A Phase 2 Trial Evaluating the Efficacy of Flotetuzumab (MGD006) for Relapsed Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS) Following Allogeneic Hematopoietic Cell Transplantation (Allo-HCT)
Phase: PHASE2
Conditions: Relapsed Acute Myeloid Leukemia
Sponsor: Washington University School of Medicine

 
 
A Phase 2 Trial Evaluating the Efficacy of Flotetuzumab for Relapsed Acute Myeloid 
Leukemia (AML) and Myelodysplastic Syndrome (MDS) Following Allogeneic 
Hematopoietic Cell Transplantation (allo-HCT) 
 
Washington University School of Medicine 
Division of Oncology 
660 South Euclid Avenue, Campus Box 8056 
St. Louis, MO  63110 
 
Protocol #: 202011122 
Version Date: 28 February 2024  
 
 
Principal Investigator: 
Matthew Christopher, M.D., Ph.D. 
Phone: (314) 273-0286 
E-mail: christopherm@wustl.edu 
 
Sub-Investigators 
 
 
 
Modality 
Zachary Crees, M.D.  
 
 
Bone Marrow Transplant 
 
John F. DiPersio, M.D., Ph.D. 
 
Bone Marrow Transplant 
 
 
Feng Gao, M.D., Ph.D. 
 
 
Biostatistics 
 
 
 
Study Drug(s): 
 
Flotetuzumab (MGD006) 
IND#: 
153399 
IND Sponsor: 
Matthew Christopher, M.D., Ph.D. 
NCT#: 
NCT04582864 
Funded by: 
MacroGenics, Inc. 
 
 
 
 
 
 
 
 
CONFIDENTIAL 
The information contained in this document is regarded as confidential and, except to the extent necessary to 
obtain informed consent, may not be disclosed to another party unless law or regulations require such 
disclosure.  Persons to whom the information is disclosed must be informed that the information is 
confidential and may not be further disclosed by them. 
 

Protocol Version: 02/28/2024  
 
Page 2 of 76 
 
A Phase 2 Trial Evaluating the Efficacy of Flotetuzumab for Relapsed Acute Myeloid 
Leukemia (AML) and Myelodysplastic Syndrome (MDS) Following Allogeneic 
Hematopoietic Cell Transplantation (allo-HCT) 
 
Protocol Revision History 
 
Initial Approval Version 
 
 
 
 
 
 
15 December 2020 
Amendment #1 Version 
 
 
 
 
 
 
23 April 2021 
Amendment #2 Version 
 
 
 
 
 
 
17 September 2021 
Amendment #3 Version 
 
 
 
 
 
 
19 October 2021 
Amendment #4 Version 
 
 
 
 
 
 
19 January 2022 
Amendment #5 Version 
 
 
 
 
 
 
27 July 2022 
Amendment #6 Version (QASMC only) 
 
 
 
 
31 January 2023 
Amendment #6 Version (PRMC only) 
 
 
 
 
24 February 2023 
Amendment #6 Version  
 
 
 
 
 
 
31 March 2023 
Amendment #7 Version 
 
 
 
 
 
 
04 May 2023 
Amendment #8 Version (QASMC only) 
 
 
 
 
21 February 2024 
Amendment #8 Version 
 
 
 
 
 
 
28 February 2024 
 
 
 

Protocol Version: 02/28/2024  
 
Page 3 of 76 
 
STATEMENT OF COMPLIANCE 
The trial will be carried out in accordance with International Conference on Harmonisation Good 
Clinical Practice (ICH GCP) and the following:  
 
• United States (US) Code of Federal Regulations (CFR) applicable to clinical studies (45 
CFR Part 46, 21 CFR Part 50, 21 CFR Part 56, 21 CFR Part 312, and/or 21 CFR Part 812)  
 
National Institutes of Health (NIH)-funded investigators and clinical trial site staff who are 
responsible for the conduct, management, or oversight of NIH-funded clinical trials have 
completed Human Subjects Protection and ICH GCP Training. 
 
The protocol, informed consent form(s), recruitment materials, and all participant materials will 
be submitted to the Institutional Review Board (IRB) for review and approval.  Approval of both 
the protocol and the consent form must be obtained before any participant is enrolled.  Any 
amendment to the protocol will require review and approval by the IRB before the changes are 
implemented to the study.  In addition, all changes to the consent form will be IRB-approved; a 
determination will be made regarding whether a new consent needs to be obtained from 
participants who provided consent, using a previously approved consent form. 
 
 
 
 
 
 
 
 

Protocol Version: 02/28/2024  
 
Page 4 of 76 
 
Glossary of Abbreviations  
 
AE 
Adverse event 
ALT (SGPT) 
Alanine transaminase (serum glutamate pyruvic transaminase) 
AML 
Acute myeloid leukemia 
ANC 
Absolute neutrophil count 
AST (SGOT) 
Aspartate transaminase (serum glutamic oxaloacetic transaminase) 
B-HCG 
Beta human chorionic gonadotropin  
BMT 
Bone marrow transplant 
CBC 
Complete blood count 
CFR 
Code of Federal Regulations 
CNS 
Central nervous system 
CR 
Complete response 
CRc 
Cytogenetic complete remission 
CRi 
Complete remission incomplete 
CRm 
Morphologic complete remission 
CRF 
Case report form 
CST 
Central standard time 
CT 
Computed tomography 
CTCAE 
Common Terminology Criteria for Adverse Events 
CTEP 
Cancer Therapy Evaluation Program 
DLT 
Dose limiting toxicity 
DNA 
deoxyribonucleic acid 
DSM 
Data and Safety Monitoring  
DSMC 
Data Safety Monitoring Committee 
ECG (or EKG) 
Electrocardiogram 
ECOG 
Eastern Cooperative Oncology Group 
EDTA 
ethylenediaminetetraacetic acid 
FDA 
Food and Drug Administration 
FISH 
fluorescent in situ hybridization 
FWA 
Federal wide assurance 
GCP 
Good Clinical Practice 
GVHD 
Graft vs. Host Disease 
HHS 
Department of Health and Human Services 
HIV 
Human Immunodeficiency Virus 
HRPO 
Human Research Protection Office (IRB) 
IND 
Investigational New Drug 
IRB 
Institutional Review Board 
MDS 
Myelodysplastic syndrome 
MM 
Multiple myeloma 
MRI 
Magnetic resonance imaging 
MTD 
Maximum tolerated dose 

Protocol Version: 02/28/2024  
 
Page 5 of 76 
 
NCCN 
National Cancer Center Network 
NCI 
National Cancer Institute 
NIH 
National Institutes of Health 
NSCLC 
Non-small cell lung cancer 
OHRP 
Office of Human Research Protections  
ORR 
Overall response rate 
OS 
Overall survival 
PBMC 
Peripheral blood mononuclear cell 
PD 
Progressive disease 
PI 
Principal investigator 
PR 
Partial response 
PSA 
Prostate-specific antigen 
QASMC 
Quality Assurance and Safety Monitoring Committee 
RECIST 
Response Evaluation Criteria in Solid Tumors (Committee) 
RFS 
Relapse free survival 
RR 
Response rate 
SAE 
Serious adverse event 
SCC 
Siteman Cancer Center 
SCT 
Stem cell transplant 
SD 
Stable disease 
TSH 
Thyroid stimulating hormone 
TTP 
Time to progression 
UPN 
Unique patient number 
US 
Ultrasound 
VEGF 
Vascular endothelial growth factor 
WBC 
White blood cell (count) 
 
 

Protocol Version: 02/28/2024  
 
Page 6 of 76 
 
Table of Contents 
PROTOCOL SUMMARY .......................................................................................................... 8 
SCHEMA ................................................................................................................................. 10 
SCHEDULE OF ACTIVITIES ................................................................................................. 11 
1.0 
INTRODUCTION .......................................................................................................... 13 
1.1 
Background ................................................................................................................. 13 
1.2 
Risk/Benefit Assessment ............................................................................................. 16 
1.3 
Overall Study Design and Plan .................................................................................... 18 
1.4 
Study Duration and Dates............................................................................................ 19 
1.5 
Definition of End of Trial ............................................................................................ 19 
2.0 
OBJECTIVES AND ENDPOINTS ................................................................................. 19 
3.0 
STUDY POPULATION ................................................................................................. 20 
3.1 
Inclusion Criteria ........................................................................................................ 20 
3.2 
Exclusion Criteria ....................................................................................................... 21 
3.3 
Inclusion of Women and Minorities ............................................................................ 22 
4.0 
REGISTRATION PROCEDURES ................................................................................. 23 
4.1 
Confirmation of Patient Eligibility .............................................................................. 23 
4.2 
Patient Registration in the Siteman Cancer Center OnCore Database........................... 23 
4.3 
Assignment of UPN .................................................................................................... 23 
4.4 
Screen Failures............................................................................................................ 23 
5.0 
STUDY TREATMENT PLAN ....................................................................................... 24 
5.1 
Premedication Administration ..................................................................................... 24 
5.2 
Study Intervention Description .................................................................................... 25 
5.3 
Response Assessments ................................................................................................ 28 
5.4 
Safety Assessments ..................................................................................................... 28 
5.5 
Definitions of Evaluability .......................................................................................... 28 
5.6 
Concomitant Therapy and Supportive Care Guidelines................................................ 29 
5.7 
Women of Childbearing Potential ............................................................................... 30 
5.8 
Duration of Therapy .................................................................................................... 31 
5.9 
Duration of Follow-up................................................................................................. 31 
5.10 Lost to Follow-Up ....................................................................................................... 31 
6.0 
DOSE DELAYS/DOSE MODIFICATIONS .................................................................. 32 
6.1 
Infusion-related Reactions including CRS ................................................................... 32 
6.2 
Premedications and Prophylaxis .................................................................................. 33 
6.3 
Management of Observed Flotetuzumab Infusion Reactions and Infusion-related 
Adverse Events ...................................................................................................................... 35 
6.4 
Graft versus Host Disease ........................................................................................... 38 
6.5 
Tumor Lysis Syndrome ................................................................................................ 41 
6.6 
Neutropenic Sepsis/Fungemia ..................................................................................... 41 
6.7 
Immune-related Adverse Experiences.......................................................................... 42 
6.8 
Neurotoxicity Monitoring............................................................................................ 42 
7.0 
CORRELATIVE STUDIES ........................................................................................... 42 
8.0 
PHARMACEUTICAL INFORMATION ....................................................................... 44 
8.1 
Flotetuzumab .............................................................................................................. 44 
9.0 
DATA SUBMISSION SCHEDULE ............................................................................... 47 
10.0 MEASUREMENT OF EFFECT ..................................................................................... 48 

Protocol Version: 02/28/2024  
 
Page 7 of 76 
 
11.0 STATISTICAL CONSIDERATIONS ............................................................................ 48 
11.1 Hypothesis .................................................................................................................. 48 
11.2 Primary Endpoint ........................................................................................................ 48 
11.3 Sample Size Estimate .................................................................................................. 49 
11.4 Stopping rules for futility ............................................................................................ 49 
11.5 Safety monitoring and determination of excess toxicity ............................................... 49 
11.6 Stopping rules for safety ............................................................................................. 50 
11.7 Statistical analyses ...................................................................................................... 51 
11.8 Patient Replacement ...................................................... Error! Bookmark not defined. 
12.0 DATA AND SAFETY MONITORING .......................................................................... 51 
13.0 REGULATORY AND REPORTING REQUIREMENTS .............................................. 52 
13.1 Reporting to the Human Research Protection Office (HRPO) at Washington University
 
53 
13.2 Reporting to the Quality Assurance and Safety Monitoring Committee (QASMC) at 
Washington University .......................................................................................................... 53 
13.3 Reporting to MacroGenics, Inc. ................................................................................... 53 
13.4 Reporting to the FDA .................................................................................................. 53 
14.0 REFERENCES ............................................................................................................... 55 
APPENDIX A: ECOG Performance Status Scale ...................................................................... 57 
APPENDIX B: Revised International Prognostic Scoring System (IPSS-R) .............................. 59 
APPENDIX C: Definitions for Adverse Event Reporting .......................................................... 60 
APPENDIX D: Reporting Timelines ......................................................................................... 62 
APPENDIX E: Neurotoxicity Grading and Management ........................................................... 65 
APPENDIX F: Acute GVHD Grading/Assessment ................................................................... 67 
APPENDIX G: Chronic GVHD Assessment (NIH Severity Score) ........................................... 69 
APPENDIX H:  Institutional Criteria for Donor Screening ........................................................ 72 
Donor Guidelines................................................................................................................... 72 
APPENDIX I: Study-Specific DSM Tables ............................................................................... 73 
 
 
List of Tables 
Table 1: Flotetuzumab Ramp & Continuous Infusion Pre-medications ...................................... 24 
Table 2: Response Criteria ........................................................................................................ 26 
Table 3: Flotetuzumab Ramp, Induction, and Consolidation Dosing .......................................... 27 
Table 4: Premedication Guidelines ............................................................................................ 34 
Table 5: Revised CRS Grading System ..................................................................................... 35 
Table 6: Guidelines for Managing Infusion Reactions and Cytokine Release Syndrome ............ 36 
Table 7: Dose Delays and Modifications for aGVHD ................................................................ 39 
Table 8: Dose Delays and Modifications for cGVHD ................................................................ 40 
 
 
 
 
 

Protocol Version: 02/28/2024  
 
Page 8 of 76 
 
PROTOCOL SUMMARY 
 
Title: 
A Phase 2 Trial Evaluating the Efficacy of flotetuzumab for 
Relapsed Acute Myeloid Leukemia (AML) and Myelodysplastic 
Syndrome (MDS) Following Allogeneic Hematopoietic Cell 
Transplantation (allo-HCT) 
Study Description: 
We hypothesize that flotetuzumab for relapsed AML and MDS 
following allo-HCT will be safe, tolerable and may facilitate 
preferential immune effector cell retargeting of leukemic cells 
resulting 
in 
improved 
patient 
outcomes. 
 
Furthermore, 
administration of a donor lymphocyte infusion (DLI) (if available) 
in combination with flotetuzumab will be safe, tolerable and may 
provide additional therapeutic efficacy.  
Objectives: 
Primary Objectives:  
• To evaluate the efficacy of flotetuzumab in post-allo-HCT 
relapsed AML and MDS following Cycle 1 of flotetuzumab 
(Cycle 1 Day 28 assessment). 
 
Secondary Objectives: 
• To evaluate the efficacy of flotetuzumab monotherapy in 
post-allo-HCT relapsed AML and MDS following Cycle 2  
• To evaluate the safety and tolerability of flotetuzumab +/- 
DLI in the post-allo-HCT setting.  
Endpoints: 
Primary Endpoint(s):  
Efficacy assessed via composite endpoint of CR and CRi (Cycle 1 
Day 28 assessment) 
 
Secondary Endpoints:  
o Efficacy assessed at Cycle 2 Day 28 (or at Cycle 1 Day 28 if 
patient receives only one cycle): 
• Composite endpoint of CR and CRi at Cycle 2 Day 28 
• Overall Response (OR) Rate (defined as PR or greater) 
• Morphologic leukemia-free state (MLFS) Rate 
• Partial Response (PR) Rate 
• Stable Disease (SD) Rate 
• Progression Free Survival (PFS) 
• Overall Survival (OS) 
o Safety and Tolerability as assessed by: 
• AE Grading per CTCAE v5.0 
• CRS & Neurotoxicity Grading per ASTCT Consensus 
Guidelines 
• Acute GvHD Grading per MAGIC criteria 
• Chronic GvHD Grading per NIH severity score 

Protocol Version: 02/28/2024  
 
Page 9 of 76 
 
Study Population: 
The study will enroll adult patients who have been diagnosed with 
acute myeloid leukemia (AML) or myelodysplastic syndrome 
(MDS) and have relapsed after allogeneic HCT. 
Phase: 
Phase 2 
Description 
of 
Sites/ 
Facilities Enrolling: 
This is a single institution open label study being conducted at 
Washington University in St. Louis. 
Description 
of 
Study 
Intervention: 
Phase 2, single-center, single-arm, open-label trial design evaluating 
the efficacy of flotetuzumab for the indication of relapsed AML and 
MDS after allo-HCT  
Study Duration: 
• Time from study opening to accrual completion – 18 months 
• Time from accrual completion to primary data analysis – 3 months 
• Total time from study opening to primary data analysis – 21 
months 
• Time from accrual completion to final data analysis (survival 
analysis) – 24 months 
• Total time from study opening to final data analysis – 42 months 
Participant Duration: 
Patients will receive the investigational treatment for the first 28 days 
of the study (Cycle 1). Based on Day 28 response assessment, 
patients with CR/CRi will continue investigational treatment for 
another 28 days (Cycle 2); patients with SD or PR may also continue 
investigational treatment for another 28 days (Cycle 2) with 
permission by the investigator.  All patients may receive a donor 
lymphocyte infusion (DLI) concurrent with flotetuzumab in either 
cycle, at the discretion of the treating physician and investigator; 
patients with PD at the end of Cycle 1 will come off study.  All 
patients will be followed for 2 years after receiving investigational 
treatment. 
 
 
 
 
 
 
 
 
 
 
 

Protocol Version: 02/28/2024  
 
Page 10 of 76 
 
SCHEMA 
 
 
 
 
 
 
 

Protocol Version: 02/28/2024  
 
Page 11 of 76 
 
SCHEDULE OF ACTIVITIES 
 
Screening
12 
Pre-
Meds 
Day0 
C1D1 
C1D7 
C1D14 
C1D21 
C1D28 
C2D1 
C2D7 
C2D14 
C2D21 
C2D28 
Follow-
up/End of 
Treatment13 
Medical History 
X 
Physical Exam 
X 
X 
X------------------------------daily while inpatient-------------------------X 
X 
Vital Signs (temp, RR, Spo2, 
HR and BP) 
X 
X 
X 
      X ------------------------- see VS frequency/timing as below1 ------------------------ X 
X 
Weight16 
X 
X 
      X ---------------------- daily while inpatient (standing preferred) ---------------------- X 
X 
ECOG 
X 
X 
X 
AE Evaluation10 
X11 
 
 
AEs are assessed from start of treatment through 28 days after last day of treatment10 
Formal GVHD Assessment14 
X 
X 
X 
X 
X 
X 
X 
X 
Disease Response 
Assessment (per IWG)2 
X 
X 
X 
X 
CBC with differential 
X 
X 
      X ----------------------- daily while inpatient3 ------------------------ X 
X 
CMP 
X 
X 
      X ----------------------- daily while inpatient3 ------------------------ X 
X 
CRP 
X 
X 
      X ----------------------- daily while inpatient3 ------------------------ X 
X 
PT/INR and PTT 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
B-HCG 
X 
X 
TSH 
X 
HIV, Hep B, Hep C 
X 
Immune Subset Analysis 
(peripheral blood)4 
 
X 
X 
X 
X 
X5 
X 
X 
X 
X 
X5 
X6 
EKG 
X 
X 
X 
TTE 
X 
PFTs 
X 
LP (only required if 
suspicion of CNS leukemia) 
X 
Bone Marrow Biopsy7 
X 
X17 
X 
X 
X6 
Flotetuzumab15 
      X -------- continuous infusion -------- X 
     X8 ------ continuous infusion ------ X 
DLI 
X9 
X9 

Protocol Version: 02/28/2024  
 
Page 12 of 76 
 
 
 
 
 
 
 
 
 
 
 
Notes: 
1For Cycle 1 Day 1, check vital signs (VS) pre-infusion, at 1 hour, and 4 hours after infusion start. On Days 2-7, check VS prior to dose change 
and at 1 hour and 4 hours after dose change. Check VS on Day 11, approximately 96 hours after bag change, and Days 15, 19, 22, and 26 prior to 
bag changes as applicable. For all other cycles, check VS at end of infusion/prior to bag change as applicable. Unless otherwise specified, VS 
will be measured every 4-8 hours, per BMT unit protocol or more frequently as medically indicated 
 
 
2Imaging only required as indicated by the presence of extramedullary disease  
 
 
 
 
3Labs daily, or as frequently as medically indicated 
 
 
 
 
4Immune subsets to be drawn pre-infusion and immediately prior to dose changes as indicated 
 
 
5In addition to immune subsets by flow, TCR and IgH clonality will be assessed 
 
 
 
 
6Follow-up bone marrow biopsy and immune subsets done at time of suspected relapse or progression 
 
7Biopsies are done within a +/-3 day window 
 
 
 
 
 
 
 
8Patients may continue with flotetuzumab monotherapy in C2 if they achieve SD or better (on C1D28 BmBx)  
9Patients may receive DLI in combination with continued flotetuzumab during either Cycle 1 and/or 2 at the discretion of the treating physician.  
DLI may take place on or after Day 8 of either/both cycles 
10CRS, ICE and ICANS toxicity assessments will be recorded in the EMR flowsheets and daily progress notes, as per BMT protocol for patients 
receiving cellular therapies and cell-engaging therapies 
11AE assessment at baseline is intended to establish patient’s current medical condition. No regulatory reporting of AEs at baseline is required 
12Once consent is obtained, screening assessments should take place no more than 28 days prior to C1D1 
13Patients will be followed every 6 months for 2 years. Follow-up visits should take place within a +/- 14 day window.  If the subject is coming off 
trial the End of Treatment Visit is identical to the follow-up visit.  
14See Appendices F and G. 
15DART bag change has window of ± 2hours. 
16Standing weight should be collected daily as clinically allowed 
17Collection of C1D14 biopsy is at the discretion of the principal investigator 
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 13 of 76 
 
1.0 
INTRODUCTION 
 
1.1 
Background 
 
1.1.1 AML and the Current Treatment Paradigm 
 
Acute myeloid leukemia (AML) is a hematopoietic neoplasm characterized by the 
presence of malignant, clonal cells which typically harbor recurrent chromosomal 
and genetic abnormalities. AML is projected to account for >21,000 new cases and 
~11,000 deaths in the United States in 2019 (1). Clinically, AML often presents 
with signs/symptoms related to bone marrow dysfunction that can include 
leukopenia/leukocytosis, anemia and thrombocytopenia; as well as complications 
from these hematologic abnormalities. The treatment paradigm for AML includes 
induction chemotherapy, aimed at achieving a remission, followed by consolidation 
treatment with either high dose chemotherapy or allogeneic hematopoietic cell 
transplantation (allo-HCT). For those undergoing allo-HCT, 30-50% of patients 
achieve long-term, disease-free survival at 5 years (2). Meanwhile, post-HCT 
relapse occurs in ~40% of patients (2) and remains the leading cause of post-HCT 
mortality, with a median survival of 2-4 months without therapy (3). Standard 
therapy for post-HCT relapse is reinfusion of donor cells (donor lymphocyte 
infusion, 
DLI), 
sometimes 
preceded 
by 
debulking 
chemotherapy 
or 
hypomethylating agents, and second allo-HCT in select individuals.  Unfortunately, 
many relapsing patients are not candidates for intensive therapy, and those who do 
undergo further therapy have transient responses at best (3, 4). Therefore, additional 
novel therapies are needed to improve post-HCT relapse outcomes while reducing 
the associated toxicity.  
 
1.1.2 Donor Lymphocyte Infusion (DLI) 
 
DLI represents a non-specific form of adoptive cell therapy which involves infusion 
of a pool of allogeneic immune cells, including CD4+ T cells, CD8+ T cells, 
regulatory T cells (T Regs), natural killer (NK) cells and professional antigen 
presenting cells. The DLI is believed to work in part through the graft-versus-
leukemia (GvL) effect of allo-HCT, in which donor immune cells control leukemic 
blasts through both direct cellular cytotoxicity and secretion of inflammatory 
cytokines such as interferon gamma (IFN-γ). Cytokine release in the tumor 
microenvironment likely plays a role in promoting tumor antigen expression by 
major histocompatibility complex (MHC) class I/II, as well as through direct 
toxicity to leukemia cells.  However, while these mechanisms can mediate potent 
anti-tumor effects, they are not inherently tumor specific, as evidenced by 60-70% 
rates of acute and chronic graft-versus-host disease (GVHD) following DLI (5). 
Meanwhile response rates following DLI alone for relapsed AML post-HCT are 
15-40% (6-9), with only 15-20% survival at 2 years (7). Therefore, the therapeutic 
utility of DLI is limited by both toxicity and poor efficacy. 
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 14 of 76 
 
1.1.3 Chemotherapy & Hypomethylating Agent (HMA) Monotherapy 
 
While combined chemotherapy followed by administration of a DLI remains 
standard therapy for relapsed AML post-HCT, as many as 30-50% of patients are 
unable to receive a DLI (10, 11). This results from a number of factors, including 
progressive disease despite chemotherapy, the presence of active GVHD, and the 
lack of available donor lymphocytes for infusion (10, 11).  In such cases, patients 
are often treated with chemotherapy alone with CR rates of 10-15% and significant 
toxicity (11). Meanwhile, HMAs have recently emerged as an alternative to 
chemotherapy. Besides direct anti-leukemic effects, both azacitidine and decitabine 
are thought to enhance GvL effect, potentially via modulation of T Regs and 
cytotoxic CD8+ T cells.  HMAs have been shown to have a favorable toxicity 
profile relative to traditional cytotoxic chemotherapy. However, studies evaluating 
the efficacy of HMA monotherapy in the post-HCT setting have demonstrated CR 
rates of ~10% or less (10, 11). Therefore, chemotherapy alone and HMA 
monotherapy for relapsed AML post-HCT are limited by efficacy, toxicity or both. 
Additional evaluation of alternative agents that may enhance the GvL effect and 
improve outcomes while mitigating toxicity is warranted. 
 
1.1.4 Flotetuzumab (MGD006) 
 
Flotetuzumab is a CD123 x CD3 (DART®) protein. DART proteins are bispecific, 
antibody-based molecules that can bind 2 distinct antigens simultaneously. 
Flotetuzumab is designed to target CD123-positive cells for recognition and 
elimination by CD3-expressing T lymphocytes as effector cells. CD123 is 
expressed by leukemic blasts and leukemia stem cells but not by normal 
hematopoietic stem cells (HSCs). Therefore, flotetuzumab represents a promising 
therapy for the treatment of AML via redirected T cell targeting of the leukemic 
cells. Data from early phase studies have shown flotetuzumab was relatively well-
tolerated, with the most common AEs being infusion reactions and the majority of 
AEs being graded as mild to moderate in severity (12). Meanwhile, 69.5% (16/23) 
of AML patients who received target doses (500 ng/kg/day) of flotetuzumab 
experienced a clinical benefit (13); and recent data from patients with primary 
refractory AML treated with target doses of flotetuzumab showed 32.1% (9/28) 
achieving a CR/CRi (14).  
 
1.1.5 Immune Retargeting in Relapsed AML post-HCT with Flotetuzumab 
and DLI 
 
A significant driver of long-term remissions in allo-HCT is the GvL effect. 
Additionally, relapse post-HCT may, in part, be related to loss of GvL.  This likely 
occurs both through exhaustion of donor T cells as well as epigenetic changes in 
AML cells that promote immune escape (15, 16). The potential of T cell engaging 
therapies, such as flotetuzumab, to reestablish and retarget GvL in the post-HCT 
relapsed setting may be an effective approach to treat AML relapse after allo-HCT. 
In support of this, patients with relapsed/refractory ALL following allo-HCT who 
were treated with blinatumomab, a CD19 x CD3 bi-specific T cell engager (BiTE), 

 
 
Protocol Version: 02/28/2024  
 
Page 15 of 76 
 
achieved a 45% CR/CRi rate with 65% of these responses being MRD negative 
CRs (17). Additionally, GVHD rates were infrequent, mild and did not lead to 
discontinuation of therapy on trial (17).  
 
Therefore, the administration of a T cell retargeting agent such as the 
flotetuzumab DART represents a promising approach to restore the GvL 
effect, putting AML patients relapsing after allo-HCT back in remission. 
Additionally, administration of fresh donor-derived immune cells through 
DLI may enhance the ability of flotetuzumab to target AML cells, while 
reducing post-DLI GVHD by redirecting donor lymphocytes away from 
normal host tissues.  
 
Finally, one recently identified mechanism for the loss of GvL is the down-
regulation of specific MHC class II genes on AML cells, observed in 30-50% of 
patients (15, 16). Loss of MHC class II expression is predicted to weaken GvL by 
preventing antigen expression to donor immune cells.  In preclinical experiments, 
treatment of MHC class II-low AML cells with flotetuzumab in the presence of 
donor T cells restores MHC class II expression on AML cells through IFN-γ release 
in the tumor microenvironment, leading to AML cell death even in the absence of 
CD123 expression (unpublished). Therefore, flotetuzumab may be an especially 
effective treatment for patients relapsing with MHC class II-low AML cells, both 
through the direct flotetuzumab-mediated T cell engagement with CD123+ AML 
cells (MHC class-II independent), as well as indirectly through upregulation of 
MHC class II by IFN-γ release in the tumor microenvironment.   
 
1.1.6 Hypothesis 
 
We hypothesize that flotetuzumab for relapsed AML following allo-HCT will be 
safe, tolerable and may facilitate preferential immune effector cell retargeting of 
leukemic cells resulting in improved patient outcomes.  Furthermore, 
administration of a DLI (if available) in combination with flotetuzumab will be 
safe, tolerable and may provide additional therapeutic efficacy. 
 
1.1.7 Justification for Dose 
 
MGD administered as a continuous IV infusion on 28-day cycles has been studied 
in a phase 1/2 clinical trial (CP-MGD006-01) in MDS/AML patients.  
 
Dose Selection: 
During the phase 1 dose escalation portions of this study, doses of flotetuzumab 
including 3, 10, 30, 100, 300, 500 and 700 ng/kg/day were evaluated. Based on the 
safety and tolerability data from this portion of the trial, the 500 ng/kg/day dose 
was determined to be the maximum tolerated dose (MTD) and recommended phase 
II dose (RP2D).  
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 16 of 76 
 
Schedule of Administration: 
Two schedules of administration were evaluated in the Phase 1 dose escalation and 
first cohort (n-30) of the Phase 2 cohort expansion, including: 1) a 4-day on/3-day 
off each week administration schedule for 28 days and 2) a continuous infusion for 
the entire 28-day cycle. Ultimately, both approaches were shown to be feasible, 
however the continuous infusion schedule was selected to carry forward for the 
remainder of the dose expansion cohorts (n=132), because continuous infusion 
without 3-day breaks offered improved safety with respect to adverse events (CRS) 
and improved anti-leukemic activity (some patients were observed to have transient 
increases in peripheral blast counts during the off days). 
  
Week 1, Lead-in Dosing: 
Both schedules of administration utilized a lead-in dose in Week 1, after which all 
cohorts stepped up to their target doses on their assigned schedules of 
administration for the remainder of the 28-day cycle. Initially the lead-in dose was 
100 ng/kg/day for 4 days. This lead-in dose was modified to 30 ng/kg/day for 3 
days followed by 100 ng/kg/day for 4 days for the first week of Cycle 1. A 
subsequent protocol amendment modified the lead-in dose in Week 1, to include an 
initial dose of 30 ng/kg/day on Day 1, with daily, stepwise up-titration reaching a 
final step up on Day 7 to the goal of 500 ng/kg/day (see Table 3). 
 
Safety, Tolerability and Efficacy: 
As of November, 2019, data have been reported on 50 patients with AML receiving 
flotetuzumab administered via a stepwise ramp during week 1 (see Table 3) to the 
RP2D goal of 500 ng/kg/day administered as a 7-day/week continuous infusion on 
28-day cycles. Flotetuzumab was well tolerated, with comparable cytokine release 
syndrome events in primary refractory patients (30% G1, 67% G2, 3% G3) and 
relapsed patients (26% G1, 58% G2, 16% G3). Meanwhile, 69.5% (16/23) of AML 
patients who received target doses (500 ng/kg/day) of flotetuzumab experienced a 
clinical benefit (13); and recent data from patients with primary refractory and early 
relapsed AML treated with target doses of flotetuzumab showed 32.1% (9/28) 
achieving a CR/CRi (14). 
 
Based on the above data, we propose dosing flotetuzumab with a stepwise, daily 
up-titration during week 1 (see Table 3) to a goal RP2D dose of 500 ng/kg/day 
administered as a continuous IV infusion 7 days/week on 28-day cycles. 
 
1.2 
Risk/Benefit Assessment 
 
1.2.1 Known Potential Risks 
 
As of the data cut-off date of 22 January 2021 from the most current MacroGenics 
IB v11.0, flotetuzumab has been evaluated in the ongoing first-in-human 
monotherapy clinical study (CP-MGD006-01). Overall, the preliminary safety 
profile of flotetuzumab does not show any unexpected, significant, or rare safety 

 
 
Protocol Version: 02/28/2024  
 
Page 17 of 76 
 
findings and confirms the safety observations are consistent with the mechanism of 
action of flotetuzumab or with the patients’ underlying disease.  
 
Infusion-related reaction (IRR, including cytokine release syndrome (CRS)), is the 
only important identified risk based on the observations from the 81 patients in this 
study and from the mechanism of action of flotetuzumab. Cumulatively, 71/81 
patients (87.6%) experienced at least one IRR or CRS event. The majority of 
patients experiencing infusion-related reactions (including CRS) had reactions that 
were mild to moderate in severity (62/71), whereas 9 patients experienced at least 
1 severe (Grade 3) event. None of these events have been life-threatening or fatal. 
Infusion-related reactions (including CRS) typically occurred during the initial 48 
hours of the first infusion of flotetuzumab. Infusion-related reaction symptoms 
typically included pyrexia, chills, hypotension, tachycardia, and/or respiratory 
symptoms (e.g., tachypnea, hypoxia). Most of these events were considered 
possibly, probably, or definitely related to flotetuzumab. Infusion-related reaction 
(including CRS) events have been manageable with treatment interruption, dose 
reduction, early use of tocilizumab, and medical intervention, with antipyretics, 
antihistamines, and corticosteroids. Notably, the stepwise lead-in dosing is 
associated with a reduced frequency and/or severity of IRR/CRS. 
 
Neurological events, defined as AEs of any grade of the Nervous System or 
Psychiatric Disorders System Organ Class, irrespective of attribution, have been 
seen in patients exposed to flotetuzumab. The most common of these to date were 
headache and insomnia. Other neurological events, Grade 3 or higher attributable 
to flotetuzumab, included delirium, encephalopathy, headache, mental status 
changes, and syncope. These events generally occurred in the clinical setting of 
IRR/CRS. Events reported in the Nervous System or Psychiatric Disorders System 
Organ Class to date have generally been mild to moderate in severity in most 
patients, and were reversible with no long-term clinical sequelae.  
 
Risk of capillary leak syndrome (CLS) has been associated with T-cell redirecting 
therapy, including chimeric antigen receptor T-cell (CAR-T) and CD3-engaging 
bispecific antibody-based molecules, and reported for the CD123-directed 
cytotoxin, tagraxofusp-erzs (Elzonris®). While CLS has not been frequently 
observed in patients treated with flotetuzumab, a detailed review of recent clinical 
data across all flotetuzumab studies identified three patients who received 
flotetuzumab monotherapy that, concomitant with cytokine release syndrome 
during multi-step lead-in dosing, exhibited rapid weight gain, decreased albumin, 
and systemic edema suggestive of CLS. Pleural and pericardial effusions were 
noted in some cases as well. Of note, CLS may not be associated with 
hemoconcentration in this patient population. 
 
Acute and chronic GVHD are well-described complications following allo-HCT. 
Furthermore, new onset or worsening acute and chronic GVHD has been reported 
is as many as 60-70% of patients receiving DLI alone or in combination with 
chemotherapy for relapsed AML following allo-HCT. The reported severity of both 

 
 
Protocol Version: 02/28/2024  
 
Page 18 of 76 
 
acute and chronic GVHD in this setting have ranged from mild to severe, with 
reports of grade 4 and grade 5 toxicity.  Flotetuzumab has been studied in AML 
patients with primary refractory and relapsed disease in the CP-MGD006-01 study. 
In addition, other T cell redirecting therapies have been used post-allo-HCT without 
increased GVHD (17).  Nevertheless, flotetuzumab has not been evaluated in AML 
patients with relapsed disease following allo-HCT and the risk of GVHD in this 
patient population is unknown.    
 
1.2.2 Known Potential Benefits 
 
Flotetuzumab has demonstrated anti-neoplastic activity. During cohort expansion 
in the CP-MGD006-01 study, 23 patients treated at the threshold 500 ng/kg/day 
dose have completed at least one cycle of treatment and had a post-treatment bone 
marrow biopsy. Anti-leukemic activity was documented in 69.5% (16/23) patients, 
with 4/23 patients achieving CR (2), CRi (1) or PR (1). Additionally, 12 patients 
had stable disease or other clinical benefits (defined as a decline in bone marrow 
leukemic blasts not meeting complete or partial response as classified by modified 
IWG criteria). Additional, recently reported data as of 11/2019 from the same 
cohort of patients with primary refractory and early relapsed AML treated with 
target doses of flotetuzumab showed 32.1% (9/28) achieving a CR/CRi. This 
compares favorably to historic CR/CRi rates of ~12.5% utilizing best SOC options. 
 
1.3 
Overall Study Design and Plan 
 
This is an open-label, single-arm, single-center Phase 2 study to evaluate for efficacy, 
safety and tolerability of flotetuzumab administered as a single agent and/or in combination 
with DLI in patients with relapsed AML post-allo-HCT.  
 
The study is designed to include 2 cycles of treatment. During Cycle 1, patients will be 
administered flotetuzumab as a continuous IV infusion with a week 1 ramp up to 
goal/target dose of 500ng/kg/day, which will be continued for the remaining 21 days of a 
28-day (4-week) cycle (Cycle 1). Patients found to meet the primary endpoint of complete 
remission with incomplete hematologic recovery (CRi) or better on their C1D28 response 
assessment (bone marrow biopsy) will continue on to Cycle 2 of flotetuzumab administered 
as a continuous IV infusion at a target dose of 500ng/kg/day for an additional 28-day cycle 
(Cycle 2). Patients found to be deriving clinical benefit as evidenced by stable disease (SD) 
or a partial remission (PR) on their C1D28 response assessment (bone marrow biopsy) may 
also continue to Cycle 2 of flotetuzumab at the same dose at the discretion of the treating 
physician and investigator.  Patients may receive a DLI concurrently with flotetuzumab 
treatment in Cycle 1 and/or Cycle 2 at the discretion of the investigator and treating 
physician. DLI, if administered, will be given on or after Day 8 of the respective cycle. Of 
note, if patients are off flotetuzumab for >72 hours between end of C1 and beginning of 
C2, they will require repeat week 1 ramp up to goal/target dose of 500ng/kg/day. Patients 
found to have progressive disease (PD) on their C1D28 response assessment (bone marrow 
biopsy) will proceed off study with SOC. All patients who receive investigational agent 
will then be followed for treatment response and safety monitoring. 

 
 
Protocol Version: 02/28/2024  
 
Page 19 of 76 
 
 
1.4 
Study Duration and Dates 
 
It is generally expected that ~15-20 patients will be accrued per year.  The target accrual 
for the study is 25 patients. Therefore, it is anticipated that the time from the study opening 
to completion of accrual with be ~18 months.  
 
Patients will receive the investigational treatment for the first 28 days of the study (Cycle 
1). Based on Day 28 response assessment, patients with CR/CRi/PR/SD may continue 
investigational treatment for another 28 days (Cycle 2); and patients with PD will come off 
study.  All patients will be followed for 2 years after receiving investigational treatment. 
 
1.5 
Definition of End of Trial 
 
End of Trial is defined as the date when the last patient on the study completes his or her 
End of Treatment visit and the last follow-up data is collected.  
 
 
2.0 
OBJECTIVES AND ENDPOINTS 
 
Objectives 
Endpoints 
Primary 
To evaluate the efficacy of flotetuzumab 
in post-allo-HCT relapsed AML and 
MDS following Cycle 1 of flotetuzumab 
(Cycle 1 Day 28 assessment). 
Efficacy assessed via composite endpoint of CR and 
CRi (Cycle 1 Day 28 assessment) 
Secondary 
• To evaluate the efficacy of 
flotetuzumab monotherapy in post-
allo-HCT relapsed AML and MDS 
following Cycle 2. 
• To evaluate the safety and tolerability 
of flotetuzumab +/- DLI in the post-
allo-HCT setting.  
• Efficacy assessed at Cycle 2 Day 28 (or at C1 D28 
in patients who receive only one cycle): 
o Composite endpoint of CR and CRi at C2 D28 
o Overall Response (OR) Rate (defined as PR or 
greater) 
o Morphologic leukemia-free state (MLFS) Rate 
o Partial Response (PR) Rate 
o Stable Disease (SD) Rate 
o Progression Free Survival (PFS) 
o Overall Survival (OS) 
• Safety and tolerability as assessed by: 
o AE Grading per CTCAE v5.0 
o CRS & Neurotoxicity Grading per ASTCT 
Consensus Guidelines 
o Acute GVHD Grading per MAGIC criteria 
Chronic GVHD Grading per NIH severity score 
 
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 20 of 76 
 
3.0 
STUDY POPULATION 
 
3.1 
Inclusion Criteria 
 
1. Histologically or cytologically confirmed relapsed acute myeloid leukemia (AML) or 
myelodysplastic syndrome (MDS), including any AML subtype, except acute 
promyelocytic leukemia (APL), and including AML that has evolved from a previous 
MDS or MPN.  
 
2. Patients must have peripheral blast count ≤ 20,000/mm3.  Use of hydroxyurea to 
control blast count is permitted. 
 
3. Patients must be status post allo-HCT (including: matched related, matched unrelated, 
haploidentical, mismatched unrelated; and cord blood HCT). 
 
4. Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≤ 2 (see 
Appendix A). 
 
5. Adequate organ function, defined as: 
a. Hepatic transaminase (both alanine aminotransferase (ALT) and aspartate 
aminotransferase (AST) levels <2.5 times the institutional upper limit of normal 
(ULN), 
b. Total bilirubin level <1.5 times the ULN (unless the patient has a history of 
Gilbert’s Syndrome, in which case, total bilirubin must be <2.5 times the ULN), 
c. Creatinine clearance of >50 ml/min.  
d. Adequate organ reserve including cardiovascular (ejection fraction within 
institutional normal limits), pulmonary (baseline pulmonary function test [PFT]: 
carbon monoxide diffusion capacity in the lung [DLCO] > 50%, forced expiratory 
volume in 1 second [FEV1] > 70%), renal, and hepatic functioning sufficient, in 
the judgment of the Investigator, to undergo therapy. 
e. Normal thyroid function or stable thyroid tests on supplementation, except 
euthyroid sick syndrome. 
 
6. Recovery from toxicities of clinical consequence attributed to previous chemotherapy 
to CTCAE v4.0 Grade ≤ 1 (i.e., certain toxicities such as alopecia will not be considered 
in this category). 
 
7. Female patients of childbearing potential must test negative for pregnancy at 
enrollment and during the study. Sexually active women of child-bearing potential, 
unless surgically sterile, must be willing to use a highly effective method of birth 
control defined as those which result in a low failure rate (i.e., less than 1% per year) 
such as implants, injectables, combined oral contraceptives, intra-uterine devices 
(IUDs) or vasectomized partner. Male patients with partners of childbearing potential 
must be either vasectomized or agree to use a condom in addition to having their 
partners use another method of contraception resulting in a highly effective method of 
birth control defined as those which result in a low failure rate (i.e., less than 1% per 

 
 
Protocol Version: 02/28/2024  
 
Page 21 of 76 
 
year) such as implants, injectables, combined oral contraceptives, or IUDs. Patients 
should not have sexual intercourse with females who are either pregnant or lactating 
without a condom. Contraception should be employed from the time of consent through 
12 weeks after flotetuzumab administration. Patients should also abstain from 
sperm/egg donation during the course of the study. 
 
8. Able to have corticosteroids weaned to ≤0.5mg/kg prednisone/day (or equivalent) 
 
9. Able to have non-steroidal immunosuppression discontinued, including: 
a. mycophenolate (MMF) 
b. calcineurin inhibitors (tacrolimus, cyclosporine) 
i. calcineurin inhibitors must be able to be discontinued at least 14 days prior to 
enrolling on study. 
c. JAK inhibitors (ruxolitinib) 
d. MTOR inhibitors (sirolimus) 
 
10. At least 18 years of age. 
 
11. Ability to understand and willingness to sign an IRB approved written informed 
consent document. 
 
3.2 
Exclusion Criteria 
 
1. Active GVHD requiring systemic immunosuppression with more than 0.5mg/day 
prednisone. 
 
2. Currently receiving any other investigational agents. 
 
3. Any active untreated autoimmune disorders (with the exception of vitiligo, resolved 
childhood atopic dermatitis, prior Grave’s disease now euthyroid clinically and with 
stable supplementation). 
 
4. Second primary malignancy that requires active therapy (adjuvant hormonal therapy is 
allowed). 
 
5. Antitumor therapy (chemotherapy, radiotherapy, antibody therapy, molecular- targeted 
therapy, retinoid therapy, or investigational agent) within 5 half-lives of Cycle 1 Day 
1. 
 
6. At the time of study entry, steroids >0.5mg/kg of prednisone or equivalent (except 
steroid inhaler, nasal spray or ophthalmic solution which are allowed). 
 
7. Use of immunosuppressant medications (other than steroids as noted) in the 2 weeks 
prior to study drug administration (Cycle 1 Day 1). 
 
8. Isolated extramedullary relapse (i.e., no evidence of bone marrow involvement).   

 
 
Protocol Version: 02/28/2024  
 
Page 22 of 76 
 
 
9. Known central nervous system (CNS) leukemia. Patients with suspected CNS leukemia 
must be evaluated by lumbar puncture and be free of CNS disease prior to study entry. 
Previously treated CNS leukemia is allowed provided adequate treatment has been 
provided and the patient is free of CNS disease. 
 
10. Any medical or psychiatric condition limiting full compliance or increasing the safety 
risk, at the discretion of the PI, such as: 
a. active uncontrolled infection (including, but not limited to viral, bacterial, fungal, 
or mycobacterial infection), 
b. known human immunodeficiency virus infection, 
c. known, active, or chronic hepatitis B or C infection (appropriately treated 
HBV/HCV infections with documented clearance of viral titer are allowed), 
d. Grade 3 or 4 bleeding, 
e. significant pulmonary compromise including chronic supplemental oxygen use, 
history of non-infectious pneumonitis (including radiation pneumonitis), 
pulmonary fibrosis, or severe chronic obstructive pulmonary disease (COPD), 
f. uncontrolled (persistent) hypertension (systolic pressure > 180 mm Hg or diastolic 
pressure > 100 mm Hg 
g. clinically significant arrhythmia, clinically significant baseline QTcF >480 msec, 
h. unstable angina, 
i. recent myocardial infarction within 6 months prior to study drug administration 
(Cycle 1 Day 1), 
j. clinically significant heart disease, such as, congestive heart failure, history of 
pericarditis, myocarditis, 
k. history of stroke or transient ischemic event within 3 months prior to study drug 
administration (Cycle 1 Day 1), 
l. untreated pulmonary embolism, or non-catheter-related deep-vein thrombosis in 
the 3 months prior to study drug administration (Cycle 1 Day 1), 
m. pregnancy, or breast feeding, 
n. major surgery or trauma within 4 weeks before enrollment. 
 
11. Known hypersensitivity to murine, yeast, or recombinant proteins; polysorbate 80; 
recombinant human serum albumin; benzyl alcohol; or any excipient contained in the 
flotetuzumab drug formulation. 
 
12. Dementia or altered mental status that would preclude sufficient understanding to 
provide informed consent. 
 
3.3 
Inclusion of Women and Minorities  
 
Both men and women and members of all races and ethnic groups are eligible for this trial.   
 
 
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 23 of 76 
 
 
4.0 
REGISTRATION PROCEDURES 
 
Patients must not start any protocol intervention prior to registration through the Siteman 
Cancer Center. 
 
The following steps must be taken before registering patients to this study: 
 
1. Confirmation of patient eligibility 
2. Registration of patient in the Siteman Cancer Center database 
3. Assignment of unique patient number (UPN) 
 
4.1 
Confirmation of Patient Eligibility 
 
Confirm patient eligibility by collecting the information listed below:  
 
1. The registering MD’s name  
2. Patient’s race, sex, and DOB 
3. Three letters (or two letters and a dash) for the patient’s initials 
4. Copy of signed consent form  
5. Completed eligibility checklist, signed and dated by a member of the study team 
6. Copy of appropriate source documentation confirming patient eligibility 
 
4.2 
Patient Registration in the Siteman Cancer Center OnCore Database 
 
All patients must be registered through the Siteman Cancer Center OnCore database. 
 
4.3 
Assignment of UPN 
 
Each patient will be identified with a unique patient number (UPN) for this study.  All data 
will be recorded with this identification number on the appropriate CRFs. 
 
4.4 
Screen Failures 
 
Screen failures are defined as participants who consent to participate in the clinical trial 
but are not subsequently randomized to the study intervention or entered in the study.  A 
minimal set of screen failure information is required to ensure transparent reporting of 
screen failure participants, to meet the Consolidated Standards of Reporting Trials 
(CONSORT) publishing requirements and to respond to queries from regulatory 
authorities.  Minimal information includes demography, screen failure details, eligibility 
criteria, and any serious adverse event (if applicable).   
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 24 of 76 
 
5.0 
STUDY TREATMENT PLAN 
 
5.1 
Premedication Administration 
 
Due to the risk of infusion-related reactions (IRRs), specific pre-treatment regimens are 
described below. Table 1 below presents the premedication and prophylaxis regimens. 
 
Prior to the first dose (Week 1): 
All patients are to be treated as described in Table 1 below. No additional steroids should 
be administered for infusion-related reaction prophylaxis except as detailed below. Patients 
should receive adequate hydration during study therapy, and the addition of IV fluids to 
maintain intravascular volume (e.g., 50-100 mL/hr of normal saline) is recommended for 
at least 48 hours after the start of therapy. 
 
Prior to Week 2 dosing: 
The premedication schedule should be followed as described in Table 1 below. In addition, 
these premedications should be considered after consultation with the Principal 
Investigator (PI) if patients are resuming flotetuzumab treatment after a dose interruption 
lasting > 1 day in Cycle 1 or 2: 
• Steroids should not be administered for infusion-related reaction prophylaxis 
except as indicated below, but may be used for the treatment of emerging symptoms 
as clinically appropriate.  
• Tocilizumab (8 mg/kg IV) may be used prophylactically in patients who have had 
severe IRR or CRS in the first week of dosing upon consultation with the PI.  
• Patients should receive adequate hydration during study therapy, and the addition 
of IV fluids to maintain intravascular volume (e.g., 50-100 mL/hr of normal saline) 
is recommended for at least 48 hours after the start of therapy in Week 2. 
 
Prior to subsequent doses (after Week 2): 
1. The premedication schedule should be followed as described in Table 1 below. 
Tocilizumab or steroids may be considered after consultation with the PI. 
2. For infusion-related reactions during the course of treatment, supportive care 
measures should be implemented as outlined in Section 6.1. 
3. IV fluids should be administered for all patients unless contraindicated. 
 
Table 1: Flotetuzumab Ramp & Continuous Infusion Pre-medications 
28 day continuous Flotetuzumab infusion schedule 
Medication 
Week 1 
Week 2 
Week 3 
Week 4 
Acetaminophen 
(1000mg PO) 
Day 1: 30 minutes prior to 
dosing, then q8 hrs for 48 hours 
 
Day 7 or day of target dose: 30 
minutes prior to dose change, 
then q8 hrs for 48 hours 
 
None 
None 
None 

 
 
Protocol Version: 02/28/2024  
 
Page 25 of 76 
 
28 day continuous Flotetuzumab infusion schedule 
Medication 
Week 1 
Week 2 
Week 3 
Week 4 
Diphenhydramine 
(25-50mg IV or 
PO) 
or equivalent 
Day 1: 30 minutes prior to 
dosing, then q8 hrs for 48 hours 
 
Day 7 or day of target dose: 30 
minutes prior to dose change, 
then q8 hrs for 48 hours 
 
None 
None 
None 
Ranitidine (50mg 
IV) or equivalent 
Day 1 or day of target dose: 30 
minutes prior to dosing, then q8 
hrs for 48 hours 
 
Day 7 or day of target dose: 30 
minutes prior to dose change, 
then q8 hrs for 48 hours 
 
None 
None 
None 
Dexamethasone 
(or equivalent) 
Day 1: 10-20mg IV up to 30 
minutes before dosing.  Then 
4mg IV at 12 hours after dosing. 
 
Day 7 or day of target dose: 
10mg IV up to 30 minutes prior 
to dose change, then 4mg 12 hrs 
later. 
 
None 
None 
None 
Tocilizumab 
(8mg/kg IV) 
None 
After 
consultation 
with PI 
None 
None 
 
5.2 
Study Intervention Description 
 
Patients enrolled on study will be admitted to the hospital for admission assessments, 
administered premedications and started on Cycle 1 Day 1 on the dose escalation ramp 
schedule (Table 3) of flotetuzumab as a continuous IV infusion. During the ramp week, 
patients will be initiated on flotetuzumab at 30 ng/kg/day and have their flotetuzumab dose 
increased daily to a target goal of 500 ng/kg/day by Day 7.  
 
Patients will then continue on flotetuzumab continuous IV infusion at 500 ng/kg/day for 
the remaining 21 days of the 28-day cycle.  
 
On Cycle 1 Day 28, patients will undergo repeat bone marrow biopsy for assessment of 
disease status.  Patients not deriving clinical benefit defined as PD (Table 2) will proceed 
with SOC therapy off study. Patients who have achieved a CR/CRi will proceed to a second 
cycle per protocol, while patients deriving clinical benefit defined as PR or SD or better 
may proceed to Cycle 2 with permission of the investigator. Patients with available donor 
lymphocytes may receive DLI concurrently with flotetuzumab during Cycle 1 and/or Cycle 
2. At the discretion of Principal Investigator, on Cycle 1 Day 14 patients will undergo a 
bone marrow biopsy for tissue banking and correlative studies. 

 
 
Protocol Version: 02/28/2024  
 
Page 26 of 76 
 
 
5.2.1 Cycle 1 
 
Cycle 1 will include pre-medications, a dose escalation ramp of flotetuzumab and 
then a continuous infusion of flotetuzumab (Tables 1 & 3).  
o Patients will be admitted to the hospital on day 0 for admission assessments.  
o Pre-medications will be administered, beginning on Day 1, as in the 
previous phase 2 trial NCT02152956.  
o The dose escalation ramp will begin on Day 1 and will consist of continuous 
ramp infusion of flotetuzumab starting at 30 ng/kg/day with increasing dose 
over 7 days to a target dose of 500 ng/kg/day.  
o Patients will then continue on flotetuzumab for additional 21 days at target 
dose of 500 ng/kg/day (28 days total).  
o Patients may receive a DLI at the discretion of the treating physician on or 
after Day 8 of Cycle 1. 
o At mid-Cycle 1 (Day 14), at the discretion of the Principal Investigator, 
patients will undergo a bone marrow biopsy for correlative studies only (not 
used for disease response assessments). 
o At the end of Cycle 1 (Day 28), patients will undergo bone marrow biopsy 
for correlative studies and disease response assessment. 
o Patients not deriving clinical benefit (defined as PD, Table 2) will proceed 
with SOC therapy off study. Patients with a CR/CRi (Table 2) will proceed 
to Cycle 2 per protocol.  Patients deriving clinical benefit (defined as SD or 
better, Table 2) may proceed to Cycle 2 with permission of the investigator.  
 
Table 2: Response Criteria 
Complete 
remission (CR) 
Bone marrow blasts <5%; absence of circulating blasts and blasts with 
Auer rods; absence of extramedullary disease; ANC ≥1.0 × 109/L 
(1000/µL); platelet count ≥100 × 109/L (100,000/µL), transfusion 
independence 
CR with 
incomplete 
hematologic 
recovery (CRi) 
All CR criteria except for residual neutropenia (<1.0 × 109/L 
[1000/µL]) or thrombocytopenia (<100 × 109/L [100,000/µL]) 
Morphologic 
leukemia-free state 
(MLFS) 
Bone marrow blasts <5%; absence of blasts with Auer rods; absence 
of extramedullary disease; no hematologic recovery required 
Partial remission 
(PR) 
All hematologic criteria of CR; decrease of bone marrow blast 
percentage to 5 to 25%; and decrease of pretreatment bone marrow 
blast percentage by at least 50% 
Stable disease (SD) 
Absence of CR, CRi, PR, MLFS; and criteria for PD not met 
Progressive disease 
(PD) 
Evidence for an increase in bone marrow blast percentage (>50% over 
baseline), and/or increase of absolute blast counts in the blood (>50% 
to >25 × 109/L) without differentiation syndrome, or new 
extramedullary disease 
 
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 27 of 76 
 
 
Table 3: Flotetuzumab Ramp, Induction, and Consolidation Dosing Guidelines1 
Ramp + Induction 
Cycle 
Weeks 
Days 
Dose (ng/kg/day) 
1 
1 
Day 1 
30 
Day 2 
60 
Day 3 
100 
Day 4 
200 
Day 5 
300 
Day 6 
400 
Day 7 
500 
2 
Days 8-14 
500 
3 
Days 15-21 
500 
4 
Days 22-28 
500 
Induction/Consolidation 
2 
1-4 
Days 1-28 
500 
1Table provided for dosing guidelines.  Actual dosing may be altered as clinically 
indicated.' 
 
5.2.2 Cycle 2 Flotetuzumab Consolidation  
 
Patients meeting the primary endpoint of CR/CRi and patients with PR/SD (with 
permission of the investigator) will receive Cycle 2 flotetuzumab pre-medications 
and a continuous infusion of flotetuzumab (Tables 1 & 3), beginning within 2 
weeks of completing Cycle 1. 
o Patients will be admitted to the hospital and pre-medications administered 
on Day 1.  
• If patients have been off flotetuzumab for >72 hours, then the dose 
escalation ramp will begin on Day 1 and will consist of continuous ramp 
infusion of flotetuzumab starting at 30 ng/kg/day with increasing dose 
over 7 days to a target dose of 500 ng/kg/day. Patients will then continue 
on flotetuzumab for additional 21 days at target dose of 500 ng/kg/day 
(28 days total). 
• If patients have been off flotetuzumab <72 hours, then patients will 
receive flotetuzumab dosed at 500 ng/kg/day continuous infusion for a 
total of 4 weeks (28 days).  
o At the end of Cycle 2 (Day 28), patients will undergo bone marrow biopsy 
for disease response assessment and correlative studies, and proceed to the 
follow-up phase of the study. 
 
5.2.3 Donor Lymphocyte Infusion (DLI) 
 
Patients with available donor cells may receive a donor lymphocyte infusion during 
Cycle 1 and/or Cycle 2 (if given) at the discretion of the investigator and the treating 
physician. 
o DLI should be administered on or after Day 8 of Cycle 1 and/or Cycle 2 

 
 
Protocol Version: 02/28/2024  
 
Page 28 of 76 
 
o Cell dose of DLI will vary depending on donor source at the discretion of 
the treating physician and according to institutional practices: 
• For matched unrelated donors and matched related donors DLI 
containing a range of 0.5 x 107 to 1.0 x 108 CD3+ cells/kg will be 
administered.  
• For haploidentical and mismatched donors DLI containing a range of 
0.5 x 106 to 1.0 x 107 CD3+ cells/kg will be administered. 
 
5.3 
Response Assessments 
 
Bone Marrow Biopsy (BM Bx) will be performed at the following timepoints for disease 
assessments and correlative assessments:  
• Screening/Baseline BM Bx: performed prior to starting on treatment. 
• Cycle 1 D14 (+/- 3 days) BM Bx mid-Cycle 1 (correlative assessments only, no 
disease response assessment, collected at PI’s discretion only). 
• Cycle 1 D28 (+/- 3 days) BM Bx following completion of Cycle 1.  
• Cycle 2 D28 (+/- 3 days) BM Bx following completion of Cycle 2.  
• Final BM Bx performed at the time of suspected disease relapse or progression. 
 
Responses will be assessed via IWG Criteria (Table 2). 
 
See Section 7.0 for additional details regarding bone marrow biopsy schedule and 
correlative assessments. 
 
5.4 
Safety Assessments 
 
Safety assessments will be performed on an ongoing, continual basis to monitor for any 
AEs. Additionally, formal GVHD assessments will be performed at baseline, on C1 D1 
prior to flotetuzumab dose, C1D28; for patients receiving DLI, formal GVHD assessments 
will be performed weekly following DLI and during follow up. 
 
5.5 
Definitions of Evaluability 
 
Endpoint 
To be evaluable for this endpoint, a patient 
must… 
Efficacy (CR and CRi, C1D28 
assessment) 
Have completed all Cycle 1 infusions of 
flotetuzumab (or discontinued treatment due to 
drug toxicity or disease progression).  Patients 
who are not evaluable for the primary objective 
will be replaced. 
Efficacy (CR and CRi, C2D28 
assessment) 
Have completed all Cycle 1 and 2 infusions of 
flotetuzumab (or discontinued treatment due to 
drug toxicity or disease progression) and 
undergone C2D28 disease assessment 
Efficacy (ORR defined as PR or 
greater) 
Have completed all Cycle 1 infusions of 
flotetuzumab (or discontinued treatment due to 

 
 
Protocol Version: 02/28/2024  
 
Page 29 of 76 
 
Efficacy (MLFS rate) 
drug toxicity or progression) and undergone 
C2D28 disease assessment (or C1D28 assessment 
for patients who only received Cycle 1 
treatment). 
Efficacy (PR rate) 
Efficacy (SD rate) 
Efficacy (PFS) 
Efficacy (OS) 
Have undergone any period of infusion of 
flotetuzumab 
Safety and tolerability (AEs by 
CTCAE) 
Safety and tolerability (CRS and 
neurotoxicity by ASTCT) 
Safety and tolerability (acute 
GVHD by MAGIC criteria) 
Safety and tolerability (chronic 
GVHD by NIH severity score) 
 
5.6 
Concomitant Therapy and Supportive Care Guidelines 
 
All concomitant medications defined below that are administered during the patient’s 
participation in the study must be recorded in the source document and on the electronic 
Case Report Form (eCRF). 
 
Concomitant Medications that will be recorded in the eCRF: 
• Medications related to the management of IRR, CRS and/or Neurotoxicity 
administered from admission to the hospital for Cycle 1 of flotetuzumab, during 
Cycle 1 and Cycle 2, and for the 4 weeks following completion of treatment on 
protocol will be documented in the eCRF. 
• Medications and treatments related to the management of CLS administered from 
admission to the hospital for cycle 1 of flotetuzumab, during Cycle 1 and Cycle 2, 
and for the 4 weeks following completion of treatment on protocol will be 
documented in the eCRF 
• Immunosuppressive medications and medications related to management of GVHD 
from the time of study enrollment through 28 days after the last administration of 
study drug or End-of-Treatment visit, whichever is later, will be documented in the 
eCRF. 
 
Patients may not receive the following concurrent therapy: 
• Any other therapies for leukemia. Use of hydroxyurea or other cytoreductive agents 
for the purposes of achieving an initial peripheral blast count ≤ 20,000/mm3 should 
have ceased by the time of registration. However, hydroxyurea may be reinstituted at 
the discretion of the Investigator for the prevention or treatment of signs or symptoms 
of leukostasis during the time of study participation. If this occurs, hydroxyurea and 
any other leukemia therapies used must be recorded in the eCRF. 
• Patients may not get treatment with any other investigational agent within 14 days or 
5 half- lives, whichever is longer, prior to study drug administration (Cycle 1 Day 1). 
• Patients may not receive other investigational drugs during the period of study 
participation. 
• Because flotetuzumab employs a mechanism of action dependent upon the engagement 

 
 
Protocol Version: 02/28/2024  
 
Page 30 of 76 
 
of T lymphocytes, the use of corticosteroids other than those employed for 
premedication should be limited as much as possible. Corticosteroid pretreatment 
should follow the recommended dose and schedule. Steroids may be employed in the 
treatment 
of 
suspected 
flotetuzumab-associated 
immunoinflammatory 
AEs, 
GVHD/autoimmune AEs or leukemia-associated  AEs in consultation with the PI. 
• Ruxolitinib should not be administered in patients on active treatment with 
flotetuzumab without approval from the PI. 
• Use of granulocyte colony stimulating factor or granulocyte-macrophage colony 
stimulating factor is prohibited during Cycle 1. Following Cycle 1, the use of 
hematopoietic growth factors is still discouraged. However, granulocyte colony 
stimulating factor or granulocyte-macrophage colony stimulating factor may be used in 
accordance with the practice of medicine and institutional guidelines at the 
investigator’s discretion. 
• Vaccinations (with the exception of the annual inactivated influenza vaccine) are 
prohibited while patients are actively receiving study drug (i.e. during Cycle 1 and 
Cycle 2). 
 
Patients may receive the following concurrent therapy: 
• Antiemetics, 
antidiarrheals, 
anticholinergics, 
antispasmodics, 
antipyretics, 
antihistamines, analgesics, antibiotics and other antimicrobials, histamine receptor (H2) 
antagonists or proton pump inhibitors, and any other medication intended to treat 
symptoms or signs of disease not explicitly prohibited as above are allowed. 
 
5.7 
Women of Childbearing Potential 
 
Women of childbearing potential (defined as women with regular menses, women with 
amenorrhea, women with irregular cycles, women using a contraceptive method that 
precludes withdrawal bleeding, and women who have had a tubal ligation) are required to 
have a negative serum or urine pregnancy test within 7 days prior to the first dose of 
flotetuzumab. 
 
Female and male patients (along with their female partners) are required to use a highly 
effective form of acceptable contraception, defined as those which result in a low failure 
rate (i.e., less than 1% per year) such as implants, injectables, combined oral contraceptives, 
intra-uterine devices (IUDs) or vasectomized partner. Male patients with partners of 
childbearing potential must be either vasectomized or agree to use a condom in addition to 
having their partners use another method of contraception resulting in a highly effective 
method of birth control defined as those which result in a low failure rate (i.e., less than 
1% per year) such as implants, injectables, combined oral contraceptives, or IUDs. Patients 
must agree to use contraception during participation in the study and for 12 weeks 
following the last dose of flotetuzumab. Patients should also abstain from sperm/egg 
donation during the course of the study. 
 
If a patient is suspected to be pregnant, flotetuzumab should be immediately discontinued.  
In addition, a positive urine test must be confirmed by a serum pregnancy test.  If it is 
confirmed that the patient is not pregnant, the patient may resume dosing. 

 
 
Protocol Version: 02/28/2024  
 
Page 31 of 76 
 
 
If a female patient or female partner of a male patient becomes pregnant during therapy or 
within 12 weeks after the last dose of flotetuzumab, the investigator must be notified in 
order to facilitate outcome follow-up.  
 
5.8 
Duration of Therapy 
 
If at any time the constraints of this protocol are considered to be detrimental to the 
patient’s health and/or the patient no longer wishes to continue protocol therapy, the 
protocol therapy should be discontinued and the reason(s) for discontinuation documented 
in the case report forms. 
 
In the absence of treatment delays due to adverse events, treatment may continue for 2 
months or until one of the following criteria applies: 
• Documented and confirmed disease progression 
• Death 
• Adverse event(s) that, in the judgment of the investigator, may cause severe or 
permanent harm or which rule out continuation of study drug 
• General or specific changes in the patient’s condition render the patient unable to 
receive further treatment in the judgment of the investigator 
• Suspected pregnancy 
• Serious non-compliance with the study protocol 
• Lost to follow-up 
• Patient withdraws consent 
• Investigator removes the patient from study 
• The Siteman Cancer Center decides to close the study 
 
Patients who prematurely discontinue treatment for any reason will still be followed as 
indicated in the study calendar. 
 
5.9 
Duration of Follow-up 
 
Patients will be followed at least every 6 months for 2 years or until death, whichever 
occurs first.  Patients removed from study for unacceptable adverse events will be followed 
until resolution or stabilization of the adverse event.  Patients will return to the clinic for 
routine post-transplant visits during the first 6 months of follow-up. After the first 6 
months, patients can be followed either in person via clinic visit or through a phone call or 
medical records review.  
 
5.10 
Lost to Follow-Up 
 
A participant will be considered lost to follow-up if he or she fails to return for 6 weeks 
following a scheduled visit and is unable to be contacted by the study team. 
 
The following actions must be taken if the participant fails to return to clinic for a required 
study visit: 

 
 
Protocol Version: 02/28/2024  
 
Page 32 of 76 
 
o The study team will attempt to contact the participant and reschedule the missed 
visit within 6 weeks and counsel the participant on the importance of maintaining 
the assigned visit schedule and ascertain if the participant wishes to and/or should 
continue in the study. 
o Before a participant is deemed lost to follow-up, the investigator or designee will 
make every effort to regain contact with the participant (where possible, 3 telephone 
calls and, if necessary, a certified letter to the participant’s last known mailing 
address).  These contact attempts should be documented in the participant’s medical 
record or study file. 
o Should the participant continue to be unreachable, he or she will be considered to 
have withdrawn from the study with a primary reason of lost to follow-up. 
 
 
6.0 
DOSE DELAYS/DOSE MODIFICATIONS 
 
6.1 
Infusion-related Reactions including CRS 
 
The predicted mechanism of action of flotetuzumab is the creation of an immunological 
synapse between the leukemic blast target cell bearing CD123 and immune effectors 
bearing the T cell specific CD3 complex, leading to T cell activation and killing of the 
leukemic cell. Activation of T cells is associated with the elaboration of various cytokines. 
In vitro preclinical testing using human PBMCs has suggested that the most vigorous 
cytokine production is that of IFN-γ, but increases in production of TNF-α, IL-2, IL-6, IL-
4, and IL-10 were documented. Cytokine production, primarily of IL-6, was also 
documented in normal cynomolgus monkeys receiving flotetuzumab - a circumstance in 
which relatively few target cells (mostly CD123-bearing pDCs) were present in the 
animal’s peripheral blood but elimination of those cells was observed. In the cynomolgus 
monkey, very high doses of flotetuzumab (i.e., 5 µg/kg/day) were associated with severe 
cytokine release of multiple cytokines including IL-6, IFN-γ, IL-2, TNF-α and to a lesser 
extent IL-8 and IL-4, resulting in moribundity or death. 
 
Infusion-related reactions or Cytokine Release Syndrome (CRS) may occur. 
Anaphylactic or anaphylactoid-type reactions are possible. Precautions for the 
management of these reactions should be observed during flotetuzumab 
administration. 
 
Infusion-related reactions (including CRS) associated with flotetuzumab administration 
should be managed according to the standard practice of medicine. General guidelines for 
the management of such reactions are provided in this section. However, severe reactions 
may require extraordinary interventions like those that have been required to extinguish 
the syndrome of cytokine storm or may have anaphylactoid features. 
 
Patients should be monitored closely for the development of IRRs during flotetuzumab 
infusion; with CRS, ICE and ICANS toxicity assessments recorded in the EMR flowsheets 
and daily progress notes, as per BMT protocol for patients receiving cellular therapies and 
cell-engaging therapies. Medications and supportive measures for the treatment of such 

 
 
Protocol Version: 02/28/2024  
 
Page 33 of 76 
 
reactions should be available for immediate use for an infusion reaction during study drug 
administration and may include, but are not limited to: subcutaneous (SC) epinephrine (0.3 
to 0.5 mL of a 1:1000 solution), antihistamines (e.g., diphenhydramine 25 to 50 mg IV), 
corticosteroids (e.g., dexamethasone 10 mg IV push or equivalent), IV fluids, vasopressors, 
oxygen, bronchodilators, and antipyretics. Resuscitation equipment and other supplies for 
the emergency management of an allergic/toxic reaction must be available. The patient 
should be treated according to the best available local practices and procedures. All 
supportive measures consistent with optimal patient care will be provided throughout the 
study according to institutional standards. 
 
Should symptoms of fever or chills develop it may be difficult or impossible to distinguish 
among potential causes of the symptoms including underlying leukemia, neutropenic fever, 
emerging infection, or infusion reaction. Temporarily halting the flotetuzumab infusion to 
collect cultures, institute antimicrobials, etc., may provide information regarding etiology. 
If the fever and chills are considered not related (as described in Section 6.3) to the infusion 
of study drug, the study drug may be reinstituted at the same rate of administration after 
administration of acetaminophen, H2 blockers, and diphenhydramine if not administered 
previously for premedication. More complex symptom composites may require additional 
intervention. Please refer to Section 6.3 for management of infusion reactions if the event 
is considered related to flotetuzumab. If during assessment of IRR/CRS a patient undergoes 
imaging and/or sample collection, e.g., pleural fluid, intra-articular joint aspiration, or 
ascitic fluid, a sample may be further evaluated in order to help elucidate etiology. 
 
6.2 
Premedications and Prophylaxis 
 
Based on the clinical experience to date, similar findings from other bispecific molecules 
such as blinatumomab and reported clinical experience with CAR-T therapies, all patients 
will receive premedication to prevent or mitigate potential infusion-related reactions. 
Specific pre-treatment regimens are described below (Table 4).  
 
Prior to the first dose (Week 1): 
All patients are to be treated as described in Table 4 below. No steroids should be 
administered for infusion-related reaction prophylaxis except as indicated below. Patients 
should receive adequate hydration during study therapy, and the addition of IV fluids to 
maintain intravascular volume (e.g., 50-100 mL/hr of normal saline) is recommended for 
at least 48 hours after the start of therapy. 
 
Prior to Week 2 dosing: 
The premedication schedule should be followed as described in Table 4 below. In addition, 
the same premedications should be considered after consultation with the PI if they are 
resuming flotetuzumab treatment after a dose interruption lasting > 1 day in Cycle 1. 
 
Steroids should not be administered for infusion-related reaction prophylaxis except as 
indicated below, but may be used for the treatment of emerging symptoms as clinically 
appropriate. Tocilizumab (8 mg/kg IV) may be used prophylactically in patients who have 
had severe IRR or CRS in the first week of dosing upon consultation with the PI. Patients 
should receive adequate hydration during study therapy, and the addition of IV fluids to 

 
 
Protocol Version: 02/28/2024  
 
Page 34 of 76 
 
maintain intravascular volume (e.g., 50-100 mL/hr of normal saline) is recommended for 
at least 48 hours after the start of therapy in Week 2. 
 
Prior to subsequent doses (after Week 2): 
The premedication schedule should be followed as described in Table 4 below. 
Tocilizumab or steroids may be considered after consultation with the PI. 
 
For infusion-related reactions during the course of treatment, supportive care measures 
should be implemented as outlined in Table 7 below. 
 
IV fluids should be administered for inpatients unless contraindicated and adequate oral 
hydration should be emphasized for patients treated as outpatients in Cycles 2 and beyond. 
 
Dose interruption: 
If dosing is interrupted for > 24 hours during continuous infusion, the premedication 
schedule should be followed (Table 4). 
 
Table 4: Premedication Guidelines 
28 day continuous Flotetuzumab infusion schedule 
Medication 
Week 1 
Week 2 
Week 3 
Week 4 
Acetaminophen 
(1000mg PO) 
Day 1: 30 minutes prior to 
dosing, then q8 hrs for 48 hours 
 
Day 7 or day of target dose: 30 
minutes prior to dose change, 
then q8 hrs for 48 hours 
 
None 
None 
None 
Diphenhydramine 
(25-50mg IV or 
PO) 
or equivalent 
Day 1: 30 minutes prior to 
dosing, then q8 hrs for 48 hours 
 
Day 7 or day of target dose: 30 
minutes prior to dose change, 
then q8 hrs for 48 hours 
 
None 
None 
None 
Ranitidine (50mg 
IV) or equivalent 
Day 1: 30 minutes prior to 
dosing, then q8 hrs for 48 hours 
 
Day 7 or day of target dose: 30 
minutes prior to dose change, 
then q8 hrs for 48 hours 
 
None 
None 
None 
Dexamethasone 
(or equivalent) 
Day 1: 10-20mg IV up to 30 
minutes before dosing.  Then 
4mg IV at 12 hours after dosing. 
 
Day 7 or day of target dose: 
10mg IV up to 30 minutes prior 
to dose change, then 4mg 12 hrs 
later. 
None 
None 
None 

 
 
Protocol Version: 02/28/2024  
 
Page 35 of 76 
 
28 day continuous Flotetuzumab infusion schedule 
Medication 
Week 1 
Week 2 
Week 3 
Week 4 
 
Tocilizumab 
(8mg/kg IV) 
None 
After 
consultation 
with PI 
None 
None 
 
6.3 
Management of Observed Flotetuzumab Infusion Reactions and Infusion-
related Adverse Events 
 
The following are treatment guidelines (which may be modified as needed by the 
responsible Investigator according to the best practices of medicine) for flotetuzumab IRRs 
including CRS. Early intervention at the first signs of IRR/CRS, including pyrexia, 
tachycardia, tachypnea and/or hypotension in the absence of alternative etiologies and in 
consistent temporal relationship to administration of flotetuzumab, should be undertaken. 
 
IRR/CRS is a commonly observed event during treatment with flotetuzumab 89.6% of the 
115 patients receiving flotetuzumab monotherapy experiencing at least 1 event of Grade 1-
3 IRR/CRS, as of the data cut-off date of 21 April 2020 from the most current MacroGenics 
IB v9.0. Based on current understanding gained with patients treated with CAR-T cells 
(which have a T-cell activating mechanism of action in common with flotetuzumab), CRS 
is likely to be a common toxicity that can be managed through supportive care and anti-
cytokine interventions to allow for full activity of T cells during therapy. In the 2019 
ASTCT Consensus Guidelines for grading and management of CRS proposed by Lee, et 
al (18), intensive supportive care and treatment of the underlying cause of the CRS 
(excessive cytokine production) is recommended before the event must be considered 
Grade 3 or Grade 4 severity. Adopting this definition of CRS as described in Table 5, and 
concomitantly modifying the guidelines for management of IRR/CRS (below), will allow 
for more flexible management of patients who develop CRS and who may nonetheless 
experience clinical benefit despite the need to manage through mild or moderate infusion 
reactions while not jeopardizing overall safety. 
 
IRR/CRS will be graded according to the definitions described below in Table 5.  
 
Table 5: Adapted from the ASTCT CRS Consensus Grading Criteria 
Toxicity 
Grade 
Characteristics 
Grade 1 Temperature >38°C, no hypotension or hypoxia. 
Grade 2 Temperature >38°C, not requiring vasopressors and/or requiring <6L/minute oxygen 
support. 
Grade 3 
Temperature >38°C, requiring a vasopressor (with or without vasopressin) and/or 
requiring >6L/minute oxygen support (via high flow nasal cannula, facemask, 
non-rebreather or Venturi mask). 
Grade 4 
Temperature >38°C, requiring multiple vasopressors (not including vasopressin) 
and/or requiring positive pressure ventilation (including CPAP, BiPAP and 
intubation/mechanical ventilation 

 
 
Protocol Version: 02/28/2024  
 
Page 36 of 76 
 
Grade 5 Death 
Source: Lee DW, et al. (18) 
 
The above grading scale (Table 5) should be used to grade all infusion reactions in this 
study, irrespective of the underlying mechanism of the reaction. Certain AEs may occur in 
temporal proximity to infusion of study drug and therefore, be considered “infusion-
related” while not being considered an “infusion reaction;” such events may be graded 
separately according to CTCAE specific criteria. 
 
IRR/CRS should be managed as described below, when possible. Every attempt should be 
made to continue the infusion during management of the reaction, however decisions to 
change or hold the infusion should ultimately be left to the discretion of the treating 
physician.  
 
Table 6: Guidelines for Managing Infusion Reactions and Cytokine Release 
Syndrome* 
Grade/Event 
Procedures for Management 
Grade 1  
Infusion 
Reactions, 
including 
Cytokine  
Release 
Syndrome (CRS) 
• 
Slow the infusion rate by 10%-20%; 
• 
Monitor the patient for worsening of condition; 
• 
Administer IV fluids, diphenhydramine 50 mg IV, 
acetaminophen 1000 mg PO or ibuprofen 400 mg PO for 
fever, and oxygen and bronchodilators for mild 
bronchospasm, as appropriate; 
• 
Obtain infectious work-up as clinically indicated (UA, 
blood cultures, imaging, etc) and consider empiric 
antibiotics per institutional guidelines 
• 
Corticosteroids should not be used for Grade 1 IRR/CRS. 
• 
Continue infusion at reduced rate and slowly increase 
infusion rate to the original rate in 2 steps after stabilization 
or resolution of symptoms every 4-6 hours, as tolerated. A 
more gradual increase in the rate of infusion may be 
undertaken after consultation with the PI. 
 
Grade 2 
Infusion reactions 
and infusion-
related events 
• 
Slow the infusion rate by 25%-50%; 
• 
Administer IV fluids, diphenhydramine 50 mg IV, 
acetaminophen 1000 mg PO or ibuprofen 400 mg PO for 
fever, and oxygen and bronchodilators for bronchospasm, as 
appropriate and if not administered previously; 
• 
If not already performed, obtain infectious work-up as 
clinically indicated (UA, blood cultures, imaging, etc) and 
consider empiric antibiotics per institutional guidelines 
• 
Tocilizumab (8 mg/kg IV) should be used for Grade 2 
IRR/CRS that does not resolve with other measures within 2 
hours, or that requires the use of supplemental oxygen > 4 L 
by nasal cannula.  Tocilizumab dosing may be repeated in 8 
hrs if not improved to Grade 1, with a maximum total of up 
to 4 doses for each CRS event. 

 
 
Protocol Version: 02/28/2024  
 
Page 37 of 76 
 
Grade/Event 
Procedures for Management 
• 
Corticosteroids may be used for Grade 2 IRR/CRS that 
does not respond to other measures, including tocilizumab 
• 
Continue infusion at reduced rate and slowly increase 
infusion rate to the original rate gradually by half-rate 
increments (i.e., if rate is reduced from 5 mL/hr to 2.5 
mL/hr increase to ~3.75 mL/hr, then 4.5 mL/hr, then 5 
mL/hr) after stabilization or resolution of symptoms every 
4-6 hours, as tolerated. A more gradual increase in the rate 
of infusion may be undertaken after consultation with the 
PI. 
• 
Report as an immediately reportable event (IRE); 
• 
Report the event as a serious adverse event (SAE), if 
appropriate. 
• 
Monitor for worsening condition. 
 
Grade 3 
Infusion Reaction 
and infusion-
related events 
• 
Stop the infusion, 
• 
TO AVOID EXACERBATION OF INFUSION REACTION 
OR CRS: DO NOT FLUSH THE TUBING – ASPIRATE 
RESIDUAL DRUG FROM THE PORT LUMEN; 
• 
Administer IV fluids, diphenhydramine 50 mg IV, 
acetaminophen 1000 mg PO or ibuprofen 400 mg PO for 
fever, and oxygen and bronchodilators for mild 
bronchospasm, as appropriate. 
• 
Provide appropriate circulatory support including 
vasopressors as medically indicated; 
• 
If not already performed, obtain infectious work-up as 
clinically indicated (UA, blood cultures, imaging, etc) and 
consider empiric antibiotics per institutional guidelines 
• 
Administer tocilizumab if not administered previously. 
If  administered previously, an additional dose may be 
administered in 8 hours for prolonged or recurrent 
episodes, with a maximum total of up to 4 doses for 
each CRS event. 
• 
Grade 3 IRR/CRS that is refractory to tocilizumab should 
be treated with corticosteroids; doses of dexamethasone 
(or equivalent) of greater than 30 mg may be required. 
• 
Resume the infusion at previously tolerated dose once the 
infusion reaction has resolved or decreased to Grade 1. 
Increase dose rate to the original rate, per protocol, e.g., 
500 ng/kg/day, by increasing the dose in near double 
increments as tolerated after stabilization or resolution of 
symptoms every 4-6 hours. A more gradual increase in the 
rate of infusion may be undertaken after consultation with 
the PI. 
• 
Report the event as a serious adverse event (SAE), if 
appropriate. 

 
 
Protocol Version: 02/28/2024  
 
Page 38 of 76 
 
Grade/Event 
Procedures for Management 
• 
Discontinue the infusion if not resolved to Grade 1 within 72 
hours. 
 
Grade 4  
Infusion reactions 
and infusion-
related events 
• 
Stop the infusion and disconnect the infusion tubing from the 
patient; 
• 
TO AVOID EXACERBATION OF INFUSION REACTION 
OR CRS: DO NOT FLUSH THE TUBING – ASPIRATE 
RESIDUAL DRUG FROM THE PORT LUMEN; 
• 
Administer IV fluids, diphenhydramine 50 mg IV, 
acetaminophen 1000 mg PO or ibuprofen 400 mg PO or 
paracetamol 1000 mg PO for fever, and oxygen and 
bronchodilators for mild bronchospasm, as appropriate; 
• 
Provide appropriate ventilator and circulatory 
support as medically indicated; 
• 
If not already performed, obtain infectious work-up as 
clinically indicated (UA, blood cultures, imaging, etc) and 
consider empiric antibiotics per institutional guidelines 
• 
Agents including those listed below have been 
described in the management of patients with severe 
complications of cytokine storm and/or severe 
immune-related adverse events, and may be required: 
o high doses of corticosteroids above dexamethasone 
30 mg (or equivalent) 
o tocilizumab (anti-IL6 receptor) 8 mg/kg IV, administered 
every 8 hours as indicated with a maximum total of up to 4 
doses for each CRS event 
• 
Notify the PI immediately; 
• 
Report the event as an SAE. Patients who have a Grade 4 
IRR/CRS should not receive further flotetuzumab. 
 
Grade 5 
Infusion reactions 
and infusion-
related events 
• 
Notify the PI or designee immediately. 
• 
Report the event as an SAE. 
* Table provides guidelines but treating physician should follow their discretion to manage and grade CRS/IRR 
Other types of adverse reactions may be observed during infusion that are not interpreted 
as related to cytokine release, but may be related to flotetuzumab. Such reactions should 
be diagnosed, graded and managed according to best practices.  
 
6.4 
Graft versus Host Disease 
 
Use of flotetuzumab has not been evaluated in the post-allo-HCT setting, therefore the 
impact of flotetuzumab on acute or chronic GVHD is unknown. Theoretically, the 
mechanism of action of flotetuzumab may redirect allo-reactive T cells toward malignant 
cells and thus reduce GHVD. In pre-clinical pharmacodynamic data, flotetuzumab displays 
a 10-fold greater affinity for human CD123 to favor initial binding to the CD123+ target 

 
 
Protocol Version: 02/28/2024  
 
Page 39 of 76 
 
cell and minimize CD3 engagement in the absence of target cells. It is also possible that 
there will be no impact of flotetuzumab on the incidence or severity of GVHD, or that it 
will exacerbate GVHD. The administration of a DLI is associated with GVHD rates as high 
as 60-70%, depending on cell dose and other factors. Therefore, it is expected that patients 
who receive a DLI concurrent with flotetuzumab may experience new onset GVHD or 
worsening of pre-existing GVHD.  
 
Accordingly, patients with active GVHD requiring systemic immunosuppression with 
more than 0.5mg/day prednisone will be excluded from the trial; in addition, careful 
monitoring for interval development of new or worsening GVHD for patients on trial is 
warranted. 
 
Acute and Chronic GVHD assessments (See Appendices F and G) will be performed to 
evaluate the presence of acute and chronic GVHD at screening/baseline, prior to initiation 
of Cycle 1 and prior to the initiation of Cycle 2, with documentation as below (Section 
7.7.1 and 7.7.2). Additionally, patients should be monitored during treatment for 
development of new or worsening GVHD with appropriate assessment/grading as 
clinically indicated in the opinion of Investigators. 
 
6.4.1 Acute GVHD Assessment  
 
Acute GVHD assessment will be documented with date of onset, grade, and organs 
affected (see Appendix F). Of note, evaluation for alternative etiologies for new or 
worsening rash, LFT changes or diarrhea should be pursued according to 
institutional practice and standards of care. Rashes, LFT elevations and diarrhea 
determined to be explained by an alternative etiology (i.e. not due to aGVHD) 
should not be included in the Acute GVHD Assessment. 
 
6.4.2 Chronic GVHD Grading/Assessment 
 
Chronic GVHD Assessment will be documented with date of onset, grade, and 
organs affected. See Appendix G. Of note, evaluation for alternative etiologies for 
new or worsening findings on the below listed assessments should be pursued 
according to institutional practice and standards of care. For example, rashes, LFT 
elevations and diarrhea determined to be explained by an alternative etiology (i.e. 
not due to cGVHD) should not be included in the Chronic GVHD Assessment. 
 
6.4.3 Dose Delays and Modifications for aGVHD and cGVHD 
 
Table 7: Dose Delays and Modifications for aGVHD 
MAGIC Grade I 
GVHD 
The presence of new or worsening MAGIC Grade I GVHD 
should warrant standard of care therapies for 
commensurate GVHD level and does not require any dose 
modifications to the flotetuzumab.  
 

 
 
Protocol Version: 02/28/2024  
 
Page 40 of 76 
 
MAGIC Grade II 
GVHD 
The presence of new or worsening MAGIC Grade II 
GVHD should warrant standard of care therapies for 
commensurate GVHD and the does not require any dose 
modifications to the flotetuzumab. Persistent Grade II 
GVHD not improving with SOC interventions and 
supportive care within 24-48 hours requires a 25-50% dose 
reduction in flotetuzumab with continued SOC 
interventions, supportive care and continued monitoring of 
aGVHD severity. Uptitration of flotetuzumab to target 
dose may be attempted as per CRS protocol upon 
improvement of GVHD Grade to Grade I or better. 
However, persistent Grade II GVHD not improving with 
SOC interventions and with 25-50% dose reduction after 
48-72 hours requires an immediate hold of flotetuzumab. 
Reinitiation of flotetuzumab with resolution of GVHD 
severity to Grade I or better can be attempted, resuming at 
25-50% of the target dose and uptitration as per CRS 
protocol. 
 
MAGIC Grade III 
GVHD 
The presence of MAGIC Grade III GVHD should warrant 
standard of care therapies for commensurate GVHD and 
requires immediate hold of flotetuzumab.  SOC 
interventions and supportive cares should be continued 
with daily assessment of GVHD Grade. Reinitiation of 
flotetuzumab with resolution of GVHD severity to Grade I 
or better can be attempted, resuming at 25-50% of the 
target dose and uptitration as per CRS protocol.  
 
MAGIC Grade IV 
GVHD 
The presence of MAGIC Grade IV GVHD should warrant 
standard of care therapies for commensurate GVHD and 
requires immediate hold of flotetuzumab.  SOC 
interventions and supportive cares should be continued 
with daily assessment of aGVHD Grade. Reinitiation of 
flotetuzumab should not be attempted. 
 
 
Table 8: Dose Delays and Modifications for cGVHD (see NIH cGVHD Severity 
Score in Appendix G) 
Mild cGVHD 
The presence of new or worsening Mild cGVHD should 
warrant standard of care therapies for commensurate 
GVHD level and does not require any dose modifications 
to the flotetuzumab. 
 
Moderate cGVHD 
The presence of new or worsening Moderate cGVHD 
when baseline assessment prior to flotetuzumab was rated 
as Mild or better should warrant standard of care therapies 

 
 
Protocol Version: 02/28/2024  
 
Page 41 of 76 
 
for commensurate GVHD and the does not require any 
dose modifications to the flotetuzumab. Persistent 
Moderate cGVHD not improving with SOC interventions 
and supportive cares within 24-48 hours requires a 25-50% 
dose reduction in flotetuzumab with continued SOC 
interventions, supportive cares and continued monitoring 
of cGVHD severity. Uptitration of flotetuzumab to target 
dose may be attempted as per CRS protocol upon 
improvement of cGVHD to Mild or better. However, 
persistent Moderate cGVHD not improving with SOC 
interventions and with 25-50% dose reduction after 48-72 
hours requires an immediate hold of flotetuzumab. 
Reinitiation of flotetuzumab with resolution of cGVHD 
severity to Mild or better can be attempted, resuming at 25-
50% of the target dose and uptitration as per CRS protocol. 
 
Severe cGVHD 
The presence of Severe cGVHD should warrant standard 
of care therapies for commensurate GVHD and requires 
immediate hold of flotetuzumab.  SOC interventions and 
supportive cares should be continued with daily assessment 
of cGVHD Grade.  Reinitiation of flotetuzumab should not 
be attempted. 
 
 
6.5 
Tumor Lysis Syndrome 
 
Tumor lysis syndrome (TLS) is the most common disease-related emergency encountered 
by physicians caring for children or adults with hematologic cancers. Characteristic 
findings are hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. These 
electrolyte and metabolic disturbances can progress to clinical toxic effects, including renal 
insufficiency, cardiac arrhythmias, seizures, and death due to multi-organ failure. 
 
Prophylaxis for TLS should be administered for patients with AML. Aggressive hydration, 
allopurinol, and oral phosphate binders should be implemented starting preferably 24 hours 
before flotetuzumab administration. Serum chemistries should be closely monitored during 
flotetuzumab administration in accordance with institutional standards for the treatment of 
acute leukemia. If TLS is observed, rasburicase should be considered for management as 
per institutional standards. Patients who develop TLS should be monitored closely for 
abnormal serum chemistries or signs of end organ damage and treated appropriately. 
 
6.6 
Neutropenic Sepsis/Fungemia 
 
While there is no evidence that flotetuzumab targets and depletes neutrophils in vitro in 
human samples or decreases circulating neutrophils in monkeys receiving the drug, caution 
should be exercised in assessing the possibility of infections. Early initiation of empiric 
broad-spectrum antimicrobials is recommended in the event of fever. 

 
 
Protocol Version: 02/28/2024  
 
Page 42 of 76 
 
 
Several monotherapy or multicomponent regimens have been employed. Investigators 
should employ these agents in compliance with best medical practices and institutional 
guidelines and standards. If fever persists for 4 to 7 days, an echinocandin or liposomal 
amphotericin B should be considered. The use of recombinant hematopoietic growth 
factors in AML is controversial. Their use is specifically prohibited in Cycle 1. However, 
beyond Cycle 1, while discouraged, their use is not specifically prohibited by this protocol 
and they may be employed at the discretion of the Investigator. 
 
6.7 
Immune-related Adverse Experiences 
 
Immune checkpoint blockade has been associated with several syndromes resulting from 
the breaking of immunological tolerance. Although not observed in non-clinical studies to 
date, similar immunomodulation might be expected with flotetuzumab. These syndromes 
include: pneumonitis, colitis, autoimmune hepatitis, arthritis, glomerulonephritis, 
myocarditis and cardiomyopathy, hypophysitis, or thyroiditis. Their occurrence dictates 
interruption, and potentially discontinuation, of study drug administration pending further 
evaluation. 
 
6.8 
Neurotoxicity Monitoring 
 
Neurotoxicity, including changes in mental status, has been reported with other T-cell 
directed therapies including chimeric-antigen receptor (CAR)-T cells and CD3xCD19 
based bispecific antibodies such as blinatumomab. The exact mechanism of the toxicity is 
unknown. As a result, additional monitoring of patients receiving flotetuzumab is 
indicated. An alteration in mental status refers to general changes in brain function, such 
as confusion, amnesia, loss of alertness, disorientation, defects in judgment or thought, and 
disruption in perception and psychomotor skills. Patients should be monitored for changes 
in mental status or other potential neurotoxic events and should be evaluated for orientation 
to time, place and person at baseline prior to treatment with flotetuzumab and at regular 
intervals during therapy. 
 
Any suspected neurotoxic event should prompt full evaluation including imaging studies, 
lumbar puncture and neurological consultation as indicated to rule out other causes. The 
incidence of CNS involvement by AML is low and routine lumbar puncture is not generally 
considered indicated. Patients with known, active CNS leukemia are excluded from the 
study and those with suspected disease must be evaluated by lumbar puncture prior to 
enrollment. See Appendix E for grading, evaluation and management of neurotoxicity. 
 
 
7.0 
CORRELATIVE STUDIES  
 
Patient material will be obtained at Barnes-Jewish Hospital or in the Siteman Cancer Center. 
Samples will be identified with the patient’s name, date of birth and clinic or hospital number. The 
Stem Cell Transplantation Core analyst or a designated person will be responsible for removal of 
this information from the sample container and its replacement by a label containing a Unique 
Patient Number (UPN) and sample number. Any paper copies of the master code listing UPN and 

 
 
Protocol Version: 02/28/2024  
 
Page 43 of 76 
 
sample numbers with the patient names will be kept in a locked storage. Any electronic copies of 
the master code will be kept in a secured network. Access to either paper or electronic copies will 
be restricted to the Principal and Sub-Investigators of this study and associated study personnel.  
 
Stem Cell Transplantation Core personnel will be responsible for transport of the specimens to the 
pre-defined laboratories for processing. Specimens will be identified by UPN and sample number 
and will be processed and stored at the pre-defined lab. Each lab will be responsible for sample 
processing, storage, and delivery of specimens according to established standard operating 
procedure documents generated for the purpose of this trial. The pre-defined lab will be responsible 
for establishing and maintaining standardized operating procedures as it relates to sample handling.  
 
All samples should be sent to:  
Siteman Cancer Center Tissue Procurement Core Facility  
425 S. Euclid Ave., Rm 5120  
St. Louis, MO 63110  
Phone: 314-454-7615  
Fax: 314-454-5525  
Email: tbank@pathology.wustl.edu 
 
OR 
 
Dr. Matt Christopher’s Laboratory  
Washington University School of Medicine  
4940 Parkview  
St. Louis, MO 63110  
Contact Person: Tyler Elmendorf  
Phone: 314-273-0286  
Email: elmendorft@wustl.edu 
 
During each BM Bx, samples for correlative studies will be obtained and banked at the following 
time points: (2-3 ml bone marrow aspirate in 1 EDTA tube per time point): 
• Screening/Baseline 
• Cycle 1 Day 14 (optional, at discretion of Principal Investigator.) 
• Cycle 1 Day 28 
• Cycle 2 Day 28 
• At relapse or progression of disease 
 
 
In addition, peripheral blood will be obtained from patients at these time points:  
• Cycle 1 Day 1 (pre-flotetuzumab dose) 
• Cycle 1 Day 7 (pre-week 2 infusion) 
• Cycle 1 Day 14 (pre-week 3 infusion) 
• Cycle 1 Day 21 (pre-week 4 infusion) 
• Cycle 1 Day 28 (with C1D28 bone marrow biopsy) 
• Cycle 2 Day 1 (pre-flotetuzumab) 
• Cycle 2 Day 7 (pre-week 2 infusion) 

 
 
Protocol Version: 02/28/2024  
 
Page 44 of 76 
 
• Cycle 2 Day 14 (pre-week 3 infusion) 
• Cycle 2 Day 21 (pre-week 4 infusion) 
• Cycle 2 Day 28 (with C2D28 bone marrow biopsy) 
• At the time of disease relapse/progression.  
 
These de-identified samples will be analyzed at a later time point at the discretion of the principal 
investigators and/or MacroGenics. 
 
 
8.0 
PHARMACEUTICAL INFORMATION 
 
8.1 
Flotetuzumab 
 
8.1.1 Flotetuzumab Description 
 
Flotetuzumab is a CD123 x CD3 bi-specific antibody-based molecular construct 
referred to as a DART molecule. Its purpose is to bring into close proximity 
immune effector cells bearing the CD3 antigen, which is a component of the T cell 
antigen receptor complex, and target cells bearing the CD123 antigen, which is a 
component of the interleukin-3 receptor. As a result of opposing the two cells and 
activating the T cell, it is hypothesized that the neoplastic cells will be killed. 
 
Flotetuzumab drug product (DP) is provided as a clear to slightly opalescent, 
colorless to pale yellow 5 mL sterile aqueous solution with a protein concentration 
of 0.1 mg/mL in a buffer composed of 10 mM sodium phosphate at pH 6.0, 150 
mM sodium chloride, and 0.1 mg/mL polysorbate 80. 
 
The concentration, function, and grade of each component in the DP are 
summarized below. 
 
Flotetuzumab Drug Product Composition 
 
Name of Ingredient 
Concentration 
(mg/mL) 
Nominal Amount 
per Vial (mg) a 
Function 
Flotetuzumab DS 
0.10 
0.50 
Active 
ingredient 
Sodium phosphate 
monobasic 
monohydrate 
1.13 
5.65 
Buffer 
component 
Sodium phosphate 
dibasic 
0.26 
1.3 
Buffer 
component 
Sodium chloride 
8.78 
43.9 
Tonicifier 
Polysorbate 80 
0.10 
0.50 
Surfactant 
Abbreviations: DS, drug substance 
a. Amount based on 5.0 mL fill volume; vial contains approximately 0.30 mL overfill to deliver 5 mL. 
 

 
 
Protocol Version: 02/28/2024  
 
Page 45 of 76 
 
8.1.2 Clinical Pharmacology 
 
The predicted mechanism of action of flotetuzumab is the creation of an 
immunological synapse between the leukemic blast target cell bearing CD123 and 
immune effector cells bearing the T cell-specific CD3 complex, leading to T cell 
activation and killing of the leukemic cell.  
 
8.1.3 Pharmacokinetics and Drug Metabolism 
 
See Section 5.4 of the Investigator’s Brochure for preliminary PK results from 
Study CP-MGD006-01. Overall, initial review of the data shows that there was high 
interpatient variability, but no obvious deviation of linearity across different doses. 
Preliminary analysis of flotetuzumab serum concentration indicates flotetuzumab 
PK is best fit by a two compartment PK model. In addition, flotetuzumab 
demonstrates a high clearance rate and a short half-life, as expected. Steady state 
volumes suggest there is high tissue distribution and/or binding. These data 
continue to be evaluated. 
 
8.1.4 Supplier(s) 
 
Flotetuzumab will be provided by MacroGenics Inc. 
 
Flotetuzumab Drug Product 
Flotetuzumab Drug Product is supplied as 0.5 mg/5 mL (0.1 mg/mL) sterile 
aqueous solution packaged in a USP and Ph. Eur. conforming Type I borosilicate, 
5 mL clear glass vial with a 20 mm FluroTec-coated 4432/50 gray butyl rubber 
serum stopper. The vial is sealed with a 20 mm TruEdge aluminum closure with a 
plastic overseal. 
 
MGV004 Vehicle 
The MGV004 IV Solution Stabilizer is supplied as a sterile solution of The 
MGV004 IV Solution Stabilizer is packaged in a USP and Ph. Eur. conforming 
Type I borosilicate, 50 mL clear glass vial with a 20 mm FluroTec and B2-40-
coated 4023/50 gray butyl rubber serum stopper and sealed with a 20 mm TruEdge 
aluminum closure with a plastic overseal. 
 
MGV002 Vehicle 
MGV002 IV Solution Stabilizer is a sterile, clear-colorless solution presented in a 
single use glass vial. The MGV002 IV Solution Stabilizer is supplied as a sterile 
solution containing 0.9% sodium chloride solution with 0.1 mg/mL polysorbate 80. 
The MGV002 IV Solution Stabilizer is packaged in a USP and Ph. Eur. conforming 
Type I borosilicate, 50 cc clear glass vial with a 20 mm -4432/50 gray butyl rubber 
serum stopper and sealed with a 20 mm TruEdge aluminum closure with a plastic 
overseal. 
 

 
 
Protocol Version: 02/28/2024  
 
Page 46 of 76 
 
8.1.5 Dosage Form and Preparation 
 
Flotetuzumab DP is provided as a clear to slightly opalescent, colorless to pale 
yellow 5 mL sterile aqueous solution with a protein concentration of 0.1 mg/mL in 
a buffer composed of 10 mM sodium phosphate at pH 6.0, 150 mM sodium chloride 
and 0.1 mg/mL polysorbate 80. 
 
The flotetuzumab dose solution can be prepared for administration from a syringe, 
an ambulatory cassette or a standard infusion bag. The administration options 
include the use of a syringe pump, dual ambulatory pumps, a single ambulatory 
pump, or standard IV infusion pump. Instructions for the preparation and 
administration of flotetuzumab are detailed in the Pharmacy Manual. 
 
Important: Flotetuzumab MUST NOT BE ADMINISTERED AS AN IV PUSH 
OR BOLUS. 
 
Flotetuzumab should not be mixed with other drugs or diluted with any solution 
other than MGV004 Vehicle or MGV002 Vehicle when administering the drug by 
24-hour infusion.  
 
Errors in dilution could result in fatal cytokine release syndrome; please refer to the 
Pharmacy Manual for further details on dosing schedule and dose preparation. 
 
8.1.6 Storage and Stability 
 
Vials containing flotetuzumab and MGV004 Vehicle or MGV002 Vehicle should 
be stored upright under refrigeration at 2°–8°C (36°–46°F) in an appropriate, 
locked room accessible only to pharmacy personnel, the Investigator, or a duly 
designated person. flotetuzumab and MGV004 Vehicle or MGV002 Vehicle must 
not be frozen. Monitor temperature and document and report any excursions as 
instructed in the Pharmacy Manual. Protect from light during storage as described 
in the Pharmacy Manual. DO NOT SHAKE. Use standard laboratory practices for 
avoidance of contact. Recommended safety measures for handling and preparation 
include masks, protective clothing, gloves, and vertical laminar airflow safety 
cabinet. 
 
Follow standard hygiene practices, such as hand washing after handling. If material 
is released or spilled, soak up material with absorbent material and wash spill area 
thoroughly with soap and water. Dispose of collected material in accordance with 
applicable waste disposal regulations. 
 
8.1.7 Administration 
 
When administered by syringe pump or dual ambulatory pump configuration over 
24 hours, flotetuzumab must be diluted prior to administration with appropriate 
custom vehicle, MGV004 Vehicle (2.2 mg/mL sodium phosphate monobasic 

 
 
Protocol Version: 02/28/2024  
 
Page 47 of 76 
 
monohydrate, 0.52 mg/mL sodium phosphate dibasic anhydrous, 13.2 mg/mL 
benzyl alcohol, 4.25 mg/mL methyl 4-hydroxybenzoate sodium salt (methyl 
paraben), and 0.25 mg/mL polysorbate 80, pH 8.2 ) or MGV002 Vehicle (0.9% 
sodium chloride solution with 0.1 mg/mL polysorbate 80). 
 
8.1.8 Special Handling Instructions 
 
Precautions: Patients with known hypersensitivity to recombinant proteins, 
polysorbate 80, recombinant human serum albumin, benzyl alcohol, or any 
excipient contained in the flotetuzumab drug formulation should not receive 
flotetuzumab. 
 
Infusion-related reactions including hypersensitivity/anaphylactic/anaphylactoid 
reactions or cytokine release syndrome may occur. Precautions for the management 
of these reactions should be observed during flotetuzumab administration. 
 
 
9.0 
DATA SUBMISSION SCHEDULE 
 
Case report forms with appropriate source documentation will be completed according to the 
schedule listed in this section. 
 
Case Report Form 
Submission Schedule 
On-Study Form 
Concomitant Meds Form 
Medical History Form 
Treatment History Form 
Prior to starting treatment (meds given to treat CRS and ICANS 
collected throughout treatment) 
Treatment Form 
Every cycle 
Acute GVHD form 
Chronic GVHD form 
C1D1, C1D28,  C2D7, C2D14, C2D21, C2D28, Follow-up 
Toxicity Form 
Stopping Rules form 
Continuous 
Treatment Summary Form 
Completion of treatment 
Follow Up Form 
Every 6 months for 2 years 
Research Bone Marrow 
Collection Form 
Baseline, C1D14, C1D28, C2D28, suspected disease relapse or 
progression. 
Response Assessment Form Baseline, C1D28, C2D28, end of treatment 
Progression Form 
Time of disease progression 
Death Form 
Time of death 
MedWatch Form 
See Section 13.0 for reporting requirements 
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 48 of 76 
 
10.0 
MEASUREMENT OF EFFECT 
 
Disease activity will be assessed using CBC and peripheral blood cell morphological examination, 
examination of bone marrow biopsy, and physical examination. For AML, modifications to the 
Revised Recommendations of the International Working Group for Diagnosis (IWG), 
Standardization of Response Criteria, Treatment Outcomes, and Reporting Standards for 
Therapeutic Trials in Acute Myeloid Leukemia will be used. See table below. 
 
Complete remission (CR) 
Bone marrow blasts <5%; absence of circulating blasts and blasts 
with Auer rods; absence of extramedullary disease; ANC ≥1.0 × 
109/L (1000/µL); platelet count ≥100 × 109/L (100,000/µL), 
transfusion independence 
CR with incomplete hematologic 
recovery (CRi) 
All CR criteria except for residual neutropenia (<1.0 × 109/L 
[1000/µL]) or thrombocytopenia (<100 × 109/L [100,000/µL]) 
Morphologic leukemia-free state 
(MLFS) 
Bone marrow blasts <5%; absence of blasts with Auer rods; 
absence of extramedullary disease; no hematologic recovery 
required 
Partial remission (PR) 
All hematologic criteria of CR; decrease of bone marrow blast 
percentage to 5 to 25%; and decrease of pretreatment bone marrow 
blast percentage by at least 50% 
Stable disease (SD) 
Absence of CR, CRi, PR, MLFS; and criteria for PD not met 
Progressive disease (PD) 
Evidence for an increase in bone marrow blast percentage (>50% 
over baseline), and/or increase of absolute blast counts in the 
blood (>50% to >25 × 109/L) without differentiation syndrome, or 
new extramedullary disease 
 
Time to response (first or best response) will be calculated from the time of first dose of study drug 
to the time of initial response. Response duration and time to response will be calculated for 
patients who achieve an objective response. Progression free survival and overall survival will be 
calculated as the time from the start of the first dose of study drug until the occurrence of disease 
progression or death from any cause, respectively.  
 
 
11.0 
STATISTICAL CONSIDERATIONS 
 
11.1 
Hypothesis 
 
Flotetuzumab for relapsed AML following allo-HCT will result in improved response rates 
compared to historical response rates with chemotherapy or HMA monotherapy 
 
11.2 
Primary Endpoint  
 
The primary endpoint will be efficacy assessed via composite endpoint of CR and CRi 
(Cycle 1 Day 28 assessment). 
 
Efficacy Endpoint will be defined as a combined endpoint of complete response (CR) and 
complete response with incomplete hematologic recovery (CRi), per International Working 
Group criteria (Table 2, and above.) 

 
 
Protocol Version: 02/28/2024  
 
Page 49 of 76 
 
 
11.3 
Sample Size Estimate 
 
Twenty-five evaluable patients will be enrolled for this study. Assuming a single treatment 
arm compared to historical controls treated with chemotherapy alone or HMA 
monotherapy using a dichotomous endpoint of CR/CRi vs not CR/CRi (as defined by the 
Primary Endpoint, as above), based on Simon’s Minimax two-stage design, we estimate a 
sample size of 25 patients would provide 80% power (alpha 0.05) to detect a difference 
between a 10% CR/CRi rate in historical controls treated with chemotherapy or 
hypomethylating agents alone (10, 11) compared to 30% CR/CRi rate in the treatment arm 
(effect size 20%).   
 
11.4 
Stopping rules for futility 
 
Fifteen patients will be enrolled in the first stage.  This cohort will include all patients who 
have been treated, including those who withdraw from the study.  If at least 2 CR/CRi are 
observed out of the 15 patients, then an additional 10 patients will be enrolled. If 6 or more 
CR/CRi are observed from this cohort of 15 patients, we would conclude that there is 
evidence of efficacy to warrant further investigation. There is less than 5% chance to stop 
the trial at stage 1 if the “true” response is 30% or higher. Conversely, there will be 55% 
chance to terminate the study early if the true rate is only 10% or less.  
 
11.5 
Safety monitoring and determination of excess toxicity 
 
To minimize risk to patients on study, we will perform interval analyses to determine if 
excess treatment-associated toxicity is observed during the trial.   Toxicity may occur due 
to treatment with flotetuzumab, DLI administration, or unknown factors.    Since GVHD 
may be an expected result of DLI, there will be separate stopping rules for excess non-
GVHD toxicity and for GVHD toxicity.  
 
11.5.1 Excess non-GVHD toxicity 
 
Excess non-GVHD toxicity will be defined as a combined incidence of > 20% of 
any of the following: 
• ≥ Grade 3 non-hematologic AE at least possibly attributable to protocol 
treatment, with the following exceptions: 
o 
Grade 3 fatigue, asthenia, fever, constipation or anorexia (if anorexia 
does not result in hospitalization, tube-feeding or use of total 
parenteral nutrition [TPN]) 
o 
Grade 3 nausea, vomiting or diarrhea not requiring tube feeding, TPN, 
or requiring or prolonging hospitalization 
o 
Infection, bleeding, or other expected direct complications of 
cytopenias due to active underlying leukemia 
o 
Grade 3 infusion reaction including CRS, if successfully managed 
clinically and resolves within 7 days without end-organ damage 
o 
Grade 3 or 4 isolated electrolyte abnormalities that last < 72 hours 

 
 
Protocol Version: 02/28/2024  
 
Page 50 of 76 
 
• Grade 4 neutropenia or thrombocytopenia lasting ≥ 42 days from the start 
of the cycle in the absence of MDS/AML 
• Evidence of drug-induced liver injury based on presence of any of the 
following abnormalities without an alternate explanation: 
o 
ALT or AST >8x ULN  
o 
ALT or AST >5x ULN for more than 2 weeks 
o 
ALT or AST >3x ULN and (TBL >2xULN or INR >1.5) 
o 
ALT or AST >3x ULN with the appearance of fatigue, nausea, 
vomiting, right upper quadrant pain or tenderness, fever, rash, and/or 
eosinophilia (>5%) 
 
11.5.2 Excess GVHD toxicity 
 
Excess GVHD toxicity will be defined as a > 25% incidence of Grade III-IV acute 
GVHD or severe chronic GVHD occurring at any time during treatment. 
  
11.6 
Stopping rules for safety 
 
A Bayesian sequential monitoring rule will be implemented for safety. The stopping rule 
is defined as Pr(θ > θT |data) >0.8, where θ denotes the proportion of toxicities (as defined 
in Section 11.5) and θT denotes the expected serious toxicity rate for study treatments (set 
as θT = 20% for non-GVHD toxicity and 25% for GVHD toxicity).  Interval analyses will 
be performed after every five evaluable patients (see 11.8 for patient evaluability).  If the 
accumulated observed data suggests a high chance (i.e., >80% probability) for the “true” 
toxicity (as defined in Section 11.5) to be >20% for non-GVHD events or 25% for GVHD 
events, enrollment will be paused and data for assessment of early stopping will be sent to 
QASMC for review to consider study termination.  The following tables show the number 
of patients with the number of adverse events that would result in a pause of enrollment to 
assess premature stopping of the trial.  The stopping boundaries were obtained using 
Multc99 version 2.1, a free-download software from M.D. Anderson Cancer Center 
(https://trialdesign.org/one-page-shell.html#BTOX). Specifically, we assume that the 
parameter θ follows a prior distribution of beta (1,1), i.e., θ with mean = 0.5 but with 
relatively large variability (non-informative prior). Early stopping will be recommended if 
we observe 2 non-GVHD events out of the first 6 or 2 GVHD events out of first 5 patients, 
etc. (see Tables below), in patients treated in this trial.  A simulation study is also 
performed to assess the operating characteristics for the above stopping rule (all scenarios 
are based on 10,000 simulated trials). For non-GVHD events, there will be only 15% 
chance to stop early if the “true” toxicity rate is 10%. In contrast, we will have 88% chance 
to stop early (with a median of 10 patients treated) if the “true” toxicity rate on 
flotetuzumab monotherapy is 30%. For GVHD events, there will be only 21% chance to 
stop early if the “true” rate is 15% and there will be 86% chance to stop early (with a 
median of 5 patients treated) if the “true” rate is 35%.  
 

 
 
Protocol Version: 02/28/2024  
 
Page 51 of 76 
 
Stopping rules for non-GVHD toxicity: 
# Patients treated 
5 
10 
15 
20 
25 
Stop if the # Grade ≥ 
3 non-hematologic 
toxicity   
2 
3 
4 
5 
6 
 
Stopping rules for GVHD toxicity: 
# Patients 
treated 
5 
10 
15 
20 
25 
Stop if the # 
Grade ≥ III 
aGVHD or 
severe cGVHD  
2 
4 
5 
6 
8 
 
11.7 
Statistical analyses 
 
The data will be analyzed in both intent-to-treat (ITT) and per-protocol (PP) approaches. 
The ITT cohort will include all patients who have received at least one dose of 
flotetuzumab. The PP cohort will only include evaluable patients. Patients who withdraw 
before completing Cycle 1 for a reason unrelated to drug toxicity will not be evaluable for 
the primary objective and will be replaced. The data analyses will be descriptive in nature. 
Demographic and clinical characteristics of the sample, as well as response to treatment, 
and loss to follow up will be summarized using descriptive statistics. The CR rate, overall 
response rate, PR rate, SD rate, morphologic leukemia-free state (MLFS) rate, and AEs 
that occur during flotetuzumab monotherapy and their 90% confidence intervals will be 
presented. Rate of CR, overall response rate, PR rate, SSD rate, MLFS rate, and AEs with 
subsequent treatment will also be documented with exact 90% confidence intervals.  
Overall survival (OS) and progression-free survival (PFS) will be described using Kaplan-
Meier product limit method. 
 
11.8 
Analysis Populations 
 
Safety analysis will include all patients who receive at least one dose of treatment drug. 
 
Efficacy analysis will include patients who complete at least 1 cycle of treatment or patients 
who withdraw before completing Cycle 1 for a reason at least possibly related to drug 
toxicity. 
 
 
12.0 
DATA AND SAFETY MONITORING 
 
In compliance with the Washington University Institutional Data and Safety Monitoring Plan, the 
Principal Investigator will provide a Data and Safety Monitoring (DSM) report to the Washington 
University Quality Assurance and Safety Monitoring Committee (QASMC) semi-annually 
beginning six months after accrual has opened (if at least one patient has been enrolled) or one 
year after accrual has opened (if no patients have been enrolled at the six-month mark). 

 
 
Protocol Version: 02/28/2024  
 
Page 52 of 76 
 
 
The Principal Investigator will review all patient data at least every six months, and provide a 
semi-annual report to the QASMC. This report will include: 
• HRPO protocol number, protocol title, Principal Investigator name, data coordinator 
name, regulatory coordinator name, and statistician 
• Date of initial HRPO approval, date of most recent consent HRPO approval/revision, 
date of HRPO expiration, date of most recent QA audit, study status, and phase of study 
• History of study including summary of substantive amendments; summary of accrual 
suspensions including start/stop dates and reason; and summary of protocol exceptions, 
error, or breach of confidentiality including start/stop dates and reason 
• Study-wide target accrual and study-wide actual accrual 
• Protocol activation date 
• Average rate of accrual observed in year 1, year 2, and subsequent years 
• Expected accrual end date  
• Objectives of protocol with supporting data and list the number of participants who 
have met each objective 
• Measures of efficacy  
• Early stopping rules with supporting data and list the number of participants who have 
met the early stopping rules 
• Summary of toxicities  
• Abstract submissions/publications 
• Summary of any recent literature that may affect the safety or ethics of the study  
 
The study principal investigator and Research Patient Coordinator will monitor for serious 
toxicities on an ongoing basis. Once the principal investigator or Research Patient Coordinator 
becomes aware of an adverse event, the AE will be reported to the HRPO and QASMC according 
to institutional guidelines. 
 
 
13.0 
REGULATORY AND REPORTING REQUIREMENTS 
 
The entities providing oversight of safety and compliance with the protocol require reporting as 
outlined below.  Please refer to Appendix C for definitions and Appendix D for a grid of reporting 
timelines. 
 
Adverse events will be tracked from start of treatment through 28 days following discontinuation 
of study drug flotetuzumab.  All adverse events—including adverse events associated with 
administration of DLI—must be recorded on the toxicity tracking case report form (CRF) with the 
exception of baseline adverse events, including any events related to allogenic hematopoietic cell 
transplantation (allo-HCT), which shall be recorded on the medical history CRF. 
 
Refer to the data submission schedule in Section 9 for instructions on the collection of AEs in the 
EDC. 
 

 
 
Protocol Version: 02/28/2024  
 
Page 53 of 76 
 
13.1 
Reporting to the Human Research Protection Office (HRPO) at Washington 
University 
 
Reporting will be conducted in accordance with Washington University IRB Policies. 
 
Pre-approval of all protocol exceptions must be obtained prior to implementing the change. 
 
13.2 
Reporting to the Quality Assurance and Safety Monitoring Committee 
(QASMC) at Washington University 
 
The Sponsor Investigator  (or designee) is required to notify the QASMC of any 
unanticipated problems involving risks to participants or others occurring at WU or any 
BJH or SLCH institution that has been reported to and acknowledged by HRPO.  
(Unanticipated problems reported to HRPO and withdrawn during the review process need 
not be reported to QASMC.) 
 
QASMC must be notified within 10 days of receipt of IRB acknowledgment via email to 
qasmc@wustl.edu.  Submission to QASMC must include the myIRB form and any 
supporting documentation sent with the form. 
 
13.3 
Reporting to MacroGenics, Inc. 
 
Immediately reportable events (IREs) are events that must be reported immediately to 
MacroGenics Product Safety or designee within 24 hours of being identified. IREs include: 
• SAEs 
• Pregnancy in a study patient or partner (Note: If the female partner of a male 
patient becomes pregnant, the partner must be requested to complete a Pregnant 
Partner Consent Form so that pregnant partner, fetal and/or newborn information 
can be collected.) Upon confirmation of serum pregnancy testing, the patient will 
be followed for the outcome of pregnancy. All live newborns will be followed six 
months after the birth, and all necessary information will be collected to assess 
the effects of study drug on the newborn. If necessary, the follow-up period will 
be extended for the newborn. 
 
See Appendix C for definitions of AE, SAE, SUSAR. 
 
Contact information for MacroGenics Product Safety is below: 
• Email: SAEReports@macrogenics.com (preferred transmission) or 
• Fax: (301) 354-3800 
 
13.4 
Reporting to the FDA 
 
The conduct of the study will comply with all FDA safety reporting requirements.  
PLEASE NOTE THAT REPORTING REQUIREMENTS FOR THE FDA DIFFER 
FROM REPORTING REQUIREMENTS FOR HRPO/QASMC.  It is the 

 
 
Protocol Version: 02/28/2024  
 
Page 54 of 76 
 
responsibility of the Washington University Sponsor-Investigator to report to the FDA as 
follows: 
 
• Report any unexpected fatal or life-threatening suspected adverse reaction (refer to 
Appendix C for definitions) no later than 7 calendar days after initial receipt of the 
information.   
• Report a suspected adverse reaction that is both serious and unexpected (SUSAR, 
refer to Appendix C) no later than 15 calendar days after it is determined that the 
information qualifies for reporting.  Report an adverse event (refer to Appendix C) 
as a suspected adverse reaction only if there is evidence to suggest a causal 
relationship between the drug and the adverse event, such as: 
o A single occurrence of an event that is uncommon and known to be strongly 
associated with drug exposure 
o One or more occurrences of an event that is not commonly associated with 
drug exposure but is otherwise uncommon in the population exposed to the 
drug 
o An aggregate analysis of specific events observed in a clinical trial that 
indicates those events occur more frequently in the drug treatment group than 
in a concurrent or historical control group 
• Report any findings from epidemiological studies, pooled analysis of multiple 
studies, or clinical studies that suggest a significant risk in humans exposed to the 
drug no later than 15 calendar days after it is determined that the information 
qualifies for reporting. 
• Report any findings from animal or in vitro testing that suggest significant risk in 
humans exposed to the drug no later than 15 calendar days after it is determined 
that the information qualifies for reporting.  
• Report any clinically important increase in the rate of a serious suspected adverse 
reaction of that listed in the protocol or IB within 15 calendar days after it is 
determined that the information qualifies for reporting. 
 
Submit each report as an IND safety report in a narrative format or on FDA Form 3500A 
or in an electronic format that FDA can process, review, and archive.  Study teams must 
notify the Siteman Cancer Center Protocol Development team of each potentially 
reportable event within 1 business day after initial receipt of the information, and must 
bring the signed 1571 and FDA Form 3500A to the Siteman Cancer Center Protocol 
Development team no later than 1 business day prior to the due date for reporting to the 
FDA. 
 
Each notification to FDA must bear prominent identification of its contents (“IND Safety 
Report”) and must be transmitted to the review division in the Center for Drug Evaluation 
and Research (CDER) or in the Center for Biologics Evaluation and Research (CBER) that 
has responsibility for review of the IND.  Relevant follow-up information to an IND safety 
report must be submitted as soon as the information is available and must be identified as 
such (“Follow-up IND Safety Report”). 
 

 
 
Protocol Version: 02/28/2024  
 
Page 55 of 76 
 
14.0 
REFERENCES 
 
1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2019. CA Cancer J Clin. 2019;69(1):7-
34.  
2. Bejanyan N, Weisdorf DJ, Logan BR, et al. Survival of patients with acute myeloid 
leukemia relapsing after allogeneic hematopoietic cell transplantation: a center for 
international blood and marrow transplant research study. Biol Blood Marrow Transplant. 
2015;21(3):454-9. 
3. Frassoni F, Barrett AJ, Grañena A, et al. Relapse after allogeneic bone marrow 
transplantation for acute leukaemia: a survey by the E.B.M.T. of 117 cases. Br J Haematol. 
1988;70(3):317-20. 
4. Locatelli F. The role of repeat transplantation of haemopoietic stem cells and adoptive 
immunotherapy in treatment of leukaemia relapsing following allogeneic transplantation. 
Br J Haematol. 1998;102(3):633-8. 
5. Scarisbrick JJ, Dignan FL, Tulpule S, et al. A multicentre UK study of GVHD following 
DLI: rates of GVHD are high but mortality from GVHD is infrequent. Bone Marrow 
Transplant. 2015;50(1):62-7. 
6. Collins RH, Shpilberg O, Drobyski WR, et al. Donor leukocyte infusions in 140 patients 
with relapsed malignancy after allogeneic bone marrow transplantation. J Clin Oncol. 
1997;15(2):433-44. 
7. Deol A, Lum LG. Role of donor lymphocyte infusions in relapsed hematological 
malignancies after stem cell transplantation revisited. Cancer Treat Rev. 2010;36(7):528-
38. 
8. Porter DL, Collins RH, Hardy C, et al. Treatment of relapsed leukemia after unrelated 
donor marrow transplantation with unrelated donor leukocyte infusions. Blood. 
2000;95(4):1214-21. 
9. Shiobara S, Nakao S, Ueda M, et al. Donor leukocyte infusion for Japanese patients with 
relapsed leukemia after allogeneic bone marrow transplantation: lower incidence of acute 
graft-versus-host 
disease 
and 
improved 
outcome. 
Bone 
Marrow 
Transplant. 
2000;26(7):769-74. 
10. Schroeder T, Rachlis E, Bug G, et al. Treatment of acute myeloid leukemia or 
myelodysplastic syndrome relapse after allogeneic stem cell transplantation with 
azacitidine and donor lymphocyte infusions--a retrospective multicenter analysis from the 
German Cooperative Transplant Study Group. Biol Blood Marrow Transplant. 
2015;21(4):653-60. 
11. Motabi IH, Ghobadi A, Liu J, et al. Chemotherapy versus Hypomethylating Agents 
for the Treatment of Relapsed Acute Myeloid Leukemia and Myelodysplastic Syndrome 
after Allogeneic Stem Cell Transplant. Biol Blood Marrow Transplant. 2016;22(7):1324-
1329. 
12. Jacobs K, Godwin J, Foster M, Vey N, Uy G, Rizzieri D, et al. Lead-in Dose 
Optimization to Mitigate Cytokine Release Syndrome in AML and MDS Patients Treated 
with Flotetuzumab, a CD123 X CD3 Bispecific DART¬Æ Molecule for T-cell 
Redirected Therapy. American Society of Hematology Annual Meeting. Dec 9-12, 2017. 
Atlanta, GA. 
13. MacroGenics Investigator Brochure, v9.0 

 
 
Protocol Version: 02/28/2024  
 
Page 56 of 76 
 
14. Uy G, Aldoss I, Foster MC, et al. American Society of Hematology Annual Meeting. Nov 
13, 2019. Orlando, FL. 
15. Toffalori C, Zito L, Gambacorta V, et al. Immune signature drives leukemia escape and 
relapse after hematopoietic cell transplantation. Nat Med. 2019;25(4):603-611. 
16. Christopher MJ, Petti AA, Rettig MP, et al. Immune Escape of Relapsed AML Cells after 
Allogeneic Transplantation. N Engl J Med. 2018;379(24):2330-2341. 
17. Stein AS, Kantarjian H, Gökbuget N, et al. Blinatumomab for Acute Lymphoblastic 
Leukemia Relapse after Allogeneic Hematopoietic Stem Cell Transplantation. Biol Blood 
Marrow Transplant. 2019;25(8):1498-1504. 
18. Lee DW, Santomasso BD, Locke FL, et al. Astct consensus grading for cytokine release 
syndrome and neurologic toxicity associated with immune effector cells. Biology of 
Blood and Marrow Transplantation. 2019;25(4):625-638. 
19. Jagasia MH, Greinix HT, Arora M, et al. National Institutes of Health Consensus 
Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host 
Disease: I. The 2014 Diagnosis and Staging Working Group Report. Biol Blood Marrow 
Transplant 2015; 21:389. 
20. Vadakekolathu J, Minden MD, Hood T, et al. Immune Landscapes Predict Chemotherapy 
Resistance and Anti- Leukemic Activity of Flotetuzumab, an Investigational CD123×CD3 
Bispecific Dart® Molecule, in Patients with Relapsed/Refractory Acute Myeloid 
Leukemia. Blood (2019) 134 (Supplement 1): 460. 
21. Maecker HT, McCoy JP, Nussenblatt R. Standardizing immunophenotyping for the 
Human Immunology Project. Nat Rev Immunol 2012 Mar;12(3):191-200. 
22. Uy GL, Rettig MP, Motabi IH, McFarland K, Trinkaus KM, Hladnik LM, et al. A phase 
1/2 study of chemosensitization with the CXCR4 antagonist plerixafor in relapsed or 
refractory acute myeloid leukemia. Blood 2012 Apr 26;119(17):3917-24. 
 
 
Acknowledgements 
We would like to thank the Alvin J. Siteman Cancer Center at Washington University School of 
Medicine and Barnes-Jewish Hospital in St. Louis, Missouri, for the use of the Clinical Trials 
Core, which provided protocol development services. The Siteman Cancer Center is supported in 
part by an NCI Cancer Center Support Grant #P30 CA91842. 
  
 
 
 
 
 
 
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 57 of 76 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
APPENDIX A: ECOG Performance Status Scale 
 
 
Grade 
 
 
Description 
0 
Normal activity.  Fully active, able to carry on all pre-disease 
performance without restriction. 
1 
Symptoms, but ambulatory.  Restricted in physically strenuous 
activity, but ambulatory and able to carry out work of a light or 
sedentary nature (e.g., light housework, office work). 
2 
In bed <50% of the time.  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 
 
In bed >50% of the time.  Capable of only limited self-care, confined 
to bed or chair more than 50% of waking hours. 
 

 
 
Protocol Version: 02/28/2024  
 
Page 58 of 76 
 
4 
100% bedridden.  Completely disabled.  Cannot carry on any self-care.  
Totally confined to bed or chair. 
5 
 
Dead. 
 
 
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 59 of 76 
 
APPENDIX B: Revised International Prognostic Scoring System (IPSS-R) 
 
IPSS-R Prognostic Score Values 
Prognostic Variable 
Score 
0 
0.5 
1.0 
1.5 
2.0 
3.0 
4.0 
Cytogenetics* 
Very 
good 
 
Good 
 
Intermediate Poor 
Very 
poor 
Bone marrow blast 
(percent) 
≤2 
 
>2 to 
<5 
 
5 to 10 
>10 
 
Hemoglobin (g/dL) 
≥10 
 
8 to 
<10 
<8 
 
 
 
Platelets 
(cells/microL) 
≥100 
50 to 
<100 
<50 
 
 
 
 
ANC (cells/microL) 
≥0.8 
<0.8 
 
 
 
 
 
*See cytogenetics in table below (MDS Cytogenetic Scoring System) for classifications. 
 
MDS Cytogenetic Scoring System 
Prognostic subgroups 
Cytogenetic Abnormalities 
Very good 
−Y, del(11q) 
Good 
Normal, del(5q), del(12p), del(20q), double including del(5q) 
Intermediate 
del(7q), +8, +19, i(17q), any other single or double independent 
clones 
Poor 
−7, inv(3)/t(3q)/del(3q), double including −7/del(7q), complex: 3 
abnormalities 
Very poor 
Complex: > 3 abnormalities 
 
IPSS-R Prognostic Risk Categories/Scores 
Risk Category 
Risk Score 
Very low 
≤ 1.5 
Low 
>1.5 – 3  
Intermediate 
> 3 – 4.5  
High 
> 4.5 – 6  
Very high 
> 6 
 
Taken from: Greenberg PL, Tuechler H, Schanz J, Sanz G, Garcia-Manero G, Sole F, et al. Revised international 
prognostic scoring system for myelodysplastic syndromes. Blood. 2012;120(12):2454-65. 
 
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 60 of 76 
 
APPENDIX C: Definitions for Adverse Event Reporting 
 
A. Adverse Events (AEs) 
 
As defined in 21 CFR 312.32: 
 
Definition: any untoward medical occurrence associated with the use of a drug in humans, 
whether or not considered drug-related. 
 
Grading: the descriptions and grading scales found in the revised NCI Common Terminology 
Criteria for Adverse Events (CTCAE) version 5.0 will be utilized for all toxicity reporting.  A 
copy of the CTCAE version 5.0 can be downloaded from the CTEP website. 
 
Attribution (relatedness), Expectedness, and Seriousness: the definitions for the terms 
listed that should be used are those provided by the Department of Health and Human Services’ 
Office for Human Research Protections (OHRP).  A copy of this guidance can be found on 
OHRP’s website: 
http://www.hhs.gov/ohrp/policy/advevntguid.html 
 
B. Suspected Adverse Reaction (SAR) 
 
As defined in 21 CFR 312.32: 
 
Definition: any adverse event for which there is a reasonable possibility that the drug caused 
the adverse event.  “Reasonable possibility” means there is evidence to suggest a causal 
relationship between the drug and the adverse event.  “Suspected adverse reaction” implies a 
lesser degree of certainty about causality than adverse reaction, which means any adverse event 
caused by a drug. 
 
C. Life-Threatening Adverse Event / Life Threatening Suspected Adverse Reaction  
 
As defined in 21 CFR 312.32: 
 
Definition: any adverse drug event or suspected adverse reaction is considered “life-
threatening” if, in the view of the investigator, its occurrence places the patient at immediate 
risk of death. It does not include an adverse event or suspected adverse reaction that, had it 
occurred in a more severe form, might have caused death. 
 
D.  Serious Adverse Event (SAE) or Serious Suspected Adverse Reaction 
 
As defined in 21 CFR 312.32: 
 
Definition:  an adverse event or suspected adverse reaction is considered “serious” if, in the 
view of the investigator, it results in any of the following outcomes: 
o Death 
o A life-threatening adverse event 

 
 
Protocol Version: 02/28/2024  
 
Page 61 of 76 
 
o Inpatient hospitalization or prolongation of existing hospitalization 
o A persistent or significant incapacity or substantial disruption of the ability to conduct 
normal life functions 
o A congenital anomaly/birth defect 
o Any other important medical event that does not fit the criteria above but, based upon 
appropriate medical judgment, may jeopardize the subject and may require medical or 
surgical intervention to prevent one of the outcomes listed above 
 
E. Protocol Exceptions 
 
Definition: A planned change in the conduct of the research for one participant. 
 
F. Deviation 
 
Definition: Any alteration or modification to the IRB-approved research without prospective 
IRB approval.  The term “research” encompasses all IRB-approved materials and documents 
including the detailed protocol, IRB application, consent form, recruitment materials, 
questionnaires/data collection forms, and any other information relating to the research study. 
 
A minor or administrative deviation is one that does not have the potential to negatively impact 
the rights, safety, or welfare of participants or others or the scientific validity of the study. 
 
A major deviation is one that does have the potential to negatively impact the rights, safety, or 
welfare of participants or others or the scientific validity of the study 
 

 
 
Protocol Version: 02/28/2024  
 
Page 62 of 76 
 
 
APPENDIX D: Reporting Timelines 
 
Expedited Reporting Timelines 
Event 
HRPO 
QASMC 
FDA 
MacroGenics, Inc. 
Serious AND 
unexpected suspected 
adverse reaction 
 
 
Report no later than 15 
calendar days after it is 
determined that the 
information qualifies for 
reporting 
Report within 24 hours of 
being identified to 
SAEReports@macrogenic
s.com 
Unexpected fatal or 
life-threatening 
suspected adverse 
reaction 
 
 
Report no later than 7 
calendar days after initial 
receipt of the information 
Report within 24 hours of 
being identified to 
SAEReports@macrogenic
s.com  
Unanticipated 
problem involving risk 
to participants or 
others 
Report within 10 working days.  
If the event results in the death 
of a participant enrolled at 
WU/BJH/SLCH, report within 
1 working day. 
Report via email after 
IRB acknowledgment 
 
 
Pregnancy 
 
 
 
Report within 24 hours of 
being identified to 
SAEReports@macrogenic
s.com 
Major deviation 
Report within 10 working days.  
If the event results in the death 
of a participant enrolled at 
WU/BJH/SLCH, report within 
1 working day. 
 
 
 
A series of minor 
deviations that are 
being reported as a 
continuing 
noncompliance 
Report within 10 working days.    
 
 
Protocol exception 
Approval must be obtained 
prior to implementing the 
change 
 
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 63 of 76 
 
Expedited Reporting Timelines 
Event 
HRPO 
QASMC 
FDA 
MacroGenics, Inc. 
Clinically important 
increase in the rate of 
a serious suspected 
adverse reaction of 
that list in the protocol 
or IB 
 
 
Report no later than 15 
calendar days after it is 
determined that the 
information qualifies for 
reporting 
 
Complaints 
If the complaint reveals an 
unanticipated problem 
involving risks to participants 
or others OR noncompliance, 
report within 10 working days.  
If the event results in the death 
of a participant enrolled at 
WU/BJH/SLCH, report within 
1 working day.  Otherwise, 
report at the time of continuing 
review. 
 
 
 
Breach of 
confidentiality 
Within 10 working days. 
 
 
 
Incarceration 
If withdrawing the participant 
poses a safety issue, report 
within 10 working days.   
 
If withdrawing the participant 
does not represent a safety issue 
and the patient will be 
withdrawn, report at continuing 
review. 
 
 
 
 
 
 

 
 
Protocol Version: 02/28/2024  
 
Page 64 of 76 
 
 
Routine Reporting Timelines 
Event 
HRPO 
QASMC 
FDA 
Adverse event or SAE 
that does not require 
expedited reporting 
If they do not meet the definition of an 
unanticipated problem involving risks to 
participants or others, report summary 
information at the time of continuing review 
Adverse events will be 
reported in the toxicity 
table in the DSM report 
which is typically due 
every 6 months. 
The most current 
toxicity table from the 
DSM report is provided 
to the FDA with the 
IND’s annual report. 
Minor deviation 
Report summary information at the time of 
continuing review. 
 
 
Complaints 
If the complaint reveals an unanticipated problem 
involving risks to participants or others OR 
noncompliance, report within 10 working days.  If 
the event results in the death of a participant 
enrolled at WU/BJH/SLCH, report within 1 
working day.  Otherwise, report at the time of 
continuing review. 
 
 
Incarceration 
If withdrawing the participant poses a safety 
issue, report within 10 working days.   
 
If withdrawing the participant does not represent a 
safety issue and the patient will be withdrawn, 
report at continuing review. 
 
 

 
Protocol Version: 02/28/2024  
 
Page 65 of 76 
 
APPENDIX E: Neurotoxicity Grading and Management 
 
Grade 1 
Grade 2 
Grade 3 
Grade 4 
Decreased LOC, 
awakens 
spontaneously 
ICE score 7-9 (see 
table below for ICE 
scoring parameters) 
Decreased LOC, 
awakens to voice 
ICE score 3-6 
Decreased LOC, 
awakens only to 
tactile stimulus 
ICE score 0-2 
Seizure: transient 
Cerebral Edema on 
imaging 
Decreased LOC, 
unarousable 
ICE score 0 
Seizure: prolonged 
(>5 minutes) or 
recurrent 
Cerebral Edema on 
imaging 
Focal neurologic 
weakness/deficits 
Slow infusion by 10-
20% 
 
Frequent neuro 
checks 
 
Supportive care 
 
Consider seizure 
prophylaxis (e.g. 
Levetiracetam 
1000mg twice daily) 
 
 
Slow infusion by 25-
50% 
 
Obtain brain MRI, 
LP (with opening 
pressure) and EEG 
 
Neuro checks, 
including 
fundoscopy and 
Glasgow coma scale 
assessments 
 
Start telemetry and 
continuous SpO2 
monitoring 
 
If concurrent CRS, 
administer 
Tocilizumab and 
Consider steroids 
per CRS algorithm 
 
Administer seizure 
prophylaxis, or 
increase dose if 
already started 
Stop infusion 
 
Manage as Grade 2, 
plus: 
 
If concurrent CRS, 
administer 
Tocilizumab and 
administer steroids 
per CRS algorithm 
 
Consider ICU care 
Manage as Grade 3, 
plus:  
 
Consider high dose 
steroids plus CRS 
algorithm 
management (e.g. 
Methylprednisolone 
1000mg IV daily x3 
days, then rapid 
taper over 6 days) 
 
Treat cerebral edema  
 
Transfer to ICU care 
with aggressive 
supportive care 
LOC: level of consciousness; MRI: magnetic resonance imaging; LP: lumbar puncture; EEG: 
electroencephalogram  
 
 
 
 

 
Protocol Version: 02/28/2024  
 
Page 66 of 76 
 
Immune Effector Cell-Associated Encephalopathy (ICE) Score 
Orientation: oriented to year, month, city, hospital: 1 point each, 4 points total 
Naming: ability to name 3 objects (e.g. clock, pen, button): 1 point each, 3 points total 
Follow Commands: can follow a simple command (e.g. show me 2 fingers): 1 point total 
Writing: can write standard sentence (e.g. Our national bird is the bald eagle): 1 point total 
Attention: can count backwards from 100 by 10: 1 point total 
Scoring 
10 = no 
impairment 
7-9 = ICANS 
grade 1 
3-6 = ICANS 
grade 2 
0-2 = ICANS 
grade 3 
0 = ICANS 
grade 4 
ASTCT Consensus Grading for Cytokine Release Syndrome and Neurologic Toxicity 
Associated with Immune Effector Cells (Biol Blood Marrow Transplant 2019;25: 625). 

 
Protocol Version: 02/28/2024  
 
Page 67 of 76 
 
APPENDIX F: Acute GVHD Grading/Assessment 
 
MAGIC CRITERIA FOR STAGING AND GRADING FOR ACUTE GVHD 
 
Stage 
Skin 
(Active Erythema 
Only) 
Liver 
(Bilirbuin) 
Upper GI 
Lower GI 
(Stool Output/Day) 
 
Overall Clinical Grade 
 
Grade 0: 
No stage 1-4 of any organ 
 
Grade I: 
Skin Stage 1-2 (without 
liver, upper GI, or lower 
GI) 
 
Grade II: 
Stage 3 rash and/or Stage 1 
liver and/or Stage 1 upper 
GI and/or Stage 1 lower GI 
 
Grade III: 
Stage 2-3 liver and/or Stage 
2-3 lower GI with Stage 0-3 
Skin and/or Stage 0-1 upper 
GI 
 
Grade IV: 
Stage 4 skin, liver, or lower 
GI with Stage 0-1 upper GI 
0 
No active 
(erythematous) 
GVHD rash 
< 2 mg/dL 
No or 
intermittent 
nausea, 
vomiting, or 
anorexia 
Adult: < 500 mL/day or < 
3 episodes day 
Child: < 10 mL/kg per 
day or < 4 episodes/day 
1 
Maculpapular rash 
< 25% BSA 
2-3 mg/dL 
Persistent 
nausea, 
vomiting, or 
anorexia 
Adult: 500-900 mL/day 
or 3-4 episodes day 
Child: 10-19.9 mL/kg per 
day or 4-6 episodes/day 
2 
Maculpapular rash 
25-50% BSA 
3.1-6 
mg/dL 
- 
Adult: 1000-1500 
mL/day or 5-7 episodes 
day 
Child: 20-30 mL/kg per 
day or 7-10 episodes/day 
3 
Maculpapular rash 
> 50% BSA 
6.1-15 
mg/dL 
- 
Adult: > 1500 mL/day or 
> 7 episodes day 
Child: > 30 mL/kg per 
day or > 10 episodes/day 
4 
Generalized 
erythroderma (> 
50% BSA) plus 
bullous formation 
and desquamation 
> 5% BSA 
> 15 
mg/dL 
- 
Severe abdominal pain 
with or without ileus or 
grossly bloody stool 
(regardless of stool 
volume) 
 
 
Acute GVHD Specifications 
Chronic GVHD Specifications 
• _____________%BSA 
• Stool Output: 
_____________mL/day OR 
episodes/day. 
• Grade: _____________ 
• ECOG: _____________ 
Does the subject have signs/symptoms of Chronic 
GVHD? ___________ 
• If yes, please circle overall grade and describe: 
Mild / Moderate / Severe 
• Describe:_____________________________ 
_____________________________________. 
 
 
 
Signature 
 
 
 
 
 
 
Date 
 
 

 
Protocol Version: 02/28/2024  
 
Page 68 of 76 
 
Date of Acute GVHD staging and grading 
 
 
Skin rash extent (% of BSA) 
 
 
Skin rash stage 
□ Stage 0 
□ Stage 1 
□ Stage 2 
□ Stage 3 
□ Stage 4 
Stool output (episodes per day) 
 
 
Stool output (estimated total volume in mL per 
day) 
 
 
Lower GI stage 
□ Stage 0 
□  Stage 1 
□  Stage 2 
□  Stage 3 
□  Stage 4 
Upper GI stage 
□  Stage 0 
□  Stage 1 
□  Stage 2 
□  Stage 3 
□  Stage 4 
Upper GI features due to GVHD 
□  Persistent nausea 
□  Persistent vomiting 
□  Persistent anorexia 
□  None 
Liver stage 
□  Stage 0 
□  Stage 1 
□  Stage 2 
□  Stage 3 
□  Stage 4 
MAGIC Criteria Overall Clinical Grade 
□  Grade 0 
□  Grade I 
□  Grade II 
□  Grade III 
□  Grade IV 
Did the subject experience a GVHD flare since the 
last visit? 
□  No 
□  Yes 
 
 
 

 
Protocol Version: 02/28/2024  
 
Page 69 of 76 
 
APPENDIX G: Chronic GVHD Assessment (NIH Severity Score) 
 
 
0 
1 
2 
3 
Skin 
Score 
  No 
Symptoms 
  <18% BSA with 
disease signs but NO 
sclerotic features 
  19-50% BSA OR 
involvement with 
superficial sclerotic 
features “not 
hidebound” (able to 
pinch) 
 
 
  >50% BSA OR deep 
sclerotic features 
“hidebound” (unable to 
pinch) OR impaired 
mobility, ulceration or 
severe pruritus 
 
Mouth 
Score 
  No 
symptoms 
  Mild symptoms 
with disease signs 
but not limiting oral 
intake significantly 
  Moderate 
symptoms with signs 
with partial limitation 
of oral intake 
  Severe symptoms 
with disease signs on 
examination with major 
limitation of oral intake 
GI Tract 
Score 
(symptoms 
averaged 
over the last 
3 days) 
  No 
symptoms 
  Symptoms such 
as dysphagia, 
anorexia, nausea, 
vomiting, abdominal 
pain or diarrhea 
without significant 
weight loss (<5%) 
  Symptoms 
associated with mild to 
moderate weight loss  
(5-15%) 
  Symptoms associated 
with significant weight 
loss >15%, requires 
nutritional supplement 
for most calorie needs OR 
esophageal dilation 
Eye 
Score 
  No 
symptoms 
  Mild dry eye 
symptoms not 
affecting ADL 
(requiring eye drops  
≤3x per day) OR 
asymptomatic signs 
of kerato-
conjunctivitis sicca 
  Moderate dry eye 
symptoms partially 
affecting ADL 
(requiring eye drops 
>3x per day or 
punctual plugs) 
WITHOUT vision 
impairment 
  Severe dry eye 
symptoms significantly 
affecting ADL (special 
eyewear to relieve pain) 
OR unable to work 
because of ocular 
symptoms OR loss of 
vision caused by kerato-
conjunctivitis sicca 
Joint 
and 
Fascia 
Score 
  No 
symptoms 
  Mild tightness of 
arms or legs, normal 
or mild decreased 
range of motion 
(ROM) AND not 
affecting ADL 
  Tightness of arms 
or legs OR joint 
contractures, erythema 
thought due to fasciitis, 
moderate decrease 
ROM AND mild to 
moderate limitation of 
ADL 
  Contracture WITH 
significant decrease of 
ROM AND significant 
limitation of ADL (unable 
to tie shoes, button shirts, 
dress self etc.) 

 
Protocol Version: 02/28/2024  
 
Page 70 of 76 
 
Genital 
Tract 
Score 
(score even if 
no GYN exam, 
required for 
men too) 
 
 No GYN 
Exam 
  No 
symptoms 
  Symptomatic 
with mild distinct 
signs on exam AND 
no effect on coitus 
and minimal 
discomfort with GYN 
exam 
  Symptomatic with 
distinct signs on exam 
AND with mild 
dyspareunia or 
discomfort with GYN 
exam 
  Symptomatic WITH 
advanced signs (stricture, 
labia agglutination or 
severe ulceration) AND 
severe pain with coitus or 
inability to insert vaginal 
spectrum 
Lung 
Score 
  No 
symptoms 
  Mild symptoms 
(shortness of breath 
after climbing one 
flight of steps) 
  Moderate 
symptoms (shortness 
of breath after walking 
on flat ground) 
  Severe symptoms 
(shortness of breath at 
rest; requiring O2) 
Liver 
Score 
 Normal 
LFTs 
  Elevated 
bilirubin, alkaline 
phosphatase, AST or 
ALT <2x ULN 
  Bilirubin > 3 mg/dl 
or bilirubin, AST or 
ALT 2-5x ULN 
  Bilirubin, AST or ALT 
> 5x ULN 
 
Liver score to be completed using most recent LFTs from within +/- 2 weeks of the assessment 
 
 
Date LFT sample obtained __________ 
 
 
PFT values from within one month of the assessment 
 
% FEV1   _______%    
Date of FEV1 __________ 
 
 
 Not done    
 
% DLCOc   ______%    
Date of DLCOc _________  
 
 Not done 
 
 
Is an erythematous or maculopapular rash present?        
 Yes       
 No    
 
Does the patient have nausea, vomiting or diarrhea?       
 Yes       
 No    
 
Date of diagnosis of cGVHD  __________ 
 
Previous assessment of NIH severity grade  __________ 
 
 

 
Protocol Version: 02/28/2024  
 
Page 71 of 76 
 
 
Please rate the severity of this person’s chronic GVHD 
on this 
scale    
 None (1) 
 Mild (2) 
 Moderate  (3) 
 Severe  (4) 
 
 
 
 
 
and on 
this scale 
 
 
 
(circle one) 
 
 cGVHD 
symptoms 
are not at 
all severe 
cGVHD  
symptoms 
are most 
severe  
possible 
 
 
0 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
 
 
 
 
 

 
Protocol Version: 02/28/2024  
 
Page 72 of 76 
 
APPENDIX H:  Institutional Criteria for Donor Screening 
 
Donor Guidelines 
(adopted from Donor Screening Policy dated 5/2021, refer to this for complete guidelines) 
 
Patients with SD/PR on their C1D28 response assessment may receive a DLI from their original 
donor at the discretion of the treating physician.  Patients may receive cryopreserved cells from 
the original donation, or the previous donor must be willing to donate again.  Donor selection 
will be in compliance with 21 CFR Part 1271 and with our institutional guidelines governing 
donor eligibility.    
 
If requesting additional collections from an unrelated donor, donor assessment and consent 
process will occur in the apheresis center or similar donor facility.  For matched related or 
haploidentical donors, donor assessment take place at Washington University School of 
Medicine.  In cases where the donor medical evaluation occurred more than 6 months prior to re-
donation, evaluation will be repeated per our institutional guidelines and will include the 
following testing:  
• Complete health history and physical examination including vaccination history 
if greater than 6 months since original donor evaluation 
• Required Tests: 
o CMP, CBC with manual differential, PT/PTT 
o HSV serology, qualitative HCG (Females of childbearing potential only) 
o BMT Donor Evaluation Test (panel includes the following tests: hepatitis B 
surface antigen, hepatitis C antibody, hepatitis B core total, Hep B NAT, 
HCV NAT, HIV NAT, WNV NAT, HIV 1-2, HTLV-I/II, trypanosome cruzi 
antibody, RPR, CMV titer. These tests must be performed by the American 
Red Cross). 
o Hemoglobinopathy Assessment: G-CSF mobilized, leukapheresis donors, 
must have a negative sickle cell test or be cleared for leukapheresis by the 
transplant physician. 
o ABO/Rh typing, red cell antibody screen 
 
• All infectious disease testing must be done within seven days of an 
unstimulated DCI collection and within 30 days within a stimulated DCI 
collection 
• A negative pregnancy assessment result is required within seven days prior to 
initiation of donor starting collection 
 
Collection of unmobilized peripheral blood lymphocytes from donors is performed by 
leukopheresis.  Unmanipulated donor cells are washed, counted, analyzed for viability, 
and cryopreserved. 
 
 
 

 
Protocol Version: 02/28/2024  
 
Page 73 of 76 
 
APPENDIX I: Study-Specific DSM Tables 
 
Protocol Objectives and Subject Evaluability 
Objective 
# of patients evaluable for 
this endpoint to date 
Primary 
To evaluate the efficacy of flotetuzumab in post-allo-HCT 
relapsed AML and MDS following Cycle 1 of flotetuzumab 
(Cycle 1 Day 28 assessment). 
 
Secondary 
To evaluate the efficacy of flotetuzumab monotherapy in 
post-allo-HCT relapsed AML and MDS following Cycle 2 (or 
following Cycle 1 for patients that receive only one cycle). 
CR and CRi at C2D28 =  
ORR =  
MLFS = 
PR = 
SD = 
PFS = 
OS = 
To evaluate the safety and tolerability of flotetuzumab +/- DLI 
in the post-allo-HCT setting 
AEs =  
CRS and neurotoxicity =  
Acute GVHD = 
Chronic GVHD = 
 
 
Interim Analysis and Early Stopping Rules 
Does the study design include an interim toxicity analysis? 
No 
Does the study design include an interim futility analysis? 
Yes 
If yes, please insert text describing interim futility analysis from the protocol 
Fifteen patients will be enrolled in the first stage.  This cohort will include patients who 
withdraw from the study for reasons unrelated to drug toxicity.  If at least 2 CR/CRi are observed 
out of the 15 patients, then an additional 10 patients will be enrolled. If 6 or more CR/CRi are 
observed at the end of study, we would conclude that there is evidence of efficacy to warrant 
further investigation. There is less than 5% chance to stop the trial at stage 1 if the “true” 
response is 30% or higher. Conversely, there will be 55% chance to terminate the study early if 
the true rate is only 10% or less. 
If yes, please provide data from the interim futility analysis when completed: 
 
Are there early stopping rules that outline circumstances under which the study must be 
suspended or closed? 
Yes 
If yes, please insert text describing early stopping rules from the protocol 
A Bayesian sequential monitoring rule will be implemented for safety. The stopping rule is 
defined as Pr(θ > θT |data) >0.8, where θ denotes the proportion of toxicities (as defined in 
Section 11.5) and θT denotes the expected serious toxicity rate for study treatments (set as θT = 
20% for non-GVHD toxicity and 25% for GVHD toxicity).  Interval analyses will be performed 

 
Protocol Version: 02/28/2024  
 
Page 74 of 76 
 
after every five patients has completed the first cycle of treatment (see tables below).  If the 
accumulated observed data suggests a high chance (i.e., >80% probability) for the “true” toxicity 
(as defined in Section 11.5) to be >20% for non-GVHD events or 25% for GVHD events, 
enrollment will be paused and data for assessment of early stopping will be sent to QASMC for 
review to consider study termination.  The following tables show the number of patients with 
the number of adverse events that would result in a pause of enrollment to assess premature 
stopping of the trial.  The stopping boundaries were obtained using Multc99 version 2.1, a free-
download software from M.D. Anderson Cancer Center (https://trialdesign.org/one-page-
shell.html#BTOX). Specifically, we assume that the parameter θ follows a prior distribution of 
beta (1,1), i.e., θ with mean = 0.5 but with relatively large variability (non-informative prior). 
Early stopping will be recommended if we observe 2 non-GVHD events out of the first 6 or 2 
GVHD events out of first 5 patients, etc. (see Tables below), in patients treated in this trial.  
A simulation study is also performed to assess the operating characteristics for the above 
stopping rule (all scenarios are based on 10,000 simulated trials). For non-GVHD events, there 
will be only 15% chance to stop early if the “true” toxicity rate is 10%. In contrast, we will have 
88% chance to stop early (with a median of 10 patients treated) if the “true” toxicity rate on 
flotetuzumab monotherapy is 30%. For GVHD events, there will be only 21% chance to stop 
early if the “true” rate is 15% and there will be 86% chance to stop early (with a median of 5 
patients treated) if the “true” rate is 35%.  
 
Stopping rules for non-GVHD toxicity: 
# Patients treated 
5 
10 
15 
20 
25 
Stop if the # Grade ≥ 
3 non-hematologic 
toxicity   
2 
3 
4 
5 
6 
 
Stopping rules for GVHD toxicity: 
# Patients 
treated 
5 
10 
15 
20 
25 
Stop if the # 
Grade ≥ III 
aGVHD or 
severe cGVHD  
2 
4 
5 
6 
8 
 
Definitions of Excess Toxicity 
Excess non-GVHD toxicity will be defined as a combined incidence of > 20% of any of the 
following: 
• ≥ Grade 3 non-hematologic AE at least possibly attributable to protocol treatment, with 
the following exceptions: 
o 
Grade 3 fatigue, asthenia, fever, constipation or anorexia (if anorexia does not result 
in hospitalization, tube-feeding or use of total parenteral nutrition [TPN]) 
o 
Grade 3 nausea, vomiting or diarrhea not requiring tube feeding, TPN, or requiring 
or prolonging hospitalization 
o 
Infection, bleeding, or other expected direct complications of cytopenias due to 
active underlying leukemia 

 
Protocol Version: 02/28/2024  
 
Page 75 of 76 
 
o 
Grade 3 infusion reaction including CRS, if successfully managed clinically and 
resolves within 7 days without end-organ damage 
o 
Grade 3 or 4 isolated electrolyte abnormalities that last < 72 hours 
• Grade 4 neutropenia or thrombocytopenia lasting ≥ 42 days from the start of the cycle 
in the absence of MDS/AML 
• Evidence of drug-induced liver injury based on presence of any of the following 
abnormalities without an alternate explanation: 
o 
ALT or AST >8x ULN  
o 
ALT or AST >5x ULN for more than 2 weeks 
o 
ALT or AST >3x ULN and (TBL >2xULN or INR >1.5) 
o 
ALT or AST >3x ULN with the appearance of fatigue, nausea, vomiting, right 
upper quadrant pain or tenderness, fever, rash, and/or eosinophilia (>5%) 
 
Excess GVHD toxicity will be defined as a > 25% incidence of Grade III-IV acute GVHD or 
severe chronic GVHD occurring at any time during treatment. 
 
If yes, please provide data describing whether any patients have met the stopping rules: 
 
UPN 
Did pt experience 
GVHD toxicity? 
(y/n) 
Did pt experience 
non-GHVD toxicity? 
(y/n) 
If yes, enter toxicity and grade 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Response 
UPN 
On 
treatment 
date 
# cycles 
completed 
C1D28 
response 
C2D28 
response 
(or N/A) 
Date of 
progression 
Patient 
replaced? 
(y/n) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Treatment Discontinuation and Survival 
UPN 
Off treatment 
date 
Reason for discontinuation of 
treatment 
Vital 
status 
If dead, cause 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
Protocol Version: 02/28/2024  
 
Page 76 of 76 
 
 
 
Aggregated GVHD Data 
# of pts who 
experienced aGVHD 
grades I/II 
# of pts who 
experienced aGVHD 
grades III/IV 
# pts who experienced 
none/mild/moderate 
cGVHD 
# pts who 
experienced 
severe cGVHD 
 
 
 
 
 
 
Summary of Specimen Collections 
Type of specimen 
Time point 
# of patients 
eligible for 
collection at this 
time point 
% of patients who 
have reached this 
time point and had 
the specimen collected 
Bone marrow aspirate 
Screening/baseline 
 
 
C1D28 
 
 
C1D14 
 
 
C2D14 
 
 
C2D28 
 
 
Relapse/progression 
 
 
Peripheral blood 
C1D1 
 
 
C1D7 
 
 
C1D14 
 
 
C1D21 
 
 
C1D28 
 
 
C2D1 
 
 
C2D7 
 
 
C2D14 
 
 
C2D21 
 
 
C2D28 
 
 
Relapse/progression