RecruitingPhase 1Drug trialStudy to Assess Safety and Tolerability of OPN-6602 in Subjects With Relapsed and/or Refractory Multiple MyelomaPhase 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.