Venetoclax plus LDAC for newly diagnosed AML ineligible for intensive chemotherapy: a phase 3 randomized placebo-controlled trial

Abstract

Background: Effective treatment options are limited for patients with acute myeloid leukemia (AML) who cannot tolerate intensive chemotherapy. Methods: Adults ≥18 years with newly diagnosed AML ineligible for intensive chemotherapy were enrolled in this international Phase 3 randomized, double-blind, placebo-controlled trial. Patients (N=211) were randomized 2:1 to either: venetoclax (N=143) or placebo (N=68) in 28-day cycles, plus low-dose cytarabine (LDAC) on days 1-10. The primary endpoint was overall survival (OS); secondary endpoints included response rates, transfusion independence, and event-free survival. Results: Median age was 76 years (range 36-93), 38% had secondary AML, and 20% had prior hypomethylating agent (HMA) treatment. The planned primary analysis showed that the venetoclax arm provided a benefit of 25% reduction in the risk-of-death over the LDAC-alone arm (hazard ratio [HR] 0.75 [95% CI 0.52-1.07], p=0.11), although it was not statistically significant; with median OS of 7.2 months and 4.1 months, respectively. An unplanned analysis with an additional 6 months of follow up demonstrated a median OS of 8.4 months for the venetoclax arm (HR 0.70; 95% CI 0.50-0.98; p=0.04). The CR/CRi rates were 48% and 13% for the Venetoclax plus LDAC arm and LDAC-alone arm, respectively. Key grade ≥3 adverse events (Ven vs. LDAC-alone) were febrile neutropenia (32% vs 29%), neutropenia (47% vs. 16%), and thrombocytopenia (45% vs 37%). Conclusion: Venetoclax plus LDAC demonstrates a clinically meaningful improvement in remission rates and OS compared to LDAC alone, in the context of a manageable safety profile. These results confirm venetoclax plus LDAC is an important frontline AML treatment option for patients unfit for intensive chemotherapy.