Long-term safety and efficacy of pomalidomide (POM) with or without low-dose dexamethasone (LoDEX) in relapsed and refractory multiple myeloma (RRMM) patients enrolled in the MM-002 phase II trial.

Abstract

8588 Background: MM-002 is a randomized, open-label, multicenter phase II trial evaluating the safety and efficacy of POM with or without LoDEX in advanced RRMM pts. Methods: Pts who had received ≥ 2 prior therapies, including lenalidomide (LEN) and bortezomib (BORT), and were refractory to their last treatment were randomized to POM+LoDEX (POM 4 mg/day, days 1–21 of a 28-day cycle; LoDEX 40 mg/week) or POM alone. End points included progression-free survival (PFS), response rate (according to EBMT criteria and investigator assessment), response duration, overall survival (OS), and safety. The efficacy outcomes are based on the intent-to-treat population (POM+LoDEX, n = 113; POM, n = 108). Results: The median number of prior therapies in each group was 5 (range 1–13). In the POM+LoDEX arm, 30 (27%) pts had high-risk cytogenetics, including del(17p13) and/or t(4p16/14q32). The overall response rate (≥ partial response) was 34% and 15% with POM+LoDEX and POM, respectively, with a median duration of 8.3 (95% CI: 5.8–10.1) and 8.8 (95% CI: 5.5–11.4) mos, respectively. At least minimal response was observed in 45% and 31% of pts, respectively. Median PFS was 4.6 (95% CI: 3.6–5.5) and 2.6 (95% CI: 1.9–2.8) mos with POM+LoDEX and POM, respectively, with a median follow-up of 16.0 and 12.2 mos. Median OS was 16.5 (95% CI: 12.4–18.5) and 13.6 (95% CI: 9.6–18.1) mos, respectively. The most common treatment emergent Gr 3/4 adverse events (AEs) reported in the safety population (n = 219) were neutropenia (44%), anemia (23%), thrombocytopenia (21%), and pneumonia (18%); there were no reports of Gr 3/4 peripheral neuropathy. The incidence of deep-vein thrombosis was low (2%). AEs were managed through dose reductions or interruptions, and supportive care with G-CSF (52%), RBC transfusions (47%), and platelet transfusions (17%). Discontinuations due to AEs were 10%. Conclusions: POM with or without LoDEX is clinically effective and generally well tolerated in RRMM pts who have received multiple prior treatments, including LEN and BORT. AEs were predictable and manageable. Updated data will be presented at the meeting. Clinical trial information: NCT00833833.