DUBLIN, Calif., June 14, 2013 (GLOBE NEWSWIRE) -- Astex Pharmaceuticals, Inc. (Nasdaq:ASTX), a pharmaceutical company dedicated to the discovery and development of novel small molecule therapeutics, today announced that updated clinical results of its novel hypomethylating agent, SGI-110, were presented in a poster session at the 18th Congress of the European Hematology Association (EHA) being held June 13-16, 2013 in Stockholm, Sweden. The update focused on details of the biological and clinical activity as well as safety in the group of intermediate or high risk relapsed or refractory myelodysplastic syndromes (r/r MDS) patients treated in the dose-escalation phase 1 part of the SGI-110-01 study. The study enrolled 15 intermediate or high risk MDS patients including chronic myelomonocytic leukemia who were heavily pretreated with a median number of prior regimens of 2 (range 2-6 prior regimens). All 15 patients had received prior azacitidine or decitabine, and 40% of them previously received both agents. Of the 15 patients, six achieved a clinical response (4 patients with hematological improvement or HI, and 2 patients with marrow CR or mCR) for an overall response rate of 40% (95% CI of 16-68%). The median duration of response was 92 days (range 28-126 days). The two mCR patients received prior treatment with both azacitidine and decitabine, and they demonstrated pronounced DNA demethylation of >10% as measured by the LINE-1 assay (19% and 38% demethylation of LINE-1). SGI-110 subcutaneous treatment was well tolerated. The most common adverse events were injection site pain (mostly Grade 1), and myelosuppression. "We are pleased with the updated results that continue to demonstrate promising clinical activity of SGI-110 in MDS patients who were heavily pre-treated. These data confirm the potent demethylation activity of this medicine," commented James S.J. Manuso, Ph.D., Astex Pharmaceuticals chief executive officer and chairman. "We are proceeding aggressively with the enrollment in the dose-expansion phase 2 part of the study of intermediate and high risk MDS patients who are either relapsed/refractory or treatment-naive to prior hypomethylating agents."