A post hoc sensitivity analysis of survival probabilities in a multinational phase III trial of decitabine in older patients with newly diagnosed acute myeloid leukemia

Background In a multicenter, randomized, open-label phase III study, patients ≥ 65 years with newly diagnosed AML received decitabine 20 mg/m 2 once daily for 5 days every 4 weeks (n = 242) or treatment choice (supportive care or cytarabine 20 mg/m 2 once daily for 10 days every 4 weeks; n = 243). Decitabine use demonstrated greater response rates ( P = .001) and OS data favored decitabine. Patients and Methods In a post hoc sensitivity analysis of mature data of patients in the intent-to-treat population (N = 485), OS at 3, 6, 12, 18, and 24 months after randomization was estimated for each arm using Kaplan-Meier methods. Age, cytogenetic risk, and Eastern Cooperative Oncology Group performance status were used as stratification factors in the Cox regression model to estimate the hazard ratio. Results A survival advantage was seen with decitabine at each cutoff time point; hazard ratios for OS for decitabine vs. treatment choice were 0.83, 0.71, 0.83, 0.80, and 0.79 at 3, 6, 12, 18, and 24 months, respectively. A trend toward improved OS with decitabine was observed at fixed time points over 2 years. Conclusion Decitabine should be considered as a treatment option for older patients with AML and poor prognostic risk factors.