SOUTH SAN FRANCISCO, Calif., Oct. 30, 2013 (GLOBE NEWSWIRE) -- Sunesis Pharmaceuticals, Inc. (Nasdaq:SNSS) today announced the initiation of the Phase 2 cohort of the Phase 1b/2, MD Anderson Cancer Center-sponsored study of vosaroxin in combination with decitabine in older patients with previously untreated acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS). The trial is being conducted under the direction of Naval Daver, M.D., Assistant Professor, Department of Leukemia, and Farhad Ravandi, M.D., Professor of Medicine, Department of Leukemia, both of the MD Anderson Cancer Center at the University of Texas. Dr. Ravandi is also a principal investigator of the Phase 3 VALOR trial, the company's randomized, double-blind, placebo-controlled, pivotal trial of vosaroxin plus cytarabine in patients with first relapsed or refractory AML. Expansion into the Phase 2 cohort follows the successful completion of a Phase 1b open-label, single-arm dose optimization phase which included six patients with previously untreated AML or high-risk MDS. Patients were treated with vosaroxin (90 mg/m 2) intravenously on days one and four in combination with decitabine (20 mg/m 2) on days one to five. The regimen was found to be well tolerated, with no dose-limiting toxicities, no early mortality and encouraging objective responses. Results, including data from the Phase 2 cohort, are expected to be presented at a medical conference in 2014. "Older patients with AML or high-risk MDS are often intolerant or unresponsive to standard treatments," said Dr. Ravandi. "We find the tolerability and initial clinical activity in this first cohort of difficult-to-treat patients to be very encouraging and suggest important clinical potential for this combination. Based on these early data, we have designated the conduct of the Phase 2 component of this study a top priority." Patients in the Phase 2 cohort will be followed for rate of remission, leukemia-free survival, overall survival and safety. The Phase 1b/2 study is expected to enroll up to a combined total of approximately 60 patients.