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

This early-phase study is testing the safety and tolerability of a new drug called OPN-6602 in people with multiple myeloma (a type of blood cancer) whose disease has come back or stopped responding to multiple previous treatments. **You may be eligible if...** - You have a confirmed diagnosis of multiple myeloma - Your myeloma has relapsed (come back) or is refractory (not responding) after at least 3 different prior treatment regimens, which must have included an immunomodulatory drug, a proteasome inhibitor, and an anti-CD38 antibody - You are no longer a candidate for or cannot tolerate other known effective treatments - Your blood counts, kidney, liver, and heart function are within acceptable ranges **You may NOT be eligible if...** - You have MGUS, smoldering myeloma, Waldenström's macroglobulinemia, IgM myeloma, plasma cell leukemia, or POEMS syndrome - You have a history of Stevens-Johnson syndrome (a severe skin reaction) - You received radiation or a stem cell transplant recently - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.