Study to Assess Safety and Tolerability of OPN-6602 in Subjects With Relapsed and/or Refractory Multiple Myeloma

Phase 1b, open-label study evaluating the safety, tolerability, pharmacokinetics, preliminary antitumor activity, and pharmacodynamics of OPN-6602 monotherapy and in combination with dexamethasone in subjects with relapsed and/or refractory MM.

Inclusion Criteria: * Confirmed diagnosis of multiple myeloma (MM) * Relapsed or refractory to 3 or more different prior lines of therapy for MM that included immunomodulatory agents, proteosome inhibitors, and anti-CD38 antibody and not a candidate for or intolerant to established therapy known to provide clinical benefit * Adequate hematologic, renal, liver, cardiac function Exclusion Criteria: * Monoclonal gammopathy of undetermined significance (MGUS), smoldering myeloma, Waldenström's macroglobulinemia, or IgM myeloma * Active plasma cell leukemia * Polyneuropathy, organomegaly, endocrinopathy, monoclonal protein and skin changes (POEMS syndrome) * Prior Stevens Johnson syndrome * Localized radiation therapy to disease site(s) within 2 weeks of the first dose * Prior autologous peripheral stem cell transplant or prior autologous bone marrow transplantation within \