Long-Term Outcomes from the Phase 3 OCEAN (OP-103) Study: Melflufen and Dexamethasone (Dex) Versus Pomalidomide (Pom) and Dex in Relapsed Refractory Multiple Myeloma (RRMM)

Background/Introduction:Melphalan flufenamide (melflufen) is a first-in-class peptide-drug conjugate that targets aminopeptidases resulting in rapid release of alkylating agents inside tumor cells. Based on the phase 2 HORIZON study and supported by the phase 3, randomized, controlled OCEAN study, melflufen was approved in Europe for use in patients (pts) with triple-class refractory RRMM with ≥3 prior lines of therapy (LoTs) and without prior autologous stem cell transplantation (ASCT) or with a time to progression (TTP) >36 mo after prior ASCT. In the OCEAN study (NCT03151811), melflufen + dex showed superior progression-free survival (PFS) compared with pom + dex (6.8 vs 4.9 mo; hazard ratio [HR]: 0.79; P=0.032); PFS benefit in the melflufen + dex group was mainly driven by pts who had not received prior ASCT. Overall survival (OS) trended in favor of melflufen + dex in pts without prior ASCT and favored pom + dex in pts with prior ASCT (Schjesvold et al. Lancet Haematol. 2022;9:e98). Post-hoc analyses of OCEAN and HORIZON demonstrated that a TTP <36 mo after prior ASCT was a negative prognostic factor for OS with melflufen + dex (Sonneveld et al. Clin Lymphoma Myeloma Leuk. 2023;S2152). Here, we present long-term OS and safety data from the final analysis of the OCEAN study.