Pomalidomide plus low-dose dexamethasone (POM + LoDEX) versus high-dose dexamethasone (HiDEX) in relapsed/refractory multiple myeloma (RRMM): Impact of cytogenetics in MM-003.

8528 Background: RRMM patients (pts) who fail lenalidomide (LEN) and bortezomib (BORT) have poor prognosis. High-risk cytogenetics predict shorter survival. POM + LoDEX has demonstrated efficacy in pts with prior LEN and BORT and high-risk cytogenetics. MM-003 is an open-label, multicenter, phase III trial comparing POM + LoDEX vs. HiDEX in RRMM pts who failed LEN and BORT treatment (Tx) and have progressed on their last therapy. Methods: Pts must have been refractory to the last prior Tx (progressive disease [PD] during or within 60 days) and failed LEN and BORT after ≥ 2 consecutive cycles of each (alone or in combination). Randomization was 2:1 to POM 4 mg D1–21 + DEX 40 mg (20 mg for pts aged > 75 y) weekly; or DEX 40 mg (20 mg for pts aged > 75 y) D1–4, 9–12, and 17–20 (28-day cycles). Tx continued until PD or unacceptable adverse events (AEs). The primary endpoint was progression-free survival (PFS). Secondary endpoints included OS and AEs. This analysis examined pts meeting modified high-risk cytog...