Daratumumab (DARA), a human CD38 IgG1? monoclonal antibody, has demonstrated single agent efficacy while being highly tolerable as a monotherapy, and significant efficacy in combination with standard-of-care regimens in pts with multiple myeloma (MM) who have received ?1 prior lines of therapy (Lokhorst HM. NEJM 2015, 373(13):1207-19; Lonial S. Lancet 2016, 387:1551-60; Palumbo A. NEJM 2016, in press; Dimopoulos MA. NEJM 2016, in press). DARA is currently administered as an intravenous (IV) infusion. Subcutaneous (SC) delivery of DARA is being tested in combination with the recombinant human hyaluronidase enzyme (rHuPH20) to facilitate systemic absorption of DARA after SC infusion into the abdominal wall. PAVO is the first study to assess the safety, pharmacokinetics, and efficacy of SC administration of DARA plus rHuPH20 (DARA-PH20) in pts with relapsed or refractory MM (RRMM).