Sunesis' Phase III trial in AML fails to meet primary endpoint

USA-based Sunesis Pharmaceuticals (Nasdaq: SNSS) says that its pivotal Phase III trial of Qinprezo (vosaroxin) and cytarabine in patients with first relapsed or refractory acute myeloid leukemia (AML) failed to meet its primary endpoint. Shares of Sunesis were down 64% to $2.39 before markets opened yesterday.

The VALOR trial was a randomized, double-blind, placebo-controlled study with 711 patients. The trial did not meet its primary endpoint of demonstrating a statistically-significant improvement in overall survival, with a median overall survival of 7.5 months for vosaroxin and cytarabine compared to 6.1 months for placebo and cytarabine.

The company said that because transplant may confound the primary analysis, a predefined analysis of overall survival censoring for stem cell transplantation was planned. In this analysis, patients receiving the vosaroxin combination had a median overall survival of 6.7 months versus 5.3 months for placebo and cytarabine. The trial also demonstrated a clinically significant benefit in complete remission rate, the secondary endpoint.