galinpepimut-S as 
‘consolidation’ chemotherapeutic regimen, after the completion of which they received 
galinpepimut-S as ‘maintenance’ (Maslak et al, 2007; Maslak et al, 2010; Maslak et al, 2018; 
SELLAS, Data on file). There is theoretical rationale for cytocidal activity by CTLs after 
galinpepimut-S against LSCs as well, which are especially resistant to either chemotherapy 
or HMAs (McCracken et al, 2016; Lane et al, 2009; Krause and Scadden, 2015). 
Consequently, direct WT1-specific immunization with galinpepimut-S in the context of 
partially controlled disease (AML achieving PR, but not CR, while on HMAs) could 
principally convert some of these PRs into CRs.  
With regard to activity of checkpoint inhibitors in AML, to date, anti-PD1 therapies have 
shown modest activity in relapsed AML (second line) when given after HMAs (Lichtenegger 
et al, 2017; Haroun et al, 2017). However, PD1 blockers administered in combination with 
HMAs were shown to be associated with ORR values of up to 34% (Daver et al, 2016; Daver 
et al, 2017; Nagler et al, 2017; Krupka et al, 2016; Sehgal et al, 2015; 
http://www.targetedonc.com/publications/targeted-therapies- cancer/2017/2017-
february/immune-checkpoint-approaches-in-aml-and-mds-a-next-frontier). Thus, it is very 
likely that a minority of patients who are unable to respond to HMA monotherapy any deeper 
than PR may convert their response to CR after receiving concomitant therapy with 
checkpoint inhibitors. The exact frequency (rate) of achievement of CR post-combination 
therapy in such patients remains ill defined, but is probably not exceeding 15% 
(approximately 50% of the ORR of 30-34% seen in studies by Daver’s group at the MD 
Anderson Cancer Center (Daver et al, 2016; Daver et al, 2017; Boddu et al, 2018). Finally, 

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there is recent evidence suggesting that HMA therapy upregulates PD1 expression in the 
TME-infiltrated BM of AML patients as well as MHC class I molecules in blasts, thus 
providing cogent molecular targets for an effect of PD1 inhibition (Ørskov et al, 2015) and 
galinpepimut-S action, respectively. In view of the above, there is good rationale to 
investigate the combination of galinpepimut-S plus pembrolizumab in AML patients who 
cannot achieve responses deeper than PR while having been exposed to at least 4 cycles of 
HMAs given for first-line/upfront therapy. 

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2 
Study Objectives 
2.1 
Primary Objective 
Hypothesis #1: Combining galinpepimut-S with pembrolizumab could increase the clinical 
benefit of pembrolizumab monotherapy (Seledstov et al, 2015; Kleponis et al, 2015) as 
assessed by improved ORR values versus historical controls for each individual tumor type 
tested. This would constitute a “positive efficacy signal” (as relevant to a particular tumor 
type) and warrant broader future clinical investigations. Further, the combination will not 
increase the burden of toxicities and will have an overall similar/comparable AE profile as 
pembrolizumab monotherapy.  
Based on the above hypothesis, the primary objectives of the study are: 
• To evaluate the safety and tolerability of galinpepimut-S in combination with 
pembrolizumab in patients with selected advanced cancers  
• To evaluate the anti-tumor activity of the combination of galinpepimut-S and 
pembrolizumab as defined by Response Evaluation Criteria in Solid Tumors 
(RECIST) 1.1 to determine if the activity seen is sufficiently promising to evaluate 
the combination in future clinical studies. For AML patients: to study the possibility 
of achieving morphologic CR (including CR with incomplete recovery of blood 
counts or platelets [CRi/CRp]), i.e., conversion of morphologic PR into CR/CRi/CRp. 
Included are the following cohorts: 
o Patients with metastatic CRC previously treated with at least 2 lines of prior 
systemic chemotherapy (third/fourth line population) (n = 20). 
o Patients with metastatic OvC second/third line population (n = 20) 
o Patients with advanced SCLC previously treated with 1 line of prior systemic 
chemotherapy (second line population) (n = 20) 

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o Patients with TNBC previously treated with 1 line of prior systemic 
chemotherapy (second line population) (n = 15) 
o Patients with AML (any age) who are not eligible for allogeneic 
hematopoietic stem cell transplant (allo-SCT) and have only been able to 
achieve PR while receiving frontline therapy with HMAs (n = 15) 
2.2 
Secondary Objectives 
The secondary objectives of this study are: 
• To evaluate the clinical benefit of galinpepimut-S in combination with 
pembrolizumab in patients with selected advanced cancers through the analysis of 
time to response (TTR), time to next treatment, and duration of response (DOR).  
2.3 
Exploratory Objectives 
Hypothesis #2: Combining galinpepimut-S with pembrolizumab could lead to the 
development of a robust WT1-specific immune response against patients’ cancers, and 
potentially improve the abundance and functionality of the hosts’ immunocytes within the 
TME (versus pembrolizumab monotherapy) (Duraiswamy et al, 2013). Positive correlative 
analyses (as relevant to a particular tumor type) between immune and clinical outcomes 
would provide a MOA framework to inform the design of future larger, randomized clinical 
studies in that tumor type.  
Based on the above hypothesis, the exploratory objectives of this study are: 

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• To assess ORR per immune RECIST (iRECIST) in patients in the solid tumor arms 
• To assess the frequency (rate) of achievement of MRD negativity in patients in the 
AML arm  
• To further characterize the immunodynamics profile of galinpepimut-S and 
pembrolizumab combination therapy through analyses of WT1-specific CD8 and 
CD4 cells in PB, as well as WT1-specific memory CD8 T cells, MDSC, and T-
regulatory cells [Treg] in PB  
• To gauge the general immunodynamics effects upon non-antigen-specific lymphocyte 
immunophenotypic subtypes will be studied in PB via flow cytometry  
• To assess the effects of the combination on defined biomarkers of immune checkpoint 
activity in the tumors (or bone marrow for AML patients) and their surrounding 
microenvironment (pharmacodynamics specific to pembrolizumab) 
• To assess the association between selected biomarker readouts and clinical efficacy 
measures at specific time-points, using pre-treatment and on-treatment tumor biopsies 
• To assess OS and PFS  

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3 
Investigational Plan 
3.1 
Study Design 
This is a Phase 1/2, open-label, non-comparative, multicenter, multi-arm study of the 
combination of galinpepimut-S in combination with pembrolizumab in patients with selected 
advanced cancers. This study will assess the efficacy and safety of galinpepimut-S and 
pembrolizumab and investigate the effect of galinpepimut-S and pembrolizumab on various 
tumor types. Patients will be followed long-term for OS and safety. The study will enroll 
approximately 90 patients. 
Sites will primarily be major tertiary academic oncology centers and will be selected based 
on expertise in complicated dosing scenarios. WT1 IHC staining characteristics for all 
tumor/BM samples will be assessed by central pathology review (to be performed by senior 
pathologists who will undergo study-specific training).  
3.1.1. Overall Treatment Investigational Administration Schedule 
Patients will receive 70 μg sargramostim (GM-CSF) SC on Day -2 and on Day 1 before each 
galinpepimut-S injection. The first GM-CSF injection of each doublet will occur at the same 
anatomical site of the planned galinpepimut-S treatment injection within each given cycle.  
 
The first 2 galinpepimut-S injections will initially be administered as monotherapy every 3 
weeks (Week 0 and Week 3). Thereafter, galinpepimut-S will be co-administered with 
pembrolizumab every 3 weeks for 4 additional administrations (for the galinpepimut-S initial 
immunization induction phase series; weeks 6-15) to coincide with the per label 
pembrolizumab dosing frequency. After that, there will be one un-paired administration of 
pembrolizumab (week 18), and then galinpepimut-S will be resumed on an every 3-week 
schedule for 6 additional doses (early immune booster phase; weeks 21-36). At the end of 
this phase, there will be a 12-week interval where 3 unpaired administrations of 

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pembrolizumab will occur (weeks 39-45), and then galinpepimut-S will be resumed on an 
every 12-week schedule for 4 additional doses (late immune booster phase; weeks 48-84). 
After 84 weeks, continuing non-progressed patients will be treated with pembrolizumab 
alone up until week 111. Galinpepimut-S will be administered 30-60 minutes after the 
completion of IV infusion of pembrolizumab on Day 1 of each cycle during which the 2 
drugs are being co-administered. 
 
Pembrolizumab will be administered at a dose of 200 mg intravenously every 3 weeks on 
Day 1 of each cycle (3-week cycles) starting on Study Week 6 and continuing for up to 
2 years thereafter (Study Week 111). To monitor for any adverse reactions, specifically for 
systemic anaphylaxis type reactions against either GM-CSF or galinpepimut-S, patients will 
remain in the clinic for approximately 30 minutes following each GM-CSF or galinpepimut-
S injection. Safety assessments will be conducted at every visit. The end of treatment (EOT) 
visit will occur 30 days after the last injection.  
Specifically for patients in the AML arm, the timing of the administration of the 
investigational therapies (pembrolizumab and galinpepimut-S) with respect to administration 
of hypomethylating agents (HMAs) will be as follows: 
• AML patients on cycles #1 – 4 of HMA on-label therapy (treated according to 
standard clinical care) will be pre-screened to gauge potentially eligibility for the 
study.  
• If restaging bone marrow biopsy immediately after the completion of cycle #4 of 
HMA therapy demonstrates morphological partial response (PR), then such 
patients become eligible for the study and can initiate investigational therapy 
(pembrolizumab and galinpepimut-S), as long as the latter commences prior to the 
initiation of cycle #5 of the HMA. 
• Reasonable efforts will be made by the Contracted Research Organization (CRO), 
Cancer Insight, LLC,  at actively enrolling clinical sites to initiate investigational 
therapy within 14 +/7 days from the completion of cycle #4 of HMA therapy, to 
ensure relative homogeneity in the initiation timing relationship between the two 

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therapeutic modalities, i.e., HMA and investigational therapy. 
Furthermore, for clarification purposes, each cycle of therapy in patients in the AML arm 
will be defined by the frequency of administration of the study investigational agents 
(pembrolizumab and galinpepimut- S), i.e., 3 weeks. This clarification is important, because: 
a. patients in the AML arm will continue their HMA therapy throughout the administration of 
study investigational agents and  
b. the timing of initiation between HMA cycle #5 and that of the first administration of 
investigational therapies are de-linked. 
The study design is shown in  
 
 

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Figure 12 and the overall treatment schedule is provided in Figure 13. 
The study endpoints are defined in Section 7. 
 
 

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Figure 12 
Study Design 
 
 
3.1.2.  Rationale of Study Design 
There is clearly an unmet need for novel and effective therapy to improve responses and 
prolong disease remission/progression-free intervals already achieved with checkpoint 
blockade monotherapy (Farkona et al, 2016). The objectives of this proposed clinical study 

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are: (i). to explore clinical outcomes (safety and potentially promising activity) in tumors 
using a combination of agents that improve immune-mediated anticancer effects, namely, 
pembrolizumab and galinpepimut-S, and (ii). to maximize the chances of detecting a 
clinically meaningful efficacy signal in comparison to historical monotherapy data (with 
pembrolizumab alone) for further validation in larger, randomized trials. 
To meet these objectives, the current design of a Phase 1/2 open-label, non-comparative, 
multicenter, multi-arm clinical study was chosen, as it has been used successfully in similar 
studies beforehand (Menis et al, 2014; Toulmonde et al, 2018; Goldberg et al, 2016), and 
therefore considered as highly suitable for this trial.  

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4.0. Patient Selection and Withdrawal Criteria 
4.1. Selection of Study Population 
Patients will be enrolled into the study only if they meet all of the inclusion criteria and none 
of the exclusion criteria. 
Deviations from the inclusion and exclusion criteria are not allowed because they can 
potentially jeopardize the scientific integrity of the study, regulatory acceptability, or patient 
safety. Therefore, adherence to the criteria as specified in the protocol is essential. 
Patients who do not initially meet all of the inclusion criteria and none of the exclusion 
criteria may be allowed to retest for laboratory evaluations and other procedures within 
28 days of signing the informed consent form (ICF) without being considered a rescreen. If 
the patient then meets all inclusion/exclusion criteria, they are permitted to be enrolled into 
the study. If a patient does not meet inclusion/exclusion criteria within the 28 days of signing 
the ICF, the patient will be considered a screen failure and may be allowed to re-screen with 
a newly signed ICF up to 2 times. 
4.1.1. Inclusion Criteria 
Each patient must meet all of the following criteria to be enrolled in this study:  
Type of Participant and Disease Characteristics 
1. Is willing and able to understand and provide signed informed consent for the study 
that fulfills Institutional Review Board (IRB) guidelines 
2. Male or female patients  ³ 18 years of age on the day of signing informed consent. 
3. Has histologically or cytologically-confirmed advanced or metastatic solid tumors 
who have disease progression after treatment with available therapies for metastatic 
disease that are known to confer clinical benefit, or are intolerant to treatment, or 
refuse standard treatment in the context of the particular line of treatment defined in 

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this protocol (refer to #5 below) or, specifically for AML, demonstrate as their best 
observed response after 4 cycles of HMA therapy the status of “partial response” per  
European LeukemiaNet (ELN) criteria and meet the additional specified requirements 
for the cohort of the study they will enroll into.   
4. All patients will be tested for WT1 expression via IHC in both their initial primary 
tumor and recent biopsy of metastatic disease at the time of screening for study entry, 
or, specifically for AML, leukemic blasts either in the BM or PB. Specifically: 
a. Testing of patient’s archived (paraffin embedded, unstained slides) as well 
as freshly biopsied tumor nodules prior to study entry must be positive for 
WT1 protein expression. 
b. WT1 expression: The IHC technique to be used for the detection of WT1 
in tumor tissue (or AML blasts within the bone marrow - applicable only 
for subjects in the AML arm) is described in detail by Dupont et al. 
(Dupont et al, 2004) using the anti-WT1 monoclonal antibody H-1/ sc-
393498 (Santa Cruz Biotechnology, Dallas, TX, USA). In more detail, 
formalin-fixed, paraffin- embedded tissue sections are subjected to 
immunohistochemical testing using the streptavidin-biotin method. WT1 
is used at a dilution of 1:4,000. A heat-induced epitope retrieval system is 
used for the antibody, involving steam-heat incubation with citrate at pH 6 
for 30 min at 97oC. Human Wilms tumor or malignant pleural 
mesothelioma samples will used as a positive control for WT1, with 
appropriate negative controls. Positive WT1 nuclear staining is defined as 
the presence of any nuclear staining in >5% of tumor cells and positive 
WT1 cytoplasmic staining was defined as the presence of any cytoplasmic 
staining in >5% of tumor cells. WT1 expression is graded according to an 
adaptation of the German Immunoreactive Score (IRS) (Remmele and 
Stegner, 1986 & 1987). Briefly, the IRS assigns subscores for intensity of 
immunoreactivity (0–3) and distribution of immunoreactivity (0–4; based 
on percent positive cells within a cluster), which when multiplied, yield a 
product (IRS score, ranging from 0 to 12) that allows categorization of 

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weak, moderate, and strong immunoreactivity. For WT1, negative or weak 
immunoreactivity (scores 0–3) are considered negative, while moderate or 
strong immunoreactivity (scores 4–12) are considered positive. 
Assessment of all tumor/BM biopsies for WT1 expression using the 
German IRS assignment system will be performed centrally by an 
experienced Pathologist using a standardized form, which also depicts the 
IRS scale for ease of reference. This form is shows as Appendix 12.3 of 
this protocol.    
Due to essential non-expression of WT1 in normal tissues, the specificity 
for WT1 expression in tumors under study is essentially 100%. The 
sensitivity of the IHC assay is defined in relevant sections of the protocol 
for each tumor type under study, ranging from 40% in SCLC to >90% in 
AML cases.  All above specimens will undergo central pathology review.  
 
5. Patients may have received a specific maximum allowable number of prior lines 
of therapy for metastatic/advanced disease, as follows: 
a. CRC: 2 or 3 lines; b. OvC: 1 or 2 lines; c. SCLC: 1 line; d. TNBC: 1 line; 
and e. AML: 0 lines (allo-SCT-eligible status or patients with relapsed 
[2nd line] AML not allowed) 
6. Patients should have experienced resolution of toxic effect(s) of the most recent 
prior chemotherapy to Grade 1 or less (except alopecia). If the patient received 
major surgery or radiation therapy of > 30 Gy, they must have recovered from the 
toxicity and/or complications from the intervention. 
7. Specifically for patients in the AML arm, the following subject subgroups are 
eligible: 
a. Frontline (1st line) patients treated with HMAs since their initial AML 
diagnosis  
b. Patients who have required cytoreductive therapy with hydroxyurea 
or leukapheresis at the time of their initial AML diagnosis, and who 
subsequently seamlessly transitioned to HMA therapy 

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c. Subjects who have experienced induction early failure after initial therapy 
with 1 - 2 cycles of a standard chemotherapy (“7+3” and similar regimens) 
and subsequently immediately treated with HMAs  
as long as such patients have achieved PR as their best observable response after 4 
cycles of HMA therapy (per European LeukemiaNet [ELN] criteria). 
8. AML patients should continue treatment with HMAs as long as they cannot 
achieve a response deeper than PR after the completion of administration of 4 
cycles of HMAs. 
9. If female, patient is eligible to participate if she is not pregnant, not breast-
feeding, and at least 1 of the following conditions: 
a. 
Not a woman of childbearing potential (WOCBP) 
b. 
A WOCBP who agrees to follow contraceptive guidance (agree to use an 
adequate method of contraception) starting 30 days prior to the 
administration of the first dose of study therapy and continuing through 
4 months after the last study treatment. The effect of galinpepimut-S on the 
fetus is unknown. 
10. Male patients of childbearing potential must agree to use an adequate method of 
contraception, starting with the first dose of study therapy through 4 months 
following the last study treatment. It is unknown whether galinpepimut-S affects 
the sperm, or could be transmitted to the patient’s partner during sexual activity.  
 
    Informed Consent 
11. Patients (or legally acceptable representative if applicable) should provide written 
informed consent for the trial. 
12. Patients should have measurable/demonstrable active malignant disease per 
below:  
a. For patients with solid tumors: Have measurable disease based on 
RECIST 1.1 as determined by the as assessed by the local site 

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investigator/radiology. Measurable disease is defined as at least one lesion 
that can be accurately measured in at least two dimensions with spiral CT 
scan.  Minimum measurement must be > 15 mm in the longest diameter by 
> 10 mm in the short axis. Tumor lesions situated in a previously 
irradiated area are considered measurable if progression has been 
demonstrated in such lesions.  
b. For AML patients: Have evidence of morphologic partial response 
(decrease of BM blast percentage to 5% to 25% and decrease of 
pretreatment BM blast percentage by > 50%) but absence of 
extramedullary disease, as defined initially by the AML Working Group 
Criteria (Cheson et al, 2003) and also quoted in the more recent ELN 
criteria (Döhner et al, 2010). Leukemic blast burden will be determined by 
a local site investigator (physician) upon clinical and BM morphologic 
assessment. AML patients should also have received/completed 4 cycles 
of HMA therapy and have PR as their best observed response at the end of 
these 4 cycles. 
13. Patients should have provided archival tumor tissue sample or newly obtained 
core or excisional biopsy of a tumor lesion not previously irradiated. Formalin-
fixed, paraffin embedded (FFPE) tissue blocks are preferred to slides. Newly 
obtained biopsies are preferred to archived tissue. 
Note: If submitting unstained cut slides, newly cut slides should be submitted to 
the testing laboratory within 14 days from the date slides are cut (details 
pertaining to tumor tissue submission can be found in the Procedures Manual).  
14. Patients should have an Eastern Cooperative Oncology Group (ECOG) 
performance status of 0 or 1 (Appendix ).  
15. Have adequate organ function as defined in Table 1. Specimens must be collected 
within 10 days prior to the start of study treatment.  

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Table 1 
Definition of Adequate Organ Function 
 
System 
Laboratory Value 
Hematological 
 
Absolute neutrophil count (ANC) 
≥1500/µL 
Platelets 
≥100 000/µL 
Hemoglobin 
≥9.0 g/dL or ≥5.6 mmol/L1 
Renal 
 
Creatinine OR 
Measured or calculated2 creatinine clearance 
(GFR can also be used in place of creatinine or 
CrCl) 
≤1.5 × ULN OR 
≥30 mL/min for participant with creatinine 
levels >1.5 × institutional ULN 

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Hepatic 
 
Total bilirubin 
≤1.5 ×ULN OR direct bilirubin ≤ULN for 
participants 
with 
total 
bilirubin 
levels 
>1.5 × ULN 
AST (SGOT) and ALT (SGPT) 
≤2.5 × ULN (≤5 × ULN for participants with 
liver metastases) 
Coagulation 
 
International normalized ratio (INR) OR 
prothrombin time (PT) 
Activated partial thromboplastin time (aPTT) 
≤1.5 × ULN unless participant is receiving 
anticoagulant therapy as long as PT or aPTT is 
within therapeutic range of intended use of 
anticoagulants 
ALT (SGPT)=alanine aminotransferase (serum glutamic pyruvic transaminase); AST (SGOT) =aspartate 
aminotransferase (serum glutamic oxaloacetic transaminase); GFR=glomerular filtration rate; 
ULN=upper limit of normal. 
1 Criteria must be met without erythropoietin dependency and without packed red blood cell (pRBC) 
transfusion within last 2 weeks.  
2 Creatinine clearance (CrCl) should be calculated per institutional standard. 
Note: This table includes eligibility-defining laboratory value requirements for treatment; laboratory 
value requirements should be adapted according to local regulations and guidelines for the administration 
of specific chemotherapies. 
 
16. Patients should be willing and able to return to the clinical site for adequate 
follow-up, as required by this protocol.  
Additional Inclusion Criteria for Selected Tumor Types: 
(i). CRC (third/fourth line) 
a. Histologically or cytologically documented adenocarcinoma of colon or rectum at the 
time of initial presentation. 
b. Metastatic CRC with documented disease progression (per standard criteria) after the last 
administration of standard therapies or intolerance to standard therapies (and approved 

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therapies must have included all the following a fluoropyrimidine, oxaliplatin, irinotecan, 
bevacizumab, and, if KRAS wild-type, cetuximab or panitumumab). Prior use of (and 
failure after) regorafenib or trifluridine/tipiracil is allowed, but not mandated. 
(ii). OvC (second/third line)  
a. Histologically diagnosed ovarian, fallopian tube or primary peritoneal cancer at the 
time of initial presentation. 
b. Patients will have either relapsed or be disease resistant to their prior therapy. Interval 
surgery is permitted, but patients must have objective evidence of disease on 
computed tomography (CT) or magnetic resonance imaging (MRI), with concomitant 
CA-125 increase and/or biopsy showing OvC (only for recurrent disease). 
c. Patients should have received platinum-containing chemotherapy and been designated 
as harboring platinum-refractory or -resistant disease. Additionally, all eligible 
subjects should have either received (or been offered) bevacizumab therapy, and 
those with BRCA germline mutations (gBRCA mut) should have been offered 
therapy with poly-ADP ribose polymerase (PARP) inhibitors (olaparib, rucaparib or 
niraparib). 
(iii). SCLC (second line) 
a. Histologically or cytologically confirmed SCLC based on biopsy of the tumor at 
initial presentation.   
b. Asymptomatic or treated brain metastases are allowed. 
c. Patients must have measurable disease (by CT or MRI) after they progressed or were 
resistant to 1 prior systemic therapy.   
(iv). TNBC (second line) 
a. Histologically proven metastatic breast carcinoma with triple negative receptor status 
(estrogen receptor, progesterone receptor, and human epidermal growth factor 

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receptor 2 [HER2] negative by IHC and fluorescence in situ hybridization [FISH], per 
standard criteria). Patients who are weakly positive for the estrogen or progesterone 
receptor (i.e., < 5%) are eligible. 
b. Patients must have measurable disease (by CT or MRI) after they progressed or were 
resistant to 1 prior systemic therapy. 
c. Patients have undergone second line therapy after residual or recurrent disease after 
first line therapy. First line therapy may include: 
a. Neoadjuvant therapy if macroscopic disease is still present after surgery OR 
b. Adjuvant therapy but only if the macroscopic relapse occurs > 6 months from 
the start of study treatment with pembrolizumab. 
(v). AML 
a. Pathologically or morphologically confirmed de novo or secondary AML at the time 
of initial diagnosis. 
b. Achievement of no better than morphologic PR, as defined initially by the AML 
Working Group criteria (Cheson et al, 2003), and also quoted in the more recent ELN 
criteria (Döhner et al, 2010), while on active treatment with HMAs and at the time of 
completion of the 4th HMA treatment cycle.  
c. AML patients are eligible only if they received first line therapy with HMAs 
(decitabine or azacitidine) for 4 cycles and achieved only PR at the end of cycle 4. 
d. AML patients shall remain on HMA therapy while receiving investigational 
therapies. 
4.1.2. Exclusion Criteria 
Any prospective patient will be excluded from the study if any of the following criteria 
apply: 
Medical Conditions  
Pregnancy Exclusion: 

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1. 
A WOCBP who has a positive urine pregnancy test (e.g. within 72 hours) 
prior to treatment.  If the urine test is positive or cannot be confirmed as negative, a 
serum pregnancy test will be required. 
Prior/Concomitant Therapy 
2. 
Has disease that is suitable for local therapy administered with curative 
intent.3. 
Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti PD 
L2 agent or with an agent directed to another stimulatory or co-inhibitory T-cell 
receptor (e.g., CTLA-4, OX 40, CD137) and was discontinued from that treatment 
due to a Grade 3 or higher irAE 
4. 
Has received prior systemic anti-cancer therapy including investigational 
agents within 4 weeks prior to treatment. 
Note: Participants must have recovered from all AEs due to previous therapies to 
≤Grade 1 or baseline. Participants with ≤Grade 2 neuropathy may be eligible. 
Note: If participant received major surgery, they must have recovered adequately 
from the toxicity and/or complications from the intervention prior to starting study 
treatment. 
5. 
Has received prior radiotherapy within 2 weeks of start of study treatment. 
Participants must have recovered from all radiation-related toxicities, not require 
corticosteroids, and not have had radiation pneumonitis. A 1-week washout is 
permitted for palliative radiation (≤2 weeks of radiotherapy) to non-CNS disease. 
6. 
Has received a live vaccine within 30 days prior to the first dose of study 
drug. Examples of live vaccines include, but are not limited to, the following:  
measles, mumps, rubella, varicella/zoster (chicken pox), yellow fever, rabies, Bacillus 
Calmette–Guérin (BCG), and typhoid vaccine. Seasonal influenza vaccines for 
injection are generally killed virus vaccines and are allowed; however, intranasal 
influenza vaccines (e.g., FluMist®) are live attenuated vaccines and are not allowed. 

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Prior/Concurrent Clinical Study Experience 
7. 
Is currently participating in or has participated in a study of an investigational 
agent or has used an investigational device within 4 weeks prior to the first dose of 
study treatment. 
8. 
Has undergone prior allogeneic hematopoietic stem cell transplantation 
Diagnostic assessments 
9. 
Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid 
therapy (in dosing exceeding 10 mg daily of prednisone equivalent) or any other form 
of immunosuppressive therapy within 7 days prior the first dose of study drug. The 
use of physiologic doses of corticosteroids may be approved after consultation with 
the Sponsor. Steroids taken as short-term therapy (≤ 7 days) for antiemesis are 
permissible. 
10. 
Has a known additional malignancy that is progressing or has required active 
treatment within the past 5 years, even if currently inactive or unapparent.  
Note:  Specifically, AML patients with prior history of myelodysplastic syndromes or 
myeloproliferative neoplasms are not excluded. Participants in any of the study arms 
(solid tumors or AML) with basal cell carcinoma of the skin, squamous cell 
carcinoma of the skin, or carcinoma in situ (e.g., breast carcinoma, cervical cancer in 
situ) that have undergone potentially curative therapy, as well as patients with 
prostate cancer managed clinically with “watchful waiting” are not excluded. 
11. 
Has known active CNS metastases and/or carcinomatous meningitis. 
Participants with previously treated brain metastases may participate provided they 
are radiologically stable, i.e., without evidence of progression for at least 4 weeks by 
repeat imaging (note that the repeat imaging should be performed during study 
screening), clinically stable and without requirement of steroid treatment for at least 
14 days prior to first dose of study treatment.  

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12. 
Has severe hypersensitivity (≥Grade 3) to pembrolizumab and/or any of its 
excipients. 
13.  
Has known hypersensitivity to Montanide or vaccine adjuvants. 
14. 
Had a previous clinically significant systemic allergic reaction to Montanide, 
sargramostim (GM-CSF), or filgrastim (G-CSF). 
15. 
Has an active autoimmune disease that has required systemic treatment in past 
2 years (i.e., with use of disease modifying agents, corticosteroids or 
immunosuppressive drugs). Replacement therapy (e.g., thyroxine, insulin, or 
physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency) 
is not considered a form of systemic treatment and is allowed. 
16. 
Has a history of (non-infectious) pneumonitis that required steroids or has 
current pneumonitis. 
17 
Has an active infection requiring systemic therapy. 
18. 
Participants with known human immunodeficiency virus (HIV) and/or history 
of Hepatitis B or C infections, or known to be positive for Hepatitis B antigen 
(HBsAg)/ Hepatitis B virus (HBV) DNA or Hepatitis C Antibody or RNA are 
excluded. Active Hepatitis C is defined by a known positive Hep C Ab result and 
known quantitative HCV RNA results greater than the lower limits of detection of the 
assay.  
19. 
Has a history or current evidence of any condition, therapy, or laboratory 
abnormality that might confound the results of the study, interfere with the patient’s 
participation for the full duration of the study, or is not in the best interest of the 
participant to participate, in the opinion of the treating investigator. This includes any 
serious, intercurrent, chronic, or acute illness, such as cardiac disease (New York 
Heart Association [NYHA] class III or IV), hepatic disease, or other illness 
considered by the investigator as an unwarranted high risk for investigational drug 

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treatment.20. Has a known psychiatric or substance abuse disorder that would 
interfere with the participant’s ability to cooperate with the requirements of the study. 
Other Exclusions 
21. 
Is pregnant or breastfeeding or expecting to conceive or father children within 
the projected duration of the study, starting with the screening visit through 30 days 
after the last dose of study treatment. 
22. 
Has had an allogeneic tissue/solid organ transplant. 
23. 
Has received transfusion of blood products (including platelets or red blood 
cells) or administration of colony stimulating factors (excluding GM-CSF, but 
including G CSF or recombinant erythropoietin) within 4 weeks prior to first study 
treatment. 
4.1.2.1. Additional Exclusion Criteria for Selected Tumor Types 
(i). CRC: None 
(ii). OvC: None 
(iii). SCLC: Mixed histology SCLC malignancies 
(iv). TNBC: None 
(v). AML:  
a. Planned/anticipated HSCT (autologous or allogeneic, with any degree of match 
donor); acute promyelocytic leukemia (APL; M3 or any morphologic and molecular 
variants, inclusive); history or current diagnosis of CNS leukemia 
b. Relapsed (Second line) patients; Note: Patients who received any chemotherapy (“3 + 
7” or similar chemotherapy regiman) for 1- 2 cycles during initial induction therapy 

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in the first-line setting and subsequently immediately switched to HMAs are not 
excluded.  
4.2. Withdrawal of Patients from the Study 
The duration of the study is defined for each patient as the date signed written informed 
consent is provided through the end-of-treatment visit, which can be up to a maximum of 
111 weeks after enrollment, or a total of 115 weeks inclusive of screening. All patients will 
then be followed for primary, secondary, and exploratory endpoints (including PFS and OS), 
unless they die or formally withdraw their consent for survival follow-up. 
Withdrawal of consent must be patient initiated. This applies either if the patient is declaring 
that they no longer wish to receive study treatment or attend on-treatment study visits or that 
they will not allow study investigators to make any further efforts to follow them 
off-treatment for study outcomes. 
4.2.1. 
Reasons for Withdrawal/Discontinuation 
Discontinuation of study treatment does not represent withdrawal from the study. 
Patients may voluntarily withdraw from the study at any time and for any reason without 
prejudice to their future medical care by the investigator or at the study site. The investigator 
may withdraw a patient if it is in the best interest of the patient. The Sponsor also reserves 
the right to discontinue the study at any time for either clinical, administrative, or business 
reasons, and to discontinue participation by an individual investigator or site for poor 
enrollment or noncompliance. 
Patients may be removed from study treatment, from on-treatment study assessments, or 
from off-treatment study assessments but continue to be monitored in the study for the 
following reasons: 
• Recurrent Grade 2 pneumonitis 

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• Patient was erroneously admitted into the study or does not meet entry criteria 
• Patient experiences a serious or intolerable AE or clinically significant laboratory 
abnormality that, in the opinion of the investigator, would affect the ability of the 
patient to continue on the clinical study 
• Patient has progressive disease 
• Patient voluntarily decides to withdraw 
• Patient is lost to follow-up 
• Patient requires treatment with any prohibited medication outlined in the exclusion 
criteria and/or Section 5.6 other than the use of appropriate medications for the 
treatment of AEs under the direction of the investigator 
• Patient is noncompliant with the study procedures and scheduled assessments 
• Patient develops an intercurrent disease or medical condition that, in the opinion of 
the investigator, would affect the ability of the patient to continue on the clinical 
study.  
Discontinuation of treatment may be considered for patients who have attained a confirmed 
CR (either solid tumors or AML, using the corresponding response definitions), as follows: 
Such patients would have attained CR after having been treated for at least 10 cycles of 
galinpepimut-S, i.e., at least 30 weeks:2 cycles of galinpepimut-S monotherapy (6 weeks) 
followed by 9 cycles of pembrolizumab (an additional 24 weeks). Such patients in CR should 
also receive 2-additional cycles of the combination (2 doses of pembrolizumab and 
galinpepimut-S [until Week 36]) beyond the date when the initial CR was declared, so that at 
least 12 of the total 16 (75%) planned doses of galinpepimut-S would have been 
administered. At that time, 12 out of a planned total of 36 treatments (2 years) with 

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pembrolizumab (corresponding to approximately 33% of the total planned pembrolizumab 
treatments). 
4.2.2. 
Handling of Withdrawals 
If a patient discontinues study treatment but remains on study, every effort should be made to 
continue the patient’s assessments according to the schedule of assessments (Section )  
through the end of the study. For patients who withdraw from the study, procedures and 
assessments for the end-of-treatment (EOT) visit (Section 6.1.3) should be performed at the 
time of discontinuation of treatment or as soon as possible thereafter (unless the patient 
withdraws consent to do so). A follow-up assessment performing end of treatment (EOT) 
procedures should be undertaken 4 weeks after discontinuation of study treatment. 
If a patient fails to return for scheduled visits, a documented effort must be made to 
determine the reason. If the patient cannot be reached by telephone, a certified letter should 
be sent to the patient (or the patient’s legally authorized representative, if appropriate) 
requesting contact with the investigator. This information should be documented in the study 
records.  
Before enrollment into the study, the investigator or designee must explain to each patient 
that for evaluation of study results, the patient’s protected health information obtained during 
the study may be shared with the study sponsor, regulatory agencies, and IRB/independent 
ethics committee (IEC). It is the investigator’s (or designee’s) responsibility to obtain written 
permission to use protected health information per country-specific regulations, such as the 
Health Insurance Portability and Accountability Act (HIPAA) in the US, from each patient, 
or if appropriate, the patient’s legally authorized representative. If permission to use 
protected health information is withdrawn, it is the investigator’s responsibility to obtain a 
written request, to ensure that no further data will be collected from the patient, and the 
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Upon occurrence of a serious or intolerable AEs, the investigator will confer with the 
Sponsor. It is vital to obtain follow-up data on any patient withdrawn because of an AE or 
serious AE (SAE). In every case, efforts must be made to undertake protocol-specified, 
safety follow-up procedures. 
Notification of early patient discontinuation from the study and the reason for discontinuation 
will be made to the sponsor, and will be clearly documented on the appropriate electronic 
case report form (eCRF). 
4.2.3. 
Replacements 
There will be no replacements in this study. 

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5. 
Study Treatments 
5.1. Method of Assigning Patients to Treatment 
Once the investigator confirms that the patient has met all eligibility criteria, the patient will 
be enrolled in the study by the local investigators and their teams. Trial treatment should 
begin on the day of enrollment or as close as possible to the date on which the patient is 
enrolled. The investigator is responsible to maintain appropriate records and ensure 
appropriate supply, storage, handling, distribution and usage of trial treatments is in 
accordance with the protocol and any applicable laws and regulations. 
5.2. Treatments Administered 
Refer to Table 8 (Schedule of Assessments) for additional details. 
5.2.1. 
Galinpepimut-S 
Each of the 4 peptides will be supplied at a concentration of 0.2 mg/vial. After reconstitution 
with 0.6 mL sterile water for injection (SWFI), each peptide will be at a concentration of 
0.4 mg/mL (400 μg/mL of each peptide) combined in a single sterile solution in a buffer 
consisting of 10 mM histidine, pH 6.0 + 0.05% ethylene diamine tetra acetic acid (EDTA). 
As galinpepimut-S will comprise 50% (0.5 mL) of the study treatment injection 
administered, the actual dose of each peptide is 200 μg (with the total 4 active peptides 
equaling 800 μg). On galinpepimut-S administration days, blood samples will be collected 
before study treatment administration. Before injection, study staff will assess the 
immunization site. Patients will receive an injection of GM-CSF (refer to Section 5.2.3). 
A 1-mL dose of galinpepimut-S will be administered subcutaneously (SC) on the arm, leg, or 
torso of the patient, and should be positioned at least 5 cm away from the previous site of the 
study treatment injection.  
A maximum of 16 total injections will be administered as follows:  

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• First 2 galinpepimut-S injections: every 3 weeks (×2). Thereafter, galinpepimut-S will 
also be administered every 3 weeks to coincide with pembrolizumab treatment as 
detailed below:  
• Injections 3 to 6: every 3 weeks (between Weeks #6 and #15). The first series of 
6 injections of galinpepimut-S (I + II) define the initial immunization induction 
phase. 
• Injections 7 to 12: every 3 weeks (between Weeks #21 and #36). The second series of 
injections of galinpepimut-S define the early immune booster phase. 
• Injections 13 to 18: every 12 weeks (between Weeks #48 and #84). The series of the 
last 4 injections of galinpepimut-S define the late immune booster phase.  
• As galinpepimut-S will be co-administered with Montanide, specific information 
about this emulsifying agent is provided in the Montanide Investigator Brochure. 
Every effort should be made to follow the administration schedule for galinpepimut-S and 
pembrolizumab. If a patient misses a scheduled administration of either the combination or 
pembrolizumab alone, the drug(s), should be administered as soon as possible. If the patient 
is more than one-half the time interval to the next scheduled administration, the patient 
should skip that preplanned administration and have the next administration on schedule.  
Galinpepimut-S will be administered 30-60 minutes after the completion of IV infusion of 
pembrolizumab on Day 1 of each cycle during which the 2 drugs are being co-administered. 
 
Refer to Section 5.2.2 for Montanide ISA 51 VG administration. 
5.2.2. 
Montanide ISA 51 VG 
Galinpepimut-S treatment preparation will require reconstitution of the lyophilized powder 
with SWFI, followed by a mixture of the peptide solution of galinpepimut-S with the 

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immunologic adjuvant Montanide ISA 51 VG as an emulsion to a total volume of 1 mL. The 
study treatment solution will comprise 50% (0.5 mL) of galinpepimut-S and 50% (0.5 mL) 
Montanide. 
Galinpepimut-S includes concomitant administration of Montanide (adjuvant) on Day 1 of all 
sessions of administration of this direct immunizer. 
Galinpepimut-S will be subsequently mixed in a water-in-oil emulsion with the oily adjuvant 
Montanide ISA 51 at a 1:1 ratio. The resulting final emulsion will be administered to the 
patient SC as a 1 mL injection. 
5.2.3. 
Sargramostim (GM-CSF) 
Patients will receive 70 μg sargramostim (GM-CSF) SC on Day -2 and on Day 1 before each 
galinpepimut-S injection. Patients will remain in the clinic for approximately 30 minutes 
following receipt of GM-CSF.  This injection will occur at the same anatomical site of the 
next planned study treatment injection. 
5.2.4. 
Pembrolizumab 
Treatment for pembrolizumab is outlined below in Table 2. 
Table 2 
Treatment with Pembrolizumab (irrespective of whether it is 
administered alone or concomitantly with galinpepimut-S) 
Drug 
Dose/Potency 
Dose Frequency 
Route of 
Administration 
Regimen 
Use 
Pembrolizumab 
200 mg 
Every 3 weeks 
Intravenous 
Day 1 of each 
cycle (3 week 
cycles) and 
begins at Week 
6 
Experimental 
 

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Pembrolizumab will be administered as a dose of 200 mg using a 30-minute IV infusion.  
Sites should make every effort to target infusion timing to be as close to 30 minutes as 
possible. However, given the variability of infusion pumps from site to site, a window 
between -5 minutes and +10 minutes is permitted (i.e., infusion time is 
30 minutes -5 min/+10 min). 
The Pharmacy Manual contains specific instructions for the preparation of the 
pembrolizumab infusion and administration of infusion solution. 
Patients can receive up to 35 treatments (approximately 2 years) with pembrolizumab. 
During that time, patients may continue until disease progression, unacceptable toxicity, 
withdrawal of consent, physician's decision to stop therapy for the patient, or Sponsor’s 
decision to terminate the study. 
Discontinuation of treatment may be considered for patients who have attained a confirmed 
CR (either solid tumors or AML, using the corresponding response definitions), as follows: 
Such patients would have attained CR after having been treated for at least 10 cycles of 
galinpepimut-S, i.e., at least 30 weeks: 2 cycles of galinpepimut-S monotherapy (6 weeks) 
followed by 9 cycles of pembrolizumab (an additional 24 weeks). Such patients in CR should 
also receive 2-additional cycles of the combination (2 doses of pembrolizumab and 
galinpepimut-S [until Week 36]) beyond the date when the initial CR was declared, so that at 
least 12 of the total 16 (75%) planned doses of galinpepimut-S would have been 
administered. At that time, 12 out of a planned total of 36 treatments (2 years) with 
pembrolizumab (corresponding to approximately 33% of the total planned pembrolizumab 
treatments). 
Note: The number of treatment administrations is calculated starting with the first dose of 
galinpepimut-S.  

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5.3. Identity of Investigational Drug Product 
Table 3 provides a description for each of the investigational products. 
Table 3 
Description of Investigational Products 
Product 
Supplied as: 
Galinpepimut-S 
0.8 mg sterile, white preservative-free powder filled into a 2-mL 
colorless glass vial provided by the sponsor. Lyophilized 
galinpepimut-S requires reconstitution with sterile water (not 
provided by the sponsor) 
Montanide ISA 51 VG 
3-mL amber glass vial provided by the sponsor 
Sargramostim (GM-CSF) 
250-µg sterile, white, preservative-free powder in a single-use vial 
provided by the sponsor. Lyophilized sargramostim requires 
reconstitution with sterile water (not provided by the sponsor) 
Pembrolizumab 
Solution for infusion is supplied by the sponsor as 100 mg/vial liquid 
DP (manufactured using the fully formulated DS with L-histidine as a 
buffering agent, polysorbate 80 as a surfactant, and sucrose as a 
stabilizer/tonicity modifier) in a single use glass vial (will be provided 
by Merck). 
Abbreviations: GM-CSF, granulocyte-macrophage colony-stimulating factor; USP, United States 
Pharmacopeia. 
5.3.1. 
Galinpepimut-S  
Galinpepimut-S is a lyophilized preparation of 4 different WT1-derived synthetic analog 
peptides considered as a multicomponent single drug product. Each of the 4 peptides will be 
supplied at a concentration of 0.2 mg/vial. After reconstitution with 0.6 mL SWFI, each 
peptide will be at a concentration of 0.4 mg/mL (400 μg/mL of each peptide) combined in a 
single sterile solution (after reconstitution into liquid/soluble form) in a buffer consisting of 

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10 mM histidine, pH 6.0 + 0.05% EDTA. As galinpepimut-S Drug Product will comprise 
50% (0.5 mL) of the study treatment injection administered, with the other 50% of the total 
injectate volume being Montanide, the actual dose of each peptide is 200 μg per inoculation 
(with the total 4 active peptides equaling in weight 800 μg per inoculation). The peptides 
include 1 WT1-derived peptide (A1) to stimulate CD8+ responses, 2 WT1 long peptides 
(WT1-427 L, WT1-331 L) to stimulate CD4+ responses, and 1 modified peptide 
(WT1-122A1 L) that is able to stimulate both CD4+ and CD8+ cells. The WT1-A1 and 
WT1-122A1 L contain a mutated aminoacid (aa) residue (R126Y), and are, therefore, 
heteroclitic. The sequence for the heteroclitic WT1-A1 peptide is embedded within the 
sequence of the longer WT1-122A1 L peptide. The structural formulas (aa sequences) of the 
vaccine administered are depicted in Table 4. 
Table 4 
Structural Formula of Galinpepimut-S  
 
Abbreviations: DR, D-related; HLA, human leukocyte antigen; WT1, Wilms’ tumor 1 
antigen. 

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Peptide abbreviations: A, alanine; C, cysteine; D, aspartic acid; E, glutamic acid; F, phenylalanine; 
G, glycine; H, histidine; K, lysine; L, leucine; M, methionine; N, asparagine; P, proline; Q, glutamine; 
R, arginine; S, serine; T, threonine; V, valine; Y, tyrosine. *Designates single amino acid substitution 
(R>Y) by deliberately designed mutations in the heteroclitic peptides 
The Drug Substance for the 4 peptides are manufactured at Polypeptide Laboratories, Inc. 
(Torrance, CA, USA). The lyophilization process, manufacturing of Drug Product (API) and 
sterile fill and finish under Good Manufacturing Practice conditions are performed by Corden 
Pharma S.p.A. (Caponago, Italy). Each lot of the lyophilized peptide powder are tested for 
physicochemical stability, sterility, and API content at PPD GMP Laboratories, Inc. 
(Middleton, WI, USA). 
Galinpepimut-S is considered as a multicomponent single drug product comprised of 
4 peptides (described above) in a sterile lyophilized powder containing 0.8 mg peptides. 
Galinpepimut-S will be provided as a sterile, white, preservative-free powder filled into a 
2 mL vial, for reconstitution with 0.6 mL SWFI. After reconstitution with SWFI, the peptides 
will be in a buffer of 10 mM histidine, pH 6.0 + 0.05% EDTA. Galinpepimut-S will be 
mixed in a water in oil emulsion with the oily adjuvant Montanide at a 1:1 ratio. The 
resulting final emulsion, which is administered as study treatment, will also be referred to as 
galinpepimut-S for practical product administration purposes in this protocol. 
The total amount of the finished product is 0.96 mg (overfill of 20%) filled into a 2-mL 
colorless glass vial. The vial should be stored at the site at or below −20°C until use.  
5.3.2. 
Montanide ISA 51 VG 
Montanide ISA 51 VG is an adjuvant (NSC # 737063) produced by SEPPIC, Inc. (Fairfield, 
NJ) under Good Manufacturing Practice and is composed of a light oil and a surfactant 
system designed to make a water-in-oil emulsion. Montanide ISA 51 VG has been clinically 
tested based on a vegetable grade formulation used to emulsify the peptides. Montanide ISA 
51 VG has proved to be a very efficient adjuvant, activating the cellular and the humoral 

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immune response. Montanide ISA 51 VG has been administered to more than 10,000 patients 
throughout the world. Montanide is packaged in 3-mL amber glass vials. The adjuvant is 
stored between 15°C to 30°C and must not be frozen.  
5.3.3. 
Sargramostim (GM-CSF) 
Sargramostim (GM-CSF) is manufactured by Partner Therapeutics, Inc. (Lexington, MA) , 
under Good Manufacturing Practices and is provided in lyophilized form as a 250-µg sterile, 
white, preservative-free powder that requires reconstitution with SWFI. GM-CSF must be 
stored at 2°C to 8°C. For this study, the vial of GM-CSF is intended for single-use only. 
5.3.4. 
Pembrolizumab 
The pembrolizumab treatment to be used in this trial is outlined in Table 2 in Section 5.2.4. 
above. 
5.3.5. 
Overall Treatment Schedule 
The overall treatment administration schedule is shown in Figure 13 below: 

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Figure 13 
Overall Treatment Administration Schedule 
 
5.3.6. 
Toxicities 
Galinpepimut-S: The potential toxicities/side effects of galinpepimut-S include:  
Likely: 
• Induration at injection site 

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Less likely: 
• Arthralgias, myalgias 
• Fever 
• Headache 
• Edema 
• Allergic reaction 
Rare: 
• Elevated liver function tests 
• Elevated kidney function tests 
• Shortness of breath 
Montanide ISA 51 VG: The potential toxicities/side effects of Montanide ISA 51 VG 
include: 
• Mild inflammation at injection sites  
• Occasional fever 
• Allergic reactions have been observed rarely 
Sargramostim (GM-CSF): Sargramostim is an approved product, available in the US since 
1991. It has been used in a number of studies as an immunologic adjuvant with the presumed 
benefit mediated through effects on dendritic and other antigen-presenting cells. Several 
human vaccine studies in melanoma and other human malignancies have reported both 

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encouraging immunologic and clinical results. More recently, 2 melanoma vaccine studies 
have reported a harmful effect of GM-CSF when used as a vaccine adjuvant (Faries et al, 
2009; Slingluff et al, 2009). While it is important to recognize a potential negative effect, this 
study uses a different vaccine with a different dose of GM-CSF in a different disease. 
The potential toxicities/side effects of GM-CSF include (at standard doses of 250 µg/m2/day 
for 5 to 14 days):  
• Edema 
• Fluid retention 
• Headache  
• Myalgia 
• Arthralgia 
• Dyspnea 
• Allergic reactions 
• Patients with pre-existing renal and/or hepatic disorders may demonstrate elevations 
in serum creatinine or bilirubin/transaminases, respectively. 
Pembrolizumab toxicities are detailed in Section 5.3.6.3.1. 

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5.3.6.1. 
Dose-Limiting Toxicities 
All toxicities will be graded using National Cancer Institute Common Terminology Criteria 
for Adverse Events (NCI CTCAE) Version 5.0, (published in November 2017), as per the 
following link:. 
https://ctep.cancer.gov/protocolDevelopment/electronic_applications/docs/CTCAE_v5_Q 
uick_Reference_5x7.pdf. 
 
For patients enrolled across all active solid tumor cohorts (colorectal, ovarian, small cell lung 
cancer, breast cancer), the dose-limiting toxicity (DLT) window of observation will be at 
least one (1) cycle following the co-administration of galinpepimut-S in combination with 
pembrolizumab. A DLT is judged by the investigator to be possibly, probably, or definitely 
related to study drug administration. AML-specific DLTs will be considered separately 
(Section 5.3.6.2).  
The occurrence of any of the following toxicities will be considered a DLT (except for AML; 
please see Section 5.3.6.2), if judged by the investigator to be possibly, probably, or 
definitely related to study drug administration: 
1. Grade 4 nonhematologic toxicity (not laboratory) 
2. Grade 4 hematologic toxicity lasting ≥ 7 days, except thrombocytopenia: 
• Grade 4 thrombocytopenia of any duration 
• Grade 3 thrombocytopenia associated with bleeding  
3. Any nonhematologic AE ≥ Grade 3 in severity should be considered a DLT, with the 
following exceptions: Grade 3 fatigue lasting ≤ 3 days; Grade 3 diarrhea, nausea, or 
vomiting without use of anti-emetics or anti-diarrheals per standard of care; Grade 3 
rash without use of corticosteroids or anti-inflammatory agents per standard of care. 
4. Grade 3 nonhematologic toxicity (not laboratory) lasting > 3 days despite optimal 
supportive care. 
5. Any Grade 3 or Grade 4 nonhematologic laboratory value if: 

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• Clinically significant medical intervention is required to treat the patient, or 
• The abnormality leads to hospitalization, or 
• The abnormality persists for > 1 week. 
• The abnormality results in a drug-induced liver injury (DILI) 
• Exceptions: clinically nonsignificant, treatable, or reversible laboratory 
abnormalities, including liver tests, uric acid, etc. 
6. Febrile neutropenia (FN) Grade 3 or Grade 4: 
• Grade 3 is defined as absolute neutrophil count (ANC) < 1000/mm3 with a 
single temperature of > 38.3°C (101°F) or a sustained temperature of ≥ 38°C 
(100.4°F) for more than 1 hour 
• Grade 4 is defined as ANC < 1000/mm3 with a single temperature of > 38.3°C 
(101°F) or a sustained temperature of ≥ 38°C (100.4°F) for more than 1 hour, 
with life-threatening consequences and urgent intervention indicated. 
7. Any treatment-related toxicity that causes the patient to discontinue treatment during 
the period from the first administration of galinpepimut-S until the completion of the 
first cycle of galinpepimut-S plus pembrolizumab combination therapy. 
8. Missing > 25% of pembrolizumab doses as a result of drug-related AE(s) during the 
first cycle of combination therapy. 
9. Thrombocytopenia < 25,000/mm3 if associated with: 
• A bleeding event which does not result in hemodynamic instability but 
requires an elective platelet transfusion, or 
• A life-threatening bleeding event which results in urgent intervention and 
admission to an Intensive Care Unit (ICU) 
10. Prolonged delay (> 2 weeks) in initiating Cycle 2 of combination therapy due to 
treatment-related toxicity 
11. Grade 5 toxicity. 
Missing > 25% of the doses of either investigational agent as a result of drug-related AE(s) 
during the period from first administration of galinpepimut-S and up until the completion of 

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the first cycle of the co-administration of galinpepimut-S in combination with 
pembrolizumab. 
Staggered Early Enrollment: 
To minimize exposing subjects to the risk of potential unknown acute and subacute toxicities 
of combining pembrolizumab with galinpepimut-S, the inter-dosing interval in-between the 
first consecutive three (3) subjects to be enrolled in this study arm will be one (1) week 
following the administration of the first dose of pembrolizumab in these patients. 
DLT assessment and actions will be as follows (unless stopping rules apply): 
• If 2 or fewer patients of these first 6 patients have DLTs, enrollment can continue for 
up to another 6 patients across these arms with no dose adjustments made. If DLTs 
are observed in more than 2 patients of the first 6, the time interval between 
galinpepimut-S doses for the inoculation following the one associated with the DLT 
will be doubled. For example, if galinpepimut-S was given on a Q3W schedule before 
the DLT occurred, it should be given Q6W for the immediately subsequent 
administration after the dosing event associated with the DLT, while keeping the 
pembrolizumab dose and frequency stable. 
• In the next 6 patients (patients 7 to 12), if again, 2 or fewer of these patients have 
DLTs observed, enrollment can continue. If DLTs are observed in more than 2 
of patients 7 to 12, the time interval between galinpepimut-S doses for the inoculation 
following the one associated with the DLT will be doubled, , but pembrolizumab will 
continue as scheduled.  
• If DLTs are observed in more than 2 patients of the first 6 (patients 1 to 6) and again 
in more than 2 patients of the next 6 (patients 7 to 12), the time interval between 
galinpepimut-S doses will be doubled for two (2) inoculations following the one 
associated with the DLT. For example, if galinpepimut-S was given on a Q3W 
schedule before the DLT occurred, it should be given Q6W for the 2 immediately 
subsequent administrations after the dosing event associated with the DLT, while 
keeping the pembrolizumab dose and frequency stable. 

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• If DLTs continue to be observed above 2 per every 6 patients beyond these first 
12 patients, and even after the changes in administration of galinpepimut-S, the study 
will be stopped and the safety data will be examined by the sponsor in consultation 
with investigators in order to determine how to proceed or whether to discontinue the 
study. 
• Should a given patient experience any of the above DLTs at any time after the 
completion of the first cycle of co-administration of galinpepimut-S in combination 
with pembrolizumab, the time interval between galinpepimut-S doses for the 
inoculation following the one associated with the DLT will be doubled, but 
pembrolizumab will continue as scheduled.  
• If another DLT occurs in that next cycle, the time interval between galinpepimut-S 
doses will be doubled for two (2) inoculations following the one associated with the 
DLT, but pembrolizumab will continue as scheduled.  
• If no DLTs re-occur after the above periods of doubly ‘spaced out’ administrations, 
then the patient should revert back to the initial GPS Q3W schedule (as per the initial 
dosing frequency/ investigational agent administration schedule). 
• If a DLT occurs after these dose modifications in subsequent cycles, the patient will 
be discontinued from the study. 
The above dose density modifications in response to DLTs is further summarized in the 
bulleted list of actions below: 
• 
First DLT à skip the next GPS inoculation (scheduled for the next cycle, i.e., 3 wks 
ahead) and administer GPS 6 wks ahead (i.e., ‘spread out’) once thereafter, i.e. for 1 
additional cycle à DLT resolution à Return to per protocol schedule of GPS 
administration  
• 
Second DLT (after reverting to the per protocol schedule) à skip the next GPS 
inoculation (scheduled for the next cycle, i.e., 3 wks ahead) and administer GPS 6 
wks ahead (i.e., ‘spread out’) twice thereafter, i.e. for 2 additional cycles à DLT 
resolution à Return to per protocol schedule of GPS administration  

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• Third DLT (occurring either after reverting to the per protocol schedule or during the 
‘spread out’ schedule to manage the 2nd DLT above) à Discontinue patient from 
study. 
• N.B.: In all above modifications of the dose density of galinpepimut-S, as all intervals 
(in weeks) between 2 successive GPS administrations are multiples of three (3) by 
design, following these rules, co-administration with pembrolizumab is always 
secured. 
 
 
Stopping Rules: 
• Development of any SAEs at least “possibly attributable” to the study agent(s) in 2 
out of the first 6 patients in the study. In this case, the upper 90% one-sided CI 
bound for 2 patients with SAEs within 6 patients would be 66.7%, consistent with 
an excessive rate of toxicity. 
• The fraction of patients experiencing an SAE at least “possibly attributable” to the 
study agent(s) exceeds 1/3, at any time during study implementation beyond the 
first 6 patients. 
• Death at least “possibly attributable” to the study agent(s) within 30 days 
after the administration of the investigational treatment (GPS plus 
pembrolizumab). 
 
If the study is stopped due to activation of the above rules, the safety data will be examined 
by the Sponsor in consultation with investigators in order to determine how to proceed or 
whether to discontinue the study at large. 
 

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5.3.6.2. 
AML-Specific Dose-Limiting Toxicities 
For patients enrolled in the AML arm, the DLT window of observation will be defined by the 
first 8 weeks from study entry/administration of first galinpepimut-S inoculation. 
 
The occurrence of any of the following toxicities during the first 8 weeks (from the time of 
administration of the first galinpepimut-S inoculation), if assessed by the investigator to be 
reasonably possibly related to study drug, will be considered a DLT: 
1. Missing > 25% of the doses of investigational agent(s) as a result of drug-related AE 
during cycle 1 and/or 2  
2. Drug-related AE which causes patient to discontinue treatment during cycle 1 and/or 
2  
3. Grade 5 toxicity 
4. Grade 4 non-hematological toxicity (other than laboratory abnormality) 
5. Grade 3 non-hematological toxicity (other than laboratory abnormality; exception: 
fatigue, nausea, emesis, diarrhea, rash, infection, fever, or bleeding unless the event 
lasts more than 3 days despite optimal care) 
6. Grade 3 and 4 non-hematological lab abnormality, if any of the following occurs: 
a. Medical intervention is required 
b. Abnormality persists > 1 week 
c. Abnormality results in drug-induced liver injury 
7. Any treatment-related toxicity that causes a greater than 3-week delay in initiation of 
cycle 2 and/or 3 (the latter cycle being the first one whereby galinpepimut-S and 
pembrolizumab are co-administered). 
8. Development of an immune-related AE (irAE) resulting in withholding of 
pembrolizumab and initiation of steroids, for example, grade 2 or higher 
colitis/diarrhea, grade 2 or higher pneumonitis, grade 2 or higher transaminitis, any 
grade myocarditis (complete list currently shown in Table 5) 

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Any other toxicities in the AML arm will not be considered dose-limiting. 
Staggered Early Enrollment: 
To minimize exposing subjects to the risk of potential unknown acute and subacute toxicities 
of combining HMA with the investigational therapy (pembrolizumab and galinpepimut-S) in 
the AML arm, the inter-dosing interval between the first two (2) subjects to be enrolled in 
this study arm will be 12 weeks. 
AML-specific DLT assessment and actions will be as follows (unless stopping rules apply): 
• Initially up to 6 patients will be enrolled in the AML cohort. If 2 or fewer patients 
of these first 6 patients have DLTs, enrollment can continue for up to another 6 
patients in the AML arm with no dose adjustments made. If DLTs are observed in 
more than 2 patients of the first 6, the time interval between galinpepimut-S doses for 
the inoculation following the one associated with the DLT will be doubled. For 
example, if galinpepimut-S was given on a Q3W schedule before the DLT occurred, 
it should be given Q6W for the immediately subsequent administration after the 
dosing event associated with the DLT, while keeping the pembrolizumab dose and 
frequency stable.  
• In the next 6 patients (patients 7 to 12), if again, 2 or fewer of these patients have 
DLTs observed, enrollment can continue. If DLTs are observed in more than 2 
of patients 7 to 12, the time interval between galinpepimut-S doses for the inoculation 
following the one associated with the DLT will be doubled, but pembrolizumab will 
continue as scheduled.  
• If DLTs are observed in more than 2 patients of the first 6 (patients 1 to 6) and again 
in more than 2 patients of the next 6 (patients 7 to 12), the time interval between 
galinpepimut-S doses will be doubled for two (2) inoculations following the one 
associated with the DLT. For example, if galinpepimut-S was given on a Q3W 
schedule before the DLT occurred, it should be given Q6W for the 2 immediately 
subsequent administrations after the dosing event associated with the DLT, while 
keeping the pembrolizumab dose and frequency stable.  

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• If DLTs continue to be observed above 2 per every 6 patients beyond these first 
12 patients, and even after the changes in administration of galinpepimut-S, the study 
will be stopped and the safety data will be examined by the sponsor in consultation 
with investigators in order to determine how to proceed or whether to discontinue the 
study. 
• Should a given patient experience any of the above DLTs at any time after the 
completion of the first cycle of co-administration of galinpepimut-S in combination 
with pembrolizumab, the time interval between galinpepimut-S doses for the 
inoculation following the one associated with the DLT will be doubled, but 
pembrolizumab will continue as scheduled.  
• If another DLT occurs in that next cycle, the time interval between galinpepimut-S 
doses will be doubled for two (2) inoculations following the one associated with the 
DLT, but pembrolizumab will continue as scheduled.  
• If no DLTs re-occur after the above periods of doubly ‘spaced out’ administrations, 
then the patient should revert back to the initial GPS Q3W schedule (as per the initial 
dosing frequency/ investigational agent administration schedule). 
• If a DLT occurs after these dose modifications in subsequent cycles, the patient will 
be discontinued from the study. 
The above dose density modifications in response to DLTs is further summarized in the 
bulleted list of actions below: 
• 
First DLT à skip the next GPS inoculation (scheduled for the next cycle, i.e., 3 wks 
ahead) and administer GPS 6 wks ahead (i.e., ‘spread out’) once thereafter, i.e. for 1 
additional cycle à DLT resolution à Return to per protocol schedule of GPS 
administration  
• 
Second DLT (after reverting to the per protocol schedule) à skip the next GPS 
inoculation (scheduled for the next cycle, i.e., 3 wks ahead) and administer GPS 6 
wks ahead (i.e., ‘spread out’) twice thereafter, i.e. for 2 additional cycles à DLT 
resolution à Return to per protocol schedule of GPS administration  

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• Third DLT (occurring either after reverting to the per protocol schedule or during the 
‘spread out’ schedule to manage the 2nd DLT above) à Discontinue patient from 
study. 
• N.B.: In all above modifications of the dose density of galinpepimut-S, as all intervals 
(in weeks) between 2 successive GPS administrations are multiples of three (3) by 
design, following these rules, co-administration with pembrolizumab is always 
secured. 
 
Stopping rules (for AML patients): 
• Development of any SAEs at least “possibly attributable” to the study agent(s) in 2 
out of the first 6 patients in the study. In this case, the upper 90% one-sided CI 
bound for 2 patients with SAEs within 6 patients would be 66.7%, consistent with 
an excessive rate of toxicity. 
• The fraction of patients experiencing an SAE at least “possibly attributable” to the 
study agent(s) exceeds 1/3, at any time during study implementation beyond the 
first 6 patients. 
• Death at least “possibly attributable” to the study agent(s) within 30 days 
after the administration of the investigational treatment (GPS plus 
pembrolizumab) 
• Development of grade 3 or higher colitis/diarrhea, grade 3 or higher pneumonitis, 
grade 3 or higher nephritis, grade 3 or higher transaminitis, or any grade 
myocarditis in 2 out of the first 6 patients in the AML arm of the study. In this 
case, the upper 90% one-sided CI bound for 2 patients with SAEs within 6 patients 
would be 66.7%, consistent with an excessive rate of toxicity. 
• The fraction of patients experiencing grade 3 or higher colitis/diarrhea, grade 3 or 
higher pneumonitis, grade 3 or higher nephritis, grade 3 or higher transaminitis, or 
any grade myocarditis exceeds 40%, at any time during study implementation 
beyond the first 6 patients in the AML arm. 

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If the study is stopped due to activation of the above rules, the safety data will be examined 
by the sponsor in consultation with investigators in order to determine how to proceed or 
whether to discontinue the study at large. 
 
5.3.6.3. 
Dose Modification and Toxicity Management Guidelines for 
Pembrolizumab 
5.3.6.3.1. Dose Modification and Toxicity Management for Immune-related 
AEs (irAEs) Associated with Pembrolizumab 
AEs associated with pembrolizumab exposure may represent an immunologic etiology. 
These immune-related AEs (irAEs) may occur shortly after the first dose or several months 
after the last dose of pembrolizumab treatment and may affect more than one body system 
simultaneously. Therefore, early recognition and initiation of treatment is critical to reduce 
complications. Based on existing clinical trial data, most irAEs were reversible and could be 
managed with interruptions of pembrolizumab, administration of corticosteroids and/or other 
supportive care. For suspected irAEs, ensure adequate evaluation to confirm etiology or 
exclude other causes. Additional procedures or tests such as bronchoscopy, endoscopy, skin 
biopsy may be included as part of the evaluation. Based on the severity of irAEs, withhold or 
permanently discontinue pembrolizumab and administer corticosteroids. Dose modification 
and toxicity management guidelines for irAEs associated with pembrolizumab are provided 
in Table 5. 

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Table 5 
Dose Modification and Toxicity Management Guidelines for Immune-related AEs Associated with 
Pembrolizumab 
 
General instructions: 
1. Corticosteroid taper should be initiated upon AE improving to Grade 1 or less and continue to taper over at least 4 weeks. 
2. For situations where pembrolizumab has been withheld, pembrolizumab can be resumed after AE has been reduced to Grade 1 or 0 and corticosteroid 
has been tapered. Pembrolizumab should be permanently discontinued if AE does not resolve within 12 weeks of last dose or corticosteroids cannot 
be reduced to ≤10 mg prednisone or equivalent per day within 12 weeks.  
3. For severe and life-threatening irAEs, IV corticosteroid should be initiated first followed by oral steroid. Other immunosuppressive treatment should 
be initiated if irAEs cannot be controlled by corticosteroids. 
 
Immune-related 
AEs 
Toxicity grade 
or conditions 
(CTCAEv5.0) 
Action taken to 
pembrolizumab 
irAE management with 
corticosteroid and/or other 
therapies  
Monitor and follow-up  
Pneumonitis  
Grade 2 
Withhold  
Administer corticosteroids (initial 
dose of 1-2 mg/kg prednisone or 
equivalent) followed by taper 
 
Monitor participants for signs and 
symptoms of pneumonitis 
Evaluate participants with suspected 
pneumonitis with radiographic imaging and 
initiate corticosteroid treatment 
Add prophylactic antibiotics for 
opportunistic infections 
Grade 3 or 4, or 
recurrent Grade 
2 
Permanently 
discontinue 

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Diarrhea / Colitis  Grade 2 or 3 
Withhold 
Administer corticosteroids (initial 
dose of 1-2 mg/kg prednisone or 
equivalent) followed by taper 
 
Monitor participants for signs and 
symptoms of enterocolitis (i.e., diarrhea, 
abdominal pain, blood or mucus in stool 
with or without fever) and of bowel 
perforation (i.e., peritoneal signs and ileus). 
Participants with ≥ Grade 2 diarrhea 
suspecting colitis should consider GI 
consultation and performing endoscopy to 
rule out colitis.  
Participants with diarrhea/colitis should be 
advised to drink liberal quantities of clear 
fluids.  If sufficient oral fluid intake is not 
feasible, fluid and electrolytes should be 
substituted via IV infusion. 
Grade 4 
Permanently 
discontinue 
AST / ALT 
elevation or 
Increased 
bilirubin 
Grade 2 
Withhold 
Administer corticosteroids (initial 
dose of 0.5- 1 mg/kg prednisone or 
equivalent) followed by taper 
Monitor with liver function tests (consider 
weekly or more frequently until liver 
enzyme value returned to baseline or is 
stable 
Grade 3 or 4  
Permanently 
discontinue 
Administer corticosteroids (initial 
dose of 1-2 mg/kg prednisone or 
equivalent) followed by taper 
Type 1 diabetes 
mellitus (T1DM) 
or 
Hyperglycemia 
 
Newly onset 
T1DM or  
Grade 3 or 4 
hyperglycemia 
associated with 
Withhold 
Initiate insulin replacement 
therapy for participants with 
T1DM  
Administer anti-hyperglycemic in 
participants with hyperglycemia  
 
Monitor participants for hyperglycemia or 
other signs and symptoms of diabetes. 

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evidence of b-
cell failure 
Hypophysitis 
Grade 2 
Withhold 
Administer corticosteroids and 
initiate hormonal replacements as 
clinically indicated.   
 
Monitor for signs and symptoms of 
hypophysitis (including hypopituitarism and 
adrenal insufficiency)  
Grade 3 or 4  
Withhold or 
permanently 
discontinue1  
Hyperthyroidism  Grade 2 
Continue  
Treat with non-selective beta-
blockers (e.g., propranolol) or 
thionamides as appropriate  
Monitor for signs and symptoms of thyroid 
disorders.  
 
Grade 3 or 4  
Withhold or  
permanently 
discontinue1 
Hypothyroidism 
Grade 2-4 
Continue  
Initiate thyroid replacement 
hormones (e.g., levothyroxine or 
liothyroinine) per standard of care 
Monitor for signs and symptoms of thyroid 
disorders.  
 
Nephritis and 
Renal 
dysfunction 
Grade 2 
Withhold  
Administer corticosteroids 
(prednisone 1-2 mg/kg or 
equivalent) followed by taper. 
Monitor changes of renal function 
 
Grade 3 or 4  
Permanently 
discontinue 
Myocarditis 
Grade 1 or 2 
Withhold 
Based on severity of AE 
administer corticosteroids 
Ensure adequate evaluation to confirm 
etiology and/or exclude other causes 
 
Grade 3 or 4 
Permanently 
discontinue 

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All other 
immune-related 
AEs 
Intolerable/ 
persistent Grade 
2 
Withhold 
Based on type and severity of AE 
administer corticosteroids  
Ensure adequate evaluation to confirm 
etiology and/or exclude other causes 
 
Grade 3 
Withhold or 
discontinue based 
on the type of 
event.  Events 
that require 
discontinuation 
include and not 
limited to:  
Guillain-Barre 
Syndrome, 
encephalitis 
Grade 4 or 
recurrent Grade 
3  
Permanently 
discontinue 
1Withhold or permanently discontinue pembrolizumab is at the discretion of the investigator or treating physician.   
NOTE:  
For participants with Grade 3 or 4 immune-related endocrinopathy where withhold of pembrolizumab is required, pembrolizumab may be 
resumed when AE resolves to ≤ Grade 2 and is controlled with hormonal replacement therapy or achieved metabolic control (in case of 
T1DM).   

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5.3.6.3.2. Dose Modification and Toxicity Management of 
Infusion-Reactions Related to Pembrolizumab 
Pembrolizumab may cause severe or life-threatening infusion-reactions including severe 
hypersensitivity or anaphylaxis. Signs and symptoms usually develop during or shortly after 
drug infusion and generally resolve completely within 24 hours of completion of infusion. 
Dose modification and toxicity management guidelines on pembrolizumab associated 
infusion reaction are provided in  
Table 6.  
 
Table 6 
Pembrolizumab Infusion Reaction Dose Modification and 
Treatment Guidelines 
 

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NCI CTCAE Grade 
Treatment 
Premedication at  
Subsequent Dosing 
Grade 1 
Mild reaction; infusion 
interruption not 
indicated; intervention 
not indicated 
• 
Increase monitoring of vital signs as 
medically indicated until the participant 
is deemed medically stable in the opinion 
of the investigator. 
None 
Grade 2 
Requires therapy or 
infusion interruption but 
responds promptly to 
symptomatic treatment 
(e.g., antihistamines, 
NSAIDs, narcotics, IV 
fluids); prophylactic 
medications indicated 
for ≤24 hrs. 
• 
Stop Infusion. 
• 
Additional appropriate medical therapy 
may include but is not limited to: 
• 
IV fluids 
• 
Antihistamines 
• 
NSAIDs 
• 
Acetaminophen 
• 
Narcotics 
• 
Increase monitoring of vital signs as 
medically indicated until the participant 
is deemed medically stable in the opinion 
of the investigator. 
• 
If symptoms resolve within 1 hour of 
stopping drug infusion, the infusion may 
be restarted at 50% of the original 
infusion rate (e.g. from 100 mL/hr. to 50 
mL/hr.). Otherwise dosing will be held 
until 
symptoms 
resolve 
and 
the 
participant should be premedicated for 
the next scheduled dose. 
Participants who develop Grade 2 toxicity 
despite adequate premedication should be 
permanently discontinued from further study 
drug treatment 
Participant 
may 
be 
premedicated 1.5h (± 30 
minutes) prior to infusion 
with: 
-  Diphenhydramine 50 mg 
po (or equivalent dose of 
antihistamine). 
- Acetaminophen 500-1000 
mg po (or equivalent dose of 
analgesic). 

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Grades 3 or 4 
 
Grade 3: 
Prolonged (i.e., not 
rapidly responsive to 
symptomatic medication 
and/or brief interruption 
of infusion); recurrence 
of symptoms following 
initial improvement; 
hospitalization indicated 
for other clinical 
sequelae (e.g., renal 
impairment, pulmonary 
infiltrates) 
Grade 4: 
Life-threatening; pressor 
or ventilator support 
indicated 
 
• 
Stop Infusion. 
• 
Additional appropriate medical therapy 
may include but is not limited to: 
• 
Epinephrine** 
• 
IV fluids 
• 
Antihistamines 
• 
NSAIDs 
• 
Acetaminophen 
• 
Narcotics 
• 
Oxygen 
• 
Pressors 
• 
Corticosteroids 
• 
Increase monitoring of vital signs as 
medically indicated until the participant 
is deemed medically stable in the opinion 
of the investigator. 
• 
Hospitalization may be indicated. 
**In cases of anaphylaxis, epinephrine should be 
used immediately. 
Participant is permanently discontinued from 
further study drug treatment. 
 
No subsequent dosing 
Appropriate resuscitation equipment should be available at the bedside and a physician readily available during the period 
of drug administration. For further information, please refer to the Common Terminology Criteria for Adverse Events v5.0 
(CTCAE) 
at 
https://ctep.cancer.gov/protocolDevelopment/electronic_applications/docs/CTCAE_v5_Q 
uick_Reference_5x7.pdf. 
 
 
Other allowed dose interruptions for pembrolizumab  

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Pembrolizumab may be interrupted for situations other than treatment-related AEs such as 
medical/surgical events or logistical reasons not related to study therapy. Patients should be 
placed back on study therapy within 3 weeks of the scheduled interruption, unless otherwise 
discussed with the sponsor. The reason for interruption should be documented in the patient's 
study record 
5.3.7. 
Toxicity Management of Injection-reactions Related to 
Galinpepimut-S 
Expected AEs from study treatment injection (any component of galinpepimut-S, excluding 
GM-CSF) include local erythema, edema, itching, and persistent induration at the site of 
injection. These events are usually mild and may appear after each administration of the 
study treatment. These Grade 1 and Grade 2 local injection site reactions may resolve 
spontaneously but they can be treated with topical creams (e.g., aloe), analgesics and/or 
antihistamines as per investigative site guidelines and will not require treatment interruptions 
or discontinuation. 
Local injection site reactions of grade 3 or higher may require antihistamines, non-steroidal 
anti-inflammatory agents, and/or steroid therapy as per investigative site guidelines. 
Re-challenge of a patient after a local grade 3 event will need to be discussed with the 
medical monitor. Premedication with diphenhydramine 50 mg (or equivalent) and/or 
paracetamol (325 to 1,000 mg) at least 30 minutes prior to the next treatment injection will 
be required for the re-challenge. If local toxicity of grade 3 or higher persists, the patient will 
be moved to the off- treatment follow-up period.  
Systemic events of grade 3 or grade 4 toxicity that are considered possibly related to study 
treatment (any component of galinpepimut-S, excluding GM-CSF) should be quickly 
discussed with the medical monitor. Autoimmune or hypersensitivity reactions to 
components of the study treatment or skin test antigens are possibilities. Patients who 
develop events of non-skin related autoimmune disorders or anaphylactic reactions 
considered possibly related to the study treatment or any of its components (other than 

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GM-CSF) may require appropriate care with epinephrine, antihistamines, vasopressors, 
fluids, and/or steroid therapy as per investigative site guidelines. The medical monitor should 
be contacted, and these patients will be moved to the off- treatment follow-up period. 
Toxicity events related to GM-CSF should be discussed expeditiously with the medical 
monitor and consideration will be made to either allow the patient to continue the study 
treatment with or without GM-CSF or to move that particular patient to the off- treatment 
follow-up period. Treatment of GM-CSF related events are to be treated as per investigative 
site guidelines. 
Toxicity will be graded in accordance with CTCAE v5.0 developed by the NCI 
(https://ctep.cancer.gov/protocolDevelopment/electronic_applications/docs/CTCAE_v5_Q 
uick_Reference_5x7.pdf). 
). 
5.3.8. 
Definition of an Overdose of Investigational Agents for This 
Protocol 
For this trial (a fixed-dose regimen), an overdose will be defined as ≥1,000 mg (5 times the 
dose) of pembrolizumab.  No specific information is available on the treatment of overdose 
of pembrolizumab. In the event of overdose, the patient should be observed closely for signs 
of toxicity.  Appropriate supportive treatment should be provided if clinically indicated. 
No overdose is defined for galinpepimut-S. 

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5.3.9. 
Toxicity Management of Known/Expected AEs Associated with the 
Continuing Use of Hypomethylating Agents (HMAs) in Patients 
Enrolled in the AML Arm  
Dose modifications for HMA-related (known/expected) toxicities -for either azacitidine or 
decitabine- in AML patients will be based on the respective US Prescribing Information for 
these products. These documents are included as Appendices 12.1 and 12.2. 
5.3.9.1.   Toxicity Profile and Dose Modifications for Azacitidine (AML 
Patients) (Vidaza® US Prescribing Information; Appendix 12.1) 
Most common adverse reactions (>30%) of azacitidine administered by the subcutaneous 
route are: nausea, anemia, thrombocytopenia, vomiting, pyrexia, leukopenia, diarrhea, 
injection site erythema, constipation, neutropenia and ecchymosis. Most common adverse 
reactions by the IV route also included petechiae, rigors, weakness and hypokalemia. 
Adverse reactions most frequently (≥ 2%) resulting in medical/clinical intervention and/or 
dose modification in patients receiving azacitidine (S.C. or IV Route) are as follows: 
• Discontinuation: leukopenia, thrombocytopenia, neutropenia.  
• Dose Held: leukopenia, neutropenia, thrombocytopenia, pyrexia, pneumonia, febrile 
neutropenia.  
• Dose Reduced: leukopenia, neutropenia, thrombocytopenia. 
Dose Modifications: 
A. For hematologic toxicity 
For patients with baseline (start of treatment) WBC > 3.0 x109/L, ANC > 1.5 x109/L, and 
platelets > 75.0 x109/L, adjust the dose as follows, based on nadir counts for any given cycle: 
 

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Nadir Counts 
% Dose in the Next 
Course 
ANC (x109/L) 
 
Less than 0.5 
0.5 –1.5 
Greater than 1.5 
Platelets (x109/L)  
 
Less than 25 
25-50 
Greater than 50 
 
50% 
67% 
100% 
 
For patients whose baseline counts are WBC < 3.0 x109/L, ANC < 1.5x109/L, or platelets < 
75.0 x109/L, base dose adjustments on nadir counts and bone marrow biopsy cellularity at the 
time of the nadir as noted below, unless there is clear improvement in differentiation 
(percentage of mature granulocytes is higher and ANC is higher than at onset of that course) 
at the time of the next cycle, in which case continue the current dose. 
 
 
If a nadir as defined in the table above has occurred, give the next course 28 days after 
the start of the preceding course, provided that both the WBC and the platelet counts are 
greater than 25% above the nadir and rising. If a greater than 25% increase above the 
nadir is not seen by day 28, reassess counts every 7 days. If a 25% increase is not seen 
by day 42, reduce the scheduled dose by 50%. 
B. For non-hematologic (serum electrolytes and renal) toxicity  

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If unexplained reductions in serum bicarbonate levels to less than 20 mEq/L occur, reduce 
the dosage by 50% for the next course. Similarly, if unexplained elevations of BUN or serum 
creatinine occur, delay the next cycle until values return to normal or baseline and reduce the 
dose by 50% for the next course. 
 
5.3.9.2.   Toxicity Profile and Dose Modifications for Decitabine (AML 
Patients) (Dacogen® US Prescribing Information; Appendix 12.2) 
Most common adverse reactions (> 50%) seen during decitabine therapy include neutropenia, 
thrombocytopenia, anemia, and pyrexia. 
Adverse reactions most frequently (≥ 1%) resulting in medical/clinical intervention and/or 
dose modification in patients receiving decitabine are as follows: 
• Discontinuation: thrombocytopenia, neutropenia, pneumonia, Mycobacterium avium 
complex infection, cardio-respiratory arrest, increased blood bilirubin, intracranial 
hemorrhage, abnormal liver function tests.  
• Dose Delayed: neutropenia, pulmonary edema, atrial fibrillation, central line 
infection, febrile neutropenia.  
• Dose Reduced: neutropenia, thrombocytopenia, anemia, lethargy, edema, tachycardia, 
depression, pharyngitis. 
Dose Modifications: 
A. For hematologic toxicity 
If hematologic recovery from a previous decitabine treatment cycle requires more than 6 
weeks, delay the next cycle of decitabine therapy and reduce decitabine dose temporarily by 
following this algorithm: 

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• Recovery requiring more than 6, but less than 8 weeks: Delay DACOGEN dosing for 
up to 2 weeks and reduce the dose temporarily to 11 mg/m2 every 8 hours (33 
mg/m2/day, 99 mg/m2/cycle) upon restarting therapy. 
• Recovery requiring more than 8, but less than 10 weeks: Perform bone marrow 
aspirate to assess for disease progression. In the absence of progression, delay the 
decitabine dose up to 2 more weeks and reduce the dose to 11 mg/m2 every 8 hours 
(33 mg/m2/day, 99 mg/m2 /cycle) upon restarting therapy, then maintain or increase 
dose in subsequent cycles as clinically indicated. 
B. For non-hematologic toxicity 
Delay subsequent decitabine treatment for any the following non-hematologic toxicities and 
do not restart until toxicities resolve: 
• Serum creatinine > 2 mg/dL 
• SGPT, total bilirubin > 2 x ULN 
• Active or uncontrolled infection 
 
5.4. Management of Clinical Supplies 
5.4.1. 
Study Drug Packaging and Storage 
Galinpepimut-S will be provided as a sterile, lyophilized powder filled into a 2 mL colorless 
glass vial that requires reconstitution with SWFI. Galinpepimut-S should be stored at the site 
at or below –20°C until use. 
Montanide will be packaged in 3-mL amber glass vials. The adjuvant should be stored 
between 15°C and 30°C. This product must not be frozen. 
Avoid freezing and thawing of the emulsified product. 

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Sargramostim (GM-CSF) will be provided in lyophilized form as a 250-µg sterile, white, 
preservative-free powder that requires reconstitution with sterile water for injection. It should 
be stored at 2°C to 8°C. For this study, the vial of GM-CSF is intended for single-use only. 
Pembrolizumab will be provided by the sponsor as summarized in Table 7. 
Table 7 
Pembrolizumab Product Description 
Product Name & Potency 
Dosage Form 
MK-3475 100 mg/ 4 mL 
Solution for Injection 
 
These supplies will be shipped by the Sponsor indirectly via their Drug Supply packaging, 
distribution, and logistics vendor (Sharp Clinical Services, Phoenixville, PA, USA) to 
investigative sites in the appropriate packaging to maintain their recommended temperatures. 
The supplies are to be stored in their original cartons at the recommended temperatures until 
ready for use. Until dispensed to the patients, these supplies will be stored in a securely 
locked area, accessible to authorized personnel only.  
5.4.2. 
Test Article Accountability 
The investigator or designee will maintain accurate records of receipt for all study treatment, 
including dates and quantities of study drug(s) received. The study treatment will be used in 
accordance with the protocol by patients who are under the direct supervision of the 
investigator. The study treatment will be dispensed only by an appropriately qualified person 
to patients in the study. Accurate records will be kept regarding when, how much, and to 
whom study treatment is dispensed and administered (patient-by-patient, dose-specific 
accounting). Reasons for departure from the expected dispensing regimen, including study 
treatment lost or accidentally or deliberately destroyed, will be recorded. The investigator or 
designee will retain all used, unused, or expired study supplies until the study monitor has 

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confirmed the accountability data and the sponsor has approved return or destruction. All 
clinical study treatments and/or supplies will either be destroyed by the site per institutional 
policy, or be returned to SELLAS or its designee for destruction per applicable regulations. 
5.4.3. 
Other Supplies 
Additional supplies provided for this study will be described in the study pharmacy manual. 
5.4.4. 
Blinding 
This is an open-label study.  
5.4.5. 
Breaking the Blind 
Not applicable. 
5.5. Treatment Compliance 
Every effort should be made to follow the administration schedule for galinpepimut-S and 
pembrolizumab. If a patient misses a scheduled administration of either the combination or 
pembrolizumab alone, the drug(s) should be administered as soon as possible thereafter. If 
the patient is more than one-half the time interval to the next scheduled administration, the 
patient should skip that preplanned administration and have the next administration on 
schedule. The disposition of study treatment received by the site, dispensed and administered 
to the patient, returned to the sponsor, destroyed, lost, etc. must be recorded in the site’s 
pharmacy log. 
5.6. Prior and Concomitant Therapy  
Any treatments or therapies other than the study treatment, including biologics; blood 
products; prescription drugs; over-the-counter medications; and complementary or alternative 
medications including herbal products/supplements, vitamins, and minerals that the patient is 

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receiving will be documented. Use of all concomitant medications will be recorded in the 
patient’s source document and eCRF. Any changes in concomitant medications will also be 
recorded in the patient’s source document and eCRF within 28 days from such a change. 
Any concomitant medication deemed necessary for the welfare of the patient during the 
study may be given at the discretion of the investigator. However, it is the responsibility of 
the investigator to ensure that details regarding the medication are recorded in full in the 
eCRF and to consult with the study medical monitor if prohibited medications are considered 
necessary. 
The following medications/treatments are prohibited:  
• Other investigational agents given within 4 weeks prior to starting study treatment 
and during the on-treatment portion of the study. 
• Systemic glucocorticoids for any purpose other than to modulate symptoms from an 
event of clinical interest of suspected immunologic etiology. The use of physiologic 
doses of corticosteroids is allowed, in dosing that does not exceed a total of 10 mg 
daily of prednisone (or equivalent). If systemic corticosteroids are required for 
treatment of a co-morbid illness during the study, the investigator should confer with 
the medical monitor. 
o Note:  Inhaled steroids are allowed for management of asthma. 
• Immunosuppressive therapies are prohibited throughout the on-treatment portion of 
the study.  
• Patients must have received their last dose of chemotherapy within 3 months before 
receiving study treatment. Any concurrent cytotoxic chemotherapy, radiation therapy, 
hormonal therapy, immunotherapy, biologic therapy, or other systemic therapy for 
cancer is prohibited during the on-treatment portion of the study. 

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• Radiation therapy  
o Note: Radiation therapy to a symptomatic solitary lesion or to the brain may be 
considered on an exceptional case by case basis after consultation with sponsor. 
The patient must have clear measurable disease outside the radiated field. 
Administration of palliative radiation therapy will be considered clinical 
progression for the purposes of determining PFS. 
• Live vaccines within 30 days prior to the first dose of trial treatment and while 
participating in the trial. Examples of live vaccines include, but are not limited to, the 
following: measles, mumps, rubella, chicken pox, yellow fever, rabies, BCG, and 
typhoid (oral) vaccine. Seasonal influenza vaccines for injection are generally killed 
virus vaccines and are allowed. However, intranasal influenza vaccines (e.g. Flu - 
Mist®) are live attenuated vaccines, and are not allowed. 
5.7. Rescue Medications and Supportive Care 
5.7.1. 
Supportive Care Guidelines for Pembrolizumab 
Patients should receive appropriate supportive care measures as deemed necessary by the 
treating investigator.  Suggested supportive care measures for the management of AEs with 
potential immunologic etiology are outlined along with the dose modification guidelines in 
Section 5.3.6.3, Table 5. Where appropriate, these guidelines include the use of oral or IV 
treatment with corticosteroids, as well as additional anti-inflammatory agents if symptoms do 
not improve with administration of corticosteroids.  Note that several courses of steroid 
tapering may be necessary as symptoms may worsen when the steroid dose is decreased.  For 
each disorder, attempts should be made to rule out other causes such as metastatic disease or 
bacterial or viral infection, which might require additional supportive care.  The treatment 
guidelines are intended to be applied when the investigator determines the events to be 
related to pembrolizumab.  

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Note: If after the evaluation of the event, it is determined not to be related to pembrolizumab, 
the Investigator does not need to follow the treatment guidance. Refer to Table 5 in 
Section 5.3.6.3.2, for guidelines regarding dose modification and supportive care.  
It may be necessary to perform conditional procedures such as bronchoscopy, endoscopy, or 
skin photography as part of evaluation of the event.  
5.8. Diet/Activity/Other Considerations 
5.8.1. Meals and Dietary Restrictions Participants should maintain a normal diet 
unless modifications are required to manage an AE such as diarrhea, nausea, or vomiting. 
 
5.8.2. Contraception 
Galinpepimut-S and pembrolizumab may have adverse effects on a fetus in utero. 
Furthermore, it is not known if pembrolizumab has transient adverse effects on the 
composition of sperm.  Please refer to Section 6.6 for further details.   
Participants should be informed that taking the study medication may involve unknown risks 
to the fetus (unborn baby) if pregnancy were to occur during the study. In order to participate 
in the study, participants of childbearing potential must adhere to the contraception 
requirement (from the day of study medication initiation (or 14 days prior to the initiation of 
study medication for oral contraception) throughout the study period up to 120 days after the 
last dose of study medication. If there is any question that a participant of childbearing 
potential will not reliably comply with the requirements for contraception, that participant 
should not be entered into the study.  
5.8.3. Pregnancy  
If a participant inadvertently becomes pregnant while on treatment with either 
pembrolizumab or galinpepimut-S, the participant will be immediately discontinued from 

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study treatment. The site will contact the participant at least monthly and document the 
participant’s status until the pregnancy has been completed or terminated. The outcome of 
the pregnancy will be reported to the Sponsor without delay and within 24 hours if the 
outcome is a serious adverse experience (e.g., death, abortion, congenital anomaly, or other 
disabling or life-threatening complication to the mother or newborn). The study investigator 
will make every effort to obtain permission to follow the outcome of the pregnancy and 
report the condition of the fetus or newborn to the Sponsor.  
5.8.4. Nursing Women 
It is unknown whether one of the components of the investigational therapy, i.e., 
pembrolizumab is excreted in human milk. Since many drugs are excreted in human milk, 
and because of the potential for serious adverse reactions in the nursing infant, participants 
who are breastfeeding are not eligible for enrollment. 
 

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6. Study Assessments and Procedures 
All patients must sign and date the informed consent before any study-specific procedures 
are performed. The study will be discussed with the patient and he or she will have the 
opportunity to have any questions answered before signing the ICF. The investigator must 
address all questions raised by the patient. The investigator will also sign the ICF. The 
patient must also give authorization regarding privacy requirements before any study-related 
procedures. 
Each patient who provides informed consent and meets all of the inclusion criteria and none 
of the exclusion criteria at Day -3 (Baseline visit) will be enrolled using IWRS and will be 
assigned a 5-digit number that will be used on patient documentation throughout the study. 
The first 2 digits of the number will refer to the site code and the last 3 digits will be a 
patient-specific number at that site. Patient numbers at each site will be assigned in ascending 
order and numbers will not be omitted or reused. 
 
 
Refer to Table 8 for the Schedule of Assessments. 
 

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Table 8 
Schedule of Assessments 
Procedures 
Screenin
g Period 
Open-Label Treatment Perioda 
Safety Follow-up 
Period 
 
Screening 
Baselineb 
Int. 2 WT1-
immunizing 
Inj  
(Q3 wk) 
Subsequent 4 
WT1-
immunizing Inj 
(Q3 wk) 
Int. 1 
Booster Inj 
Period - A 
(Q3 wk) 
4 Series of 
Subsequent 
Intervals  
(2-4, 5-7, 8-10, and 
11-13) 
Booster Inj 
Period – B 
(Q12 wk) 
Final Pem- 
brolizumab 
Mono- 
therapy Phase 
EOT/ETc 
Off-treatment 
Week 
0, 3 
6, 9, 12, 15 
18 
21, 24, 27, 30, 
33, 36 
[39, 42, 45], [51, 54, 
57], [63, 66, 69], [75, 
78, 81] 
48, 60, 72, 
84 
87, 90, 93, 96, 
99, 102, 105, 
and 108 
30 days 
after last 
inj. 
Every 
3 
mnthsc 
Day(s) 
-28 to -4 
−3b 
-2 
1 
-2 
1 
1 
-2 
1 
1 
-2 
1 
1 
 
 
Informed consent 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Inclusion/ 
exclusion 
X 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
Tumor tissued 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Procedures 
Screenin
g Period 
Open-Label Treatment Perioda 
Safety Follow-up 
Period 
 
Screening 
Baselineb 
Int. 2 WT1-
immunizing 
Inj  
(Q3 wk) 
Subsequent 4 
WT1-
immunizing Inj 
(Q3 wk) 
Int. 1 
Booster Inj 
Period - A 
(Q3 wk) 
4 Series of 
Subsequent 
Intervals  
(2-4, 5-7, 8-10, and 
11-13) 
Booster Inj 
Period – B 
(Q12 wk) 
Final Pem- 
brolizumab 
Mono- 
therapy Phase 
EOT/ETc 
Off-treatment 
Week 
0, 3 
6, 9, 12, 15 
18 
21, 24, 27, 30, 
33, 36 
[39, 42, 45], [51, 54, 
57], [63, 66, 69], [75, 
78, 81] 
48, 60, 72, 
84 
87, 90, 93, 96, 
99, 102, 105, 
and 108 
30 days 
after last 
inj. 
Every 
3 
mnthsc 
Day(s) 
-28 to -4 
−3b 
-2 
1 
-2 
1 
1 
-2 
1 
1 
-2 
1 
1 
 
 
Demographicse 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Prior and 
concomitant 
medications  
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
 
Medical and 
surgical history 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Physical 
examinationf 
X 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
ECOG  
X 
X 
 
X 
 
X 
X 
 
X 
X 
 
X 
X 
X 
 
Vital signg 
X 
X 
 
X 
 
X 
X 
 
X 
X 
 
X 
X 
X 
 

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Procedures 
Screenin
g Period 
Open-Label Treatment Perioda 
Safety Follow-up 
Period 
 
Screening 
Baselineb 
Int. 2 WT1-
immunizing 
Inj  
(Q3 wk) 
Subsequent 4 
WT1-
immunizing Inj 
(Q3 wk) 
Int. 1 
Booster Inj 
Period - A 
(Q3 wk) 
4 Series of 
Subsequent 
Intervals  
(2-4, 5-7, 8-10, and 
11-13) 
Booster Inj 
Period – B 
(Q12 wk) 
Final Pem- 
brolizumab 
Mono- 
therapy Phase 
EOT/ETc 
Off-treatment 
Week 
0, 3 
6, 9, 12, 15 
18 
21, 24, 27, 30, 
33, 36 
[39, 42, 45], [51, 54, 
57], [63, 66, 69], [75, 
78, 81] 
48, 60, 72, 
84 
87, 90, 93, 96, 
99, 102, 105, 
and 108 
30 days 
after last 
inj. 
Every 
3 
mnthsc 
Day(s) 
-28 to -4 
−3b 
-2 
1 
-2 
1 
1 
-2 
1 
1 
-2 
1 
1 
 
 
Height 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Weight 
X 
X 
 
X 
 
X 
X 
 
X 
X 
 
X 
X 
X 
 
Beta-hCG 
X 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
HIV testing 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
12-lead ECG 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
PT, PTT, and 
INR 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Hematologyh 
X 
 
 
X 
 
X 
X 
 
X 
X 
 
X 
X 
X 
 
Serum chemistryi 
X 
 
 
X 
 
X 
X 
 
X 
X 
 
X 
X 
X 
 

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Procedures 
Screenin
g Period 
Open-Label Treatment Perioda 
Safety Follow-up 
Period 
 
Screening 
Baselineb 
Int. 2 WT1-
immunizing 
Inj  
(Q3 wk) 
Subsequent 4 
WT1-
immunizing Inj 
(Q3 wk) 
Int. 1 
Booster Inj 
Period - A 
(Q3 wk) 
4 Series of 
Subsequent 
Intervals  
(2-4, 5-7, 8-10, and 
11-13) 
Booster Inj 
Period – B 
(Q12 wk) 
Final Pem- 
brolizumab 
Mono- 
therapy Phase 
EOT/ETc 
Off-treatment 
Week 
0, 3 
6, 9, 12, 15 
18 
21, 24, 27, 30, 
33, 36 
[39, 42, 45], [51, 54, 
57], [63, 66, 69], [75, 
78, 81] 
48, 60, 72, 
84 
87, 90, 93, 96, 
99, 102, 105, 
and 108 
30 days 
after last 
inj. 
Every 
3 
mnthsc 
Day(s) 
-28 to -4 
−3b 
-2 
1 
-2 
1 
1 
-2 
1 
1 
-2 
1 
1 
 
 
TSH, FT4, and 
T3 or FT3 
X 
 
 
X 
 
X 
X 
 
X 
X 
 
X 
X 
X 
 
Urine testj 
X 
 
 
X 
 
X 
X 
 
X 
X 
 
X 
X 
X 
 
HLA typingk 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Cytogenetics and 
molecular 
analysisl 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Bone Marrow 
biopsym 
X 
 
 
 
 
Xw 
X 
 
Xx 
Xy 
 
Xz 
 
X 
 

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Procedures 
Screenin
g Period 
Open-Label Treatment Perioda 
Safety Follow-up 
Period 
 
Screening 
Baselineb 
Int. 2 WT1-
immunizing 
Inj  
(Q3 wk) 
Subsequent 4 
WT1-
immunizing Inj 
(Q3 wk) 
Int. 1 
Booster Inj 
Period - A 
(Q3 wk) 
4 Series of 
Subsequent 
Intervals  
(2-4, 5-7, 8-10, and 
11-13) 
Booster Inj 
Period – B 
(Q12 wk) 
Final Pem- 
brolizumab 
Mono- 
therapy Phase 
EOT/ETc 
Off-treatment 
Week 
0, 3 
6, 9, 12, 15 
18 
21, 24, 27, 30, 
33, 36 
[39, 42, 45], [51, 54, 
57], [63, 66, 69], [75, 
78, 81] 
48, 60, 72, 
84 
87, 90, 93, 96, 
99, 102, 105, 
and 108 
30 days 
after last 
inj. 
Every 
3 
mnthsc 
Day(s) 
-28 to -4 
−3b 
-2 
1 
-2 
1 
1 
-2 
1 
1 
-2 
1 
1 
 
 
Multigene MRD 
analysisn 
X 
 
 
 
 
 
X 
 
Xx 
Xy 
 
Xz 
 
X 
 
Immunologic 
Marker 
assessmento 
 
X 
 
 
 
Xw 
X 
 
Xaa 
Xy 
 
Xz 
 
X 
 
Biopsies of 
malignant tissue 
depositp 
X 
 
 
 
 
 
X 
 
Xx 
Xt 
 
Xz 
 
X 
 
CT or MRIq 
X 
 
 
 
 
Xw 
X 
 
Xaa 
Xbb 
 
Xz 
 
X 
 

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Procedures 
Screenin
g Period 
Open-Label Treatment Perioda 
Safety Follow-up 
Period 
 
Screening 
Baselineb 
Int. 2 WT1-
immunizing 
Inj  
(Q3 wk) 
Subsequent 4 
WT1-
immunizing Inj 
(Q3 wk) 
Int. 1 
Booster Inj 
Period - A 
(Q3 wk) 
4 Series of 
Subsequent 
Intervals  
(2-4, 5-7, 8-10, and 
11-13) 
Booster Inj 
Period – B 
(Q12 wk) 
Final Pem- 
brolizumab 
Mono- 
therapy Phase 
EOT/ETc 
Off-treatment 
Week 
0, 3 
6, 9, 12, 15 
18 
21, 24, 27, 30, 
33, 36 
[39, 42, 45], [51, 54, 
57], [63, 66, 69], [75, 
78, 81] 
48, 60, 72, 
84 
87, 90, 93, 96, 
99, 102, 105, 
and 108 
30 days 
after last 
inj. 
Every 
3 
mnthsc 
Day(s) 
-28 to -4 
−3b 
-2 
1 
-2 
1 
1 
-2 
1 
1 
-2 
1 
1 
 
 
Enrollment to 
studyr 
 
X 
 
 
 
 
 
 
 
 
 
 
 
 
 
GM-CSF SCs 
 
 
X 
X 
X 
X 
 
X 
X 
 
X 
X 
 
 
 
Assess local 
immunization 
site 
 
X 
 
X 
 
X 
 
 
X 
 
 
X 
 
 
 
Galinpepimut-St 
 
 
 
X 
 
 
 
 
 
 
 
 
 
 
 
Galinpepimut-S 
with 
pembrolizumab 
 
 
 
 
 
X 
 
 
X 
 
 
X 
 
 
 

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Procedures 
Screenin
g Period 
Open-Label Treatment Perioda 
Safety Follow-up 
Period 
 
Screening 
Baselineb 
Int. 2 WT1-
immunizing 
Inj  
(Q3 wk) 
Subsequent 4 
WT1-
immunizing Inj 
(Q3 wk) 
Int. 1 
Booster Inj 
Period - A 
(Q3 wk) 
4 Series of 
Subsequent 
Intervals  
(2-4, 5-7, 8-10, and 
11-13) 
Booster Inj 
Period – B 
(Q12 wk) 
Final Pem- 
brolizumab 
Mono- 
therapy Phase 
EOT/ETc 
Off-treatment 
Week 
0, 3 
6, 9, 12, 15 
18 
21, 24, 27, 30, 
33, 36 
[39, 42, 45], [51, 54, 
57], [63, 66, 69], [75, 
78, 81] 
48, 60, 72, 
84 
87, 90, 93, 96, 
99, 102, 105, 
and 108 
30 days 
after last 
inj. 
Every 
3 
mnthsc 
Day(s) 
-28 to -4 
−3b 
-2 
1 
-2 
1 
1 
-2 
1 
1 
-2 
1 
1 
 
 
30-minute post 
injection 
observation 
 
 
 
X 
X 
X 
 
X 
X 
 
X 
X 
 
 
 
Pembrolizumab 
administration 
alone 
 
 
 
 
 
 
X 
 
 
X 
 
 
X 
X 
 
Adverse eventsu 
X 
X 
 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Evaluation of 
survivalv 
 
 
 
X 
 
X 
X 
 
X 
X 
 
X 
X 
X 
X 

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Abbreviations: ECG, electrocardiogram; ECOG, Eastern Cooperative Oncology Group; EOT, end of treatment; GM-CSF, granulocyte-macrophage colony-
stimulating factor (sargramostim); INR, international normalized ratio; IV, intravenous; MRI, magnetic resonance imaging; MRD, minimal residual disease; 
mnths, months; PT, prothrombin time; PTT, partial thromboplastin time. 
a. 
To assess progression-free survival, relapse must be documented, and the following procedures performed: concomitant medication, AEs, ECOG 
performance status, blood samples (hematology, serum chemistry, immune/exploratory correlates), and evaluation of clinical endpoints. For AML 
patients that have relapsed, the relapse visit will also include BM aspiration. For non-progressors: At the time of progression/relapse documentation, an 
additional ‘relapse visit’ will be performed; refer to Section 6.1.5.  
b. 
At the baseline visit (Day −3), all pretreatment screening procedures and assessments must be completed, review of inclusion/exclusion criteria 
(including specific tumor histologic type verification, [e.g., TNBC]), and review of laboratory and tissue pathology results confirmed prior to enrollment 
and the first GM-CSF injection. 
c. 
Patients who complete the study treatment period or patients who discontinue early (if they have received at least 1 treatment injection) will enter an 
off-treatment follow-up period to assess progression-free survival and overall survival. A follow-up phone call for serious adverse events will occur 90 
days after the last dose of pembrolizumab OR 30 days following cessation of study treatment if the patient begins a new anticancer therapy, whichever 
is earlier.  If the patient begins a new anticancer therapy, this must be reported by the investigator. If a patient is confirmed to have 
recurrent/refractory/relapsed disease after completion of a relapse visit, the patient is to return to the site within 30 days after their last treatment 
injection to complete EOT/early termination visit procedures.  
d. 
Retrieval of archival specimens (paraffin block sections) of tumor tissue (for solid tumors) or bone marrow (for AML) for WT1 IHC testing. Biopsy of 
current tumor tissue (for solid tumors) or bone marrow (for AML) for WT1 IHC. For CRC only: additionally, collection of current tissue sample for 
microsatellite stability analysis. 
e. 
Demographics will include sex, age, race and ethnicity. 
f. 
Abnormal physical examination findings identified at the screening visit will be followed until resolution or stabilization. Any ongoing findings (after 
study enrollment) should be recorded as pretreatment adverse events (AEs) and will be graded by Common Terminology Criteria for Adverse Events 
(CTCAE), Version 5.0. 

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g. 
Vital will include body temperature, systolic and diastolic blood pressure, heart rate, and respiratory rate. 
h. 
The hematology assessment will include a complete blood count (CBC) with differential and platelet count. These samples will be collected for 
processing by the central laboratory. Samples must be collected before study treatment administration. For abnormal complete blood count results, a 
manual differential is required. Specifically for AML patients, if the differential is suggestive of abnormal or immature cells and a possible relapse, a 
bone marrow biopsy must be performed as part of a scheduled relapse visit. See the laboratory manual for more information. 
i. 
The serum chemistry assessments will include sodium, potassium, chloride, carbon dioxide, blood urea nitrogen, creatinine, calcium, total protein, 
albumin, glucose, total bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase. These samples 
will be collected for processing by the central laboratory. Samples must by collected before study treatment administration. Calculated Creatinine 
Clearance (CrCl) must be assessed during the screening period to determine eligibility. See the laboratory manual for more information.  
j. 
Urine dipstick testing will be performed locally at the site. 
k. 
Patients will provide any historical documentation of HLA type at the pretreatment screening visit. The majority of patients will not have such 
information available and must undergo HLA typing assessment at participating sites.  
l. 
For AML patients ONLY:  provide historical documentation of cytogenetic and molecular analyses results (from initial diagnosis) at the pretreatment 
screening visit. Only patients with abnormal karyotype at initial diagnosis will require to repeat karyotype plus/minus fluorescence in situ hybridization 
(FISH) at pretreatment screening in this study. Full molecular analysis (i.e., FLT3-ITD and NPM1 mutations, etc.) will also be performed on bone 
marrow biopsy samples collected during pretreatment screening in all AML patients. 
m. 
For AML patients ONLY: a bone marrow aspiration and biopsy is required during pretreatment screening to confirm morphologic partial response (PR) 
or stable disease (SD) status, for MRD analysis, and for cytogenetic and molecular analyses as defined in footnote k. Additional bone marrow biopsies 
are required as shown per schedule, as well as at the end-of-treatment/early termination visit to evaluate progression and MRD. If a peripheral blood 
differential result (including manual differentiation) at any study visit is suggestive of abnormal or immature cells and a possible relapse, a bone marrow 
biopsy must be performed as part of a scheduled AML relapse visit. If the bone marrow biopsy confirms relapse, the patient will be discontinued from 
the study and will need to return to the site 0 to 30 days after their last treatment injection for end-of-treatment/early termination procedures. The bone 
marrow aspiration performed as part of the scheduled relapse visit will serve as bone marrow aspiration procedure required at the end-of-treatment/early 

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termination visit. A bone marrow biopsy must be collected if an adequate aspiration is not attainable. Refer to the laboratory manual for collection and 
processing these samples.  
n. 
For AML patients ONLY: Analysis of MRD will be performed on samples of peripheral blood and will be evaluated by molecular analysis of 
transcripts. Peripheral blood samples will be collected from patients according to the schedule shown. Samples must be collected before study treatment 
administration. Refer to the laboratory manual for collection and processing of samples.  
o. 
Peripheral blood samples for immunologic response (IR) assessment will be collected from a large subset of patients enrolled in each of the 5 arms of 
the study at select sites as per the schedule shown. The study is aiming to analyze IR profile in at least 50% of the enrolled patients. Samples must be 
collected before study treatment administrations. Refer to the laboratory manual for collection and processing these samples. 
p. 
Biopsies of malignant tissue deposit (or bone marrow, for AML patients) will be performed according to the schedule shown in a subset of patients at 
select sites. These tissue specimens will be used to study the presence and kinetics of host immunocytes infiltrating the above tissues, as well as the 
expression of key markers of immune biological significance in the tumor microenvironment. All biopsies are in principle mandatory, as long as the 
tumor deposits are technically accessible and such biopsies can be conducted safely. 
q. 
For solid tumors only: CT or MRI staging assessment (both per RECIST and iRECIST). 
r. 
Prior to contacting IWRS to enroll a patient into the study and obtaining a patient number, the following must be reviewed and verified: 
inclusion/exclusion criteria (including specific tumor histologic type verification, [e.g., TNBC]), laboratory and tissue pathology. 
s. 
GM-CSF will be administered 2 days before and on the day of each galinpepimut-S administration. A GM-CSF dose of 70 µg will be injected 
subcutaneously at the same anatomical site as the planned subsequent galinpepimut-S injection (to be given during the same cycle of therapy). Before 
injection, study staff should assess the immunization site. On Day −1, patients will remain in the clinic for approximately 30 minutes following receipt 
of GM-CSF to monitor for any adverse reactions. Blood samples will be collected before study treatment administration. 
t. 
Immediately after the patient receives the GM-CSF injection, patients are to receive galinpepimut-S injected SC in the same anatomical location as the 
GM-CSF injection. The injection site should be on the arm, leg, or torso of the patient, and should be positioned at least 5 cm away from the previous 
site of study treatment injection.  
u. 
Adverse event reporting begins from the time of signing the ICF to 30 days after the last injection of any study treatment (GPS/placebo or 
pembrolizumab). Adverse events collected before the first injection of GM-CSF will be reported as “pre-WT1 AEs”. All AEs will be graded by 

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CTCAE, Version 5.0. A follow-up phone call for serious adverse events will occur 90 days after the last dose of pembrolizumab or 30 days following 
cessation of study treatment if the patient begins new anticancer therapy, whichever is earlier. If the patient initiates new anticancer therapy, this must be 
reported by the investigator. 
v. 
Patients who complete the study, or who discontinue because of any reason other than recurrent/refractory/relapsed disease will return to the site 30 days 
after their last injection for final safety follow-up and completion of EOT/ET visit.  
w. 
Only to occur at Week 9. 
x. 
Only to occur at Week 36. 
y. 
Only to occur at Week 54. 
z. 
Only to occur at Weeks 72 and 84.  
aa. Only to occur at Weeks 27 and 36.  
bb. Only to occur at Weeks 45, 54, and 63. 
 

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6.1. Study Visits  
6.1.1. 
Screening Period and Enrollment 
Informed consent must be obtained before any study-related procedures are conducted. All 
study-specific screening procedures must be completed within 28 days (refer to Table 8 for 
screening procedures).  At the baseline visit (Day −3), all pretreatment screening 
procedures/assessments must be completed and laboratory results confirmed prior to 
enrollment and the first injection of GM-CSF.  
If a patient does not meet inclusion/exclusion criteria within 28 days of signing the ICF, the 
patient will be considered a screen failure and may be allowed to re-screen with a newly 
signed ICF up to 2 times. 
6.1.2. 
Open-Label Treatment Period  
Refer to Section 5 (Study Treatments) and Table 8 (Schedule of Assessments) for further 
details. 
6.1.3. 
End of Treatment/Early Termination Visit 
Patients who complete the protocol-specified study injections or scheduled study visit 
evaluations, or who discontinue because of any reason other than 
recurrent/refractory/relapsed disease will return to the site 30 days after their last injection for 
final safety follow-up and completion of the EOT/early termination procedures.  
6.1.4. 
Safety Follow-up Period  
Patients who complete the study treatment period or discontinue early (if they have received 
at least 1 treatment injection) will enter an off-treatment follow-up period to assess 
progression-free survival and overall survival. A follow-up telephone call for serious adverse 
events will occur 90 days after the last dose of pembrolizumab or 30 days following 
cessation of study treatment if the patient begins new anticancer therapy, whichever is 

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earlier. If the patient initiates new anticancer therapy, this must be reported by the 
investigator.  Patients will be followed in accordance with standard guidelines, which suggest 
regular assessments every 3 months until study closure, defined as up to 2 years and 6 weeks, 
i.e., 111 weeks, after the first galinpepimut-S administration given to the last patient enrolled 
into the study (which corresponds to up to 2 years after the first injection of pembrolizumab).  
6.1.5. 
Relapse Visit 
In addition to the SOA above, one additional series of assessments will be performed at the 
time of tumor (or leukemia) relapse. Indeed, to assess PFS, it is important to document 
disease relapse. At the time of the “relapse visit”, the following assessments will be 
performed: 
• Collect and update concomitant medication information 
• Collect and update AEs 
• Obtain ECOG performance score  
• Obtain vital signs and document weight  
• Collect blood samples for the central laboratory  
o Hematology (CBC with differential and platelet count) 
o Serum chemistry 
o Immune/exploratory correlates  
• Evaluate clinical endpoints 
For AML patients in specific, PB differentials from CBCs collected during every visit will be 
used to determine initially if the patient has relapsed, as defined by loss of CR status (if 
previously achieved) or further progression beyond initially achieved PR. For abnormal 
CBCs, a manual differential is required. If the differential is suggestive of abnormal or 

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immature cells and a possible relapse, a BM aspiration must be performed as part of a 
scheduled relapse visit to confirm the diagnosis of recurrent/relapse/refractory AML. A BM 
biopsy must be performed if an adequate aspiration is not attainable. In patients with AML 
who achieve CR status while on investigational therapy (galinpepimut-S plus pemrolizumab 
– administered on top of their continuing HMA regimen), relapse (post-CR) will be defined 
as a reappearance of leukemic blasts in the PB or >5% blasts in the BM not attributable to 
any other cause (e.g., BM regeneration after chemotherapy [Cheson et al, 2003]). If relapse is 
confirmed, the patient should be discontinued from the on-treatment portion of the study due 
to recurrent/refractory/relapsed AML and will need to return to the site 0 to 30 days after 
their last treatment injection for final safety follow-up and completion of the EOT/early 
termination visit procedures. The BM aspiration performed as part of the scheduled relapse 
visit will serve as BM aspiration procedure required at the EOT/early termination visit.  
Once EOT/early termination visit procedures have been completed, the physician can choose 
to treat the documented recurrent/refractory/relapsed disease with any subsequent therapy 
they choose. The patient will be moved to the off- treatment follow-up period and will be 
followed only for AEs and OS. 
6.1.6. 
Unscheduled Visits 
As appropriate, assessments at any unscheduled visit should follow the assessments at the 
closest weekly/monthly/quarterly visit. 
6.2. Efficacy Assessments 
Signal response for each a priori statistically defined clinical outcome (ORR per RECIST 
1.1) for all patients enrolled in the solid tumor arms of the study or other appropriate 
instruments scales, such as attainment of morphologic CR in patients enrolled in the AML 
arm. In addition to RECIST 1.1, all scans will be read according to iRECIST immune 
response consensus guideline (Seymour et al, 2017) to ensure that patients are not 
discontinued from therapy due to the phenomenon of tumor “pseudoprogression”, and 
clinical decisions will be based on iRECIST (Hodi et al, 2016). ORR per iRECIST will be an 
exploratory endpoint of this study. 

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6.3. Exploratory Assessments  
Assessment of tumor response in solid tumor patients by iRECIST, as well as estimation of 
the rate of achievement of MRD negativity in AML patients are exploratory endpoints in this 
study. 
All patients will be followed and assessed for PFS and OS, as per the schedule of 
assessments and using the ITT principle. 
As an exploratory evaluation, this study will assess the effect of the study treatment on 
readouts of immunologic tests in PB samples (see below), as well as presence and density of 
immune cell infiltrates within the tumor stroma (or BM in AML patients) using at least one 
post-therapy tumor biopsy (and comparing the findings with those at baseline, i.e., prior to 
initiation of treatment). 
In more detail: 
In peripheral blood: 
The following parameters will be tested: 
• Galinpepimut-S -relevant immune resonse-relevant: 
•  WT1 peptide--specific CD8 and CD4 cell frequencies: 
o Cell frequencies (absolute cell abundance/numbers/microliter of blood) of host 
CD8 and CD4 cells that react with increased production of intracellular 
interferon-g as detected by intracellular cytokine staining (ICS) after ex vivo re-
stimulation (Pinella-Ibarz et al, 2006; Gomez-Nunez et al, 2006; Maslak et al, 
2010) with the following peptides: 
• WT1A1 (heteroclitic) 
• WT1A (cognate native of the one above) 

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• 122A1 (heteroclitic) 
• 122A (cognate native of the one above) 
• 331 (native) 
• 427 (native) 
• Complete lymphocyte population panel (non-antigen-specific) 
Cell frequencies (absolute cell abundance/numbers/microliter of blood) - for each 
patient at each timepoint of collection, as follows: 
o Naïve T cells: CD45RA+CD45RO-CCR7+CD62L+CD57- 
o Central memory T cells: CD45RA-CD45RO+CCR7+CD62L+CD57- 
o Effector memory T cells: CD45RA-CD45RO+CCR7-CD62L-CD57+ 
o Total effector cells: CD45RA+CD45RO-CCR7-CD62L-CD57+   
o Tregs: FoxP3+, CD25+, PD1, ICOS 
o Myeloid-derived suppressor cells (MDSC’s):  
o PMN-MDSC’s: CD14-CD11b+CD15+(or CD66b+) and 
o M-MDSC’s: CD11b+CD14+HLA-DRlow/−CD15− 
§ Thus, the following antibody “gates” would have to be utilized in 
methodology selected (see Laboratory Manual): CD3, CD4, CD8, 
CD45RA or CD45RO, CD57, and CCR7 or CD62L or CD27, FoxP3, 
CD25, PD1, ICOS, CD14, CD11b, CD15; HLA-DR 
• In tumoral biopsy samples (TBx):  

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o Galinpepimut-S -relevant  
o The following parameters will be tested: 
• Intratumoral CD8 and CD4 (cells within tumor stroma versus surrounding the 
tumor proper) (Arlen and Arlen, 2013) 
• MDSC, T-regulatory cells (Treg), and tumor-associated macrophages (TAMs) 
      General (non-antigen-specific) immunodynamics 
o PDL1 expression and Interferon-g tissue inflammatory gene expression 
‘signature’ assessment  
Genetic (DNA) analyses  
o The application of new technologies, such as next generation sequencing, has 
provided scientists the opportunity to identify tumor-specific DNA changes 
(i.e., mutations, methylation status, microsatellite instability, etc.). Key 
molecular changes of interest to immune-oncology drug development include 
(for example) the mutational burden of tumors and the clonality of T cells in 
the tumor microenvironment.  Increased mutational burden (sometimes 
referred to as a “hyper-mutated” state) may generate neo-antigen presentation 
in the tumor microenvironment. To conduct this type of research, it is 
important to identify tumor-specific mutations that occur across all genes in 
the tumor genome. Thus, genome wide approaches will be used for this effort. 
Note that in order to understand tumor-specific mutations; it is necessary to 
compare the tumor genome with the germline genome. 
o Specifically for CRC patients: 
§ MSI will be evaluated in all CRC patients enrolled in this study, as this 
is an important biomarker for this type of cancer. 

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6.4. Safety Assessments 
Patients will be monitored for AEs and will undergo safety assessments including vital signs 
and weight, ECOG performance status, and clinical laboratory testing, which will include 
CBC with differential and platelet count, serum chemistry assessment, and urine dipstick test.  
6.4.1. 
Adverse Events 
The investigator is responsible for reporting all AEs that are observed or reported during the 
study, regardless of their relationship to study treatment or their clinical significance. If AEs 
occur, the first concern will be the safety of the study patients. 
Any abnormal laboratory test results (hematology, clinical chemistry, or urine dipstick) or 
other abnormal finding or safety assessments (e.g., vital sign measurements), including those 
that worsen from baseline, felt to be clinically significant in the medical and scientific 
judgment of the investigator will be graded by CTCAE v5.0 criteria and are to be recorded as 
AEs or SAEs. 
Adverse event monitoring will occur from the time of signing the ICF to 30 days after the 
last injection of study treatment. 
6.4.1.1. 
Definitions of Adverse Events 
An AE is defined as any untoward medical occurrence in a patient enrolled into this study 
and does not necessarily have to have a causal relationship (association) with this treatment. 
An AE can therefore be any unfavorable or untoward sign, symptom, disease, syndrome, 
intercurrent illness, or abnormal laboratory finding that emerges or worsens relative to the 
patient’s pretreatment baseline, whether or not it is considered to be related to the 
investigational product.  
A TEAE is defined as any event not present before exposure to study treatment or any event 
already present that worsens in either intensity or frequency after exposure to study 
treatment. 

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An SAE is any AE at any dose that:  
• Results in death  
• Is life-threatening  
• Requires inpatient hospitalization or prolongation of existing hospitalization 
• Results in persistent or significant disability/incapacity 
• Is a congenital anomaly/birth defect 
• Constitutes an important medical event (i.e., the AE did not meet any of the above 
serious criteria but based on appropriate medical judgment, may have jeopardized the 
patient or required medical or surgical intervention to prevent one of the serious 
outcomes listed in these criteria)  
6.4.1.2. 
Eliciting and Documenting Adverse Events 
Adverse events will be assessed from the time the patient signs the ICF until 30 days after the 
last study treatment injection. Adverse events collected before injection of study treatment 
will be reported as pretreatment AEs and those collected after the first injection of GM-CSF 
and throughout the study will be reported as TEAEs. Serious AEs that occur more than 
30 days after the last dose of study treatment need not be reported unless the investigator 
considers them related to study treatment. Any medical condition that is present at the time 
that the patient is screened but does not deteriorate should not be reported as an AE. 
However, if it deteriorates at any time during the study, it should be recorded as an AE. 
At every study visit, patients will be asked a standard nonleading question to elicit any 
medically related changes in their well-being. They will be asked if they have been 
hospitalized, had any accidents, used any new medications, or changed concomitant 
medication regimens (both prescription and over-the-counter medications) or therapies. 
Patients will also be instructed to contact the investigator at any time after beginning study 
treatment if any signs or symptoms develop. 

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In addition to patient observations, AEs identified from any study data (e.g., laboratory 
values), or identified from review of other documents that are relevant to patient safety will 
be documented on the AE page in the eCRF. 
All AEs must be documented on the AE pages of the eCRF and in the patient’s medical 
record. The following attributes must be assigned: (1) description; (2) dates of onset and 
resolution; (3) severity (per CTCAE v5.0); (4) assessment of relatedness to the study 
medication (unrelated, possible, probable, definite); (5) “serious” criteria if applicable (see 
Section 6.4.1.3 on how to report SAEs); (6) action taken; and (7) outcome 
(recovered/resolved, not recovered/resolved, recovered/resolved with sequelae, ongoing, or 
death). The investigator will actively solicit this information and assess the AEs in terms of 
severity and relationship to study treatment. The investigator will treat the patient as 
medically required until the AE either resolves or becomes medically stable. Treatment for 
AEs may extend beyond the duration of the study. The investigator will record treatment and 
medications required for treatment on the appropriate eCRF(s). In the event that a patient is 
withdrawn from the study because of an AE or SAE, it must be recorded on the Termination 
eCRF as the reason for discontinuation. The Medical Dictionary for Regulatory Activities 
(MedDRA) will be used to code all AEs. 
6.4.1.3. 
Reporting Adverse Events 
AE, SAEs, and other reportable safety events will be reported by the patient (or, when 
appropriate, by a caregiver, surrogate, or the patient's legally authorized representative).  
The investigator, who is a qualified physician, and any designees are responsible for 
detecting, assessing, documenting, and reporting events that meet the definition of an AE or 
SAE as well as other reportable safety events. Investigators remain responsible for following 
up AE, SAEs, and other reportable safety events for outcome. 
Any AE that meets SAE criteria (Section 6.4.1.1) must be reported to SELLAS (via its CRO, 
i.e., Cancer Insight, LLC, San Antonio, TX, USA) immediately (i.e., within 24 hours) after 
the time site personnel first learn about the event. The following contact information is to be 
used for SAE reporting:  

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E-mail: safety@prevailinfoworks.com  
Fax Number: +1-888-400-5240 
Phone Number: +1-888-846-7268 
In addition, the investigator must record the SAE in the appropriate AE section of the eCRF 
within 24 hours of learning of the event. The eCRF should be completed as much as possible, 
but should not be held until all information is available if obtaining that information will take 
longer than 24 hours. Additional information and/or corrections should be submitted as they 
are obtained and reported in the eCRF as soon as possible.All deaths, whether considered 
study related or not, must be reported immediately to SELLAS and its designee with a copy 
of the autopsy report and the death certificate provided, if available. All initial suspected 
unexpected serious adverse reaction (SUSAR) events that are life-threatening or result in 
death will also be reported to the site’s IRB/IEC of record within 7 calendar days and follow 
up within 15 calendar days. All other SUSAR’s experienced will be reported to the IRB/IEC 
within 15 calendar days. If the SUSAR results in death or is life threatening, a SUSAR report 
will be submitted initially to the regulatory authority within 7 calendar days and follow up 
within 15 calendar days. All other SUSAR’s must be reported to the regulatory authority 
within 15 days. It is the responsibility of the contract research organization (CRO, i.e., 
Cancer Insight, LLC) to report all SUSARs to the appropriate ethics committees, 
investigators, and sponsor. It is the responsibility of SELLAS to report all SUSARs to the 
appropriate regulatory authority (FDA) in accordance with the Code of Federal Regulations. 
 
The site may contact the medical monitor with any questions at any time. Refer to the cover 
page for medical monitor contact information. Reports of all (expected or unexpected) SAEs 
must be reported to the CRO (Cancer Insight, LLC) via email – clinical@cancerinsight.com 
and to Prevail Pharmacovigilance - safety@prevailinfoworks.com. In accordance with the 
FDA regulations and the International Council on Harmonisation (ICH) guidelines, 
investigators will be notified of the occurrence of new, serious, unexpected AEs associated 
with the use of the study medication (i.e., there is a reasonable possibility that the AE may 

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have been caused by the drug) via a written report. Expedited SAEs will be reported to all 
study investigators via a “Dear Doctor” letter sent by SELLAS, or its designee. It is the 
responsibility of the investigator to promptly inform the relevant IRB of record of these new 
AEs/risks to patients, in accordance with 21 Code of Federal Regulations (CFR) 312.66.  
6.4.1.4. 
Assessment of Severity 
The severity, or intensity, of an AE refers to the extent to which an AE affects the patient’s 
daily activities. The investigator must make a clinical determination of the intensity and 
severity of each AE by using the NCI CTCAE v5.0. Adverse events that do not have a 
corresponding CTCAE term will be assessed according to the general guidelines for grading 
used in the CTCAE v5.0. The CTCAE displays grades 1 through 5 with unique clinical 
descriptions of severity for each AE based on the following guideline:  
Grade 1: Mild: asymptomatic or mild symptoms; clinical or diagnostic observations only; 
intervention not indicated 
Grade 2: Moderate: minimal, local, or noninvasive intervention indicated; limiting 
age-appropriate instrumental activities of daily living. 
Grade 3: Severe or medically significant but not immediately life threatening: 
hospitalization or prolongation of hospitalization indicated; disabling; limiting self-care 
activities of daily living.  
Grade 4: Life threatening or debilitating: consequences; urgent intervention indicated 
Grade 5: Death 
Changes in the severity of an AE should be documented to allow an assessment of the 
duration of the event at each level of intensity to be performed. Adverse events characterized 
as intermittent do not require documentation of onset and duration of each episode. 

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6.4.1.5. 
Assessment of Causality 
As part of the AE documentation process, investigators are required to assess whether there 
is a reasonable possibility that study medications caused or contributed to an AE. This is not 
a factor in determining what is or is not reported in the study. If there is any doubt as to 
whether a clinical observation is an AE, the event should be reported. The following general 
guidance for assessment of causality may be used: 
Unrelated: 
This relationship suggests that there is no association between the study drug 
and the reported event.  
Possible: 
This relationship suggests that treatment with the study drug caused or 
contributed to the AE, i.e., the event follows a reasonable temporal sequence 
from the time of drug administration or follows a known response pattern to the 
study drug, but could also have been produced by other factors.  
Probable: 
This relationship suggests that a reasonable temporal sequence of the event 
with drug administration exists and, based upon the known pharmacological 
action of the drug, known or previously reported adverse reactions to the drug 
or class of drugs, or judgment based on the investigator’s clinical experience, 
the association of the event with the study drug seems likely. The event 
disappears or decreases on cessation or reduction of the dose of study drug.  
Definite: 
This relationship suggests that a definite causal relationship exists between drug 
administration and the AE, and other conditions (concurrent illness, 
progression/expression of disease state, or concurrent medication reaction) do 
not appear to explain the event. The event reappears or worsens if the study 
drug is re-administered. 
Causality will be assessed for GM-CSF and study treatments separately when the AE or SAE 
is clearly related to the administration of GM-CSF. 

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6.4.1.6. 
Exceptions 
Progression of the cancer under study is not considered an adverse event. 
The following events will not be reported as AEs or SAEs: 
• Relapse or recurrence of baseline tumor type 
• Hospitalization for a procedure for protocol-related investigations  
• Hospitalization for an elective treatment or procedure for a pre-existing condition 
unrelated to the study 
• Hospitalization or prolongation of hospitalization for social or practical reasons 
Relapse or recurrence of a patient’s cancer will be documented on forms provided to the site 
and filed in the patient’s chart. The patient will be discontinued from the on-treatment 
portion of the study, and moved to the off-treatment follow-up period. Any therapy initiated 
for the treatment of the relapse will be documented. 
6.4.1.7. 
Follow-Up of Patients Reporting Adverse Events 
All AEs must be reported in detail on the appropriate page in the eCRF and followed to 
satisfactory resolution, until the investigator deems the event to be chronic or not clinically 
significant, or until the patient is considered to be stable.  
For SAEs, the investigator will follow the patient until the SAE resolves, returns to baseline 
condition or stabilization, or is determined to be permanent, whichever occurs first. Serious 
AEs that are ongoing at the time of clinical database closure will be recorded as ongoing on 
the eCRF page. A follow-up phone call for SAEs will occur 90 days after the last dose of 
pembrolizumab or 30 days following cessation of study treatment if the patient begins new 
anticancer therapy, whichever is earlier. If the patient initiates new anticancer therapy, this 
must be reported by the investigator. 

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6.4.1.8. 
Events of Clinical Interest 
Selected non-serious and SAEs are also known as Events of Clinical Interest (ECI) and must 
be reported to the sponsor. 
For the time period beginning when the consent form is signed until treatment allocation, any 
ECI, or follow up to an ECI, that occurs to any patient must be reported within 24 hours to 
the sponsor if it causes the patient to be excluded from the trial, or is the result of a protocol-
specified intervention, including but not limited to washout or discontinuation of usual 
therapy, diet, placebo treatment or a procedure. 
For the time period beginning at treatment allocation through 30 days following cessation of 
treatment, any ECI, or follow up to an ECI, whether or not related to the sponsor’s product, 
must be reported within 24 hours to the sponsor, either by electronic media or paper.  
Electronic reporting procedures can be found in the electronic data capturing (EDC) data 
entry guidelines.  Paper reporting procedures can be found in the Investigator Trial File 
Binder (or equivalent). 
Events of clinical interest for this trial include: 
1. An overdose of pembrolizumab, as defined in Section  5.3.8. - Definition of an 
Overdose for this Protocol, which is not associated with clinical symptoms or 
abnormal laboratory results. 
N.B.: No overdose is defined for galinpepimut-S. 
2. An elevated AST or ALT laboratory value that is greater than or equal to 3´ the upper 
limit of normal (ULN) and an elevated total bilirubin laboratory value that is greater 
than or equal to 2´ ULN and, at the same time, an alkaline phosphatase laboratory 
value that is less than 2´ ULN, as determined by way of protocol-specified laboratory 
testing or unscheduled laboratory testing.* 

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*Note: These criteria are based upon available regulatory guidance documents. The purpose 
of the criteria is to specify a threshold of abnormal hepatic tests that may require an 
additional evaluation for an underlying etiology. The trial site guidance for assessment and 
follow up of these criteria can be found in the Investigator Trial File Binder (or equivalent). 
6.5. Safety Monitoring Committee 
Not applicable.  
6.6. Pregnancy in Partners of Male Patients 
Sexually active male patients are required to use a medically acceptable form of birth control 
while receiving study treatment and for a period of 4 months following the last study 
treatment injection. It is unknown whether galinpepimut-S affects the sperm or could be 
transmitted to the patient’s partner during sexual activity. The effect of galinpepimut-S on the 
fetus is unknown. If a male patient’s partner becomes pregnant, the pregnant partner will be 
requested to sign a pregnant partner consent form. The pregnancy will be followed-up to 
determine the outcome (including complications, spontaneous miscarriage, elective 
termination, normal birth, or congenital abnormality) and status of mother and child. The 
occurrence of pregnancy and the outcome of any pregnancy in a partner of a patient treated 
with galinpepimut-S must be reported to SELLAS (via its CRO, Cancer Insight, LLC) and to 
the pertinent IRB. 
Any partner pregnancy that is brought to the site investigator’s attention after the patient has 
completed the study with a timeframe of pregnancy that coincides with the study treatment 
period or within 4 months following the last study treatment injection or that has an outcome 
(such as a miscarriage) considered by the site investigator as possibly related to the study 
treatment must be promptly reported to SELLAS. 
6.7. Laboratory Analyses 
Laboratory analyses are provided in Table 9 and detailed below. 

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Blood samples will be drawn for coagulation (INR, PT, PTT), hematology (CBC with 
differential and platelet count), serum chemistry (sodium, potassium, chloride, carbon 
dioxide, blood urea nitrogen, creatinine, calcium, total protein, albumin, glucose, total 
bilirubin, alkaline phosphatase, AST, ALT, and lactate dehydrogenase), and thyroid function 
(TSH [thyroid stimulating hormone], FT4 [free thyroxine], and T3 [triiodothyronine] or FT3 
[free triiodothyronine]) and will be sent to the central laboratory for processing.  
The urine dipstick test will be performed locally at the site.  
For abnormal CBC results, a manual differential is required. Specifically for AML, if the 
differential is suggestive of abnormal or immature cells and a possible relapse, a BM biopsy 
must be performed as part of a scheduled relapse visit. See the laboratory manual for more 
information. 
For serum chemistry, calculated creatinine clearance (CrCl) must be assessed during the 
screening period to determine eligibility. See the laboratory manual for more information. 
WT1 IHC will be performed locally and is widely available at all surgical pathology 
laboratories; to further ensure expertise and consistency, sites will be selected based on 
experience and will have a designated sub-investigator pathologist trained on the 
interpretation of WT1 staining. For more details on WT1 IHC, please refer to Section 4.1.1., 
subheading 4 (b). of this protocol. 
 

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Table 9 
Laboratory Analyses 
Category 
Parameters 
Hematology 
Hematocrit, hemoglobin, platelet count, RBC count, RBC distribution, width, and 
WBC count with differential (basophils, eosinophils, lymphocytes, monocytes, 
neutrophils), ANC  
Not reported to sites: MCH, MCHC, MCV, MPV 
Coagulation 
INR, PT, PTT 
Serum Chemistry 
 
     Electrolytes 
Sodium, potassium, chloride, calcium 
     Liver Function  
ALT, AST, alkaline phosphatase, total bilirubin, direct bilirubin 
     Renal Function 
BUN, creatinine 
     Serum pregnancy 
Serum β-hCG 
     Thyroid Function 
T3 or FT3, FT4, TSH 
     Other 
LDH, total protein, glucose  
Urinalysis 
Dipstick (performed locally at site) 
ALT = alanine aminotransferase, ANC = absolute neutrophil count, AST = aspartate aminotransferase, -hCG = beta-
human chorionic gonadotropin, BUN = blood urea nitrogen, FT3 = free triiodothyronine, FT4 = free thyroxine, INR= 
international normalized ration, LDH = lactate dehydrogenase, MCH = mean corpuscular hemoglobin, MCHC = mean 
corpuscular hemoglobin concentration, MCV = mean corpuscular volume, MPV = mean platelet volume, PT = prothrombin 
time. PTT = partial thromboplastin time, RBC = red blood cells, T3 = triiodothyronine, TSH = thyroid stimulating hormone, 
WBC = white blood cells 
6.8. Tumor Imaging and Assessment of Disease 
Tumor assessments will be performed by the investigators based on both modified RECIST 
1.1 and iRECIST. The former will be used for assessment of the primary endpoint or the trial 

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(in the solid tumor arms), which is ORR; the latter is an exploratory endpoint. Treatment 
decisions by the investigator will be based on iRECIST.  All scans for tumor assessments 
performed during the study should be archived in accordance with the standard local practice. 
The scans from this study will be accessible in the event it may be requested for them to be 
submitted central review. If it is decided that central review might be warranted, images 
acquired for tumor assessments will be sent to an imaging core laboratory for archiving and 
potential independent analysis. 
The process for image collection can be found in the Site Imaging Manual (SIM).  
Tumor imaging is strongly preferred to be acquired by CT. For the abdomen and pelvis, 
contrast-enhanced MRI may be used when CT with iodinated contrast is contraindicated, or 
when mandated by local practice. MRI is the strongly preferred modality for imaging the 
brain. The same imaging technique regarding modality, ideally the same scanner, and the use 
of contrast should be used in a patient throughout the study to optimize the reproducibility of 
the assessment of existing and new tumor burden and improve the accuracy of the assessment 
of response or progression based on imaging. Note: for the purposes of assessing tumor 
imaging, the term “investigator” refers to the local investigator at the site and/or the 
radiological reviewer located at the site or at an offsite facility.   
Imaging should include the chest, abdomen, and pelvis.  
For TNBC patients, bone scans are also required for patients with a history of bone 
metastases and/or for those patients with new bone pain.  
6.8.1. 
Initial Tumor Imaging 
Initial tumor imaging at screening must be performed within 28 days prior to the date of the 
first dose of trial treatment or date of allocation. The site study team must review screening 
images to confirm the patient has measurable disease per RECIST 1.1.  

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6.8.2. 
Tumor Imaging During the Study 
For solid tumors only, the first on-study imaging assessment should be performed at Week 9 
Day 1 ± 7 days) from the date of enrollment. Subsequent tumor imaging should be performed 
at Weeks 18, 27, 36, 45, 54, 63, 72, and 84 (Day 1 ±7 days) or more frequently if clinically 
indicated. Imaging timing should follow calendar days and should not be adjusted for delays 
in cycle starts. Imaging should continue to be performed until disease progression is 
identified by the investigator.   
Objective response should be confirmed by a repeat imaging assessment. Tumor imaging to 
confirm PR or CR should be performed at least 4 weeks after the first indication of a 
response is observed. Patients will then return to regular scheduled imaging, starting with the 
next scheduled imaging time point. Patients who receive additional imaging for confirmation 
do not need to undergo the next scheduled tumor imaging if it is less than 4 weeks later; 
tumor imaging may resume at the subsequent scheduled imaging time point.  
Per iRECIST (Section 6.8.5), disease progression should be confirmed by the site 4 to 8 
weeks after. 
6.8.3. 
End of Treatment and Follow-up Tumor Imaging 
For patients who discontinue study treatment, tumor imaging should be performed at the time 
of treatment discontinuation (±4 week window). If previous imaging was obtained within 
4 weeks prior to the date of discontinuation, then imaging at treatment discontinuation is not 
mandatory. For patients who discontinue study treatment due to documented disease 
progression, this is the final required tumor imaging if the investigator elects not to 
implement iRECIST. 
For patients who discontinue study treatment without documented disease progression, every 
effort should be made to continue monitoring disease status by tumor imaging every 
3 months until the start of a new anticancer treatment, disease progression, pregnancy, death, 
withdrawal of consent, or the end of the study, whichever occurs first. 

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6.8.4. 
RECIST 1.1 Assessment of Disease 
RECIST 1.1 will be used as the primary measure for assessment of tumor response, date of 
disease progression, and as a basis for all protocol guidelines related to disease status. 
Although RECIST 1.1 references a maximum of 5 target lesions in total and 2 per organ, this 
protocol allows a maximum of 10 target lesions in total and 5 per organ, if clinically relevant 
to enable a broader sampling of tumor burden. 
6.8.5. 
iRECIST Assessment of Disease 
iRECIST is based on RECIST 1.1, but adapted to account for the unique tumor response seen 
with immunotherapeutic drugs. iRECIST will be used by the Investigator to assess tumor 
response and progression, and make treatment decisions. When clinically stable, patients 
should not be discontinued until progression is confirmed by the investigator, working with 
local radiology, according to the rules outlined in Appendix 12.6.
This allowance to continue treatment despite initial radiologic PD takes into account 
the observation that some patients can have a transient tumor flare in the first few months 
after the start of immunotherapy, and then experience subsequent disease response. This data 
will be captured in the clinical database. 
Clinical stability is defined as the following:  
• Absence of symptoms and signs indicating clinically significant progression of 
disease 
• No decline in ECOG performance status  
• No requirements for intensified management, including increased analgesia, 
radiation, or other palliative care 
Any patient deemed clinically unstable should be discontinued from study treatment at site-
assessed first radiologic evidence of PD, and is not required to have repeat tumor imaging for 
confirmation of PD by iRECIST. 

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If the Investigator decides to continue treatment, the patient may continue to receive study 
treatment and the tumor assessment should be repeated 4 to 8 weeks later to confirm PD by 
iRECIST, per Investigator assessment. Images should be archived for potential retrospective 
Blinded Independent Central Review (BICR).  
If repeat imaging does not confirm PD per iRECIST, as assessed by the Investigator, and the 
patient continues to be clinically stable, study treatment may continue and follow the regular 
imaging schedule.  If PD is confirmed, patients will be discontinued from study treatment. 
If a patient has confirmed radiographic progression (iRECIST confirmed progressive disease 
[iCPD]) as defined in Appendix . study treatment should be discontinued; however, 
if the patient is achieving a clinically meaningful benefit, an exception to continue study 
treatment may be considered following consultation with the sponsor. In this case, if study 
treatment is continued, tumor imaging should continue to be performed following the 
intervals as outlined in Appendix 
A description of the adaptations and iRECIST process is provided in Appendix , 
with additional details in the iRECIST publication >6eymour et al, 2017]. A summary of imaging 
and treatment requirements after first radiologic evidence of progression is provided in Table 
10 and illustrated as a flowchart in Figure . 

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Table 10 
Imaging and Treatment after First Radiological Evidence of Progressive Disease 
 
Clinically Stable 
Clinically Unstable 
Imaging 
Treatment 
Imaging 
Treatment 
First radiologic evidence of PD 
by RECIST 1.1  
Repeat imaging at 4 to 
8 weeks to confirm PD. 
May continue study treatment at the 
Investigator’s 
discretion 
while 
awaiting 
confirmatory 
tumor 
imaging by site by iRECIST. 
Repeat imaging at 4 to 
8 weeks to confirm PD per 
Investigator’s 
discretion 
only. 
Discontinue treatment 
Repeat 
tumor 
imaging 
confirms 
PD 
(iCPD) 
by 
iRECIST 
per 
Investigator 
assessment 
No 
additional 
imaging 
required. 
Discontinue treatment (exception is 
possible upon consultation with 
Sponsor). 
No 
additional 
imaging 
required. 
Not applicable 
Repeat tumor imaging shows 
iUPD 
by 
iRECIST 
per 
Investigator assessment 
Repeat imaging at 4 to 
8 weeks to confirm PD.  May 
occur 
at 
next 
regularly 
scheduled imaging visit. 
Continue study treatment at the 
Investigator’s discretion. 
Repeat imaging at 4 to 
8 weeks to confirm PD per 
Investigator’s 
discretion 
only. 
Discontinue treatment 
Repeat tumor imaging shows 
iSD, iPR, or iCR by iRECIST 
per Investigator assessment. 
Continue regularly scheduled 
imaging assessments. 
Continue study treatment at the 
Investigator’s discretion. 
Continue regularly scheduled 
imaging assessments. 
May 
restart 
study 
treatment 
if 
condition 
has 
improved 
and/or 
clinically stable per Investigator’s 
discretion.  Next tumor imaging should 
occur according to the regular imaging 
schedule. 

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Clinically Stable 
Clinically Unstable 
Imaging 
Treatment 
Imaging 
Treatment 
iCPD = iRECIST confirmed progressive disease; iCR = iRECIST complete response; iRECIST = modified Response Evaluation Criteria in Solid Tumors 1.1 for immune-based 
therapeutics; iSD = iRECIST stable disease; iUPD = iRECIST unconfirmed progressive disease; PD = progressive disease; RECIST 1.1 = Response Evaluation Criteria in Solid 
Tumors 1.1.   

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Figure 14 
Imaging and Treatment for Clinically Stable Patients Treated with 
Pembrolizumab after First Radiologic Evidence of PD Assessed by 
Investigator 
 
 

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7. 
Statistical and Analytical Plan 
7.1. Primary Efficacy Endpoints 
The primary efficacy endpoints are the safety and tolerability of the combination and ORR 
within each tumor-specific cohort. 
7.2. Secondary Efficacy Endpoints 
The secondary efficacy endpoints are TTR, time to next treatment and DOR. 
7.3. Exploratory Endpoints 
The exploratory endpoints are WT1-specific immune response dynamics in PB, select 
general immunodynamics assessments (in PB and tissue samples, as applicable), genomic 
testing (including MSS/MSI assessment for CRC) in tissue samples, as well as OS, and PFS. 
7.4. Sample Size Calculations 
Approximately 90 patients will be enrolled in the study. The planned number of patients 
within each tumor-specific cohort is as follows: CRC (N = 20), OvC (N = 20), SCLC 
(N = 20), TNBC (N = 15), and AML (N = 15). This study uses a Bayesian monitoring 
approach to guide decision-making using data on the primary efficacy endpoint (ORR) 
within each tumor-specific cohort. If the data provide high confidence that the true ORR (or 
rate of CR, incl. CRi/CRp, in AML patients) exceeds a minimal clinically meaningful level, 
then the results would support continued development (a “Go” decision) for that cohort. If 
the data suggest that the true ORR is unlikely to meet the desired level of clinical activity, 
then the results would support a decision to halt further continuation of accrual (a “Stop” 
decision) for that cohort. Definitions of the decision boundaries can be found in Section 
7.6.6. Results that do not meet either the Stop or Go criteria are said to be in the consider 
zone, where determination of the next course of action will be guided by additional 
information such as secondary endpoints or external data on similar compounds. This 

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approach is based on the decision-making framework described in Lalonde et al, 2007 and 
Frewer et al, 2016. 
The minimal clinically meaningful level is defined by the “lower reference value” (LRV), 
and the desired level of clinical activity is defined by the “target value” (TV). The LRV and 
TV for each tumor type are determined by medical opinion, evidence from the literature, or 
data from other compounds developing in the same area. These values are as follows: CRC 
LRV=10%, TV=20%; OvC LRV=10%, TV=20%; SCLC LRV=30%, TV=40%; TNBC 
LRV=15%, TV=25%; AML LRV=15%, TV=25%. 
Enrollment in a cohort may be stopped for futility prior to reaching the planned sample size if 
there is a high predicted probability of a Stop decision at the planned sample size. Enrollment 
in a cohort may be increased by approximately 10 additional patients beyond the planned 
sample size if the sponsor determines that further data on the primary or secondary endpoints 
is needed to clarify the efficacy signals for a Go/No-Go decision.  
Performance of the study design is evaluated on the basis of the probability of entering each 
decision zone for given true ORR values at the planned sample size within each cohort. 
Based on the performance characteristics summarized in Table 11 through Table 13, the 
sample sizes are adequate to address the study’s objectives. 
Table 11 
Statistical Design Performance for CRC or OvC Cohorts of 
20 Patients 
 
Probability of Making Each Decision for a 
Given True ORR 
True ORR 
Go (%) 
Consider (%) 
Stop (%) 
20% (TV) 
59 
34 
7 
15% 
35 
47 
18 
10% (LRV) 
13 
48 
39 
CRC = colorectal cancer; ORR = overall response rate; OvC = ovarian cancer; LRV = lower reference 
value; TV = target value 

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Table 12 
Statistical Design Performance for SCLC Cohort of 20 Patients 
 
Probability of Making Each Decision for a 
Given True ORR 
True ORR 
Go (%) 
Consider (%) 
Stop (%) 
40% (TV) 
58 
29 
13 
35% 
40 
36 
25 
30% (LRV) 
23 
36 
42 
ORR = overall response rate; LRV = lower reference value; SCLC = small cell lung cancer; TV = 
target value 
Table 13 
Statistical Design Performance for TNBC and AML Cohorts of 15 
Patients 
 
Probability of Making Each Decision for a 
Given True ORR 
True ORR 
Go (%) 
Consider (%) 
Stop (%) 
25% (TV) 
54 
38 
8 
20% 
35 
48 
17 
15% (LRV) 
18 
50 
32 
AML = acute myeloid leukemia; ORR = overall response rate; LRV = lower reference value; TNBC = 
triple negative breast cancer; TV = target value 
Calculations and simulations to determine decision boundaries and performance 
characteristics were performed using version 3.3.3 of the R software package (R Core Team). 
7.5. Analysis Sets 
• The full analysis set (FAS) comprises all patients who are assigned to receive study 
treatment as per the ITT principle, regardless of whether or not they subsequently go 
on to receive study treatment or whether they deviate from the protocol in any major 
way. 

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• The modified intent-to-treat (mITT) set comprises all patients who are assigned to 
receive study treatment and have at least 1 post-baseline efficacy assessment 
(RECIST 1.1), even if they deviate from the protocol in any major way. The mITT 
will also include any patient that goes off study treatment because of clinical 
progression prior to the first scheduled per-protocol scan. 
• The safety analysis set comprises all patients who receive any amount of study drug. 
• The per-protocol set (PPS) comprises all patients who are assigned to receive study 
treatment, receive at least 1 injection of study treatment, have at least 1 post-baseline 
efficacy assessment (RECIST 1.1), and do not deviate from the protocol in any major 
way. 
All efficacy analyses will be based on the FAS and will be conducted on the mITT set and 
PPS populations for exploratory purposes. For CRC patients, only those with MSS and 
MSI-L will be included in the efficacy primary analysis. The safety analyses will be based on 
the safety analysis set and will group patients according to treatment actually received. 
Secondary and exploratory efficacy analyses will be performed on the ITT/FAS as well as on 
the mITT and PPS populations for exploratory purposes. 
Major protocol deviations will be defined in more detail in the study statistical analysis plan 
(SAP), and may include, but not be limited to, incorrect diagnosis and poor compliance. 
All analyses using the PPS will group patients according to treatment actually received. 
7.5.1. 
Prior Therapies 
All prior therapies used in the treatment of any of the tumor types under study will be 
collected from patients, including drug name, start and stop dates and treatment response. 
Data will be summarized in tables and presented in the listings. Descriptive statistics will be 
used to assess the impact of prior treatments on the efficacy endpoints. 

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7.6. Statistical Analysis Methodology 
Data will be summarized and/or analyzed by cohort. Safety and demographic data will be 
summarized using standard tabulations and listings. Continuous variables will be 
summarized using descriptive statistics such as mean, standard deviation, median, minimum 
value, and maximum value. Continuous variables may be summarized by a clinically relevant 
discretization, as appropriate. Categorical variables will be summarized using frequency 
counts and percentages. Time-to-event data will be summarized using the Kaplan-Meier 
method. Where appropriate, 95% confidence intervals around point estimates will be 
presented, and estimates of the median and other quantiles, as well as individual time points 
(e.g., 3-month, 6-month, and 12-month rates), will be produced. Data will be provided in data 
listings. 
Details of the statistical analyses, methods, and data conventions are described in the SAP. 
7.6.1. 
Analysis of Primary Efficacy Endpoint 
For each tumor-specific cohort, a Bayesian approach with non-informative Jeffreys prior beta 
distribution with parameters a = 0.5 and b = 0.5 will be used to estimate the ORR and its 95% 
credible interval based on the posterior distribution. 
At the time of analysis, within each tumor-specific cohort, the prior distribution will be 
updated with all available data to obtain the posterior distribution of the true ORR. The 
posterior probabilities that ORR exceeds TV and LRV will be reported for each cohort. A 
high posterior probability that ORR > LRV will support a “Go” decision to continue 
development in the cohort, and a low posterior probability that ORR > TV will support a 
“Stop” decision to halt development in the cohort. A “Consider” decision results if neither a 
Stop nor a Go decision can be made. The specific criteria for making a Stop, Consider, or Go 
decision within each tumor-specific cohort are derived using the following acceptable risks: 
• 10% false stop risk: maximum acceptable probability that ORR > TV given that a 
Stop decision is made. 

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• 20% false go risk: maximum acceptable probability that ORR ≤ LRV given that a Go 
decision is made 
Before reaching the planned sample size in a cohort, the posterior probabilities will be 
updated continuously after each patient or group of patients and will be used to determine, 
within each cohort, the predictive probability of eventually reaching a Stop decision at the 
planned sample size. If this predictive probability is ≥ 80%, then enrollment in that cohort 
may be stopped early for futility. Definitions of the decision boundaries can be found in 
Section 7.6.6. 
In general, Stop/Go and futility decision criteria are non-binding and may be regarded as 
guidance and information to be integrated with a full medical review of safety and efficacy 
data observed at the time of analysis in determining the next course of action. 
No tests of statistical significance are planned. 
Patients with missing ORR will be conservatively classified as non-responders for the 
primary analysis. 
7.6.2. 
Analysis of Secondary Efficacy Endpoints 
Secondary endpoints will be summarized by cohort using descriptive statistics. No formal 
tests of hypotheses are planned. Duration of response (DOR) and TTR will be evaluated 
using Kaplan-Meier estimates and curves will be generated based on these estimates.  
7.6.3. 
Analyses of Exploratory Endpoint 
Analysis of exploratory endpoints will be defined in the study SAP. 
7.6.4. 
Safety Analyses 
All safety analyses will be based on the safety analysis set. Specifically for safety, t-zero for 
all time measurements assumes the date of first GM-CSF administration (day -2 of the entire 
protocol schedule). 

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7.6.4.1. 
Adverse Events 
Missing information regarding AEs will be imputed in a conservative manner. For example, 
a missing relatedness will be assumed to be certainly related; a missing severity will be 
assumed to be severe and so on. 
All AEs will be coded using the latest version of MedDRA.  
The severity of AEs will be coded using CTCAE v5.0.  
All TEAEs will be summarized and presented in the listings by the number of patients 
reporting an event, the percentage of patients with that event, and the grade, duration, and 
relationship to treatment. Percentages will be based on the number of patients who received 
each treatment during the study. The incidence of SAEs, including death, and AEs leading to 
study treatment discontinuation will also be tabulated. 
7.6.4.2. 
Laboratory Test Results 
For all laboratory tests with continuous results, absolute value and change from baseline will 
be summarized by visit and treatment group. For laboratory tests with categorical results, 
shift from baseline will be summarized by visit and treatment group. 
Shift tables for laboratory test results by severity will be produced and, for a subset of tests to 
be specified in the study SAP, separate shift tables indicating hyper- and hypodirectionality 
of change will be produced.  
Shift tables for urine dipstick test results by grade may also be produced as appropriate. 
Clinically significant laboratory test results will be flagged and listed. Reference ranges will 
be provided. 

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7.6.4.3. 
12-Lead Electrocardiogram Results 
Twelve-lead electrocardiogram (ECG) measurements will be recorded at the pretreatment 
screening visit. Each ECG will be classified as “abnormal” or “normal” and the relevance of 
the abnormality will be recorded as “clinically significant” or “not clinically significant.” 
7.6.4.4. 
Physical Examination 
Physical examinations will be performed at the pretreatment screening visit. Abnormal 
findings identified will be followed until resolution or stabilization. All ongoing findings will 
be recorded as pretreatment AEs and will be graded by CTCAE v5.0. 
7.6.4.5. 
Vital Signs 
Vital signs (body temperature [centigrade or Fahrenheit], systolic and diastolic blood 
pressure [BP], heart rate, and respiratory rate) and weight at each visit, plus height and 
weight at pretreatment screening for calculation of body mass index will be summarized over 
time in terms of absolute values and changes from baseline by visit and treatment group. For 
each parameter, a shift table comparing the baseline value to the maximum on-treatment 
value by treatment group will be presented. 
7.6.4.6. 
Eastern Cooperative Group Performance Status 
The ECOG performance status will be measured at each visit. The definition of each ECOG 
grade is presented in Appendix 12.3 (Oken et al, 1982). The ECOG data will be summarized 
by treatment group and visit. 
7.6.5. 
Interim Analyses 
Not applicable. 

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7.6.6. 
Go/No-Go and Futility Monitoring Guidelines 
This study uses a Bayesian monitoring approach to guide decision-making using data on the 
primary efficacy endpoint (ORR) within each cohort. The specific criteria for making a Stop, 
Consider, or Go decision within each tumor-specific cohort at the planned sample size are 
derived using the following acceptable risks: 
• 10% false stop risk: maximum acceptable probability that ORR > TV given that a 
Stop decision is made. 
• 20% false go risk: maximum acceptable probability that ORR ≤ LRV given that a Go 
decision is made 
The Stop or Go decision criteria in each cohort are presented in Table 14.  
Table 14 
Decision Criteria for a Stop or Go Decision in Each Cohort at the 
Planned Sample Size 
 
Planned 
Sample Size 
Target 
Value 
(TV) 
Lower 
Reference 
Value 
(LRV) 
Minimum 
Number of 
Responses 
for a Go 
Decision 
Maximum 
Number of 
Responses 
for a Stop 
Decision 
CRC 
20 
20% 
10% 
4 
1 
OvC 
20 
20% 
10% 
4 
1 
SCLC 
20 
40% 
30% 
8 
5 
TNBC 
15 
25% 
15% 
4 
1 
AML 
15 
25% 
15% 
4 
1 
AML = acute myeloid leukemia; CRC = colorectal cancer; ORR = overall response rate; OvC = ovarian cancer; LRV = 
lower reference value; SCLC = small cell lung cancer; TV = target value 
 

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Before reaching the planned sample size in a cohort, the posterior probabilities will be 
updated continuously after each patient or group of patients and will be used to determine, 
within each cohort, the predictive probability of a Stop decision at the planned sample size. If 
this predictive probability is ≥ 80%, then enrollment in that cohort may be stopped early for 
futility. The criteria for early futility stopping within each cohort are as follows: 
CRC or OvC (N = number of patients currently enrolled in the cohort): 
• If N < 8, there is insufficient data on ORR for a futility recommendation; 
• If N ≥ 8, futility stopping considered if no responses observed; 
• If N ≥ 18, futility stopping considered if ≤1 response observed. 
SCLC (N = number of patients currently enrolled in the cohort): 
• If N < 3, there is insufficient data on ORR for a futility recommendation; 
• If N ≥ 3, futility stopping considered if no responses observed; 
• If N ≥ 7, futility stopping considered if ≤1 response observed; 
• If N ≥ 11, futility stopping considered if ≤2 responses observed; 
• If N ≥ 14, futility stopping considered if ≤3 responses observed  
• If N ≥ 17, futility stopping considered if ≤4 responses observed 
TNBC or AML: 
• If N < 6, there is insufficient data on ORR for a futility recommendation; 
• If N ≥ 6, futility stopping considered if no responses observed; 
• If N ≥ 13: futility stopping considered if ≤1 response observed. 
After reaching the planned sample size in a cohort, enrollment may be increased by 
approximately 10 additional patients in that cohort if the sponsor determines that further data 
on the primary or secondary endpoints is needed to clarify the efficacy signals for a Go/No-
Go decision. In case additional patients are enrolled in a cohort, the decision boundaries for 
the expanded cohorts will be calculated using the same levels of acceptable risks used to 

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derive the initial boundaries, and futility monitoring will continue as before using ≥ 80% 
predictive probability of a Stop decision as a threshold to recommend early futility stopping. 
In general, Stop/Go and futility decision criteria are non-binding and may be regarded as 
guidance and information to be integrated with a full medical review of safety and efficacy 
data observed at the time of analysis in determining the next course of action.  
7.7. Data Quality Assurance 
Data entered on the eCRFs must be verifiable against the existing medical records at the 
investigational site. Data captured on the eCRFs will be reviewed by a SELLAS clinical 
monitor or designee against the existing medical records at the investigational site for 
validity and completeness according to procedures outlined in the monitoring plan. After 
completion of monitoring of the eCRFs, the eCRFs will be reviewed by SELLAS or its 
designee for data management and analysis purposes. If necessary, the investigational site 
will be periodically contacted for corrections and/or clarifications of the data. 
7.7.1. 
Data Management 
As part of the responsibilities assumed by participating in the study, the investigator agrees to 
maintain adequate case histories for the patients participating in this study. Data will be 
collected for all patients signing consent. The investigator agrees to maintain accurate source 
documentation as part of the case histories. Source documents may include a patient’s 
medical records, hospital charts, clinic charts, the investigator’s patient study files, and 
patient-reported assessments, as well as the results of diagnostic tests such as laboratory tests 
and ECGs.  
Investigative site personnel will enter patient data into eCRFs. The eCRFs are used to record 
study data and are an integral part of the study and subsequent reports. All data entered into 
the eCRF must be substantiated by a source document. Accurate completion of the eCRFs for 
all patients is the responsibility of the investigator. The analysis data sets will be a 
combination of these data and data from other sources (e.g., laboratory data).  

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SELLAS Life Sciences Group (SELLAS) or its designee will designate the EDC system to 
be used. The eCRFs must be kept current to reflect patient status at each phase during the 
course of the study. Patients are not to be identified on eCRFs by name; appropriate coded 
identification and patient initials must be used. The investigator must keep a separate log of 
patient names and addresses. This log is subject to regulatory authority inspection. Because 
of the potential for errors and inaccuracies in recording data onto eCRFs, originals of 
laboratory and other test results must be kept on file with the patient's clinical chart. These 
test results must be available at all times for inspection by the regulatory authority, the 
sponsor, and the sponsor representatives such as CRO monitors.  
An eCRF must be completed for each patient enrolled in the study, including those removed 
from the study for any reason. The reason for removal must be noted by the investigator for 
each patient.  
SELLAS Life Sciences Group or its designee will review all eCRFs for completeness. The 
investigator will be contacted for corrections and/or clarifications. Intensive efforts will be 
made to minimize missing data. Those patients with missing data regarding OS will be 
censored at that time. Missing data on secondary endpoints will be addressed using 
imputation methods that reduce the risk for bias. 
Clinical data management will be performed in accordance with applicable SELLAS policies 
and data cleaning procedures to ensure the integrity of the data, (e.g., removing errors and 
inconsistencies in the data). Adverse events and concomitant medication terms will be coded 
using the latest version of MedDRA, an internal validated medication dictionary. 
After database lock, each study site will receive a CD-ROM containing all of their 
site-specific eCRF data as entered into the electronic data capture system for the study, 
including full discrepancy and audit history. Additionally, a CD-ROM copy of all of the 
study site’s data from the study will be created and sent to the sponsor for storage. The CRO 
will maintain a duplicate CD-ROM copy for their records. In all cases, patient initials will 
not be collected or transmitted to the sponsor. 

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8. 
Ethics 
8.1. Independent Ethics Committee or Institutional Review Board 
Federal regulations (United States 21 CFR Part 56.103) and the ICH guidelines require that 
approval be obtained from an IRB before participation of human patients in research studies. 
Before study onset, the protocol, informed consent, advertisements to be used for the 
recruitment of study patients, and any other written information regarding this study to be 
provided to the patient or the patient’s legal guardian must be approved by the IRB/IEC. 
Documentation of all IRB approvals and of the IRB compliance with ICH harmonised 
tripartite guideline E6(R2): Good Clinical Practice (GCP) will be maintained by the site and 
will be available for review by the sponsor or its designee. Copies of all IRB correspondence 
with the investigator should be provided to SELLAS. 
All IRB/IEC approvals should be signed by the IRB chairperson or designee and must 
identify the IRB name and address, the clinical protocol by title or protocol number or both, 
and the date approval or a favorable opinion was granted. SELLAS Life Sciences Group is to 
be notified immediately if the responsible IRB has been disqualified or if proceedings 
leading to disqualification have begun. 
The investigator is responsible for providing written summaries of the progress and status of 
the study at intervals not exceeding 1 year or otherwise specified by the IRB. Adverse events 
must be reported to the IRB as required. The investigator must promptly supply the sponsor 
or its designee, the IRB, and, where applicable, the institution, with written reports on any 
changes significantly affecting the conduct of the study or increasing the risk to patients. The 
IRB will receive notification of the completion of the study and final report within 3 months 
of study completion or termination. 
8.2. Ethical Conduct of the Study 
The study will be performed in accordance with the ethical principles that have their origin in 
the Declaration of Helsinki, ICH GCP, relevant SELLAS policies and procedures, and all 
applicable regulations. 

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8.3. Patient Information and Consent 
In accordance with guidelines in the Federal Register, Volume 48, Number 17, 1982, 
pages 8951-8952, a written informed consent shall be obtained from each patient before 
entering the study or performing any study procedure. This Phase 2 study involves research 
that presents risk, but holds the possibility of direct benefit to the individual patient 
(46.405-45 CFR part 46).  
An informed consent form (ICF) template will be provided by SELLAS or its designee to 
investigative sites. If any institution-specific modifications to the informed consent are 
proposed or made by the site, the consent should be reviewed by the sponsor or its designee 
or both before IRB submission. Once reviewed, the consent will be submitted by the 
investigator to his or her IRB for review and approval before the start of the study. If the ICF 
is revised during the course of the study, all active participating patients must sign the revised 
form.  
Before recruitment and enrollment, each prospective patient or his or her legal guardian will 
be given a full explanation of the study and be allowed to read the approved ICF. Once the 
site investigator is assured that the patient/legal guardian understands the implications of 
participating in the study, the patient/legal guardian will be asked to give consent to 
participate in the study by signing the ICF. The site investigator shall retain the original 
signed consent form(s) with the study center’s records. Each patient/legal guardian will also 
be given a copy of his or her signed consent form(s). 

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9. 
Investigator’s Obligations 
The following administrative items are meant to guide the investigator in the conduct of the 
study but may be subject to change based on industry and government standard operating 
procedures, working practice documents, or guidelines. Changes will be reported to the IRB 
but will not necessarily result in protocol amendments. 
9.1. Confidentiality 
A report of the results of this study may be published or sent to the appropriate health 
authorities in any country in which the study treatment may ultimately be marketed, but the 
patient’s name will not be disclosed in these documents. Appropriate precautions will be 
taken to maintain confidentiality of medical records and personal information. All laboratory 
specimens, evaluation forms, reports, and other records will be identified in a manner 
designed to maintain patient confidentiality. All records will be kept in a secure storage area 
with limited access. Clinical information will not be released without the written permission 
of the patient (or the patient’s legal guardian), except as necessary for monitoring and 
auditing by the sponsor, its designee, the governing regulatory authority(ies), or the IRB. The 
patient’s name may be disclosed to the sponsor of the study, SELLAS, or the governing 
health authorities if they inspect the study records. 
Written authorization is to be obtained from each patient and/or the patient’s legally 
authorized representative in accordance with the applicable privacy requirements (i.e., the 
HIPAA Standards for Privacy of Individually Identifiable Health Information). 
In accordance with HIPAA requirements, additional purposes of this study include the 
following: 
• To publish anonymous patient data from the study; and  
• To create and maintain a data repository. 

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The investigator and all employees and coworkers involved with this study may not disclose 
or use for any purpose other than performance of the study any data, record, or other 
unpublished, confidential information disclosed to those individuals for the purpose of the 
study. Prior written agreement from the sponsor or its designee must be obtained for the 
disclosure of any said confidential information to other parties. 
9.2. Financial Disclosure and Obligations 
Investigators are required to provide financial disclosure information to allow the sponsor to 
submit the complete and accurate certification or disclosure statements required under 
21 CFR 54. In addition, the investigator must provide to the sponsor a commitment to 
promptly update this information if any relevant changes occur during the course of the 
investigation and for 1 year following the completion of the study. 
Neither the Sponsor (SELLAS) nor CRO (Cancer Insight, LLC)  is financially responsible 
for further testing or treatment of any medical condition that may be detected during the 
screening process. In addition, in the absence of specific arrangements, neither the Sponsor 
nor CRO is financially responsible for further treatment of the patient’s disease. 
9.3. Investigator Documentation 
Prior to beginning the study, the investigator will be asked to comply with ICH E6(R2) 8.2 
and Title 21 of the CFR by providing the following essential documents, including but not 
limited to: 
• IRB approval 
• Original investigator-signed investigator agreement page of the protocol 
• Form FDA 1572, fully executed, and all updates on a new fully executed Form FDA 
1572 
• Curriculum vitae for the investigator and each subinvestigator listed on Form 
FDA 1572 

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• Financial disclosure information to allow the sponsor to submit complete and 
accurate certification or disclosure statements required under 21 CFR 54. In addition, 
the investigators must provide to the sponsor a commitment to promptly update this 
information if any relevant changes occur during the course of the investigation and 
for 1 year after the completion of the study 
• IRB -approved informed consent, samples of site advertisements for recruitment for 
this study, and any other written information regarding this study that is to be 
provided to the patient or legal guardian 
9.4. Study Conduct 
The investigator agrees that the study will be conducted according to the principles of 
ICH E6(R2). The investigator will conduct all aspects of this study in accordance with all 
national, state, and local laws or regulations. Study information from this protocol will be 
posted on publicly available clinical trial registers before enrollment of patients begins. 
9.5. Adherence to Protocol 
The investigator agrees to conduct the study as outlined in this protocol in accordance with 
ICH E6(R2) and all applicable guidelines and regulations. 
9.6. Adverse Events and Study Report Requirements 
By participating in this study, the investigator agrees to submit reports of SAEs according to 
the timeline and method outlined in the protocol. In addition, the investigator agrees to 
submit annual reports to the study site IRB as appropriate. 
In accordance with the regulation 21 CFR 312.32, the sponsor shall within 60 days of the 
anniversary date that the investigational new drug application went into effect to submit a 
brief report of the progress of the investigation. 

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9.7. Investigator’s Final Report 
Upon completion of the study, the investigator, where applicable, should inform the 
institution; the investigator/institution should provide the IRB with a summary of the study’s 
outcome and the sponsor and regulatory authority(ies) with any reports required. 
9.8. Records Retention 
For countries falling within the scope of the ICH guidelines, the sponsor-specific essential 
documents should be retained until at least 2 years after the last approval of a marketing 
application in an ICH region and until there are no pending or contemplated marketing 
applications in an ICH region or at least 2 years have elapsed since the formal 
discontinuation of clinical development of the investigational product. 
The following documents will be maintained for 2 years beyond product FDA and European 
Union full approval of the combination of galinpepimut-S plus pembrolizumab (if such is 
granted in the future based on the results of this study or other studies) or until SELLAS 
notifies the site in writing with permission to either send the documents to another location or 
locally destroy these documents: 
• eCRFs - a copy of each patient’s full eCRF must be kept. 
• Patient files/signed informed consent - which substantiates the data entered on the 
eCRFs for all required test and evaluation procedures and verifies that the patient has 
signed an informed consent to enter the study. 
• Patient exclusion record - which should reflect the reason any patient was screened 
and found ineligible for the study. 
• Monitoring log - listing dates of monitor visits. 
• Regulatory documents - including protocol and all versions, investigator brochure and 
all versions, FDA Form 1572, curricula vitae, IRB correspondence, IRB 

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approval/renewals and IRB approved consent form, copy of all investigators and 
subinvestigator curricula vitae, financial disclosure forms each year filed with their 
IRB of record, current medical license during duration of the study, and other 
documents as requested by SELLAS or any regulatory agency. 
• AE eCRF - which should explain any serious or unexpected adverse experiences. 
This also includes all SAE reports, MedWatch forms, and/or Council for International 
Organizations of Medical Sciences forms. All correspondence with the site’s 
IRB/IEC of record, regulatory authority(ies), and SELLAS. 
These documents should be retained for a longer period, however, if required by the 
applicable regulatory requirement(s) or if needed by the Sponsor.  
SELLAS Life Sciences Group requires that it be notified in writing if the investigator wishes 
to relinquish ownership of the data so that mutually agreed-upon arrangements can be made 
for transfer of ownership to a suitably qualified, responsible person. 
9.9. Publications 
SELLAS Life Sciences Group, as the Sponsor, has proprietary interest in this study. Data are 
the property of the Sponsor and cannot be published without prior authorization from the 
sponsor. After completion of the study, the data may be considered for reporting at a 
scientific meeting and/or for publication in a scientific journal. Authorship and manuscript 
composition of any publication will reflect joint cooperation between multiple investigators 
and sites and SELLAS personnel. SELLAS will work with the investigators to determine 
how the manuscript is written and edited, the number and order of authors, the publication to 
which it will be submitted, and other related issues. Authorship will be established by site 
enrollment. The first author will be from the highest enrolling site. The last author will be 
from the site that contributes the most to the development of the protocol, data analysis, and 
drafting of the article for publication. The sponsor has final approval authority over all such 
issues. No individual publications will be allowed before completion of the final report of the 
multicenter study except as agreed by SELLAS, but data and publication thereof will not be 
unduly withheld. 

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10. Study Management and Monitoring10.1. External Data Monitoring 
Committee 
Not applicable. 
10.2. Monitoring of the Study 
All aspects of the study will be carefully monitored, by the Sponsor or its designee, for 
compliance with applicable government regulation with respect to current GCP and current 
standard operating procedures. The determination of the extent and nature of monitoring will 
be based on considerations such as the objective, purpose, design, complexity, blinding, size, 
and endpoints of the study. 
Prior to initiation of the study, SELLAS or its designee will visit the study site to review with 
the site personnel information about the study treatment, protocol, and other regulatory 
document requirements, source document requirements, eCRFs, monitoring requirements, 
and procedures for reporting AEs including SAEs. 
During the study, a monitor will visit the investigator and study site at periodic intervals, in 
addition to maintaining necessary telephone and letter contact. The monitor will assess the 
site for compliance with regulatory documentation and will focus on accurate and complete 
recording of data on eCRFs from source documents, adherence to protocol and GCP, SAE 
reporting, and drug accountability records. At all times, study-related correspondence, patient 
records, original signed consent forms, patient privacy documentation, records of the 
distribution and use of all investigational products, and electronic copies of eCRFs, if 
applicable, should be maintained on file. 
The investigator must agree to allow the monitor access to the clinical supplies, dispensing, 
and storage areas and to all relevant clinical files of the study patients. Key study personnel 
must be available to assist the monitor during the visits. In addition, the investigator should 
make every effort to be available for 30 to 60 minutes at the time of the clinical monitoring 
check-out meeting at the end of each day of the monitoring visit to discuss findings and 
needed assistance to complete the monitoring visit successfully.  

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10.2.1. Inspection of Records 
Investigators and institutions involved in the study will permit study-related monitoring, 
audits, IRB/IEC review, and regulatory inspections by providing direct access to all study 
records. In the event of an audit, the investigator agrees to allow the sponsor, representatives 
of the sponsor, or a regulatory agency (e.g., FDA or other regulatory agency) access to all 
study records. 
The investigator should promptly notify SELLAS and CRO of any audits scheduled by any 
regulatory authorities and promptly forward copies of any audit reports received to the 
sponsor. 
10.3. Management of Protocol Amendments and Deviations 
10.3.1. Modification of the Protocol 
Each site investigator must not implement any deviation from or changes to the protocol 
without approval by SELLAS and prior review and documented approval/favorable opinion 
from the IRB, except where necessary to eliminate immediate hazards to study patients or 
when the changes involve only logistical or administrative aspects of the study (e.g., change 
in monitors, change of telephone numbers). Amendments to the protocol must be submitted 
in writing to the investigator’s IRB for approval before patients can be enrolled into an 
amended protocol. The site investigator will report to the IRB and SELLAS and SELLAS 
will report to the regulatory authority any changes in the research protocol and all 
unanticipated problems involving risks to human patients and others, and no changes will be 
made in the research activity without IRB approval. SELLAS will report to the regulatory 
authority any changes in the research protocol. 
 

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10.3.2. Protocol Deviations 
A deviation from the protocol is an unintended or unanticipated departure from the 
procedures or processes approved by the sponsor and the IRB and agreed to by the 
investigator. A significant deviation occurs when there is nonadherence to the protocol by the 
patient or investigator that results in a significant, additional risk to the patient. Significant 
deviations can include nonadherence to inclusion or exclusion criteria, enrollment of the 
patient without prior sponsor approval, or nonadherence to regulatory authority regulations or 
ICH GCP guidelines and will lead to the patient being withdrawn from the study 
(Section 4.2). 
There should be no deviations or departures from the protocol. The investigator may 
implement a deviation from, or a change of, the protocol to eliminate an immediate hazard to 
study patients without prior IRB approval. If an emergency occurs that requires departure 
from this protocol, the investigator or other physician in attendance in such an emergency 
will, if circumstances and time permit, contact the medical monitor. Such contacts will be 
made to permit a decision as to whether or not the patient will be continued on the study. As 
soon as possible after such an occurrence, the implemented deviation or change, the reasons 
for it, and any proposed protocol amendments should be submitted to the IRB for review and 
approval, to the sponsor for agreement (if not already done), and to the regulatory authorities, 
if required. 
The site investigator or designee must clearly document and explain in the patient’s source 
documentation any deviation from the approved protocol. Protocol deviations will also be 
documented by the clinical monitor throughout the course of monitoring visits. Principal 
investigators will be notified in writing by the monitor of deviations. The sponsor and IRB 
should be notified of all protocol deviations in a timely manner. 
10.4. Study Termination 
Although SELLAS has every intention of completing the study, the sponsor reserves the right 
to close an investigational site or terminate the study at any time for clinical or administrative 

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reasons. In addition, the study may be stopped at a site at any time by the site investigator 
with appropriate notification. 
10.5. First Interpretable Results (FIR) Report 
A first interpretable results (FIR) report will be prepared. The exact data to be included  in 
the FIR and its structure will be determined by the study master co-Principal Investigators, 
the data management/analysis and biostatistical teams (designees of SELLAS), the medical 
monitor(s), and the Chief Medical Officer and Head of Clinical Development of SELLAS 
10.6. Final Complete Clinical Study Report (CSR) 
Whether the study is completed or prematurely terminated, the investigator, where 
applicable, should inform the institution. The investigator/institution should provide the IRB 
with a summary of the study’s outcome. 
SELLAS Life Sciences Group will ensure that both interim, as well as final complete clinical 
study reports are prepared (as applicable) and provided to the regulatory agency(ies) as 
required by the applicable regulatory requirement(s). The sponsor will also ensure that the 
clinical study reports in marketing applications meet the standards of the ICH harmonised 
tripartite guideline E3: Structure and content of clinical study reports. 
Where required by applicable regulatory requirements, an investigator signatory will be 
identified for the approval of the clinical study report. The investigator will be provided 
reasonable access to statistical tables, figures, and relevant reports and will have the 
opportunity to review the complete study results. 
Upon completion of the clinical study report, the sponsor will provide the investigator with 
the full summary of the study results. The investigator is encouraged to share the summary 
results with the study patients, as appropriate. The study results will be posted on publicly 
available clinical trial registers. 

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with nab-paclitaxel in patients with metasatic triple-negative breast cancer (mTNBC). J Clin 
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Al-Hussaini M, Stockman A, Foster H, et al. WT-1 assists in distinguishing ovarian from 
uterine serous carcinoma and in distinguishing between serous and endometrioid ovarian 
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Alonso-Dominguez JM, Tenorio M, Velasco D, et al. Correlation of WT1 expression with 
the burden of total and residual leukemic blasts in BM samples of acute myeloid leukemia 
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Andre T, Lonardi S, Wong KYM, et al. Combination of nivolumab (nivo) + ipilimumab (ipi) 
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Antonia SJ, López-Martin JA, Bendell J, et al: Nivolumab alone and nivolumab plus 
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Appelbaum FR, Gundacker H, Head DR, et al: Agne and acute myeloid leukemia. Blood 
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Arlen M, Arlen P. Optimizing the immune system to achieve control of the metastatic 
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Asemissen AM, Keilholz U, Tenzer S, et al. Identification of a highly immunogenic HLA-
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Aucouturier J, Dupius L, Deville S, et al. Adjuvants designed for veterinary and human 
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Babiak A, Steinhauser M, Götz M, et al. Frequent T cell responses against immunogenic 
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Barnhill DR, Hoskins WJ, Heller PB, et al., The second-look surgical reassessment for 
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12. Appendices 
 
12.1 Appendix 1. Azacitidine (Vidaza®) US Prescribing Information 
https://media.celgene.com/content/uploads/vidaza-pi.pdf (Celgene Corporation, Summit, NJ, 
USA, Sep, 2018) 
12.2. Appendix 2. Decitabine (Dacogen®) US Prescribing 
Information  
https://www.otsuka-us.com/media/static/dacogen-pi.pdf (Otsuka America Pharmaceutical, 
Inc., Rockville, MD, Dec. 2018) 
12.3. Appendix 3. WT1 IHC Assessment and Documentation Form 
 
 

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CLINICAL STUDY PROTOCOL SLS17-201/ MK3475-770 
A PHASE 1/2 STUDY OF GALINPEPIMUT-S IN COMBINATION WITH 
PEMBROLIZUMAB (MK-3475) IN PATIENTS WITH SELECTED ADVANCED 
CANCERS 
WT1 IHC Assessment and Documentation Form 
Assessment of Tumor Positivity for Expression of WT1 in Biopsy Material by WT1 
Immunohistochemistry (IHC) 
Per Section 4.1.1. (Subject Inclusion Criteria), subheading 4 (b). of of the protocol: 
Patients’ metastatic disease deposits (for patients with solid tumors)/bone marrow leukemic 
cell deposits (for patients with AML) will be evaluated for WT1 protein expression, as 
detectable by IHC analysis of banked (paraffin-embedded) or freshly biopsied tumor 
material. 
• IHC evidence of WT1 expression will be performed according to the technique 
described by Dupont et al. (Gynecol Oncol. 2004;94:449-55).  
• Expression will be graded according to an adaptation of the German Immunoreactive 
Score (IRS) (Remmele W & Stegner H-E. Dtsch Ärztbl. 1986;83:3362-4; Idem. 
Pathologe. 1987;8:138-40). 
• Only WT1 tumors with moderate to strong immunoreactive scores (4-12) will be 
considered positive. 
The German IRS Scale for WT1 assessment by IHC is shown below: 
Percentage of positive cells 
X    Intensity of Staining 
=   IRS (0 – 12)  
(multiplication product) 
0 = no positive cells 
0 = no color reaction 
0 – 1 = negative 
1 = < 10% of positive cells 
1 = mild reaction 
2 – 3 = mild 
2 = 10-50% positive cells 
2 = moderate reaction 
4 – 8 = moderate 
3 = 51-80% positive cells 
3 = intense reaction 
9 – 12 = strongly positive 
4 = > 80% positive cells 
  
  
 
IRS – points 
  
IRS – classification 

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0 – 1 
  
0 = negative 
2 – 3 
  
1 = positive, weak expression 
4 – 8 
  
2 = positive, moderate expression 
9 – 12 
  
3 = positive, strong expression 
 
The data on patient’s tumor/leukemic BM deposits WT1 expression levels will be collected 
using the Table below: 
Patient Initials              
Patient Study ID        
WT1 Immunoreactive 
Score (IRS) 
Date of Score 
Confirmation 
 
 
 
 
Source of Tested 
Slides: 
 
Institution                          Date of Accession             Accession Number            Section/Specimen Type 
 
 
 
 
 
 
_______________________________         
____________________________ 
Pathologist’s Name and Signature 
 
Date 
 

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12.4.  Appendix 4. Eastern Cooperative Group Performance Status 
ECOG Performance Status 
Developed by the Eastern Cooperative Oncology Group, Robert L. Comis, MD, Group 
Chair.* 
GRADE 
ECOG PERFORMANCE STATUS 
0 
Fully active, able to carry on all pre-disease performance without restriction 
1 
Restricted in physically strenuous activity but ambulatory and able to carry out work of a light 
or sedentary nature, e.g., light house work, office work 
2 
Ambulatory and capable of all self-care but unable to carry out any work activities; up and 
about more than 50% of waking hours 
3 
Capable of only limited self-care; confined to bed or chair more than 50% of waking hours 
4 
Completely disabled; cannot carry on any self-care; totally confined to bed or chair 
5 
Dead 
*Oken M, Creech R, Tormey D, et al. Toxicity and response criteria of the Eastern Cooperative Oncology 
Group. Am J Clin Oncol. 1982;5:649-655. 

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12.5.  Appendix 5. Revised Recommendations of The International 
Working Group for Diagnosis, Standardization of Response Criteria, 
Treatment Outcomes, and Reporting Standards for Therapeutic 
Trials in Acute Myeloid Leukemia 
 
 

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Response Criteria in AML 
Response 
Criterion 
Time of 
Assessment 
Neutrophils 
(µ/L) 
Platelets  
(µ/L) 
Bone Marrow 
Blasts (%) 
Other 
Early 
treatment 
assessment 
7-10 days after 
therapy 
NA 
NA 
< 5 
 
Morphologic 
leukemia-free 
state  
Varies by 
protocol 
NA 
NA 
< 5 
Flow 
cytometry 
EMD 
Morphologic 
CR 
Varies by 
protocol 
>1,000 
> 100,000 
< 5 
Transfusion 
EMD 
Cytogenetic 
CR 
Varies by 
protocol 
>1,000 
> 100,000 
< 5 
Cytogenics-
normal, EMD 
Molecular CR  
Varies by 
protocol 
>1,000 
> 100,000 
< 5 
Molecular-
negative, EMD 
Partial 
remission (PR) 
Varies by 
protocol 
> 1,000 
> 100,000 
> 50% 
decrease vs 
baseline or 
decrease to 
5-25% 
Blasts  < 5% if 
Auer rod 
positive (FAB 
M2 & M3 
subtypes only) 
Abbreviations: AML, acute myelogenous leukemia; EMD, extramedullary disease; CR, complete remission. 
From: Cheson BD, Bennett, JM, Kopecky, KJ, et al. Revised recommendations of the International 
Working Group for Diagnosis, Standardization of Response Criteria, Treatment Outcomes, and Reporting 
Standards for Therapeutic Trials in Acute Myeloid Leukemia. J Clin Oncol. 2003;21(24):4642-49.  

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12.6.  Appendix 6. Description of the iRECIST Process for Assessment of Disease 
Progression 
Assessment at Screening and Prior to RECIST 1.1 Progression 
Until radiographic disease progression based on RECIST 1.1, there is no distinct iRECIST 
assessment. 
Assessment and Decision at RECIST 1.1 Progression 
For patients who show evidence of radiological PD by RECIST 1.1 as determined by the 
Investigator, the Investigator will decide whether to continue a patient on study treatment 
until repeat imaging is obtained (using iRECIST for patient management (see Table 10 and 
Figure 14 in earlier sections of this document). This decision by the site investigator should 
be based on the patient’s overall clinical condition. 
Clinical stability is defined as the following:  
• Absence of symptoms and signs indicating clinically significant progression of 
disease 
• No decline in ECOG performance status  
• No requirements for intensified management, including increased analgesia, 
radiation, or other palliative care 
Any patient deemed clinically unstable should be discontinued from study treatment at site-
assessed first radiologic evidence of PD, and is not required to have repeat tumor imaging for 
confirmation of PD by iRECIST. 
If the Investigator decides to continue treatment, the patient may continue to receive study 
treatment and the tumor assessment should be repeated 4 to 8 weeks later to confirm PD by 

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iRECIST, per Investigator assessment. Images should continue to be archived for potential 
retrospective BICR. 
Tumor flare may manifest as any factor causing radiographic progression per RECIST 1.1, 
including: 
• Increase in the sum of diameters of target lesion(s) identified at baseline to ≥20% and 
≥5 mm from nadir 
o Note: the iRECIST publication uses the terminology “sum of measurements”, but 
“sum of diameters” will be used in this protocol, consistent with the original 
RECIST 1.1 terminology. 
• Unequivocal progression of non-target lesion(s) identified at baseline 
• Development of new lesion(s) 
iRECIST defines new response categories, including iUPD (unconfirmed progressive 
disease) and iCPD (confirmed progressive disease). For purposes of iRECIST assessment, 
the first visit showing progression according to RECIST 1.1 will be assigned a visit (overall) 
response of iUPD, regardless of which factors caused the progression. 
At this visit, target and non-target lesions identified at baseline by RECIST 1.1 will be 
assessed as usual. 
New lesions will be classified as measurable or non-measurable, using the same size 
thresholds and rules as for baseline lesion assessment in RECIST 1.1. From measurable new 
lesions, up to 5 lesions total (up to 2 per organ), may be selected as New Lesions – Target.  
The sum of diameters of these lesions will be calculated, and kept distinct from the sum of 
diameters for target lesions at baseline.  All other new lesions will be followed qualitatively 
as New Lesions – Non-target. 
Assessment at the Confirmatory Imaging 

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On the confirmatory imaging, the patient will be classified as progression confirmed (with an 
overall response of iCPD), or as showing persistent unconfirmed progression (with an overall 
response of iUPD), or as showing disease stability or response (iSD/iPR/iCR). 
Confirmation of Progression 
Progression is considered confirmed, and the overall response will be iCPD, if ANY of the 
following occurs: 
• Any of the factors that were the basis for the initial iUPD show worsening 
o For target lesions, worsening is a further increase in the sum of diameters of 
≥5 mm, compared to any prior iUPD time point 
o For non-target lesions, worsening is any significant growth in lesions overall, 
compared to a prior iUPD time point; this does not have to meet the 
“unequivocal” standard of RECIST 1.1 
o For new lesions, worsening is any of these: 
§ An increase in the new lesion sum of diameters by ≥5 mm from a prior iUPD 
time point  
§ Visible growth of new non-target lesions  
§ The appearance of additional new lesions 
• Any new factor appears that would have triggered PD by RECIST 1.1 
Persistent iUPD 
Progression is considered not confirmed, and the overall response remains iUPD, if: 
• None of the progression-confirming factors identified above occurs AND 

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• The target lesion sum of diameters (initial target lesions) remains above the initial PD 
threshold (by RECIST 1.1) 
Additional imaging for confirmation should be scheduled 4 to 8 weeks from the imaging on 
which iUPD is seen. This may correspond to the next visit in the original visit schedule.  The 
assessment of the subsequent confirmation imaging proceeds in an identical manner, with 
possible outcomes of iCPD, iUPD, and iSD/iPR/iCR. 
Resolution of iUPD 
Progression is considered not confirmed, and the overall response becomes iSD/iPR/iCR, if: 
• None of the progression-confirming factors identified above occurs, AND 
• The target lesion sum of diameters (initial target lesions) is not above the initial PD 
threshold.  
The response is classified as iSD or iPR (depending on the sum of diameters of the target 
lesions), or iCR if all lesions resolve. 
In this case, the initial iUPD is considered to be pseudo-progression, and the level of 
suspicion for progression is “reset”. This means that the next visit that shows radiographic 
progression, whenever it occurs, is again classified as iUPD by iRECIST, and the 
confirmation process is repeated before a response of iCPD can be assigned. 
Management Following the Confirmatory Imaging 
If repeat imaging does not confirm PD per iRECIST, as assessed by the Investigator, and the 
patient continues to be clinically stable, study treatment may continue and follow the regular 
imaging schedule. If PD is confirmed, patients will be discontinued from study treatment. 
NOTE: If a patient has confirmed radiographic progression (iCPD) as defined above, but the 
patient is achieving a clinically meaningful benefit, an exception to continue study treatment 
may be considered following consultation with the sponsor. In this case, if study treatment is 

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continued, tumor imaging should continue to be performed following the intervals as 
outlined below. 
Detection of Progression at Visits After Pseudo-progression Resolves 
After resolution of pseudo-progression (i.e., achievement of iSD/iPR/iCR), iUPD is indicated 
by any of the following events: 
• Target lesions 
o Sum of diameters reaches the PD threshold (≥20% and ≥5 mm increase from 
nadir) either for the first time, or after resolution of previous pseudo-progression. 
The nadir is always the smallest sum of diameters seen during the entire trial, 
either before or after an instance of pseudo-progression. 
• Non-target lesions 
o If non-target lesions have never shown unequivocal progression, their doing so for 
the first time results in iUPD. 
o If non-target lesions have shown previous unequivocal progression, and this 
progression has not resolved, iUPD results from any significant further growth of 
non-target lesions, taken as a whole. 
• New lesions 
o New lesions appear for the first time 
o Additional new lesions appear 
o Previously identified new target lesions show an increase of ≥ 5 mm in the new 
lesion sum of diameters, from the nadir value of that sum 
o Previously identified non-target lesions show any significant growth 

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If any of the events above occur, the overall response for that visit is iUPD, and the iUPD 
evaluation process (see Assessment at the Confirmatory Imaging above) is repeated. 
Progression must be confirmed before iCPD can occur. 
The decision process is identical to the iUPD confirmation process for the initial PD, with 
one exception:  if new lesions occurred at a prior instance of iUPD, and at the confirmatory 
imaging the burden of new lesions has increased from its smallest value (for new target 
lesions, the sum of diameters is ≥5 mm increased from its nadir), then iUPD cannot resolve 
to iSD or iPR. It will remain iUPD until either a decrease in the new lesion burden allows 
resolution to iSD or iPR, or until a confirmatory factor causes iCPD. 
Additional details about iRECIST are provided in the iRECIST publication (Seymour et al, 
2017).