e19528 Background: Pomalidomide (POM) is a third –generation immunomodulatory drug shown to be safe and effective for the treatment of relapsed/refractory multiple myeloma (RRMM) for patients (pts) previously treated with bortezomib and lenalidomide (LEN) and in combination with dexamethasone it has been shown to overcome resistance in RRMM. In this phase 2 trial, we are evaluating the efficacy, safety and tolerability of POM as a replacement therapy for LEN for pts who have progressed receiving a LEN combination regimen. Methods: This is a phase 2, multicenter, open-label and non-randomized study. Pts who have failed a combination regimen containing LEN were treated with POM along with all of the other drugs previously used in the regimen. POM administered orally (dose is determined based on the previous regimen) on days 1-21 of a 28-day cycle, whereas other drugs are administered using the same schedule(s), dose(s) and drug combination as the last LEN-containing regimen that the patient received and failed. The planned enrollment on the study will be 45 pts. Results: To date, a total of 29 pts have been enrolled, 25 pts are evaluable and 12 pts have discontinued treatment. Of the evaluable pts, 9 (36%) and 16 (64%) received 3mg and 4mg of POM, respectively. The median age of all pts was 72 years (range, 52-81), and 17 (68%) were males. Pts have received a median of 3 prior treatments (range, 1-7). The median follow-up time for all pts is 3.1 months (range, 0.2-8.1). Amongst evaluable pts, 5 (23.8%) pts achieved at least a minimal response, 10 (47.6%) pts showed stable disease while 6 (28.6%) pts exhibited disease progression. At the time of data cutoff, only 17 pts have completed more than 1 full cycle of treatment; and, thus, the overall response and clinical benefit rates are fairly low (14.3% and 23.8%, respectively) but expected to improve with further follow up. The median PFS for the cohort was 7.6 months. Common ≥ Gr3 adverse events were neutropenia (8%), hypomania (4%) and leukopenia (4%). Conclusions: We show thatPOM appears to be promising replacement therapy for LEN in RRMM pts who have progressed within receiving a LEN combination regimen.
Randomized phase 2 trial of ixazomib and dexamethasone in relapsed multiple myeloma not refractory to bortezomib