Study of ISB 1342, a CD38/CD3 Bispecific Antibody, in Subjects With Previously Treated Multiple Myeloma

A Phase 1, First-in-Human, Multicenter, Open-Label, Two-Part Dose-Escalation and Cohort Expansion Study of Single-Agent ISB 1342 in Subjects With Previously Treated Multiple Myeloma

The purpose of this study is to assess safety, efficacy, pharmacokinetic (PK)/pharmacodynamic (PD), and immunogenicity with ISB 1342 in subjects with relapsed/refractory multiple myeloma.

This study is an open-label, multi-center, Phase 1 study of ISB 1342 in subjects with relapsed/refractory multiple myeloma refractory to proteasome inhibitors (PIs), immunomodulators (IMiDs), and daratumumab. There will be a dose escalation phase (Part 1) and dose expansion phase (Part 2). In Part 1 of the study, subjects will be treated at escalating dose levels. Once the recommended part 2 dose (RP2D) of ISB 1342 is declared in Part 1, the expansion phase (Part 2) will be initiated at the RP2D.

Inclusion Criteria:

• Documented diagnosis of multiple myeloma with measurable disease (serum, urine, or free light chain) per International Myeloma Working Group (IMWG) criteria, including non-secretory or oligo-secretory multiple myeloma which has relapsed after or is refractory to prior therapies, including proteasome inhibitors (PIs), immunomodulators (IMiDs) and anti-CD38 targeted therapies (daratumumab, isatuximab).
• Eastern Cooperative Oncology Group (ECOG) performance-status score of 2 or less and 1 or less (for France).
• Adequate hematologic, renal, and hepatic functions
• Seronegative for hepatitis B antigen; positive hepatitis B tests can be further evaluated by confirmatory tests, and if viral load is negative, the subject can be enrolled.
• Seronegative for hepatitis C antibody; if positive, then further test for the presence of antigen by hepatitis C virus polymerase chain reaction (HCV PCR). If HCV antigen tests are negative, then the subject can be enrolled.
• Oxygen saturation level ≥92% on room air.
• Left ventricular ejection fraction (LVEF) ≥50% and no pericardial or pleural effusion at Screening

Exclusion Criteria:

• Active central nervous system involvement
• Exposure to daratumumab or isatuximab within 2 months prior to the start of study treatment
• Active plasma cell leukemia
• Active infectious disease
• Clinically significant cardiovascular and respiratory conditions
• History of HIV infection
• Subjects requiring prohibited concomitant medications