Background: Pts with RRMM who are heavily pretreated often have advanced disease and comorbidities, increasing their susceptibility to AEs. The management of AEs is important to ensure that pts remain on the therapy for as long as needed to receive a clinical benefit. In this analysis, safety data from 3 POM + LoDEX clinical trials (Richardson Blood 2014; San Miguel Lancet Oncol 2013; Dimopoulos ASH 2015) were pooled to better characterize the safety profile of POM + LoDEX and management of AEs. Methods: The 3 trials enrolled pts with ≥ 2 prior therapies, including lenalidomide and bortezomib, who had progressed on or within 60 days of their last therapy. Pts received POM 4 mg/day on days 1-21 of each 28-day cycle and LoDEX 40 mg (20 mg for those > 75 years of age) weekly until disease progression or unacceptable toxicity. Thromboprophylaxis was required. Grouped AE terms were used for analysis. Results: A total of 1088 pts from the 3 trials were included in the safety population. The most common grade 3/4 AEs were neutropenia (56%), infections (34%), anemia (32%), and thrombocytopenia (26%). AEs were managed by dose modifications and/or supportive care (Table). The rate of grade 3/4 venous thromboembolic events was low (2%). Peripheral neuropathy (PN) of any grade occurred in 17% of pts; 1% experienced grade 3/4 PN. AEs leading to POM dose reductions or interruptions occurred in 24% and 66% of pts, respectively. AEs leading to discontinuation of POM were infrequent (7%). Conclusions: In this large pooled safety analysis, POM + LoDEX showed an acceptable safety profile in pts with RRMM. AEs were manageable, and discontinuations due to AEs were uncommon. Clinical trial information: NCT00833833 (MM-002), NCT01311687 (MM-003), and NCT01712789 (MM-010)

^a Grouped AE terms.