Safety of Lenalidomide (LEN) Plus Low-Dose Dexamethasone (DEX; Rd) in Chinese Patients (Pts) With Relapsed/Refractory Multiple Myeloma (RRMM) Treated With Prior Thalidomide (THAL) and Bortezomib (BORT): Subanalysis of the MM-024 Extended Access Program (EAP)

PO-392 Safety of Lenalidomide (LEN) Plus Low-Dose Dexamethasone (DEX; Rd) in Chinese Patients (Pts) With Relapsed/Refractory Multiple Myeloma (RRMM) Treated With Prior Thalidomide (THAL) and Bortezomib (BORT): Subanalysis of the MM-024 Extended Access Program (EAP) L. Yu, Z. Cai, J. Jin, X. Du, F. Chen, D.-b. Zhou, X. Ke, X. Li, D. Wu, F. Meng, D. DeMarco, J. Zhang, J. Mei, J. Hou The 301 Hospital-Chinese PLA General Hospital, Beijing, China; The First Affiliated Hospital, Zhejiang University, Hangzhou, China; Guangdong General Hospital, Guangzhou, China; Xiangya Hospital of Central South University, Changsha, China; Peking Union Medical College Hospital, Beijing, China; Peking University 3rd Hospital, Beijing, China; Shanghai 6th Hospital, Shanghai, China; The 1st Affiliated Hospital of Soochow University, Suzhou, China; Nanfang Hospital of Southern Medicine University in Guangzhou, Guangzhou, China; Celgene Corporation, Summit, NJ, USA; Department of Hematology, Shanghai Changzheng Hospital, Shanghai, China Introduction: The efficacy and safety of Rd (LEN 25 mg/day on D1e21 and low-dose DEX 40 mg/day on D1, 8, 15, and 22 of each 28-day cycle) given until progressive disease or discontinuation of LEN for any reason in Chinese pts with RRMM was demonstrated in the multicenter phase 2 MM-021 trial (Hou J, et al. J Hematol Oncol. 2013;6:41). Pts in MM-021 received a median of 4 (range 1e15) prior antimyeloma treatments (Tx) with 90 (45%) pts treated with both THAL and BORT. MM-024 is an EAP for Table Pt baseline characteristics and selected safety outcomes wi THAL (n [ 18) BO (n [ Baseline characteristics, n (%) Age > 65 yrs 4 (22) 3 (1 ECOG performance status score 2 1 (6) 0 Durie-Salmon stage III 12 (67) 14 ( 5 prior Tx 6 (33) 4 (2 Gr 3e4 AEs, n (%) Any Gr 3e4 AE 13 (72) 8 (5 Neutropenia 4 (22) 1 ( Anemia 3 (17) 0 Thrombocytopenia 0 0 Pneumonia 2 (11) 2 (1 Fatigue 2 (11) 0 Peripheral neuropathy 0 1 ( Deep-vein thrombosis 0 0 AE, adverse event; gr, grade. Includes pneumonia, lobar pneumonia, and bronchopneumonia. MM-021, and was designed to monitor the long-term safety of Rd. The aim of this subanalysis of the MM-024 EAP was to investigate the long-term safety of Rd in Chinese pts with RRMM previously treated with both THAL and BORT, or treated with neither THAL nor BORT. Patients and Methods:MM-024 pts received the same Rd regimen as those in the MM-021 study. Starting doses of Rd were the same as the last doses received in MM-021 unless dose adjustments were required prior to rollover, per protocol. Tx continued until disease progression, withdrawal due to toxicity, or lost to follow-up, and pts were followed for up to 5 years (yrs; including 1 yr spent in MM-021). The primary endpoint was safety. Results: Of the 80 pts enrolled in MM-024, 18 (23%) had received prior Tx with THAL, 16 (20%) prior Tx with BORT, 41 (51%) prior Tx with both THAL and BORT, and 5 (6%) prior Tx with neither THAL nor BORT (data cutoff November 5, 2014). Baseline characteristics were generally similar across prior Tx subgroups (Table); as expected, pts who had received prior Tx with THAL and BORT were more likely to have received multiple prior Tx. The incidences of Gr 3e4 neutropenia, anemia, and thrombocytopenia AEs were generally similar across subgroups (Table). Gr 3e4 pneumonia was reported in about 10% of pts with prior THAL, BORT, or both THAL and BORT. Rates of Gr 3e4 peripheral neuropathy and deep-vein thrombosis were low. No pts discontinued Rd due to AEs; however, 2 pts died due to Tx-related AEs: 1 had received prior THAL only (lung infection), and 1 had received prior THAL and BORT (cerebral infarction). The safety profile of Rd in pts with prior THAL and BORT was consistent with the overall safety results from the MM-024 and MM-021 trials. Conclusion: Results of this subgroup analysis suggest that Rd has an acceptable long-term safety profile in Chinese pts with RRRM, regardless of prior Tx with THAL and/or BORT. This abstract was developed with editorial support from Excerpta Medica. th Rd, according to prior Tx subgroups RT 16) THAL and BORT (n [ 41) Neither THAL nor BORT (n [ 5) 9) 15 (37) 1 (20) 3 (7) 1 (20) 88) 33 (81) 5 (100) 5) 23 (56) 1 (20)