Application of the French prognostic score (FPS) to assess overall survival (OS) in a U.S.-based cohort of patients (pts) treated with azacitidine (Aza).
7126 Background: In pts with IPSS high-risk myelodysplastic syndrome (HR-MDS), Aza prolonged OS. The FPS was developed for Aza-treated HR-MDS pts based on 4 baseline clinical criteria: Performance status, karyotype, presence of circulating blasts, and RBC transfusion dependency (TD) (Itzykson et al, Blood 2011). The FPS discriminated 3 risk groups [low-risk [LR), intermediate-risk (IR), and high-risk (HR), with significantly different median OS at 32, 15, and 6 months (M), respectively. We sought to validate the FPS in a U.S.-based cohort. Methods: The North American Leukemia Intergroup Trial E1905 randomized 150 pts with MDS, CMML, and AML with dysplastic changes to Aza 50 mg/m2/day (d) for 10 d +/- entinostat (Ent) 4 mg/m2/d on d3 and d10. OS was defined as time from registration to death from any cause, with follow-up censored at last contact. Kaplan-Meier estimates were used for survival distribution. Results: The FPS could be determined for 115 pts. Median follow-up was 48.5 M. The median OS was significantly different between the HR, IR, and LR FPS groups in the 115 pts (9.7, 14.7, 25.3 M, respectively, log Rank test P=0.017), and for pts in Aza arm (n=55) (7.8, 19.3, 26.4 M, respectively, P=0.008), but not for patients in the Aza+Ent arm (n=60) (12.5, 12.4, 24.1 M, respectively, P=0.21). Using multivariate Cox model with WBC count, hemoglobin, disease type, and platelet TD, the prognostic effect of HR vs. LR FPS groups remained significant for the entire cohort (P=0.046) and for the Aza arm (P=0.037). No significant differences in response rates were observed. Conclusions: The FPS warrants further evaluation as a baseline prognostic tool that can define a subgroup of pts with lower probabilities of achieving survival benefit from Aza therapy. Such pts might be considered from alternative therapeutic interventions.