Clinical Outcomes of Patients with Multiple Myeloma after Daratumumab Failure

Anti-CD38 monoclonal antibody (MoAB) therapy has significantly improved the prognosis of patients with multiple myeloma. However, not all patients sustain durable responses. We aimed to describe the natural history of patients relapsed or refractory (R/R) to CD38 MoAB therapy. We performed a single-center, retrospective analysis of the clinical characteristics and outcomes of 81 patients with multiple myeloma who progressed after treatment with daratumumab. Our cohort was heavily pretreated, with a median of two lines prior to daratumumab and only 17 patients received daratumumab as a first line. A total of 38.2% had received a previous autologous stem cell transplantation (ASCT), and 61.7% had received both an immunomodulatory drug (IMID) and a proteasome inhibitor (PI). The median overall survival (OS) was 21 months for the global cohort but it decreased to 14 months for triple-class refractory patients and 5 months for penta-refractory patients. Most of the patients (83.9%) received treatment after daratumumab progression, in many cases with second generation IMID or PI, but seven patients were treated with anti-BCMA therapy and three patients received CART therapy within a clinical trial. In conclusion, patients R/R to daratumumab represent an unmet clinical need with poor prognosis and in need of incorporation of new treatments.