untitled h1
untitled h2

Abbreviated Title: LMB-100 plus SEL-110 CC Protocol \#: 18C0057D Version Date: October 1, 2018 NCT Number: NCT03436732 Title: A Phase I Study of the Mesothelin-Targeted Immunotoxin LMB-100 in Combination with SEL-110 in Subjects with Malignant Pleural or Peritoneal Mesothelioma Investigators:  
| NCI Principal Investigator:   | Raffit Hassan, M.D. A-E Thoracic and GI Malignancies Branch (TGMB), CCR, NCI  Building 10, Room 4-5330  9000 Rockville Pike  Bethesda, MD 20892  Telephone: 240-760-6232  E-mail: hassanr@mail.nih.gov   |                                                                                                 |
|-------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------|
| NIH Collaborators             | Ronald Germain, M.D., Ph.D.F , NIAID, NIH                                                                                                                                                                |                                                                                                 |
| Roles                         | A.                                                                                                                                                                                                       | Obtain information by intervening or interacting with  living individuals for research purposes |
| B.                            | Obtaining identifiable private information about living  individuals                                                                                                                                     |                                                                                                 |
| C.                            | Obtaining the voluntary informed consent of individuals to  be subjects                                                                                                                                  |                                                                                                 |
| D.                            | Makes decisions about subject eligibility                                                                                                                                                                |                                                                                                 |
| E.                            | Studying, interpreting, or analyzing identifiable private  information or data/specimens for research purposes                                                                                           |                                                                                                 |
| F.                            | Studying, interpreting, or analyzing coded, linked data or  specimens for research purposes                                                                                                              |                                                                                                 |  
| Drug Name:    | LMB-100 (formerly           | SEL-110                     |
|---------------|-----------------------------|-----------------------------|
| RO6927005)    |                             |                             |
| IND Number:   | 136483                      | 136483                      |
| Sponsor:      | Center for Cancer Research, | Center for Cancer Research, |
| NCI, NIH      | NCI, NIH                    |                             |
| Manufacturer: | F. Hoffmann-La Roche        | Selecta Biosciences, Inc.   |
untitled h1
precis background

x LMB-100 and a closely related immunotoxin also targeting mesothelin have been studied in previous Phase 1 clinical studies for mesothelioma and pancreatic cancer.  
x Results from these studies showed that the majority of patients formed anti-drug-antibodies
(ADAs) that neutralized subsequent injection of the product making it ineffective.  
x In a small subset of patients that did not form ADAs to the product, good response and regression of tumors was seen.  
x In a different application SEL-110, a biodegradable nanoparticle containing rapamycin, has been shown in clinical trials to prevent the formation of ADAs to an immunogenic enzyme when co-administered. Preclinical data show that SEL-110 also prevents the formation of ADAs to LMB-100.  
x This clinical trial will investigate whether SEL-110 when administered with LMB-100 is able to prevent the formation of ADAs and thus allow patients to receive multiple, effective injections of LMB-100.
Objectives:
x The primary objective of the study is to assess the safety and tolerability of LMB-100 in combination with SEL-110.  
Eligibility: Primary Inclusion Criteria x  18 years of age  
x Histologically confirmed epithelial or biphasic pleural or peritoneal mesothelioma not amenable to potentially curative surgical resection.  
x Patients must have measurable disease per RECIST 1.1. x Patients must have had at least one prior chemotherapy regimen that includes pemetrexed and cisplatin or carboplatin. There is no limit to the number of prior chemotherapy regimens received.  
x Patients for whom no standard curative therapy exists
Primary Exclusion Criteria:  
x Known or clinically suspected CNS primary tumors or metastases including leptomeningeal metastases.  
x Evidence of significant, uncontrolled concomitant diseases which could affect compliance with the protocol or interpretation of results.  
x Evidence of active or uncontrolled infections.
x Live attenuated vaccinations 14 days prior to treatment x Pregnant women are excluded from this study
untitled h1
design

x This is a Phase I, single center, dose escalation study of LMB-100 in combination with SEL-110 x Patients will receive the combination using a dose escalation scheme in which different doses of LMB100 and SEL-110 will be evaluated.  
x Patients will receive 4 cycles of LMB-100 with SEL-110. A cycle will consist of i.v.  
infusion of SEL-110 on Day 1 of the cycle followed immediately by an i.v. infusion of LMB-100, then on Days 3 and 5 of the cycle patients will receive an i.v. infusion of LMB100 only. Treatment cycles will be separated by 21 days.  
| TABLE OF CONTENTS      |                                                                                                                                 |                    |
|------------------------|---------------------------------------------------------------------------------------------------------------------------------|--------------------|
| PRÉCIS .               |                                                                                                                                 |                    |
| TABLE OF CONTENTS.     |                                                                                                                                 |                    |
| INTRODUCTION .         |                                                                                                                                 |                    |
| l                      | 1.1                                                                                                                             | Study Objectives . |
| 1.1.1                  | Primary Objective                                                                                                               |                    |
| 1.1.2                  | Secondary Objectives                                                                                                            |                    |
| 1.1.3                  | Exploratory Objectives .                                                                                                        |                    |
| 1.2                    | Background and Rationale                                                                                                        |                    |
| 1.2.1                  | Background on Mesothelioma .                                                                                                    |                    |
| 1.2.2                  | Mesothelin as a target for cancer therapy                                                                                       |                    |
| 1.2.3                  | LMB-100                                                                                                                         |                    |
| 1.2.4                  | SEL-110                                                                                                                         |                    |
| 1.2.5                  | Rationale for the study                                                                                                         |                    |
| 2                      | ELIGIBILITY ASSESSMENT AND ENROLLMENT                                                                                           |                    |
| 2.1                    | Eligibility Criteria .                                                                                                          |                    |
| 2.1.1                  | Inclusion Criteria .                                                                                                            |                    |
| 2.1.2                  | Exclusion Criteria .                                                                                                            |                    |
| 2.1.3                  | Recruitment Strategies .                                                                                                        |                    |
| 2.2                    | Screening Evaluation .                                                                                                          |                    |
| 2.3                    | Registration Procedures                                                                                                         |                    |
| 2.4                    | Treatment Assignment Procedures ............................................................................................ 49 |                    |
| STUDY IMPLEMENTATION . |                                                                                                                                 |                    |
| 3                      | 3.1                                                                                                                             | Study Design       |
| 3.1.1                  | Dose Limiting Toxicity                                                                                                          |                    |
| 3.1.2                  | Dose Escalation                                                                                                                 |                    |
| 3.2                    | D Drug Administration                                                                                                           |                    |
| 3.2.1                  | SEL-110                                                                                                                         |                    |  
| Version date: 10/01/18  3.2.2 LMB-100 54 3.2.3 Co-administration of SEL-110 and LMB-100 57 3.2.4 Premedications for Patients Receiving LMB-100 57 3.3 Dose Modifications 58 3.3.1 LMB-100 58 3.3.2 SEL-110 60 3.4 Study Calendar 65 3.5 Criteria for Removal from Protocol Therapy and Off Study Criteria 68 3.5.1 Criteria for removal from protocol therapy 68 3.5.2 Off-Study Criteria 68 3.5.3 Off Protocol Therapy and Off-Study Procedure 68 4 CONCOMITANT MEDICATIONS/MEASURES 68 4.1.1 Permitted Therapy 68 4.1.2 Prohibited Therapy 69 5 BIOSPECIMEN COLLECTION 69 5.1 Correlative Studies for Research/Pharmacokinetic Studies 69 5.1.1 LMB-100 Pharmacokinetic Assessments 69 5.1.2 SEL-110 Pharmacokinetic assessments 70 5.1.3 Assessment of LMB-100 anti-drug antibodies (ADAs) 71 5.1.4 Assessment of anti-PEG antibodies 72 5.1.5 Mesothelin and Megakaryocyte Potentiating Factor (MPF) Serum Samples: 73 5.1.6 Retrospective Analysis of Mesothelin Expression in tumor tissue 74 5.1.7 Cytokines for identification of mechanism for PE-mediated capillary leak syndrome 74 5.1.8 Gene expression-based characterization of the immune landscape before and after  treatment with LMB-100 75 5.1.9 Tumor Microenvironment Studies Using Multiplex Staining Technologies 76 5.2 Sample Collection schedule 77 5.3 Sample Storage, Tracking and Disposition 80   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
untitled h1
abbreviated title lmb-100 plus sel-110

| Version date: 10/01/18                                                                                                                                |                                                                                                                                                        |
|-------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------|
| 5.3.1                                                                                                                                                 | Clinical Pharmacology Program                                                                                                                          |
| 5.3.2                                                                                                                                                 | Leidos Biomedical, Inc. Lab                                                                                                                            |
| 5.3.3                                                                                                                                                 | Laboratory of Dr. Raffit Hassan .............................................................................................................. 81      |
| NCI Laboratory of Pathology ...................................................................................................................... 81 |                                                                                                                                                        |
| 5.3.4                                                                                                                                                 |                                                                                                                                                        |
| 5.3.5                                                                                                                                                 | CAT-I Laboratory .                                                                                                                                     |
| 5.3.6                                                                                                                                                 | Protocol Completion/Sample Destruction ........................................................................................ 82                     |
| 6                                                                                                                                                     | DATA COLLECTION AND EVALUATION                                                                                                                         |
| 6.1                                                                                                                                                   | DATA COLLECTION                                                                                                                                        |
| 6.2                                                                                                                                                   | DATA SHARING Plans                                                                                                                                     |
| 6.2.1                                                                                                                                                 | Human Data Sharing Plan                                                                                                                                |
| 6.2.2                                                                                                                                                 | Genomic Data Sharing Plan                                                                                                                              |
| 6.3                                                                                                                                                   | Response Criteria                                                                                                                                      |
| 6.3.1                                                                                                                                                 | Peritoneal Mesothelioma                                                                                                                                |
| 6.3.2                                                                                                                                                 | Pleural Mesothelioma .............................................................................................................................. 89 |
| 6.3.3                                                                                                                                                 | D Duration of Response                                                                                                                                 |
| 6.3.4                                                                                                                                                 | Progression-Free Survival                                                                                                                              |
| 6.3.5                                                                                                                                                 | Objective Response Rate                                                                                                                                |
| 6.4                                                                                                                                                   | TOXICITY Criteria                                                                                                                                      |
| 7                                                                                                                                                     | SAFETY REPORTING REQUIREMENTS/DATA AND SAFETY MONITORING PLAN                                                                                          |
| ..                                                                                                                                                    |                                                                                                                                                        |
| 7.1                                                                                                                                                   | Definitions                                                                                                                                            |
| 7.1.1                                                                                                                                                 | A Adverse Event                                                                                                                                        |
| Suspected adverse reaction .                                                                                                                          |                                                                                                                                                        |
| 7.1.2                                                                                                                                                 | Unexpected adverse reaction                                                                                                                            |
| 7.1.3                                                                                                                                                 |                                                                                                                                                        |
| 7.1.4                                                                                                                                                 | Serious                                                                                                                                                |
| 7.1.5                                                                                                                                                 | Serious Adverse Event                                                                                                                                  |
| 7.1.6                                                                                                                                                 | Disability                                                                                                                                             |
| 7.1.7                                                                                                                                                 | Life-threatening adverse drug experience                                                                                                               |
| 7.1.8                                                                                                                                                 | Protocol Deviation (NIH Definition) ................................................................................................... 93             |
| 6                                                                                                                                                     |                                                                                                                                                        |
untitled h1
abbreviated title lmb-100 plus sel-110

Version date: 10/01/18  
| Version date: 10/01/18                                                                                                                  |                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------|
| 7.1.9                                                                                                                                   | Non-compliance (NIH Definition)                                                                                                       |
| 7.1.10 Unanticipated Problem                                                                                                            |                                                                                                                                       |
| 7.2                                                                                                                                     | NCI-IRB and Clinical Director Reporting ............................................................................ 93               |
| 7.2.1                                                                                                                                   | NCI-IRB and NCI CD Expedited Reporting of Unanticipated Problems and Deaths                                                           |
| ..                                                                                                                                      |                                                                                                                                       |
| 7.2.2                                                                                                                                   | NCI-IRB Requirements for PI Reporting at Continuing Review ............................... 93                                         |
| 7.2.3                                                                                                                                   | NCI-IRB Reporting of IND Safety Reports                                                                                               |
| 7.3                                                                                                                                     | IND Sponsor Reporting Criteria ................................................................................................... 94 |
| 7.3.1                                                                                                                                   | Reporting Pregnancy                                                                                                                   |
| 7.4                                                                                                                                     | Safety Reporting Criteria to the Pharmaceutical Collaborators                                                                         |
| 7.5                                                                                                                                     | DATA AND SAFETY MONITORING Plan                                                                                                       |
| 7.5.1                                                                                                                                   | Principal Investigator/Research Team .................................................................................. 95            |
| 7.5.2                                                                                                                                   | Sponsor Monitoring Plan                                                                                                               |
| Safety Monitoring Committee (SMC) .......................................................................................... 96         |                                                                                                                                       |
| 7.5.3                                                                                                                                   |                                                                                                                                       |
| 8                                                                                                                                       | STATISTICAL CONSIDERATIONS                                                                                                            |
| 8.1                                                                                                                                     | Statistical hypotheses .                                                                                                              |
| 8.1.1                                                                                                                                   | Primary endpoints: .                                                                                                                  |
| 8.1.2                                                                                                                                   | Secondary endpoints: .                                                                                                                |
| 8.2                                                                                                                                     | Sample size determination                                                                                                             |
| 8.3                                                                                                                                     | Populations for analysis .                                                                                                            |
| 8.4                                                                                                                                     | Statistical analyses .                                                                                                                |
| 8.4.1                                                                                                                                   | General approach .                                                                                                                    |
| Analysis of the primary endpoints .................................................................................................. 98 |                                                                                                                                       |
| 8.4.2                                                                                                                                   | Analysis of the secondary endpoints............................................................................................ 98    |
| 8.4.3                                                                                                                                   |                                                                                                                                       |
| 8.4.4                                                                                                                                   | Se                                                                                                                                    |
| 8.4.5                                                                                                                                   | Baseline Descriptive Statistics .                                                                                                     |
| 8.4.6                                                                                                                                   | Planned interim analyses                                                                                                              |
| 8.4.7                                                                                                                                   | SUBGROUP ANALYSES                                                                                                                     |
| 8.4.8                                                                                                                                   | Tabulation of individual participant data                                                                                             |
| 7                                                                                                                                       |                                                                                                                                       |  
| Version date: 10/01/18                                                                                                                                    |                                                                                                                                                                  |                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------|
| 9                                                                                                                                                         | COLLABORATIVE AGREEMENTS .                                                                                                                                       |                                 |
| 9.1                                                                                                                                                       | Collaborative Research and Development Agreement (CRADA) ............................. 100                                                                       |                                 |
| HUMAN SUBJECTS PROTECTIONS .                                                                                                                              |                                                                                                                                                                  |                                 |
| 10                                                                                                                                                        | 10.1                                                                                                                                                             | Rationale For Subject Selection |
| 10.2                                                                                                                                                      | Participation of Children                                                                                                                                        |                                 |
| 10.3                                                                                                                                                      | Participation of Subjects Unable to Give Consent.......................................................... 100                                                   |                                 |
| 10.4                                                                                                                                                      | Evaluation of Benefits and Risks/Discomforts .............................................................. 101                                                  |                                 |
| 10.4.1                                                                                                                                                    | Risks from Study Drugs                                                                                                                                           |                                 |
| 10.4.2                                                                                                                                                    | Blood Collection ........................................................................................................................................... 101 |                                 |
| Image Guided Biopsy Collection                                                                                                                            |                                                                                                                                                                  |                                 |
| 10.4.3                                                                                                                                                    | Risks/Benefits Analysis                                                                                                                                          |                                 |
| 10.5                                                                                                                                                      | Consent Process and Documentation                                                                                                                                |                                 |
| 10.6                                                                                                                                                      | Telephone consent and re-consent ........................................................................................... 102                                 |                                 |
| 10.6.1                                                                                                                                                    |                                                                                                                                                                  |                                 |
| 10.6.2 Informed consent of non-English speaking subjects ..................................................... 102                                        |                                                                                                                                                                  |                                 |
| 11                                                                                                                                                        | PHARMACEUTICAL INFORMATION                                                                                                                                       |                                 |
| 11.1                                                                                                                                                      | LMB-100 (IND # 136483)                                                                                                                                           |                                 |
| 11.1.1                                                                                                                                                    | S SOURCE .                                                                                                                                                       |                                 |
| 11.1.2                                                                                                                                                    | T Toxicity                                                                                                                                                       |                                 |
| 11.1.3                                                                                                                                                    | Formulation and preparation                                                                                                                                      |                                 |
| Stability and Storage ............................................................................................................................... 104 |                                                                                                                                                                  |                                 |
| 11.1.4                                                                                                                                                    | Administration procedures ............................................................................................................... 104                    |                                 |
| 11.1.5                                                                                                                                                    |                                                                                                                                                                  |                                 |
| 1.1.6 Incompatibilities                                                                                                                                   |                                                                                                                                                                  |                                 |
| 11.2                                                                                                                                                      | SEL-110 (IND # 136483) .                                                                                                                                         |                                 |
| 11.2.1                                                                                                                                                    | S SOURCE .                                                                                                                                                       |                                 |
| 11.2.2                                                                                                                                                    | TOXICITY                                                                                                                                                         |                                 |
| 11.2.3                                                                                                                                                    | Formulation and preparation                                                                                                                                      |                                 |
| 1.2.4 Stability and Storage                                                                                                                               |                                                                                                                                                                  |                                 |
| 11.2.5 Administration procedures                                                                                                                          |                                                                                                                                                                  |                                 |
untitled h1
abbreviated title lmb-100 plus sel-110

| 1.2.6 Incompatibilities    |                                                                                                                         |
|----------------------------|-------------------------------------------------------------------------------------------------------------------------|
| 1.2.7 Mechanism of Action. |                                                                                                                         |
| 12                         | REFERENCES .                                                                                                            |
| 13                         | Appendices                                                                                                              |
| 13.1                       | Appendix A-Performance Status Criteria ............................................................................. 18 |
| 13.2                       | Appendix B - Cockroft-Gault formula                                                                                     |
untitled h1
1 introduction 1.1 study objectives

1.1.1 Primary Objective x The primary objective of the study is to assess the safety and tolerability of LMB-100 in combination with SEL-110  
1.1.2 Secondary Objectives
x To determine if the use of SEL-110 along with LMB-100 for treatment of mesothelioma is associated with decreased formation of antibodies to LMB-100 x To define the effect of SEL-110 on the pharmacokinetics characteristics of LMB-100 x To assess the objective response rate (complete response + partial response) of SEL-110 in combination with LMB-100 1.1.3 Exploratory Objectives x To establish the correlation of response to treatment with tumor mesothelin expression  
x To investigate the potential of soluble mesothelin levels and levels of megakaryocyte potentiating factor to predict any therapeutic response
x To determine the frequency anti-PEG antibody formation x To identify the mechanism for Pseudomonas exotoxin-mediated capillary leak syndrome x To evaluate changes in the tumor microenvironment following treatment with LMB-100 +
SEL-110
untitled h1
1.2 background and rationale 1.2.1

Mesothelioma is a neoplasm originating from the mesothelial cells lining human body cavities. Mesothelioma may involve the pleura and less frequently, the peritoneum. Approximately 3000 new cases are diagnosed every year in the US alone. The epithelioid variant is the most common, comprising about 60 percent of all mesotheliomas. Malignant pleural mesothelioma is an aggressive disease with poor prognosis. Although patients with a limited tumor burden may benefit from surgical resection, most patients have advanced disease at diagnosis and are not candidates for cytoreductive surgery.(1) For patients who are not eligible for curative surgery, the median survival with supportive care alone is 6 months whereas with the current standard treatment, a combination of cisplatin and pemetrexed, the median survival is 12 months.(2) Peritoneal mesothelioma represents about one-fifth to one-third of all forms of mesothelioma; there are approximately 400 new cases in the United States each year.(3) Cytoreductive surgery and hyperthermic perioperative chemotherapy is the accepted initial management for suitable patients with peritoneal mesothelioma.(4-7) Peritoneal mesothelioma patients with surgically unresectable disease or whose medical co-morbidities preclude surgery are considered for palliative systemic therapy. Due to its relatively low incidence and inherent difficulties of radiologic assessment, few studies of systemic therapy have been conducted. Treatment recommendations are often extrapolated from pleural mesothelioma and outcomes are poor.
untitled h1
1.2.2 mesothelin as a target

Mesothelin is a glycosylphosphatidylinositol (GPI)-anchored membrane glycoprotein, which is present in a restricted set of normal adult tissues, such as the mesothelial lining of the pleura and pericardium. Immunohistochemistry has shown that mesothelin is highly expressed in nearly all epithelioid mesotheliomas as well as epithelial components of biphasic mesothelioma in addition to pancreatic ductal adenocarcinomas and in a high percentage of epithelial ovarian cancers and non-small cell lung cancer (NSCLC).(8) Although the normal biological function of mesothelin is unknown, growing evidence suggests that it may play a role in tumorigenesis and metastasis. Its limited expression in normal human tissue and high expression in tumor makes mesothelin an excellent target antigen for antibody-based immunotherapy.(9) Because of the high expression of mesothelin in many malignancies, a variety of agents are being developed to target mesothelin. Results of several ongoing clinical trials of immunotherapy agents directed against mesothelin have shown that targeting mesothelin is safe and does not result in toxicity to essential normal tissues. Both antibody-based therapies, as well as mesothelin vaccines, are being investigated.(10) The Laboratory of Molecular Biology (LMB) and the Thoracic and GI Malignancies Branch, Center for Cancer Research, National Cancer Institute have pioneered the use of mesothelin- targeted agents and clinical trials over the last decade.
untitled h1
1.2.2.1 recombinant immunotoxins (rits) 1.2.2.1.1

RITs are antibody-based therapeutics that carry a toxin payload. RITs that target mesothelin contain a genetically engineered variant of Pseudomonas exotoxin A (PE) in which the native cellbinding domain of PE is replaced by a mesothelin-binding antibody fragment. In this way, the RIT
binds specifically to mesothelin on the cell surface and gets internalized through endocytic processes. In the cytosol, PE catalyzes an irreversible, inactivating modification of eukaryotic Elongation Factor-2 (eEF-2). This prevents the elongation step of protein synthesis, halting production of new cellular proteins, a stressor that triggers apoptosis. This mechanism of action results in cytotoxicity to both proliferating and non-dividing cells, therefore proper targeting is critical to the safety profile.(11) Tumor-targeted bacterial toxins that inhibit the protein synthesis of cancer cells have previously shown signs of preclinical and clinical efficacy. For instance, SS1P, a classical immunotoxin format molecule consisting of the mouse anti-mesothelin Fv, SS1 and a 38 kDa PE toxin fragment (PE38) is one example. Besides SS1P, the most clinically advanced PE-based immunotoxins are moxetumomab pasudotox, a CD22-targeted fusion protein in development by LMB/Astra Zeneca/ Medimmune, and LMB2, a CD25-targeted PE fusion protein developed by LMB. Both agents have shown encouraging signs of efficacy in different hematological malignancies and are currently in Phase II and III clinical trials. Denileukin difitox is the only immunotoxin approved by the US Food and Drug Administration (FDA); a fusion protein of diphtheria toxin with interleukin-2 that is clinically used for intravenous treatment of cutaneous T cell lymphoma. 1.2.2.1.2 *SS1P - a recombinant immunotoxin targeting mesothelin* The first mesothelin directed agent to enter the clinic was the recombinant immunotoxin (RIT) SS1P. The safety and tolerability of SS1P was determined in two phase I clinical trials in patients. In one trial SS1P was given as a bolus infusion over 30 minutes and the dose-limiting toxicity was pleuritis.(12) In another trial SS1P was given as a continuous infusion for 10 days. Dose-limiting side effects were very similar to the bolus infusion trial.(13) In neither trial were major responses observed, although there was shrinkage of small volume disease in some patients. Phase I studies established a maximum tolerated dose (MTD) of 45 mcg/kg for SS1P given every other day for three total doses per cycle. Dose limiting toxicities (DLTs) were pleuritis, an expected on-target off-tumor toxicity caused by SS1P-induced inflammation of the normal pleura, and secondly, vascular leak syndrome (VLS).  
These early trials demonstrated that the efficacy of SS1P is limited by its immunogenicity. AntiSS1P neutralizing antibodies (Nabs) formed after one cycle in ~90% of patients preventing effective drug exposure in subsequent cycle.(12, 14) Development of human antibody response to immunotoxins in patients with solid tumors has been a significant impediment to their clinical development and previous efforts to limit their immunogenicity by treatment with single agents such as steroids, cyclophosphamide, cyclosporine or rituximab have not been successful.(15-17) However, we have recently shown that when SS1P was administered with a lymphocyte-depleting conditioning regimen of pentostatin and cyclophosphamide, it delayed the development of antiSS1P antibodies in immunocompetent mice.(18)
This strategy of using pentostatin and cyclophosphamide to prevent human antibody response to SS1P was evaluated in a pilot study of heavily pre-treated chemotherapy refractory mesothelioma patients. Eleven patients were enrolled in the study and received pentostatin and cyclophosphamide prior to SS1P administration. This regimen was well tolerated and no patient developed opportunistic infections. As predicted this regimen decreased the development of human antibodies to SS1P; only two of ten patients developed antibodies after cycle 1 of therapy, which was significantly better than in prior clinical trials where about 90% of patients developed antibodies after one cycle of therapy.(19) Remarkably, three of the ten evaluable patients with extensive tumor burden had durable partial response and two of these patients had complete metabolic response by PET scan. All three patients were alive after 27, 25 and 22 months of starting therapy. In addition, two patients who did not initially respond to SS1P had a dramatic anti-tumor response when treated with chemotherapy to which they had not previously responded. SS1P plus pentostatin/cyclophosphamide regimen is currently being evaluated in more patients with mesothelioma. Major tumor shrinkage in the neck and abdomen of a patient with metastatic peritoneal mesothelioma treated with SS1P in combination with pentostatin and cyclophosphamide is shown in Figure 1. These results provide a proof of principle that RITs can have meaningful clinical efficacy in patients with advanced solid tumors. A new generation of immunotoxin molecules with reduced immunogenicity and non-specific toxicity has been developed through protein engineering techniques. Figure 1. **Representative response to SS1P in a mesothelioma patient**
untitled h1
1.2.3 lmb-100 1.2.3.1 rationale for

The clinical use of SS1P, and of immunotoxins in general, has been hampered mainly by their high immunogenicity which limits the number of effective treatment cycles that patients can receive.  
LMB-100 (see Figure 2 for structure) is a next generation PE-fusion protein that has been proteinengineered to maximally reduce its immunogenicity by:
1. Using a fully humanized Fab fragment derived from the anti-mesothelin antibody SS1 for tumor targeting 2. Substituting the bulk of domain II (residues 251–273 and 284–394 of native PE) by an extended furin cleavable linker whose sequence is devoid of any T cell neo-epitopes 3. Deimmunizing domain III of PE, which has the catalytic activity for ADP-ribosylation by introducing 7 point mutations that silence B- and T-cell epitopes Classical PE-based immunotoxins, such as SS1P, contain a 38 kD fragment of the exotoxin encompassing the so-called translocation domain II and the catalytic domain III. Omission of the domain II from LMB-100 has not only removed a highly immunogenic 14 kD portion of PE that contains the main T-cell epitopes,(20) but has also resulted in reduced incidents of VLS in animal models of VLS.(21)
untitled h1
1.2.3.2 development of lmb-100

LMB-100 (previously RO6927005 and RG7787) is a next generation anti-mesothelin RIT developed in NCI's Laboratory of Molecular Biology in collaboration with Roche (Figure 2). LMB-100 contains a newly engineered PE fragment that has improved activity against most mesothelin-expressing cancer cell lines in vitro, and is also much less toxic than SS1P in preclinical models. This improved therapeutic window allows administration of three to eight times the dose of RIT to mice, rats and monkeys compared to SS1P. The new PE contains modifications specifically designed to reduce immunogenicity of the molecule. This includes deletion of a 14 kD sequence that precedes the catalytic domain and seven point mutations within the catalytic domain itself. These changes ablate the major human B cell epitopes within the molecule and also the most antigenic T cell epitope.(21, 22) The anti-mesothelin targeting region of LMB-100 uses a humanized Fab fragment instead of the smaller dsFv fragment used in SS1P. This increases molecular weight of the RIT above the threshold required to prevent filtration by the kidney and increases half-life.
untitled h1
1.2.3.3 nonclinical studies 1.2.3.3.1 nonclinical

In vitro LMB-100 inhibited viability of a variety of mesothelin-positive cancer cell lines at effective concentrations typically around 14 pM (~1 ng/mL). The cytotoxic potency of LMB-100 varied between 0.35 ng/mL in primary mesothelioma cells (RH21) and 15.7 ng/mL in an adenosquamous lung carcinoma cell line (H596). Binding studies showed that while the Fab fragment did not bind to mouse or rat mesothelin, the binding affinities to cynomolgus and human mesothelin were identical. In agreement with this, LMB-100 induced apoptosis in mesothelinpositive primary cynomolgus pericardial cells and significantly impaired viability of HEK293 cells transfected with human mesothelin, but not of rat mesothelin transfected or untransfected HEK293 cells. In addition, control experiments showed that free PE24 was 1001000 fold less potent on mesothelin-positive target cell lines, confirming low cytotoxic potential of PE24 lacking a targeting moiety. LMB-100 showed broad activity against different mesothelin-expressing cancer cell lines and patient derived xenograft models.(23, 24) Animal studies demonstrated that a single cycle of LMB-100 treatment given at an optimal dose of approximately 2 mg/kg, 3 uper week, every other day (QOD) achieved tumor regressions in subcutaneous xenografts of adenosquamous lung carcinoma (H596) in severe combined immunodeficient (SCID) beige mice. Three consecutive treatment cycles, given with 1 week breaks in between, led to massive shrinkage of large tumors with an average initial volume of 600 mm3. Tumor regressions in monotherapy were also achieved when treating subcutaneous xenografts of mesothelioma (NCI-H226), gastric (MKN-28), and triple negative breast (HCC70) cancer cell lines in athymic nude mice. Highly synergistic antitumor efficacy was observed in combination therapy with paclitaxel when treating subcutaneous xenografts of the recombinant high mesothelin expressing A431/H9 cell line or the pancreatic cancer cell line KLM1. Synergy was also observed in the HCC70 and MKN-28 cell lines. These results support evidence that LMB100 in monotherapy or in combination with standard chemotherapies may provide clinical benefit to patients with cancer.
untitled h1
1.2.3.3.2 pharmacokinetics in animals

The pharmacokinetics (PK) of LMB-100 were tested in cynomolgus monkeys following a single IV administration at doses ranging from 0.03 mg/kg to 0.3 mg/kg. Two different enzyme-linked immunosorbent based formats were used for analyzing plasma levels of LMB-100; free and total drug assay (where the total drug assay was the sum of free LMB-100 and LMB-100 complexed with binding molecules). LMB-100 showed a relatively rapid plasma clearance and a volume of distribution at steady-state similar to the plasma volume. Within the dose range tested, non-linear PK was observed for free drug with an extended half-life at higher doses (mean terminal half-life approximately 0.6 hours at 0.3 mg/kg compared to 0.3 hours at 0.03 mg/kg) suggesting saturation of MSLN-mediated clearance pathways. Clearance of total drug was consistently lower than that for free drug implying the presence of soluble binding partners such as soluble mesothelin and ADAs. Induction of anti-drug antibodies (ADA) responses was frequently detectable in all dose groups tested. Overall, given the limited predictive value of immunogenicity reactions in animals to human, a risk for immunogenicity in humans cannot be excluded. Toxico-kinetics after repeated IV dosing in cynomolgus monkeys demonstrated an increase in total exposure in a dose proportional manner between 0.1 mg/kg and 3.0 mg/kg. No accumulation was observed over 5 consecutive days of treatment or over two dosing cycles with 3 uper week dosing. Almost all monkeys developed ADAs upon treatment, while induction of high ADA levels impaired the exposure of free drug. In some cases, the induction of ADAs may have induced a slight increase in exposure The relationship between systemic drug exposure and anti-tumor activity of LMB-100 was investigated on human lung cancer NCI-H596 xenograft growth in female SCID beige mice. Free and total drug profiles were similar in mice. Modeling estimated a plasma concentration of 6800 ng/mL (r36%) to trigger a half maximal rate of tumor regression. Concentrations of LMB-100 above this level resulted in potent tumor regression after dosing. Normalized for exposure, SS1P was found to be ~3-fold more potent than LMB-100 in terms of tumor growth inhibition.
untitled h1
1.2.3.3.3 toxicology and safety pharmacology

The toxicological profile of LMB-100 was assessed after repeated intravenous administration to cynomolgus monkeys, the only relevant species, for a maximum of 5 daily doses for one week or 2 cycles with QOD u3 dosing, separated by a 9-day dosing free period. Four daily doses of 3 mg/kg exceeded the maximum tolerated dose with animals being found in moribund condition, indicated by clinical signs of hypoactivity, hunched posture, ataxia, and tremors. There were no histopathological changes to account specifically for the deteriorating physical condition of these animals. Histopathological findings such as kidney tubular degeneration/regeneration and changes at serosal-lining tissues were observed at lower doses as well. In general, administration of LMB100 resulted in both on- and off-target toxicities.  
On-target effects were observed on serosal-lining tissues, consistent with high expression of mesothelin. Mesothelium hypertrophy accompanied by subpleural cellular hypertrophy and serosal fibrin exudate was observed in the lung at doses t1 mg/kg. Mesothelium hypertrophy also occurred in heart (epicardium), spleen, and stomach. Off-target or non-specific toxicity included degeneration/regeneration of kidney tubular epithelium after repeated doses of t0.3 mg/kg. Local inflammatory findings at the injection sites were observed after administration of LMB-100 in several studies. Clinically, reddening of the skin, swelling, and skin being warm to touch or flaky injection sites were reported. In the 2-cycle GLP study (3 intermittent doses over a 5-day period, 9-days apart), impaired movement of animals from all dose groups was likely related to injection site findings and an overall inflammatory profile. One female at 1 mg/kg was sacrificed early on Day 4 after 2 doses due to severe clinical signs most likely attributed to inflammatory changes at injection sites resulting in moribundity of the animal. Clinically observed inflammatory changes correlated with histopathological changes such as hemorrhages and/or acute inflammation at the injection sites and clinical pathology changes consistent with an overall inflammatory profile (increases in monocytes, neutrophils, CRP, and haptoglobin). Microscopic changes reversed completely after the 4-week recovery period in the 2-cycle GLP study. The Highest Non Severely Toxic Dose in this study was 0.3 mg/kg, which resulted in a mean AUC for total drug of 16.0 μg·h/mL (study day 1, preliminary data). In a subsequent 1 cycle GLP study (QOD u3 dosing),
markedly reduced Injection site findings were observed after administration of a batch with reduced levels of product related modifications of LMB-100. In this study, the HNSTD was 1 mg/kg, resulting in an AUC for total drug of 27.4 and 23.6 μg·h/mL after the first and third dose (preliminary data). The potential of LMB-100 to induce off-target vascular leak in lungs was assessed in female Wistar rats. Mild perivascular edema was reported microscopically, but did not correlate with macroscopic or serum chemistry findings consistent with VLS. Ultrasound evaluation in the NHP GLP study revealed minimal accumulation of pericardial fluid with limited biological significance at the highest dose of 1 mg/kg. No appreciable accumulation of pleural fluid was observed at necropsy.  
In vitro evaluation of LMB-100 in human whole blood assay indicated a low risk for cytokinemediated infusion related reaction (IRR)/cytokine release syndrome (CRS) upon first administrations. LMB-100 caused no hemolysis when added to human peripheral blood up to the highest concentrations of 0.5 mg/L. 1.2.3.4 Clinical testing of single agent LMB-100 (Roche Study) Initial clinical testing of LMB-100 was performed by Roche in a multi-center international first in human trial (NCT02317419). The primary objective of the Phase I study was to define the safety and tolerability (including the MTD) and pharmacokinetics of the drug in participants with MSLNexpressing metastatic or locally advanced solid tumors for whom no standard therapy was available. Secondary objectives included determination of the RP2D and schedule, exploration of preliminary anti-tumor activity by assessing objective response rate (ORR) and disease control rate (DCR), and assessment of pharmacodynamic effects. A total of 15 participants were enrolled onto the study before termination. Median age of participants was 60.8 years and 53.3% were female. All participants had received prior anti-cancer therapy for their tumors. Enrolled participants had advanced mesothelioma (7), ovarian cancer (3), pancreatic cancer (3), and gastroesophageal cancer (2). Tumors from 13 of the 15 participants treated had moderately to strongly positive MSLN expression as measured by central IHC analysis.  
LMB-100 was administered intravenously on Days 1, 3 and 5 of a 21-day treatment cycle. No premedications were given. Treatment was initiated at the MTD of SS1P, 45 mcg/ kg. Five different dose levels were tested (see Table 1). Dose limiting toxicity (DLT) was reached at 250 mcg/kg, with 2 of 4 participants treated at this dose level experiencing vascular leak syndrome (grade 2 and grade 4). Additional toxicities were associated with this dose level. At this point, a sixth cohort receiving 200 mcg/kg of study drug was enrolled, however, the study was terminated by the company before the two accrued participants completed cycle 1 of therapy. Therefore, the single agent MTD was not determined.  
| Dose (mcg/kg)   | No. of patients   | Pts with DLT   |
|-----------------|-------------------|----------------|
| 45              | 1                 | 0              |
| 65              | 1                 | 0              |
| 100             | 3                 | 0              |
| 170             | 4                 | 0              |
| 200             | 2                 | NE             |
| 250             | 4                 | 2              |  
| Table 1. LMB-100 Dose escalation study- NCT02317419 Dose (mcg/kg) No. of patients Pts with DLT  DLTs were vascular leak syndrome and proteinuria  NE, Study terminated before DLT assessment period was complete and  patients only received single dose of LMB-100   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
untitled h1
1.2.3.4.1 lmb-100 adverse events

Overall, 14 participants (93.3%) experienced at least one AE. The most common AEs were hypoalbuminemia (60.0%), fatigue (53.3%), peripheral edema (53.3%), nausea (46.7%), pyrexia (40.0%), decreased appetite (33.3%), dyspnea (33.3%), and myalgia (33.3%). SAEs included vascular leak syndrome, pyrexia, atrial flutter, infusion related reaction, arthritis, glomerulonephritis minimal lesion and dyspnea. No participants experienced an AE that led to withdrawal of study treatment. Four participants experienced a total of 8 infusion-related reactions that were independent of drug dose level. These AEs were non-serious and resolved within approximately 1 hour of onset. Pre-medication for infusion reaction was administered to these participants prior to subsequent doses of LMB-100. Two suspected Type III hypersensitivity reactions were observed. These consisted of arthritis (1 patient) and rash with fever (1 patient), both of which were fully reversible. When other AEs attributed to the study drug are presented by dose level of drug, it becomes clear that toxicity was strongly associated with the 250 mcg/kg dose level at which DLT was reached. Two of four patients treated at 250 mcg/kg experienced serious VLS which manifested with hypotension, respiratory compromise, serosal membrane reaction and hyponatremia as well as the hypoalbuminemia and edema that can be seen with mild VLS. Other symptoms associated with the DLT dose were fatigue, nausea, vomiting, decreased appetite and mild elevation of transaminases. Table 2 summarizes any adverse event related to LMB-100 while as Table 3 summarizes grade 3 or 4 toxicity related to LMB-100. As shown in Table 3 most grade 3 or 4 toxicity were seen in patients treated at 250 mcg/kg dose level. However, patients receiving LMB-100 doses less than 250 mcg/kg had mainly grade 1-2 adverse events except 1 patient having grade 3 arthritis and 1 patient with grade 3 anemia.  
| Dose (mcg/kg)              | 45   | 65   | 100   | 170   | 250   | ALL   |
|----------------------------|------|------|-------|-------|-------|-------|
| # of patients treated      | 1    | 1    | 3     | 4     | 4     | 13    |
| Vascular Leak              | -    | -    | 1     | 1     | 2     | 4     |
| grade 3 or 4 vascular leak | -    | -    | -     | -     | 1     | 1     |
| hypotension                | -    | -    | -     | -     | 2     | 2     |
| hypoalbuminemia            | -    | 1    | 3     | 2     | 3     | 9     |
| peripheral edema           | 1    | 1    | 3     | 2     | 4     | 11    |
| facial edema               | -    | 1    | 2     | -     | 1     | 4     |
| weight gain                | -    | -    | 1     | -     | 1     | 2     |
| hyponatremia               | -    | -    | -     | -     | 3     | 3     |  
| Version date: 10/01/18  Dose (mcg/kg)                                                                                                                                                                       | 45   | 65   | 100   | 170   | 250   | ALL   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------|------|-------|-------|-------|-------|
| # of patients treated                                                                                                                                                                                       | 1    | 1    | 3     | 4     | 4     | 13    |
| hypophosphatemia                                                                                                                                                                                            | -    | -    | -     | -     | 1     | 1     |
| dyspnea                                                                                                                                                                                                     | -    | 1    | -     | -     | 2     | 3     |
| Infusion related reaction                                                                                                                                                                                   | -    | -    | 2     | -     | 2     | 4     |
| Constitutional  fatigue                                                                                                                                                                                     | -    | -    | -     | 1     | 4     | 5     |
| asthenia                                                                                                                                                                                                    | -    | -    | 3     | -     | -     | 3     |
| fever                                                                                                                                                                                                       | 1    | -    | 2     | 1     | 2     | 6     |
| Musculoskeletal  myalgia                                                                                                                                                                                    | -    | -    | 1     | 1     | 2     | 4     |
| arthralgia                                                                                                                                                                                                  | 1    | -    | -     | -     | 1     | 2     |
| arthritis                                                                                                                                                                                                   | -    | -    | 1     | -     | -     | 1     |
| muscle spasm                                                                                                                                                                                                | -    | -    | -     | 1     | -     | 1     |
| Cardiac  pericardial effusion                                                                                                                                                                               | -    | -    | -     | -     | 1     | 1     |
| Atrial flutter                                                                                                                                                                                              | -    | -    | -     | 1     | -     | 1     |
| Renal Disorders  glomerulonephritis minimal                                                                                                                                                                 | -    | -    | -     | 1     | -     | 1     |
| proteinuria                                                                                                                                                                                                 | -    | -    | -     | 1     | 1     | 2     |
| Creatinine increase                                                                                                                                                                                         | -    | -    | -     | -     | 2     | 2     |
| Gastrointestinal  decreased appetite                                                                                                                                                                        | -    | 1    | -     | 1     | 2     | 4     |
| nausea                                                                                                                                                                                                      | 1    | -    | 1     | 1     | 4     | 7     |
| abdominal pain                                                                                                                                                                                              | -    | 1    | -     | 1     | 1     | 3     |
| diarrhea                                                                                                                                                                                                    | 1    | -    | 1     | -     | -     | 2     |
| vomiting                                                                                                                                                                                                    | -    | -    | -     | -     | 2     | 2     |
| abdominal distension                                                                                                                                                                                        | -    | 1    | -     | -     | -     | 1     |
| constipation                                                                                                                                                                                                | -    | -    | -     | 1     | -     | 1     |
| dyspepsia                                                                                                                                                                                                   | -    | -    | -     | 1     | -     | 1     |
| AST increase                                                                                                                                                                                                | -    | -    | -     | -     | 2     | 2     |
| Hematologic  anemia                                                                                                                                                                                         | -    | -    | -     | 1     | -     | 1     |
| decreased lymphocytes                                                                                                                                                                                       | -    | -    | -     | -     | 1     | 1     |
| Total Grade 3 or greater                                                                                                                                                                                    | -    | -    | 2     | 1     | 2     | 5     |
| Orange highlighting indicates that one of the patients experienced a grade 3 or 4 toxicity in this category. Please  note that there was only 1 patient who experienced a high-grade toxicity of each type. |      |      |       |       |       |       |  
| Dose (mcg/kg)                                                                                              | 45   | 65   | 100   | 170   | 250   | ALL   |
|------------------------------------------------------------------------------------------------------------|------|------|-------|-------|-------|-------|
| # of patients treated                                                                                      | 1    | 1    | 3     | 4     | 4     | 13    |
| Vascular leak (gr 4)                                                                                       | -    | -    | -     | -     | 1     | 1     |
| Hyponatremia (gr 3)                                                                                        | -    | -    | -     | -     | 1     | 1     |
| Anemia (gr 3)                                                                                              | -    | -    | -     | 1     | -     | 1     |
| Decreased lymphocytes (gr 3)                                                                               | -    | -    | -     | -     | 1     | 1     |
| Dyspnea (gr 3)                                                                                             | -    | -    | -     | -     | 1     | 1     |
| Infusion-related reaction (gr 3)                                                                           | -    | -    | 1     | -     | -     | 1     |
| Arthritis (gr 3)                                                                                           | -    | -    | 1     | -     | -     | 1     |
| 1 adapted from Clinical Study Report No 1066017 from Roche dated December 2015, "Summary of Adverse Events |      |      |       |       |       |       |
untitled h1
1.2.3.4.2 anti-drug antibodies (adas) and

Twelve participants were evaluable for efficacy. The best confirmed overall response was stable disease in 3 participants. A Roche-developed ELISA test was used to retrospectively assess antidrug antibody (ADA) titers. Four of 13 patients had detectable ADAs at study enrollment while the remaining participants did not; however, the remaining 10 participants developed detectable ADAs by the end of Cycle 2. (Figure 3, Table 4 and Table 5). All evaluable participants achieved expected serum drug levels during the first cycle of treatment. Six of 7 participants without preexisting ADAs achieved effective drug levels during the second cycle, while 0 of 2 participants with pre-existing ADAs did. One of 3 participants that received a third cycle of treatment also achieved effective drug levels during this cycle. A positive test for ADAs did not definitively predict poor blood levels in the subsequent cycle (see patient 1101 in Table 5, who had very good LMB-100 blood levels despite the presence of ADA). In summary, the data regarding LMB-100 ADA and LMB-100 blood levels show:  
x Presence of ADA is not predictive of ability to achieve measurable LMB-100 concentration in the serum, which is the most important parameter for drug efficacy.  
x Patients who have presence of pre-existing ADA can achieve good LMB-100 blood levels during cycle 1 (4/4 patients), but may not do so during cycle 2 (2/2 patients with undetectable blood levels) although the numbers are small.  
x Patients who do not have presence of pre-existing ADA can achieve good LMB-100 blood levels during cycle 1 (7/7 patients) as well as cycle 2 (6/7 patients).  
x Very few patients have been treated to determine LMB-100 blood levels during cycle 3 and beyond. However, 1/3 patients had good LMB-100 blood levels that were in fact higher than those achieved during cycle 1 and 2 despite the presence of ADA. In addition, another patient had low but detectable blood levels during cycle 3. More patients need to be treated
to determine what percent of patients will achieve good blood levels during cycle 3 and beyond.  
Figure 3. Effect of anti-drug antibodies (ADA) on the ability to achieve good LMB-100 blood  
 levels in patients treated with LMB-100.
untitled h1
table 4. effect of ada

The table shows patients treated at different dose levels of LMB-100; ADA prior to start of each cycle and LMB-100 blood levels as Cmax (ng/ml). In addition, the change in LMB-100 Cmax concentration (as percent increase or percent decrease) during cycle 2 and 3 is shown as dC1/dC2 and dC1/dC3 respectively. Please note that - means the PK assay was not performed.  
|          | Cycle 1   | Cycle 2   | Cycle 3   |         |        |        |         |        |      |
|----------|-----------|-----------|-----------|---------|--------|--------|---------|--------|------|
| Dose     | ADA       | Cmax      | ADA       | Cmax    | dC1/dC | ADA    | Cmax    | dC1/dC |      |
| (mcg/kg) | (Day1)    | (ng/ml)   | (Day1)    | (ng/ml) | (%)    | (Day1) | (ng/ml) | (%)    |      |
| 1002     | 65        | 0         | 1150      | 8100    | 711    | -38    | -       | -      | -    |
| 1401*    | 100       | 0         | 1790      | 0       | 1610   | -10    | 24300   | 267    | -85  |
| 1402     | 100       | 0         | 1650      | 0       | 1360   | -18    | 8100    | 0      | -100 |
| 1101*    | 170       | 0         | 2760      | 300     | 3950   | 43     | 900     | 3490   | 26   |
| 1202     | 170       | 0         | 3040      | 0       | 1940   | -36    | -       | -      | -    |
| 1301     | 170       | 0         | 3430      | 72900   | 527    | -85    | -       | -      | -    |
| 1403     | 170       | 0         | 1930      | 900     | 1550   | -20    | -       | -      | -    |
| 1102*    | 250       | 0         | 5480      | 0       | 4770   | -13    | -       | -      | -    |
| 1302     | 250       | 0         | 4340      | -       | -      | -      | -       | -      | -    |  
|                                                    | Cycle 1   | Cycle 2   | Cycle 3   |        |         |        |
|----------------------------------------------------|-----------|-----------|-----------|--------|---------|--------|
| Patien                                             | Dose      | ADA       | Cmax      | ADA    | Cmax    | dC1/dC |
| t                                                  | (mcg/kg)  | (Day1)    | (ng/ml)   | (Day1) | (ng/ml) | (%)    |
| * Patient's treatment stopped due to study closure |           |           |           |        |         |        |  
Patien  
t  
Dose  
(mcg/kg)  
ADA  
(Day1)  
Cmax  
(ng/ml)  
ADA  
(Day1)  
Cmax  
(ng/ml)  
dC1/dC  
(%)  
ADA  
(Day1)  
Cmax  
(ng/ml)  
dC1/dC  
(%)  
* Patient's treatment stopped due to study closure  
ADA data are from Roche "Bioanalytical Report (ADA) for Clinical Study BP29387"with ADA time  
point codes translated as specified in the BP29837 Lab Manual Version 1.0. Cmax data were taken from  
the Roche final study report.
untitled h1
table 5. effect of ada

The table shows patients treated at different dose levels of LMB-100; ADA prior to start of each cycle and LMB-100 blood levels as Cmax (ng/ml). In addition, the change in LMB-100 Cmax concentration (as percent increase or percent decrease) during cycle 2 and 3 is shown as dC1/dC2 and dC1/dC3 respectively. Please note that - means the PK assay was not performed. 1.2.3.5 Clinical testing of single agent LMB-100 at NCI (Study - 16C0127 - ongoing) As of July 12, 2017, ten patients have been enrolled on the study. Out of these 10 patients 7 had peritoneal mesothelioma and 3 pleural mesothelioma; 6 female and 4 male and median age was 62 years old. The first 3 patients were treated at dose level 1 i.e. 170 mcg/kg with patient \#1 initiating treatment on July 28, 2016. All three patients at this dose level during cycle 1 had grade 1 or 2 increase in serum creatinine). Since increase in serum creatinine was a common toxicity pattern at this dose level it was defined as DLT per protocol established criteria. The protocol was subsequently amended to allow the treating these three patients at dose level -1 (140 mcg/kg) during cycle 2-4 though the protocol prior to the amendment would have allowed retreatment at 170 mcg/kg as long as they met inclusion criteria for the study especially adequate renal function, defined in the protocol as creatinine clearance (by Cockcroft Gault formula) >50 mL/min. However, we felt it would be safer to re-treat these patients at dose level-1 instead of dose level 1 and adjusted the dose modification section of the protocol accordingly.  
|                                                    | Cycle 1   | Cycle 2   |        |         |      |         |
|----------------------------------------------------|-----------|-----------|--------|---------|------|---------|
| Patient                                            | Dose      | ADA       | Cmax   | ADA     | Cmax | dC1/dC2 |
| (mcg/kg)                                           | (Day1)    | (ng/ml)   | (Day1) | (ng/ml) | (%)  |         |
| 1001                                               | 45        | 2700      | 620    | 196830  | 0    | -100    |
| 1201                                               | 100       | 8100      | 495    | 196830  | 0    | -100    |
| 1501*                                              | 250       | 2700      | 3730   | 196830  | -    | -       |
| 1003                                               | 250       | 900       | 2960   | 196830  | -    | -       |
| * Patient's treatment stopped due to study closure |           |           |        |         |      |         |  
All subsequent patients have been treated at 140 mcg/kg. Patients 001-003 have completed 4 cycles of LMB-100 treatment (LMB-100 170 mcg/kg during cycle 1 and LMB-100 140 mcg/kg during cycle 2-4) and seven additional patients have been enrolled at dose level -1 (140 mcg/kg). No DLT's have been observed at the LMB-100 dose level of 140 mcg/kg. Therefore, the recommended phase of single agent LMB-100 is 140 mcg/kg given every 3 weeks.  
Grade 2 infusion reactions were seen in 5 patients at some point during the treatment with LMB100. In 2 patients, it was seen during cycle 2 and 3 patients during cycle 3 and cycle 4 of treatment.  
In most case the infusion reaction was managed by administration of dexamethasone and increasing infusion duration as per protocol. However, in two patients who had infusion reaction during cycle 4 of LMB-100 the treatment was discontinued. No serious adverse events were observed. The most frequently occurring events were hypoalbuminemia (11 events), anemia (6), increased creatinine (4), decreased lymphocytes (4), hyperglycemia (3), dyspepsia (2) and fever (2). There were single occurrences of limb edema, decreased platelets, weight gain and weight loss. Most of the events were grade 2 with the exception of one grade 3 decreased lymphocytes and three grade 3 hyperglycemia. Out of 10 patients who have been evaluated for tumor response after cycle 2, 9 had stable disease and 1 had progressive disease. Between July 2016 and November 2016, 10 patients were treated with LMB-100 monotherapy. Details of the treatment related adverse events (highest grade per patient) are provided in Table 6. In summary, there were no treatment-related grade 4 or 5 events. One patient had grade 3 hyponatremia. Most common grade 2 adverse events included hypoalbuminemia, infusion reactions, anemia, and lymphedema. Best response was stable disease in 9 patients and progressive disease in one. Of 9 patients who had stable disease, 2 patients progressed at the end of that course of therapy (4 cycles). Duration of stable disease in the remaining patients ranged between 2 months to ongoing at 8 months.  
| Toxicity                             | Grade 1   | Grade 2   | Grade 3   | Grade 4   | Grade 5   |
|--------------------------------------|-----------|-----------|-----------|-----------|-----------|
| Alanine aminotransferase increased   | 5         |           |           |           |           |
| Anemia                               | 3         |           |           |           |           |
| Anorexia                             | 3         |           |           |           |           |
| Arthralgia                           | 2         |           |           |           |           |
| Aspartate aminotransferase increased | 8         |           |           |           |           |
| Atrial flutter                       | 2         |           |           |           |           |
| Chills                               | 1         | 1         |           |           |           |
| Creatinine increased                 | 4         | 2         |           |           |           |
| Dizziness                            | 1         |           |           |           |           |
| Dyspepsia                            | 2         | 1         |           |           |           |
| Dyspnea                              | 5         |           |           |           |           |
| Edema face                           | 2         |           |           |           |           |
| Edema limbs                          | 6         | 3         |           |           |           |
| Fatigue                              | 8         |           |           |           |           |
| Fever                                | 3         | 1         |           |           |           |
| Flushing                             | 2         |           |           |           |           |  
| Toxicity                  | Grade 1   | Grade 2   | Grade 3   | Grade 4   | Grade 5   |
|---------------------------|-----------|-----------|-----------|-----------|-----------|
| Headache                  | 1         |           |           |           |           |
| Hypertension              | 2         |           |           |           |           |
| Hyperuricemia             | 1         |           |           |           |           |
| Hypoalbuminemia           | 3         | 7         |           |           |           |
| Hyponatremia              | 2         | 1         |           |           |           |
| Hypotension               | 3         |           |           |           |           |
| Infusion related reaction | 5         |           |           |           |           |
| Myalgia                   | 9         |           |           |           |           |
| Nausea                    | 6         | 1         |           |           |           |
| Pain                      | 3         |           |           |           |           |
| Palpitations              | 2         |           |           |           |           |
| Pelvic pain               | 1         |           |           |           |           |
| Periorbital edema         | 2         |           |           |           |           |
| Platelet count decreased  | 1         | 1         |           |           |           |
| Pleuritic pain            | 1         |           |           |           |           |
| Sinus tachycardia         | 6         |           |           |           |           |
| Tumor pain                | 2         | 1         |           |           |           |
| Vomiting                  | 2         |           |           |           |           |
| Weight gain               | 4         | 2         |           |           |           |
untitled h1
1.2.3.5.1 pharmacokinetics of lmb-100

Free LMB-100 plasma concentrations were measured with a validated ELISA with a lower limit of quantification of 2.1 ng/mL. Doses ranged from 140 mcg/kg - 170 mcg/kg. Samples for pharmacokinetic (PK) analysis were obtained from patients at pre-dose, end of infusion (EOI; 30min post start), and 1 hour, 2 hours, 3 hours, 4 hours and 6 hours post EOI. Concentration data for each dose was plotted over time to assess the impact of increasing anti-drug antibodies (ADAs) that are generated in response to LMB-100 exposure. PK analysis for the 10 patients treated with single agent LMB-100 is shown in Table 7 below. Measured LMB-100 plasma concentrations were consistent during the first week of treatment, with a near dose-proportional increase in CMAX
from 140 mcg/kg to 170 mcg/kg. However, the suspected generation of ADAs greatly reduced LMB-100 exposure by cycle 2. As shown in Table 7, all 10 patients had good LMB-100 blood levels during cycle 1. However, only 5 of 10 patients had good blood levels during cycle 2. None of the 8 patients who got cycle 3 and 4 of LMB-100 had good LMB-100 blood levels during cycle 3 or 4. We defined good blood levels, as LMB-100 Cmax concentration of >200 ng/mL at end of infusion on day 1 for each cycle. Although an arbitrary cut-off, it represents blood levels more than 50 to 100 fold greater than those required to kill mesothelin expressing cells in-vitro. However, more patients will need to be treated to truly correlate LMB-100 blood levels with therapeutic benefit and is one of the objectives of this protocol.  
| C1D1                                                                                                                | C2D1    | C3D1    | C4D1    |         |         |         |         |      |
|---------------------------------------------------------------------------------------------------------------------|---------|---------|---------|---------|---------|---------|---------|------|
| Patient                                                                                                             | Dose    | Cmax    | Dose    | Cmax    | Dose    | Cmax    | Dose    | Cmax |
| (μg/kg)                                                                                                             | (ng/mL) | (μg/kg) | (ng/mL) | (μg/kg) | (ng/mL) | (μg/kg) | (ng/mL) |      |
| 1                                                                                                                   | 170     | 1991    | 140     | 1091    | 140     | 21      | 140     | 21   |
| 2                                                                                                                   | 170     | 2286    | 140     | 297     | 140     | 70      | 140     | 21   |
| 3                                                                                                                   | 170     | 2760    | 140     | 4.4     | 140     | BQL     | 140     | BQL  |
| 4                                                                                                                   | 140     | 1054    | 140     | 681     | 140     | BQL     | 140     | BQL  |
| 5                                                                                                                   | 140     | 1124    | 140     | BQL     | 140     |        | 140     |     |
| 6                                                                                                                   | 140     | 2584    | 140     | 1099    | 140     | BQL     | 140     | BQL  |
| 7                                                                                                                   | 140     | 3118    | 140     | 2450    | 140     | BQL     | 140     | BQL  |
| 8                                                                                                                   | 140     | 1721    | 140     | BQL     | 140     | BQL     | 140     | BQL  |
| 9                                                                                                                   | 140     | 1526    | 140     | 27.8    | 140     | 20      | 140     | BQL  |
| 10                                                                                                                  | 140     | 2689    | 140     | 5.1     | 140     | N/A     | 140     | N/A  |
| * BQL: below assay's quantifiable limit (2.1 ng/mL);  Because of disease progression patient did not receive cycle |         |         |         |         |         |         |         |      |  
* BQL: below assay's quantifiable limit (2.1 ng/mL);  Because of disease progression patient did not receive cycle  
3 and 4; N/A: data not available  
Note: Anti-drug (LMB-100) antibodies (ADAs) were measured pre-dose on C1D1. Inhibition percentages t41.8%
indicate presence of pre-existing ADAs These results show that all patients can have good blood levels during cycle 1 and half had detectable blood levels during cycle 2. These results are in agreement with the Roche phase I clinical trial. It is also clear that administration of LMB-100 beyond cycle 2 is unlikely to result in meaningful clinical benefit since there are no detectable blood levels during cycle 3 and 4.
untitled h1
1.2.4 sel-110 1.2.4.1 administration of

As seen above, even with the reduced immunogenicity of LMB-100 compared to SS1P, most patients are only able to complete 1 to 2 cycles of LMB-100 before the level of ADAs prevents achievement of efficacious blood concentrations of LMB-100 in subsequent cycles. Selecta Biosciences is developing a biodegradable nanoparticle drug product containing rapamycin (SEL- 110), which has been shown in preclinical models to induce antigen specific tolerance and has been shown in a Phase 1 clinical study and an ongoing Phase 2 clinical study to prevent the formation of antibodies to a highly immunogenic enzyme when co-administered. SEL-110 is comprised of rapamycin, a licensed small molecule immunomodulator, encapsulated in a biodegradable PLA-PEG nanoparticle. SEL-110 is designed to inhibit the formation of ADAs when concomitantly administered with a biologic drug during the first few doses of the biologic. Upon i.v. administration, like all nanoparticles, SEL-110 accumulates primarily in the spleen. Once in the spleen the mechanism of action of SEL-110 suggested by evidence to date proposes that the PLA-PEG nanoparticles are avidly taken up by antigen-presenting cells (APCs), such as dendritic cells (DCs) and macrophages, and the subsequent intracellular release of rapamycin, an inhibitor of the mTOR pathway, induces a tolerogenic phenotype in APCs. Dendritic cells are an attractive target for immunotherapies due to their central role in antigen presentation to T-cells and their ability to induce and control regulatory responses to ensure self-tolerance.(25-27) Thomson and colleagues(28, 29) and data from Selecta have demonstrated that treating DCs *in vitro* with rapamycin, induces a tolerogenic DC phenotype capable of inducing Treg differentiation and antigen-specific immune tolerance. Selecta has demonstrated that SEL-110 co-administered with antigen induces tolerogenic DCs and antigen-specific Treg in vivo.(30) NCI embarked on a preclinical collaboration with Selecta that demonstrated that the application SEL-110 in conjunction with LMB-100 prevented the formation of antibodies to LMB-100 in mouse models. The goal of this clinical trial is to administer SEL-110 with LMB-100 to prevent the formation of antibodies to LMB-100 and allow for effective blood concentrations of LMB-100 to be achieved for multiple cycles.
untitled h1
1.2.4.2 sel-110 prevents the formation

Female BALB/c mice were injected IV QOW with LMB-100 (2.5 mg/kg) 7 times or a combination of LMB-100 and SEL-110 (2.5 mg/kg) QOW 7 times or the combination 3 times followed by 4 injections of LMB-100 alone (arrows in Figure 4 indicate injections). Plasma was collected and analyzed for anti-LMB-100 antibodies by ELISA. In the groups treated with either 3 injections of SEL-110 in combination with LMB-100 followed by 4 injections of LMB-100 or 7 injections of SEL-110 in combination of LMB-100 the mice did not make appreciable anti-LMB-100 antibodies, whereas the group receiving only LMB-100 had high levels of anti-LMB-100 antibodies. The error bars indicate SEM and the P value was determined by comparing AUC using one way ANOVA (n=8).  
Figure 4. **Co-administration of SEL-110 with LMB-100 prevent the formation of anti-LMB100 antibodies in mice.**  
  
1.2.4.3 One Dose Per Cycle is Sufficient to Prevent the Formation of ADAs to LMB-100 in Preclinical Studies In the clinical setting LMB-100 is given on Days 1, 3 and 5 of each 21-day cycle. In this experiment, we closely mimic the clinical regiment by giving mice LMB-100 IV injections (2.5 mg/kg) on Days 1, 3 and 5 of an every two weeks cycle and giving SEL-110 (2.5 mg/kg) IV with the LMB-100 on Day 1 only, Day 1 and 3 or Day 1,3 and 5 of the first and second cycle. As shown in Figure 5 (error bars are SEM and P value was determined by comparing AUC using one way ANOVA), mice dosed only with LMB-100 made significant anti-LMB-100 antibodies but all groups receiving either 1, 2 or 3 doses of SEL-110 in each of the first two cycles did not produce any anti-LMB-100 antibodies. As such in the proposed clinical design patients will receive LMB100 and SEL-110 on the first day of the cycle and then just LMB-100 only on days 3 and 5 of each cycle.  
Figure 5. One dose of SEL-110 at the beginning of the first two cycles prevent the formation of anti-LMB-100 antibodies.  
  
1.2.4.4 Administration of SEL-110 on the First Day of the Cycle is Most Effective Mice were injected IV with LMB-100 (2.5 mg/kg) on Days 1, 3 and 5 of bi weekly cycles for 9 weeks as described in 1.2.7. SEL-110 (2.5 mg/kg) was co-administered IV on the following days of cycles 1 and 2: Day 1, Day 3, Day 1 and 3, Day 3 and 5, and Day 1, 3 and 5. The final mean titer Figure 6. Co-administration of SEL-110 with LMB-100 on the first day of a cycle is key to prevention of anti-LMB-100 antibodies in a mouse model.  
  
SEL-110 Prevents Boost of Anti-LMB-100 Antibody Response in Mice with Pre-existing 1.2.4.5 Anti-LMB-100 Antibodies Female BALB/C mice were injected IV 4 times with LMB-100 (2.5 mg/kg) over two weeks to establish a pre-existing LMB-100 immune response. On week 10 the mice were injected IV with either LMB-100 alone, PBS, or LMB-100 and SEL-110 every other day for a total of 3 injections.  
Plasma was collected and analyzed for anti-LMB-100 antibodies by ELISA as shown in Figure 7
(error bars are SEM). The mice with pre-existing antibodies had an approximately 30-fold increase in anti-LMB-100 antibody levels while the PBS and LMB-100 plus SEL-110 treated mice saw the anti-LMB-100 antibody levels drop, with the LMB-100 plus SEL-110 group dropping close to baseline. This suggests that SEL-110 could potentially lower pre-existing ADAs to LMB-100 in a patient allowing the patient to receive additional effective cycles of treatment.  
Figure 7. **SEL-110 prevents the boost of anti-LMB-100 antibody levels in mice with preexisting anti-LMB-100 antibodies**  
  
1.2.4.6 Co-administration of LMB-100 and SEL-110 Induces LMB-100 Specific Immune Tolerance in Mice As opposed to immunosuppression, where all immune responses are suppressed, SEL-110 appears to induce antigen specific tolerance as demonstrated by mice treated with LMB-100 and SEL-110 not making anti-LMB-100 antibodies but making normal ant-OVA antibodies when given the different antigen Ovalbumin (OVA). Mice were injected IV 3 times weekly with LMB-100 (2.5 mg/kg) or with a combination of IV LMB-100 (2.5 mg/kg) with IV SEL-110 (2.5 mg/kg). On weeks 4 to 8 mice were challenged with a weekly IV dose of LMB-100 and a sub-cutaneous dose of Ovalbumin (2.5 mg/kg). Plasma was collected and analyzed for ant-LMB-100 and anti-OVA
antibodies by ELISA. Figure 8 shows that the mice treated with LMB-100 alone and then LMB100 plus OVA made significant levels of antibodies to both LMB-100 and OVA while the mice treated with LMB-100 plus SEL-110 and then with LMB-100 plus OVA did not make antibodies to LMB-100 but made the same, normal immune response to OVA having essentially the same level of anti-OVA antibodies as the group that did not receive SEL-110 (error bars are SEM and AUC for each curve was calculated and analyzed using Mann-Whitney test, n=5). This demonstrates that the co-administration of SEL-110 plus LMB-100 induced antigen specific tolerance to LMB-100 and did not disrupt normal immune responses to other antigens.  
  
1.2.4.7 Administration of SEL-110 Does Not Accelerate Tumor Growth The administration of SEL-110 does not accelerate tumor growth. Female BALB/c mice were inoculated with AB1 (murine mesothelioma) in the flank. SEL-110 (2.5 mg/kg) or vehicle (saline) were injected IV on days 6, 8, 10, 13, 15 and 17. Tumor size was measured using caliper for 20 days. Figure 9A shows average tumor size (error bars are SEM, n=8 and P value determined by AUC using Mann Whitney test, n=7). The results show that the SEL-110 treated group actually had a slower tumor progression than the PBS treated group. In another mouse tumor model, mice were inoculated with 66c14 (murine breast cancer) in the flank. Tumor size was measured using calipers for 30 days and SEL-110 or vehicle (saline) was IV injected on days 12, 15 and 17. Figure 9B shows average tumor size (error bars are SEM, n=5). In this tumor model the SEL-110 treated mice had tumors that grew at the same rate as the PBS treated mice. In both these tumor models the administration of SEL-110 did not increase the rate of tumor growth. Figure 9. Administration of SEL-110 does not accelerate tumor growth in two mouse tumor  
 models. 1.2.4.8 SEL-110 Clinical Experience SEL-110 is being studied as part of Selecta's combination product therapy SEL-212, which combines SEL-110 with SEL-037 (pegsiticase, a peglyated recombinant uricase) for the reduction of serum uric acid levels (sUAs) in patients with severe chronic gout under IND 124184. The study of LMB-100 with SEL-110 will be the first study to evaluate SEL-110 in patients with cancer.
untitled h1
1.2.4.8.1 sel-212/101 clinical trial

SEL-110 was studied alone and in combination with SEL-037 in a single ascending dose Phase 1b study, SEL-212/101. This first study has been completed with final analysis and Clinical Study Report. For the double-blind SEL-110 portion of the study, a total of 28 subjects with elevated uric acid levels (excluding the potential need for replacement subjects) were dosed in four cohorts in a stepwise, ascending manner. Within each cohort, five subjects received active drug substance and two subjects received placebo (saline). The doses of SEL-110 evaluated were 0.03, 0.1, 0.3, and 0.5 mg/kg. In the open-label SEL-212 portion of the study, six cohorts received a combination of SEL-037 at a dose of 0.4 mg/kg and increasing doses of SEL-110 (0.03, 0.1, 0.15, and 0.3 mg/kg). Adult male and female subjects (N= 36) were enrolled on a dose level (cohort) basis with 5 subjects per cohort, with each cohort administered study drug in an ascending, stepwise manner. Due to study drugrelated serious adverse events (SAEs) of stomatitis observed in two subjects in Cohort 7 (0.5 mg/kg SEL-110), the Sponsor did not dose subjects in Cohort 8 at the planned highest dose of SEL-212 (i.e., 0.5 mg/kg SEL-110 + 0.4 mg/kg SEL-037) and determined the maximum tolerated dose (MTD) of SEL-110 to be 0.3 mg/kg in the SEL-212/101 study. Instead, Cohort 12 was added to evaluate subjects at an intermediate dose of SEL-212 (0.15 mg/kg SEL-110 + 0.4 mg/kg SEL037).  
Overall, SEL-110 and SEL-212 was well tolerated by subjects in all cohorts other than Cohort 7. Overall, the majority of TEAEs were mild or moderate in severity and most were assessed as not related to study drug. Serious AEs were reported in 6 subjects. The events in 4 subjects were assessed as related to study drug. All subjects with SAEs were reported as recovered from the events. One subject (Subject ID 104-0086) who received SEL-212 in Cohort 10 (0.03 mg/kg SEL-110 + 0.4 mg/kg SEL-037) had a non-serious TEAE of an infusion-related reaction that was assessed as moderate in severity and possibly related to study drug; this subject was subsequently withdrawn from study drug. No drug-related SAEs were observed in the two highest dose levels of SEL-212 tested (Cohorts 12:
0.15 mg/kg SEL-110 + 0.4 mg/kg SEL-037, and Cohort 6: 0.3 mg/kg SEL-110 + 0.4 mg/kg SEL037).  
In the open-label portion of the clinical study SEL-212/101, combination product SEL-212 demonstrated the ability to reduce serum uric acid rapidly and to maintain serum uric acid levels below 6 mg/dL for 30 days with the 0.4 mg/kg SEL-037 dose tested. SEL-212 also reduced or prevented the formation of anti-uricase antibodies in a dose-dependent fashion. The uric acid level of all subjects treated with SEL-212 dropped to below 0.1 mg/dL within 24 hours after infusion (Figure 10). SEL-110 appeared to inhibit the formation of anti-uricase antibodies in a dose-dependent manner, which correlated with more sustained control of uric acid levels (Table 8). Evaluation of anti-uricase, anti-PEG, and anti-pegsiticase antibodies showed that anti-uricase antibodies were the most sensitive measure of ADAs in the Phase I study, corresponding with decreased pharmacodynamic activity of SEL-037 as evidenced by increased serum uric acid levels (Table 8).
untitled h1
figure 10. sel-212/101 uric acid

Table 8. Day 30 Serum Uric Acid Levels and Corresponding Anti-Uricase and Anti-PEG Titers  
| Treatment            | Subject ID   | Serum UA Level   | Anti-Uricase   |          |      |     |     |
|----------------------|--------------|------------------|----------------|----------|------|-----|-----|
| (mg/dL)              | (Titer)      |                  |                |          |      |     |     |
| 0.4 mg/kg SEL-037    | 108-0010     | 7                | 1080           | 3300.7   |      |     |     |
| 103-0015             | 6            | 9720             | 3013.4         |          |      |     |     |
| 104-0032             | 1.9          | 1080             | Neg            |          |      |     |     |
| 109-0012             | 6.3          | 1080             | Neg            |          |      |     |     |
| 104-0036             | 8.8          | 9720             | Neg            |          |      |     |     |
| 0.03 mg/kg SEL-110 + | 104-0012     | 7.5              | 120            | Neg      |      |     |     |
| 0.4 mg/kg SEL-037    | 104-0016     | 6.5              | 3240           | Neg      |      |     |     |
| 107-0016             | 7.1          | 1080             | Neg            |          |      |     |     |
| 108-0001             | 6.6          | 29160            | Neg            |          |      |     |     |
| 104-0017             | 6.8          | 1080             | Neg            |          |      |     |     |
| 0.1                  | mg/kg        | SEL-110          | +              | 107-0018 | <0.1 | Neg | Neg |
| 0.4 mg/kg SEL-037    | 107-0021     | <0.1             | Neg            | Neg      |      |     |     |
| 104-0027             | 6.1          | 29160            | Neg            |          |      |     |     |
| 108-0008             | <0.1         | 120              | Neg            |          |      |     |     |
| 102-0005             | <0.1         | Neg              | Neg            |          |      |     |     |
| 111-0018             | <0.1         | 120              | 446.9          |          |      |     |     |
| 111-0022             | 8.6          | 360              | 419.3          |          |      |     |     |
| 111-0028             | <0.1         | Neg              | Neg            |          |      |     |     |
| 111-0029             | 6.4          | 9720             | 1444.9         |          |      |     |     |
| 106-0004             | <0.1         | Neg              | Neg            |          |      |     |     |
| 0.15 mg/kg SEL-110 + | 111-0043     | <0.1             | Neg            | Neg      |      |     |     |
| 0.4 mg/kg SEL-037    | 111-0045     | <0.1             | Neg            | Neg      |      |     |     |
| 104-0091             | <0.1         | Neg              | Neg            |          |      |     |     |
| 104-0094             | <0.1         | Neg              | Neg            |          |      |     |     |
| 111-0049             | 2.5          | 9720             | Neg            |          |      |     |     |
| 0.3                  | mg/kg        | SEL-110          | +              | 107-0027 | <0.1 | Neg | Neg |
| 0.4 mg/kg SEL-037    | 107-0028     | <0.1             | Neg            | Neg      |      |     |     |
| 104-0050             | <0.1         | Neg              | Neg            |          |      |     |     |
| 104-0060             | <0.1         | 120              | Neg            |          |      |     |     |
| 103-0019             | <0.1         | Neg              | Neg            |          |      |     |     |  
Pharmacokinetic results are summarized in Table 9 for cohorts of patients who received SEL-110 doses above 0.1 mg/kg (i.e., suggested minimum therapeutic dose) and showed dose-dependent responses to SEL-110 with potential influence by co-administration with SEL-037. .  
| 0.5 mg/kg SEL-110  (alone)                                      | 30827, 40881             | 32363, 43749    |                 |                |          |           |          |
|-----------------------------------------------------------------|--------------------------|-----------------|-----------------|----------------|----------|-----------|----------|
| 2142, 3130                                                      |                          |                 |                 |                |          |           |          |
| Cohort 7                                                        | 177, 229                 |                 |                 |                |          |           |          |
| 2464.3  (463.91)                                                | 1.0, 1.0                 | 37538  (4543.7) | 39813  (5077.8) |                |          |           |          |
| 39222                                                           | 41569                    | 207.6  (23.68)  |                 |                |          |           |          |
| 2293                                                            | 212.1                    |                 |                 |                |          |           |          |
| 1.0                                                             | 4                        | 4               | 2               |                |          |           |          |
| 4                                                               | 4                        | 4               |                 |                |          |           |          |
| +                                                               | 25217, 46916             | 26629, 47451    |                 |                |          |           |          |
| 0.3mg/kg  SEL-110 0.4mg/kg  SEL-037                             | 1942, 3096               |                 |                 |                |          |           |          |
| Cohort 6                                                        | 37950  (7590.1)          | 235, 375        |                 |                |          |           |          |
| 2434  (428.8)                                                   | 1.0, 2.0                 | 284.4  (54.46)  |                 |                |          |           |          |
| 37015  (7920)  36848                                            | 37635                    |                 |                 |                |          |           |          |
| 2320                                                            | 278.5                    |                 |                 |                |          |           |          |
| 1.0                                                             |                          |                 |                 |                |          |           |          |
| 5                                                               | 5                        | 5               | 5               | 5              | 5        |           |          |
| 0.3 mg/kg SEL-110  (alone)                                      | 16065, 31381             |                 |                 |                |          |           |          |
| 7056, 28308                                                     |                          |                 |                 |                |          |           |          |
| Cohort 5                                                        | 854, 1640                | 24.7, 333       |                 |                |          |           |          |
| 1174  (326.81)                                                  | 18043  (7908.5)  19620.0 | 23241  (6277.7) | 214.7  (131.67) |                |          |           |          |
| 1.0, 1.0                                                        | 22759                    | 290.6           |                 |                |          |           |          |
| 1076                                                            | 1.0                      |                 |                 |                |          |           |          |
| 5                                                               | 5                        | 5               | 4               | 5              | 4        |           |          |
| 0.1 mg/kg  SEL-110 +  0.4 mg/kg  SEL-037                        | 6223, 18548              | 6802, 8524      |                 |                |          |           |          |
| Cohort 4                                                        | 631  (177.87)            | 495, 942        | 10332  (4912.1) | 7818  (901.59) | 231, 346 |           |          |
| Table 9. Summary of SEL-110 Whole Blood PK Parameters           | Parameter                | 1.0, 1.1        | 299.7  (60.73)  |                |          |           |          |
| 582.3                                                           | 8178                     | 8126            | 322.4           |                |          |           |          |
| 1.0                                                             |                          |                 |                 |                |          |           |          |
| 5                                                               | 5                        | 5               | 3               | 3              | 3        |           |          |
| 0.1 mg/kg SEL110  (alone)                                                                 |                          |                 |                 |                |          |           |          |
| Cohort 3                                                        | 4187, 8877               | 4865, 8358      |                 |                |          |           |          |
| 6671.4  (2006.87)                                               |                          |                 |                 |                |          |           |          |
| 558.5  (181.92)                                                 | 291, 700                 | 6596  (1747.1)  | 259, 294        |                |          |           |          |
| 1.0, 1.5                                                        | 6811.0                   | 280.2  (18.36)  |                 |                |          |           |          |
| 621.5                                                           | 287.7                    |                 |                 |                |          |           |          |
| 6566                                                            |                          |                 |                 |                |          |           |          |
| 1.0                                                             |                          |                 |                 |                |          |           |          |
| 4                                                               | 4                        | 4               | 3               | 3              | 3        |           |          |
| Abbreviated Title: LMB-100 plus SEL-110  Version date: 10/01/18 | Mean (SD)                | Mean (SD)       | Min, Max        | Mean (SD)      | Min, Max | Mean (SD) | Min, Max |
| Statistic                                                       | Min, Max                 | Min, Max        |                 |                |          |           |          |
| Median                                                          | Median                   | Median          | Median          | Median         |          |           |          |
| N                                                               | N                        | N               | N               | N              | N        |           |          |
| AUC0-last (h*ng/mL)                                             | AUC0-inf (h*ng/mL)       |                 |                 |                |          |           |          |
| (ng/mL)                                                         |                          |                 |                 |                |          |           |          |
| Cmax                                                            | Tmax                     | (h)             | t½z             | (h)            | CL       |           |          |  
| Abbreviations: AUC0-inf = area under the plasma concentration-time curve from time 0 to infinity; AUC0-last = area under the plasma concentration-time curve from  time 0 to the time t of the last quantifiable concentration; CL = total plasma clearance; Cmax = maximum observed plasma concentration; max = maximum;  min = minimum; NA = not applicable; PK = pharmacokinetics; SD = standard deviation; t½z = apparent terminal elimination half-life; Tmax = time of maximum  observed plasma concentration; Vd = distribution volume in the terminal elimination phase; n = number of actual reliable observations, may be lower for elimination  parameters due to exclusion of unreliable PK parameters based on PK acceptance criteria as described in SAP.   |                   |                 |          |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|-----------------|----------|
| 0.5 mg/kg SEL-110  (alone)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                   |                 |          |
| Cohort 7                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 1.217  (0.15249)  | 1.1, 1.44       | 338, 380 |
| 360.9  (18.04)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                   |                 |          |
| 1.161                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | 362.8             |                 |          |
| 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                   |                 |          |
| +                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                   |                 |          |
| 0.3mg/kg  SEL-110 0.4mg/kg  SEL-037                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 0.569, 1.46       |                 |          |
| Cohort 6                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0.9555  (0.36861) | 380.1  (114.56) | 204, 495 |
| 0.9661                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | 396.5             |                 |          |
| 5                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                   |                 |          |
| 0.3 mg/kg SEL-110  (alone)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                   |                 |          |
| Cohort 5                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0.905, 1.44       |                 |          |
| 1.159  (0.22069)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | 433.6  (159.46)   | 220, 604        |          |
| 1.144                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | 454.8             |                 |          |
| 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                   |                 |          |
| 0.1 mg/kg  SEL-110 +  0.4 mg/kg  SEL-037                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0.976, 1.22       | 453.9, 608      |          |
| Cohort 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 1.139  (0.14129)  | 489.8  (105.15) |          |
| 1.219                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | 407               |                 |          |
| 3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                   |                 |          |
| 0.1 mg/kg SEL110  (alone)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |                   |                 |          |
| Cohort 3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 1.415  (0.16299)  | 1.28, 1.6       | 478, 676 |
| 574.4  (99.00)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                   |                 |          |
| 1.372                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | 569.5             |                 |          |
| 3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                   |                 |          |
| Mean (SD)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 | Mean (SD)         | Min, Max        |          |
| Statistic                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 | Min, Max          |                 |          |
| Median                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | Median            |                 |          |
| N                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                   |                 |          |
| Parameter                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 | (L/h)             | Vd              | (L)      |
untitled h1
1.2.4.8.2 sel-212/201 clinical trial

SEL-110 is also being currently studied as part of SEL-212 combination therapy in an ongoing multi-dose Phase 2 clinical study under IND 124184. The Phase II study of SEL-212 (Clinical study SEL-212/201) was designed as an open-label, multiple-dose clinical study of the combination drug, SEL-212, which was combined with an openlabel, multiple-dose evaluation of pegsiticase alone (SEL-037). Cohorts included patients receiving SEL-037 alone, patients receiving 3 combination doses of SEL-110 plus SEL-037 each 28 days apart followed by two doses of SEL-037 alone each 28 days apart and patients receiving 5 combination doses of SEL-110 plus SEL-037 each 28 days apart. The primary endpoint of the study is safety and tolerability od SEL-212. Additional assessments include the ability of SEL-212 to reduce serum uric acid levels and prevent anti-drug antibodies to uricase, PEG, and pegsiticase as well as PK of rapamycin. The planned enrollment for the study is now estimated to be approximately 140 subjects among 14 dosing cohorts, each consisting of 6-20 subjects. It is important to note that two dose levels of SEL-037 (0.2 and 0.4 mg/kg) have been evaluated thus far with each ascending dose level of SEL110 (Table 10) in order to define the minimally effective dose levels of each component of the combination SEL-212 product. Based on the efficacy data acquired to date, future cohorts are now planned with a dose level of SEL-037 of 0.4 mg/kg only. Dose escalation will proceed in a stepwise manner to 0.15 mg/kg of SEL-110. A summary of safety and efficacy data to date from the ongoing study to support this proposed dose escalation regimen is provided as follows: The first subject was treated on 18 October 2016. As of 30 November 2017, 83 patients have been enrolled and treated as summarized in Table 10. At this time Cohorts 1-8 have completed enrollment. Remaining cohorts will continue to enroll until they are closed due to enrollment caps or the stopping rules for individual cohorts.  
| Table 10. Summary of Enrollment by Treatment Cohort (as of 30 November 2017)  Treatment Subjects (n) Treatment Subjects (n)  Cohort 1 (SEL-037  only)  0.2 mg/kg SEL-037  3 Cohort 2 (SEL-037  only)  0.4 mg/kg SEL-037  3  Cohort 3 (SEL-212)  0.05 mg/kg SEL-110+  0.2 mg/kg SEL-037  9 Cohort 4 (SEL-212)  0.05 mg/kg SEL-110+  0.4 mg/kg SEL-037  10  Cohort 5 (SEL-212)  0.08 mg/kg SEL-110+  0.2 mg/kg SEL-037  6 Cohort 6 (SEL-212)  0.08 mg/kg SEL-110+  0.4 mg/kg SEL-037  11  Cohort 7 (SEL-212)  0.10 mg/kg SEL-110+  0.2 mg/kg SEL-037  11 Cohort 8 (SEL-212)  0.10 mg/kg SEL-110+  0.4 mg/kg SEL-037  10  Cohort 10 (SEL-212)  0.125 mg/kg SEL110+  0.4 mg/kg SEL-037  10 Cohort 12 (SEL-212)  0.15 mg/kg SEL-110+  0.4 mg/kg SEL-037  10  Cohort 11 (SEL-212)  0.15 mg/kg SEL-110  + 0.2 mg/kg SEL-037  0 Cohort 13 (SEL-212)  0.15 mg/kg + 0.2  mg/kg SEL-037  0  Cohort 15 (SEL-212)  0.15 mg/kg SEL-110  (first dose), 0.1 mg/kg  SEL-110 (subsequent  doses) + 0.2 mg/kg  SEL-037  0 Cohort 17 (SEL-212)  0.1 mg/kg SEL-110 +  0.2 mg/kg SEL-037  0  Cohorts 9 and 11 are intentionally omitted from this protocol in order to maintain  the cohort numbering convention of associating even numbered cohorts with the  0.4 mg/kg SEL-037 dose.   |
|---|  
Preliminary analyses of safety data are available for the 83 subjects enrolled and treated as of 30 November 2017, with approximately 215 study drug treatments. SAEs characterized as related to study drug have involved anaphylactic reactions or infusion-related reactions in 7 subjects that occurred with temporal proximity to initiation of the second dose of either SEL-037 in Cohort 1 (1 subject, 0.2 mg/kg), SEL-037 in Cohort 2 (1 subject, 0.4 mg/kg), SEL-212 in Cohort 3 (2 subjects at 0.05 mg/kg SEL-110 + 0.2 mg/kg SEL-037), SEL-212 in Cohort 7 (1 subject at 0.1 mg/kg SEL-110 + 0.2 mg/kg SEL-037), and SEL-212 in Cohort 8 (1 subject at 0.1 mg/kg SEL110 + 0.4 mg/kg SEL-037) and with temporal proximity to initiation of the first dose of SEL-212 in Cohort 6 (1 subject at 0.08 mg/kg SEL-110 + 0.4 mg/kg SEL-037). All patients were treated with antihistamines, bronchodilators, and/or corticosteroids and all were reported as having recovered from the events. No deaths have been reported. Two withdrawals due to adverse events (other than the listed SAEs) have been reported, both for infusion reactions, one in Cohort 6 and one in Cohort 10. After the observation of the anaphylactic reactions and infusion reaction in Cohorts 1-3, the stopping rules were modified so that additional doses of SEL212 or SEL-037 would not be administered if sUA levels rose above 6 mg/dL 21 days after the previous dose, and then further restricted to a sUA level threshold of 1 mg/dL at 21 days after the previous dose. The rise in SUA at day 21 is predictive of the presence of ADAs, based on the Phase Ib study of SEL-212. During the period in which the modified stopping rule was being implemented, 5 subjects in Cohorts 1-4 missed their dosing window for the second dose and were removed from the study. Those subjects removed from Cohorts 3 and 4 were replaced, while dosing in Cohorts 1 and 2 was terminated. To date, 215 single and repeat doses of study drug (SEL-212 or SEL-037) have been administered. Following the modification of the stopping rules to a 1 mg/dL threshold at day 21 post-dose, one anaphylactic event was observed in Cohort 8, which was the result of a protocol violation wherein the subject was administered a second dose of SEL-212 despite having met the stopping criteria. A second anaphylactic event occurred in a patient in Cohort 7 during treatment cycle 2 despite passing the stopping rules. A single infusion reaction event occurred in a Cohort 6 patient who was receiving SEL-110 for the first treatment prior to receiving SEL-037. It is expected that the risk of anaphylaxis will decrease with increasing doses of SEL-110 due to inhibition of ADA formation. Preliminary analyses of pharmacodynamic data show that SEL-037 administered alone at 0.2 mg/kg (Cohort 1) and 0.4 mg/kg (Cohort 2) reduced sUA (in green) through Day 7, but reduced levels of sUA were not maintained in the physiologic context of rising anti-uricase antibody (in blue) titer (Figure 11). In Cohorts 3, 4, 5, 6, 7,8, 10, and 12, preliminary analyses of pharmacodynamic data as of 30 November 2017 show that SEL-037 administered at 0.2 mg/kg and 0.4 mg/kg in combination with SEL-110 (0.05 mg/kg, 0.08 mg/kg, 0.1 mg/kg, 0.125 mg/kg, and 0.15mg/kg) (i.e., SEL-212) reduced sUA levels and maintained low sUA levels in the physiological context of low anti-uricase antibody titers. A clear relationship between rising sUA and concurrently rising anti-uricase antibody titers was observed in some subjects, and suggests that preventing the formation of ADAs by concomitant administration of SEL-110 at the start of treatment with SEL-037 will induce persistent immune tolerance, such that subsequent treatment with SEL-037 alone does not evoke an immune reaction that may compromise its pharmacodynamic activity. Data for cohort 6 and cohort 8 are shown Figure 12 and Figure 13 respectively. Thus, on the basis of these data, an initial efficacy signal has been demonstrated with repeated dosing of SEL-212 as evidenced by persistent suppression of serum uric acid levels below 6 mg/dL and anti-uricase specific antibody suppression in conjunction with increasing the dose of SEL-110 up to 0.1 mg/kg. Based on the Phase Ib study, it is anticipated that further increases in SEL-110 would result in more complete inhibition of ADAs, which may potentially reduce the incidence of infusion reactions upon repeat dosing. Figure 11. Interim sUA and Anti-Uricase Titer: Cohort 1 (0.2 mg/kg SEL-037) and Cohort 2 (0.4 mg/kg SEL-037)  
  
Abbreviated Title : LMB-100 plus SEL-110 Version date: 10/01/18 Interim sUA and Anti-Uricase Titer: Cohort 6 (0.08 mg/kg SEL-110 +
Figure 12.  
0.4 mg/kg SEL-037)  
  
* Patient 106-0026 received live attenuated vaccine for shingles (protocol deviation). The patient was withdrawn from the study and was replaced per protocol.  
  
The data from this open label Phase 2 clinical study show that the administration of SEL-110 with the pegylated enzyme SEL-037 prevents the formation of anti-drug antibodies in a majority of patients at the relatively low dose of 0.08 mg/kg. Dose escalation is continuing in this trial and improved efficacy at higher doses is expected.
untitled h1
1.2.5 rationale for the study

There is clearly an unmet need to identify improved therapies for patients with malignant mesothelioma. LMB-100 is a reduced immunogenicity anti-mesothelin RIT developed in NCI's Laboratory of Molecular Biology in collaboration with Roche. Mesothelin is expressed in over 95% of epithelioid subtype of malignant mesothelioma. Limited dose escalation completed to date indicates safety and provides preliminary data on immunogenicity. The immunogenicity data suggests that despite the reduced immunogenicity of LMB-100 compared to SS1P, significant numbers of patients can only receive one or two cycles of LMB-100 before the level of ADAs to LMB-100 prevent future doses from being effective. For anti-tumor efficacy it is likely patients will need more than two cycles of LMB-100 with adequate serum concentration of the drug. Although it is hard to predict what is the minimum number of LMB-100 cycle that need to be administered we think that at least four cycles will provide adequate drug exposure for efficacy. There is strong preclinical evidence that the addition of SEL-110 to the LMB-100 can prevent the formation of ADAs and thus allow patients to receive multiple effective dosing cycles of LMB100. Additionally, clinical data from Selecta Biosciences, with a different antigen but still a very immunogenic enzyme, has demonstrated clinically the ability to prevent ADAs. Together this gives strong support to conduct a Phase 1 clinical trial of the LMB-100 and SEL-110 combination to explore if the combination can allow patients to take multiple cycles of LMB-100 treatment and achieve significant tumor regression. If safe and successful this approach could be used to treat other mesothelin expressing cancers and later expanded to other centers.
untitled h1
2 eligibility assessment and enrollment

2.1.1 Inclusion Criteria 2.1.1.1 Histologically confirmed epithelial or biphasic pleural or peritoneal mesothelioma not amenable to potentially curative surgical resection. However, patients with biphasic tumors that have a more than or equal to 50% sarcomatoid component will be excluded. The diagnosis will be confirmed by the Laboratory of Pathology, CCR, NCI.  
2.1.1.2 Archival sample or fresh biopsy or tumor effusion must be available for confirmation of diagnosis.  
2.1.1.3 Patients must have measurable disease per RECIST 1.1. See section 6.3.1.1. 2.1.1.4 Patients must have had at least one prior chemotherapy regimen that includes pemetrexed and cisplatin or carboplatin. There is no limit to the number of prior chemotherapy regimens received.  
2.1.1.5 The last dose of previous therapy must have occurred at least 3 weeks prior to the start of study therapy. Palliative radiotherapy is allowed up to 2 weeks before the first LMB-100 infusion.  
2.1.1.6 Patients for whom no standard curative therapy exists 2.1.1.7 Age greater than or equal to 18 years. Because no dosing or adverse event data are currently available on the use of LMB-100 + SEL-110 in patients <18 years of age, children are excluded from this study 2.1.1.8 All acute toxic effects of any prior radiotherapy, chemotherapy, or surgical procedure must have resolved to Grade less than or equal to 1, except alopecia (any grade) and Grade 2 peripheral neuropathy.  
2.1.1.9 ECOG performance status (PS) 0 or1 (See Appendix A)
2.1.1.10 Adequate hematological function: neutrophil count of more than or equal to 1.0 x 109 cells/L, platelet count of greater than or equal to 100,000/mcL, hemoglobin more than or equal to 9 g/dL
2.1.1.11 Adequate liver function: Bilirubin less than or equal to 2.5 x the upper limit of normal
(ULN) (excluding Gilbert s Syndrome, see below).  
2.1.1.12 Patients with Gilbert s syndrome will be eligible for the study. The diagnosis of Gilbert's syndrome is suspected in people who have persistent, slightly elevated levels of unconjugated bilirubin without any other apparent cause. A diagnosis of Gilbert s syndrome will be based on the exclusion of other diseases based on the following criteria:
a. Unconjugated hyperbilirubinemia noted on several occasions b. No evidence of hemolysis (normal hemoglobin, reticulocyte count, and LDH)
c. Normal liver function tests d. Absence of other diseases associated with unconjugated hyperbilirubinemia  
2.1.1.13 Adequate renal function: creatinine clearance (by Cockcroft Gault formula - see Appendix B) greater than or equal to 50 mL/min.  
2.1.1.14 Must have serum albumin > 2.5 g/dL without intravenous supplementation 2.1.1.15 Must have left ventricular ejection fraction > 50% 2.1.1.16 Must have an ambulatory oxygen saturation of > 90% on room air 2.1.1.17 The effects of LMB-100 in combination with SEL-110 on the developing human fetus are unknown. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry until 3 months after the last dose of study therapy. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately 2.1.1.18 Ability of subject to understand and the willingness to sign a written informed consent document 2.1.2 Exclusion Criteria 2.1.2.1 Known or clinically suspected CNS primary tumors or metastases including leptomeningeal metastases. History or clinical evidence of CNS metastases unless they have been previously treated, are asymptomatic, and have had no requirement for steroids or enzyme-inducing anticonvulsants in the last 14 days.  
2.1.2.2 Evidence of significant, uncontrolled concomitant diseases which could affect compliance with the protocol or interpretation of results, including significant pulmonary disease other than primary cancer, uncontrolled diabetes mellitus, and/or significant cardiovascular disease (such as New York Heart Association Class III or IV cardiac disease, myocardial infarction within the last 6 months, uncontrolled arrhythmias,
unstable angina, non-compensative congestive heart failure, or clinically significant pericardial effusion)
2.1.2.3 Active or uncontrolled infections. 2.1.2.4 HIV or active HBV or HCV infection. HIV positive patients will be excluded due to a theoretical concern that the degree of immune suppression associated with the treatment may result in progression of HIV infection.  
2.1.2.5 Patients with prior pneumonectomy 2.1.2.6 Prior therapy with LMB-100 2.1.2.7 Any other diseases, metabolic dysfunction, physical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that would contraindicate the use of an investigational drug 2.1.2.8 Major surgery or significant traumatic injury greater than or equal to 28 days prior to the first LMB-100 infusion (excluding biopsies) or anticipation of the need for major surgery during study treatment 2.1.2.9 Dementia or altered mental status that would prohibit informed consent 2.1.2.10 Live attenuated vaccinations 14 days prior to treatment 2.1.2.11 Pregnant women are excluded from this study because it is unknown whether LMB-100
+ SEL 100 has the potential for teratogenic or abortifacient effects. Because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with LMB-100+SEL-110, breastfeeding should be discontinued if the mother is treated with LMB-100+SEL-110. These potential risks may also apply to other agents used in this study.  
2.1.2.12 Known hypersensitivity to any of the components of LMB-100 and/or SEL-110 2.1.2.13 Presence of immunosuppressive conditions, including administration of any medications or treatments that may adversely affect the immune system such as allergy injections, immune globulin, interferon, immunomodulators, cytotoxic drugs, or systemic corticosteroids (oral or injectable) during 3 months prior to enrollment. Inhaled and topical corticosteroids allowed.  
2.1.2.14 Known allergy to PEGylated products. 2.1.2.15 History of anaphylactic reaction to a recombinant protein or hypersensitivity to PEG. 2.1.2.16 Taken an investigational drug within 4 weeks prior to study drug administration or plans to take an investigational agent during the study.  
2.1.2.17 Taken a strong inhibitor or inducer of CYP3A4 within 14 days prior to enrollment (see Flockhart Table or similarly updated source for a list of such agents)
2.1.2.18 Taken drugs known to interact with Rapamune such as cyclosporine, diltiazem, erythromycin, ketoconazole (and other antifungals), nicardipine (and other calcium channel blockers), rifampin, verapamil within 14 days prior to enrollment 2.1.2.19 Uncontrolled hypertension (above 150/95 mm Hg). 2.1.2.20 History of end-stage renal disease requiring dialysis. 2.1.2.21 Serum phosphorus less than 2.0 mg/dL 2.1.2.22 Organ transplant recipient
untitled h1
2.1.3 recruitment strategies

Information about the study will be posted on sites such as clinicaltrials.gov and the CCR recruitment website. Subjects will also be drawn from patients seen at the mesothelioma clinic at the NIH Clinical Center as well as from referrals from outside providers.
untitled h1
2.2 screening evaluation

Screening assessments will be performed within 28 days prior to study enrollment unless otherwise indicated. Assessments may be performed on an NIH screening protocol.  
x Archival tumor sample for NCI LP confirmation of diagnosis (at any time prior to enrollment). A block of primary tissue (or 5-10 unstained sections on charged slides) from the time of diagnosis will be required from each patient. Tissue blocks from a known recurrence will be accepted if original tumor samples are unavailable. Referring institutions will send the tumor block or 5-10 unstained sections on charged slides to CCR/NCI for correlative studies and confirmation of diagnosis. A fresh biopsy or tumor effusion sample may be collected if archival tumor tissue is not available.  
x History and physical exam x Vital signs including pulse oximetry x ECOG performance status x Urine or serum hCG in women of childbearing potential x ECG x Echocardiogram x CT scan of chest, abdomen and/or pelvis and areas of known or suspected disease involvement; MRI may also be performed when appropriate x FDG-PET scan x CBC with differential, Acute Care Panel (sodium, potassium, chloride, bicarbonate, creatinine, glucose, BUN), Hepatic Panel (alkaline phosphatase, AST, ALT, total bilirubin, direct bilirubin), Mineral Panel (albumin, calcium, magnesium, phosphorus), Lipid Panel
(total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol), creatine kinase, Creactive protein, Coagulation (PT, PTT, fibrin degradation products)
x Urinalysis x Viral markers - HBSAg, anti-HCV, anti-HIV
untitled h1
2.3 registration procedures

Authorized staff must register an eligible candidate with NCI Central Registration Office (CRO) within 24 hours of signing consent. A registration Eligibility Checklist from the web site (http://home.ccr.cancer.gov/intra/eligibility/welcome.htm) must be completed and sent via encrypted email to: NCI Central Registration Office ncicentralregistration-l@mail.nih.gov. After confirmation of eligibility at Central Registration Office, CRO staff will call pharmacy to advise them of the acceptance of the patient on the protocol prior to the release of any investigational agents. Verification of Registration will be forwarded electronically via e-mail to the research team. A recorder is available during non-working hours.
untitled h1
2.4 treatment assignment procedures

| Number   | Name            | Description                                                                                                                |
|----------|-----------------|----------------------------------------------------------------------------------------------------------------------------|
| 1        | Dose escalation | The first 12 eligible and evaluable patients will be treated with a  fixed dose of LMB-100 and escalating doses of SEL-110 |
| 2        | Dose Expansion  | Up to 6 additional eligible and evaluable patients will be treated with  highest safe dose observed in Arm 1/Cohort 1      |
untitled h1
stratifications randomization and arm assignment

| Number   | Name            | Description                                                                     |
|----------|-----------------|---------------------------------------------------------------------------------|
| 1        | Dose Escalation | LMB-100 + SEL-110 (escalating doses)                                            |
| 2        | Dose Expansion  | LMB-100 + SEL-110 (at dose determined in dose escalation portion  of the study) |  
No stratification of randomization will occur on the study. Patients in Cohort 1 will be directly assigned to Arm 1. Patients in Cohort 2 will be directly assigned to Arm 2.
untitled h1
3 study implementation 3.1 study

This is a Phase I, inpatient/outpatient, single center, dose escalation study of LMB-100 in combination with SEL-110. Two different doses of SEL-110 will be evaluated in combination with a fixed dose of LMB-100. Up to 4 cycles (1 cycle = 21 days) of combination therapy may be administered. SEL-110 will be administered intravenously on day 1 of each 21-day cycle. LMB100 will be administered intravenously on days 1, 3 and 5 of each 21-day cycle.  
Pharmacokinetic measurements will be performed with each cycle. Assessment of anti-LMB-100 antibodies will be performed at the start of each cycle. Response to therapy will be assessed following every two cycles by CT scan. Response will be assessed by RECIST 1.1 or modified RECIST for MPM. Tumor mesothelin expression will be assessed retrospectively. Optional tumor biopsy will be performed in consenting patients when deemed feasible at the following time points: before initiation of therapy (archival tissue may also be used) and after two cycles of therapy.
untitled h1
3.1.1 dose limiting toxicity

For the purpose of the study, a DLT will be defined as any of the following events occurring within 21 days after the first dose of LMB-100 or SEL-110, the DLT evaluation period. Toxicities determined to be unequivocally related to disease progression or intercurrent illness will not be regarded as DLTs.
untitled h1
hematological toxicities

x Grade 4 neutropenia (i.e. absolute neutrophil count (ANC) <0.5 x 109 cells/L) for a minimum duration of 7 days)
x Grade 3 and 4 febrile neutropenia (i.e. ANC < 1.0 x109 cells/L with a single temperature of >38.3°C or a sustained temperature of 38°C for more than one hour x Grade 4 thrombocytopenia (25.0 x109 cells/L)
x Grade 3 thrombocytopenia associated with bleeding episodes  
x Grade 4 anemia
Grade  3 non-hematological toxicity with the exception of:
x Alopecia (any grade) x Grade 3 nausea and vomiting lasting >48 hours despite appropriate treatment x Grade 3 diarrhea lasting for  2 days with no fever or dehydration x Infusion-related reactions up to and including Grade 3. They are not considered to be DLTs since, based on experience with monoclonal antibodies, IRRs are idiosyncratic and not dose-related events. Precautions will be taken if IRRs Grade 2 occur (see Section 3.3).  
x Laboratory values of  grade 3 that are judged not clinically significant by the investigator.  
x **Isolated** Grade 3 fever **(without signs and/or symptoms of an infection)**
occurring within 48 hours after LMB-100 infusion and resolving within 48 hours to  Grade 2 and fully resolved within 1 week Other toxicities:
x Any other drug related toxicity considered significant enough to be qualified as a DLT in the opinion of the principal investigator.  
x Inability to start cycle 2 within 3 weeks after completing cycle 1 due to drug-
related adverse events.  
If a patient experiences a DLT, the patient will be removed from study therapy.
untitled h1
3.1.2 dose escalation

Dose escalation will proceed in cohorts of 3–6 patients. The MTD is the dose level at which no more than 1 of up to 6 patients experience DLT during the first cycle of treatment, and the dose below that at which at least 2 (of 6) patients have DLT as a result of the drug. If a patient did not experience DLT and did not finish treatment, he or she will not be evaluable for toxicity and will be replaced in the dose level.  
| Dose Level                                                                                                     | LMB-100 Dose (mcg/kg)   | SEL-110 Dose (mg/kg)   |
|----------------------------------------------------------------------------------------------------------------|-------------------------|------------------------|
| - 1                                                                                                            | 100                     | 0.15                   |
| -1A                                                                                                            | 100                     | 0.3                    |
| 1                                                                                                              | 140                     | 0.15                   |
| 2                                                                                                              | 140                     | 0.3                    |
| Dose level -1A to be explored if there is acceptable toxicity (per standard 3 plus 3  design) at dose level -1 |                         |                        |  
Dose escalation will follow the rules outlined in the Table below.  
| Number of Patients with  DLT      | Escalation Decision Rule                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| at a Given Dose Level  0 out of 3 | Enter up to 3 patients at the next dose level                                                                                                                                                                                                                                                                                                                                                                                                                              |
| > 2                               | Dose escalation will be stopped. This dose level will  be declared the maximally administered dose (highest  dose administered). Up to three (3) additional patients  will be entered at the next lowest dose level with no  letter designation if only 3 patients were treated  previously at that dose OR up to six (6) additional  patients will be entered at the next lowest dose level if  next lowest dose level with no letter designation  previously unexplored. |
| 1 out of 3                        | Per PI discretion, follow instructions for - 2 DLT OR  Enter up to 3 more patients at this dose level.  x If 0 of these 3 patients experience DLT, proceed  to the next dose level.                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |  
| Number of Patients with  DLT                                              | Escalation Decision Rule                                                                                                              |                                                                                                                                                                                                                                                                                    |
|---------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| at a Given Dose Level                                                     | x                                                                                                                                     | If 1 or more of this group suffer DLT, then dose  escalation is stopped, and this dose is declared the  maximally administered dose. UP to three (3)  additional patients will be entered at the next  lowest dose level if only 3 patients were treated  previously at that dose. |
| <1 out of 6 at highest dose  level below the maximally  administered dose | This is the MTD and is generally the recommended  phase 2 dose. At least 6 patients must be entered at  the recommended phase 2 dose. |                                                                                                                                                                                                                                                                                    |
untitled h1
3.2 drug administration 3.2.1 sel-110

The thawed SEL-110 will be withdrawn from the vial and dosed via IV infusion with an in-line filter set-up along with a syringe infusion pump at a single steady rate to deliver the dose over a period of 55 minutes starting concurrently with a 60-minute infusion of 125 mL of normal saline. The maximum rate of infusion of SEL-110 for the first 30 minutes should not exceed 5.5 mL/hr. If the calculation of the infusion rate to deliver the entire dose is greater than 5.5 mL/hr, then the infusion rate should be set for 5.5 mL/hr for the first 30 minutes, then the infusion rate should be increased to deliver the rest of the dose over the remaining 25 minutes. Follow instructions below:
1. Convert weight of subject to kg, as needed (weight in pounds divided by 2.20462).  
2. Calculate the volume (mL) of SEL-110 required for a subject.
Volume (mL) SEL-110 required = (dose in mg/kg) x (subject weight in kg) / (concentration of SEL110 per ml in vial i.e., 2 mg/mL)  
3. Calculate the number of vials of SEL-110 required for a subject. Round the calculation up to the next whole number.
Number of SEL-110 vials required =[Volume (mL) SEL-110 required + priming volume (mL)]/ (5 mL/vial)  
4. Thaw the required number of vials at room temperature for approximately 2 hours. Once the vials are thawed, invert slowly (don't shake) each vial twenty times to ensure product is uniform. Do not use any vials with visible clumping. Thawed SEL-110 should be administered as soon as possible but thawed SEL-110 is stable at room temperature and normal light conditions for 24 hours.  
5. Load a syringe with the appropriate size for the dose. In order to prime the line between the syringe and the injection site valve, an additional priming volume of SEL-110 (approximately 0.5mL) equal to the volume of the connecting line used and the volume of the 5 micrometer membrane filter (Pall Medical, PN HP1050 or equivalent) should be added to the syringe. When loading syringes, do not bubble air through the product to avoid the formation of foam.  
6. Start an infusion of 125 mL of normal saline solution over 60 ± 2 minutes using an IV set with an injection site valve.  
7. Using the injection site valve, immediately after starting the normal saline IV, slowly inject the SEL-110 using a syringe infusion pump at a single steady rate to deliver the dose over a period of 55 ± 2 minutes, if this rate is greater than 5.5 mL/hr then set the infusion rate to 5.5 mL/hr for the first 30 minutes then increase the infusion rate to deliver the rest of the dose over the remaining 25 minutes. A 5 μm syringe filter (5 μm syringe filter Supor (PES) membrane, Pall Medical P/N HP1050 or equivalent) for single use should be included in the SEL-110 line downstream of the syringe and proximal to the injection site valve. At the end of the 55 minutes, continue the saline infusion for the additional 5 minutes after the SEL-110 infusion stops to flush the main line. Do not flush the line between the syringe and the injection site valve
x The 125 mL of normal saline should be delivered from IV bags via the main line while SEL-110 is delivered in parallel to the normal saline via a syringe infusion pump connected to the injection site valve.  
Example for subject weighing 200 pounds at 0.3 mg/kg SEL-110  
| Step 1: If not already done convert weight to kg:                                                 | = 200 pounds / 2.20462 = 90.7 kg                                            |
|---------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------|
| Step 2: Calculate volume of SEL-110 needed:                                                       | = (0.3 mg/kg) x (90.7 kg) / (2 mg/mL)  = 27.2/2 = 13.6 mL SEL-110           |
| Step 3: Calculate number of vials needed:                                                         | = 13.6 mL SEL-110 required / (5 mL/vial)  = 2.7 vials. Round up to 3 vials. |
| Step 4 and 5: Thaw 3 vial and load syringe with 13.6 mL SEL-110 plus the priming volume (assuming |                                                                             |  
Step 4 and 5: Thaw 3 vial and load syringe with 13.6 mL SEL-110 plus the priming volume (assuming prime volume = 0.5mL, giving a total syringe fill volume of 14.1 mL of SEL-110). Thaw an additional vial if necessary to supply the priming volume. Step 6: Start infusion of 125 mL of normal saline solution over 60 ± 2 minutes. Step 7: Immediately after the start of the normal saline infusion, slowly inject 13.6 mL of SEL-110 using a 5 μm syringe filter proximal to the injection site valve. As the infusion rate to deliver 13.6 mL of SEL-110 over 55 minutes is 14.8 mL/hr (> 5.5 mL/hr), set the infusion rate to 5.5 mL/hr for the first 30 minutes. To deliver the remaining 10.85 mL (13.6 - 5.5/2) of SEL-110 over the last 25 minutes set the infusion rate to 26 mL/hr. At the end of the 55 minutes, continue the saline infusion for the additional 5 minutes after the SEL-110 infusion stops to flush the main line.  
Only if medically warranted in response to an AE will the Investigator modify the infusion parameters (decrease the rate of infusion, interrupt the infusion, or reduce the dose volume infused). The Investigator will notify the study team of any changes in infusion parameters. Please refer to Table 13.
untitled h1
3.2.2 lmb-100

The qualified health care professional responsible for dispensing the study drug will prepare the correct dose according to the cohort allocation of each patient. LMB-100 will be given as an IV solution on Days 1, 3, and 5 (QOD× 3) of every 21 day cycle for up to 4 cycles. LMB-100 must be administered in a hospital or clinic equipped for IV chemotherapy. Full emergency resuscitation facilities should be immediately available and patients should be under close supervision of the investigator or delegate at all times. The compatibility and stability of the active ingredient was tested under simulated preparation/administration conditions.  
3.2.2.1 General Instructions 1. LMB-100 drug product should be inspected visually for particulates prior to administration.  
2. Do not use the solution if there is particulate matter or if it is discolored. 3. Do not shake or freeze the vial contents. 4. Ensure the drug vial content is protected from light during preparation and administration
(ambient light conditions are acceptable but avoid exposure to direct sunlight).  
5. LMB-100 drug product does not contain any preservatives. Vials are for single use only and partially used vials must not be reused.  
6. Any unused product should be kept for drug reconciliation.
7. No dilution of LMB-100 drug product into 0.9% saline bags should be performed.  
8. Do not administer as IV push or bolus. 9. Other drugs that require parenteral co-administration (if applicable) should be delivered via separate infusion lines and at separate infusion sites and should not be mixed with the study drug.
3.2.2.2 Specific Instructions LMB-100 is diluted with 0.9% NaCl (1:10) **in-line** immediately prior to administration (see Figure 14 below). The undiluted LMB-100 drug product, filled in a disposable syringe, is administered by intravenous syringe infusion using a syringe driver pump. In order to allow **in-line dilution (1:10) immediately prior** to administration of drug product, a side flow with 0.9% NaCl must be applied (as illustrated in Figure 14). An IV infusion pump and syringe driver should be used to control the infusion rate of isotonic 0.9% NaCl solution and LMB100 respectively.  
LMB-100 is administered using peripheral vein access and should not be administered using a  
  
central venous catheter.  
The LMB-100 drug product should be filtered during withdrawal from the vial using a BD filter needle.  
1. The syringes for administration must be prepared under appropriate aseptic conditions as LMB-100 drug product does not contain antimicrobial preservatives. All preparation should be conducted under laminar flow hood with safety glasses, lab coat and arm protection and a work procedure to minimize particle contamination.  
2. As a measure of precaution, a BD 18G (USA: 19G) blunt filter needle Versapore will be used, for the withdrawal of the undiluted drug product (LMB-100) from the vial into the syringe.  
3. Withdraw up to 2 ml excess volume of LMB-100 to the intended dosing volume into the syringe for priming and purging the syringe extension lines before administration (see step 7).  
4. The prepared syringe should be stored and transported with a closing cone/stopper.
5. Since LMB-100 drug product does not contain antimicrobial preservatives and to comply with the chemical and physical in-use stability, the prepared syringes for infusion should be used immediately. If not used immediately, total in-use storage times of prepared syringes should not exceed 24 hours to limit microbial growth in case of potential accidental contamination. Storage conditions should generally be at 2°C to 8°C, but syringes may be held at room temperature for up to a maximum of 4 hours. The temperature during syringe preparation, storage and drug administration must not exceed 25 °C.  
6. Establish the saline flow first by flushing the lines including the 4-way stopcock and extension lines with saline.  
7. Put the filled syringe in the pre-programmed syringe driver, remove the cap and attach the infusion set. Follow the syringe driver manual/local instructions regarding how to set up and prime/purge the system before the line is attached to the closed 4-way stopcock before starting the administration.  
8. The end of infusion is defined as the time point at which the syringe driver finishes administering the total volume of LMB-100 to be infused.  
9. At the end of the first infusion, the IV line should remain in place for 2 hours. If no infusion related symptoms occur during this time, the infusion line may be removed. For subsequent infusions and if no IRR has been reported, the IV line should remain in place for at least 30 minutes from the end of the infusion. If no adverse events occur during the 30 minutes, the infusion line may be removed. If feasible, the line for drawing blood for PK samples (opposite extremity to the one with the infusion line) will remain in place until the 24-hour sample is taken.
During infusion, vital signs (including, if possible, supine diastolic and systolic blood pressure, pulse rate, and temperature) must be monitored pre-infusion, every 15 minutes (± 5 minutes) until the end of the infusion, and thereafter, every 30 minutes (± 10 minutes) until the infusion line is removed. Vital signs during the infusion are not required to be captured in the eCRF unless abnormalities are observed. LMB-100 drug product (DP) should be administered diluted using a side flow set-up at 1:10 (0.1 mg/mL DP). In order to not compromise drug product physico-chemical stability, the dilution with 0.9% NaCl should be done **in line**, immediately prior to administration of the DP. The infusion duration should be 30 minutes (± 5 minutes); however the duration can be increased at the discretion of the investigator based on the total dose and volume to be administered and the patient's physical condition. Syringe preparation and infusion duration should not exceed a maximum of 4 hours. In case of any adverse events related to the infusion, please refer to the specific recommendation described in section 3.3.1.
untitled h1
3.2.3 co-administration of sel-110 and

On days when both LMB-100 and SEL-110 are scheduled to be administered (Day 1 of each cycle), SEL-110 will be administered first. LMB-100 infusion will be initiated within 15 minutes after completion of the SEL-110 administration.
untitled h1
3.2.4 premedications for patients receiving

Due to the prevalence of infusion related reactions (IRRs) seen in the previous study of LMB-100, all patients will be premedicated 30-60 minutes (+ 30 minutes) prior to each LMB-100 administration or, on days when both SEL-110 and LMB-100 are administered, prior to each SEL110 infusion with the following medications:  
o Diphenhydramine 25-50 mg PO or IV o Ranitidine 150 mg PO
o Acetaminophen 650 mg PO
o Dexamethasone 20 mg, PO, 6-12 hours prior to LMB-100 administration, OR
o Dexamethasone 10 mg, IV, 30 - 60 minutes (+30 minutes) prior to LMB-100 administration, OR
o equivalent dose of another corticosteroid as clinically indicated
(See section 3.3.1 for complete instructions on response to IRRs) Participants who experienced an IRR of Grade 3 or 4 on a previous infusion where dexamethasone or another steroid was pre-administered should not receive further LMB-100 and will be discontinued from study therapy.  
| Dose (mg)                                           | Route   |              |
|-----------------------------------------------------|---------|--------------|
| Acetaminophen                                       | 650     | Orally       |
| Ranitidine                                          | 150     | Orally       |
| Diphenhydraminea                                    | 25-50   | Orally or IV |
| Dexamethasoneb                                      | 10      | IV           |
| OR                                                  |         |              |
| Dexamethasoneb                                      | 20      | Orally       |
| a or alternative antihistamine at an adequate dose. |         |              |  
b or equivalent dose of another corticosteroid administered if a >grade 2 IRR occurred on a previous infusion despite standard pre-medication.