MM-234: Outcomes of VDPACE with an Immunomodulatory Agent (IMiD) as a Salvage Therapy in Relapsed/Refractory Multiple Myeloma (RRMM) with Extramedullary Disease (EMD)

Abstract

Context: Despite novel agents and increased better outcomes over the last years, MM is still an incurable disease marked by a relapse-remission pattern. EMD is an aggressive presentation at diagnosis and relapse for with a reported incidence of EMD in the course of the disease ranging from 6%–20%. Objective: To evaluate the clinical efficacy and tolerability of VDPACE + IMiD in patients with RRMM with EMD. Design: We performed a single-center retrospective analysis of RRMM patients with EMD treated with VDPACE with IMiD from January 2012 to May 2020. The diagnosis of EMD was based on the histology of tumor bulk or on imaging studies. Methods: Seventeen patients received VDPACE+IMiD as a salvage therapy. The regimen consists of bortezomib, doxorubicin, cisplatin, cyclophosphamide, etoposide, and an IMiD (either thalidomide or lenalidomide) every 28 days. Descriptive analyses were performed on available data for patient characteristics, disease course, and outcomes. Responses were evaluated using the IMWG criteria. Results: Seventeen patients were reviewed in the analysis with a median age of 61 years (41–77). Fifty-nine percent had IgG isotype, 23% had ISS stage III, and 59% had high-risk cytogenetics. The median number of previous lines of therapy was 2 (1–8). Out of the 17 patients: 82% received high-dose chemotherapy followed by autologous stem cell transplant (HDCT/ASCT) prior to VDPACE+IMiD. In addition, 88%, 82%, and 76% were refractory to proteasome inhibitors (PI) and IMiDs and were double refractory to IMiDs and PI, respectively. The median number of VDPACE cycles received was 2 cycles. The median progression-free survival was 9.44 months (95%, CI=NA), median overall survival was 14.9 months. The overall response rate (ORR) was 71%; (9/12) patients who responded to treatment received HDCT/ASCT. The most common grade ≥3 adverse events observed were thrombocytopenia (94%), neutropenia (94%), and anemia (88%) and a noted incidence of febrile neutropenia of 35%. All adverse events were manageable. Conclusions: Our single institution experience demonstrates that patients with extramedullary RRMM can achieve a significant response using VDPACE+IMiD as salvage therapy. We believe that this treatment followed by high-dose chemotherapy with ASCT should be encouraged if the patient is eligible for transplant.