DUBLIN, Calif., Dec. 10, 2012 (GLOBE NEWSWIRE) -- Astex Pharmaceuticals, Inc. (Nasdaq:ASTX), a pharmaceutical company dedicated to the discovery and development of novel small molecule therapeutics, announced encouraging Phase I clinical results during a presentation at the American Society of Hematology (ASH) of SGI-110, a novel second generation hypomethylation agent. Data from the completed SGI-110 dose escalation part of a randomized Phase 1/2 first-in-human clinical trial, in patients with relapsed/refractory intermediate or high-risk myelodysplastic syndromes (MDS) or acute myelogenous leukemia (AML) demonstrated a differentiated pharmacokinetic (PK) profile resulting in an extended half-life and exposure to decitabine as delivered by subcutaneous SGI-110. Excellent hypomethylation was achieved with higher doses in the daily regimen up to the Biologically Effective Dose (BED). BED was reached before the Maximum Tolerated Dose (MTD). Of the 17 heavily pretreated relapsed/refractory AML patients who were given therapeutic doses of SGI-110 and achieved adequate hypomethylation, 5 major responses were observed. Treatment was well tolerated by most patients with the most common drug-related adverse events being expected myleosuppression, and Grade 1 injection site pain. The data was presented at an oral session at the ASH 54th Annual Meeting in Atlanta, Georgia today by Hagop M. Kantarjian, MD, Professor and Department Chair, Department of Leukemia, Cancer Medicine Division, The University of Texas MD Anderson Cancer Center, Houston, TX. The randomized Phase 1/2 dose escalation part enrolled 78 patients of which 44 patients were on the daily regimen and 34 patients were on the weekly regimen. Sixty four patients had relapsed/refractory AML while 14 patients had MDS. The PK profile of subcutaneous SGI-110 demonstrated a longer therapeutic exposure window to decitabine of at least 8 hours, which is more than double the reported exposure achieved by Dacogen intravenous infusion (DAC IV), and a longer decitabine half-life (1.5-2.5 hours) which is up to 4-fold longer than that of DAC IV.