Thrombocytopenia is among the strongest predictors of decreased survival for patients with myelodysplastic syndromes (MDS) across all prognostic risk groups. The safety and efficacy of CC-486 (oral azacitidine) was investigated in early-phase studies; we assessed clinical outcomes among subgroups of MDS patients from these studies, defined by presence or lack of pretreatment thrombocytopenia (≤75 × 109/L platelet count). Patients received CC-486 300 mg once-daily for 14 or 21 days of repeated 28-day cycles. Overall, 81 patients with MDS, median age 72 years, comprised the Low Platelets (n = 45) and High Platelets (n = 36) cohorts. Pretreatment median platelet counts were 34 × 109/L and 198 × 109/L, respectively. Grade 3-4 bleeding events occurred in 2 patients in the Low Platelets and 1 patient in the High Platelets groups; events resolved without sequelae. Treatment-related mortality was reported for 7 patients, 5 of whom had pretreatment platelet values <25 × 109/L. Overall response rates were 38% and 46% in the Low Platelets and High Platelets groups, respectively. Five thrombocytopenic patients attained complete remission and 9 attained platelet hematologic improvement. In both cohorts, platelet counts dropped during the first CC-486 treatment cycle, then increased thereafter. Extended CC-486 dosing was generally well tolerated and induced hematologic responses in these patients regardless of pretreatment thrombocytopenia.
Keywords: CC-486; Hypomethylating agent; MDS; Myelodysplastic syndromes; Thrombocytopenia.
Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.