Astex Pharmaceuticals, Inc. (NASDAQ: ASTX) today announced that the U.S. Food and Drug Administration has issued a Complete Response Letter to partner Eisai for their supplemental New Drug Application (sNDA) for Dacogen® (decitabine) for Injection for patients with acute myeloid leukemia (AML) in adults 65 years of age or older who are not considered candidates for induction therapy. The FDA declined to approve the application because the pre-specified analysis of the primary endpoint in the study (DACO-016) did not demonstrate statistically significant superiority of Dacogen over the control arm (p=0.11). A separate Marketing Authorization Application was submitted to the European Medicines Agency (EMA) in May 2011 by Janssen for Dacogen in the treatment of patients with AML. It is expected the EMA will issue a decision on this application later this year. About DACOGEN DACOGEN is currently approved for the treatment of MDS in about 30 countries. DACOGEN is licensed to Eisai Co., Ltd and Eisai has licensed rights outside of North America to Janssen-Cilag International NV and other Janssen affiliates. Astex receives royalties on global sales of DACOGEN. DACOGEN is approved, in the United States, for treatment of patients with myelodysplastic syndromes (MDS), including previously treated and untreated, de novo and secondary MDS of all French-American-British (FAB) subtypes (refractory anemia, refractory anemia with ringed sideroblasts, refractory anemia with excess blasts, refractory anemia with excess blasts in transformation, chronic myelomonocytic leukemia), and Intermediate-1, Intermediate-2 and High-Risk International Prognostic Scoring System (IPSS) groups. Important Safety Information Treatment with DACOGEN is associated with neutropenia and thrombocytopenia. Complete blood and platelet counts should be performed as needed to monitor response and toxicity but at a minimum prior to each dosing cycle. After administration of the recommended dosage for the first cycle, treatment for subsequent cycles should be adjusted if indicated by dose adjustment guidelines. Clinicians should consider the need for early institution of growth factors and/or antimicrobial agents for the prevention or treatment of infections in patients with MDS.