Subcutaneous Daratumumab (DARA SC) Plus Standard-of-Care (SoC) Regimens in Multiple Myeloma (MM) across Lines of Therapy in the Phase 2 Pleiades Study: Initial Results of the Dara SC Plus Carfilzomib/Dexamethasone (D-Kd) Cohort, and Updated Results for the Dara SC Plus Bortezomib/Melphalan/Prednisone (D-VMP) and Dara SC Plus Lenalidomide/Dexamethasone (D-Rd) Cohorts

Introduction:DARA is a human IgGκ monoclonal antibody targeting CD38 and is approved for intravenous (IV) infusion across lines of therapy for MM. In phase 3 clinical studies, DARA IV plus Rd for RRMM (POLLUX) and DARA IV plus VMP for transplant-ineligible (TIE) NDMM (ALCYONE) led to deep and durable responses and reduced the risk of disease progression or death by ≥56% (Kaufman J, Blood2019. 134[Suppl 1]:1866; Mateos M, Lancet2020). In the phase 1b MMY1001 study of DARA IV plus carfilzomib/dexamethasone (Kd) in RRMM, DARA IV plus Kd was well tolerated and demonstrated deep responses, regardless of prior lenalidomide treatment (Chari A, Blood2019.134[Suppl 1]:1876). In the phase 3 CANDOR study, DARA IV plus Kd reduced the risk of disease progression or death by 37% in pts with RRMM (Dimopoulos M, Lancet2020). A formulation of DARA for subcutaneous administration (DARA SC) was developed (1,800 mg DARA co-formulated with recombinant human hyaluronidase PH20 [rHuPH20]; ENHANZE® drug delivery technology, Halozyme, Inc.). Advantages of DARA SC include reduced administration time (3-5 minutes) and lower rates of infusion-related reactions (IRRs). The phase 2 PLEIADES study is evaluating the safety and efficacy of DARA SC combined with SoC for MM, including D-Kd for RRMM, D-Rd for RRMM, and D-VMP for TIE NDMM. In the primary analysis of the D-Rd and D-VMP cohorts in PLEIADES, D-Rd and D-VMP demonstrated clinical activity and safety comparable to corresponding DARA IV regimens, with low rates of IRRs, leading to approval in the United States (Chari A, Clin Lymphoma Myeloma Leuk2019.19[10]:e16-e17). Here, we present the primary analysis of the D-Kd cohort and updated data for the D-Rd and D-VMP cohorts of PLEIADES.