A Study of Daratumumab With the Addition of Recombinant Human Hyaluronidase (rHuPH20) for the Treatment of Participants With Relapsed or Refractory Multiple Myeloma

This is an open-label (identity of assigned study drug will be known), multicenter, 3-part, Phase 1b dose escalation/expansion study to evaluate the safety, pharmacokinetics (study of what the body does to a drug), and antitumor activity of SC delivery of daratumumab to participant with relapsed or refractory multiple myeloma. Up to approximately 53 participants in part 1, 80 participants in part 2 and 15 participants per corticosteroid tapering cohort (up to approximately 30 participants total) in Part 3 will be enrolled. The purpose of Part 1 is to select an appropriate SC therapeutic dose for the mixture of daratumumab with rHuPH20 based on safety and pharmacokinetics. This dose, selected from part 1 will be the initial dose for the co-formulated daratumumab and rHuPH20 preparation to be evaluated in Part 2. The purpose of Part 2 is to evaluate the SC delivery of CF and confirm the dose level selected from Part 1 based on the pharmacokinetics, safety, and antitumor activity. The purpose of Part 3 is to evaluate the safety of Dara-CF 1800 mg SC delivery without pre-dose and post-dose corticosteroids. Participant's safety will be monitored throughout the study.