Azacytidine is the only drug approved by FDA for the treatment of MDS. The median survival for patients with MDS and a Intermediate/high IPSS score, treated with conventional care regimens, is assumed to be 11 months. Patients treated with Azacytidine in the CALGB 9221 trial had a median survival of 18 months. Responses occurred in 60% of patients on the Aza C arm (7% complete response, 16% partial response, 37% improved) compared with 5% (improved) receiving supportive care (P <.001). Median time to leukemic transformation or death was 21 months for Aza C versus 13 months for supportive care (P =.007). Transformation to acute myelogenous leukemia occurred as the first event in 15% of patients on the Aza C arm and in 38% receiving supportive care (P =.001). Furthermore, Aza-C improved quality of life, compared to supportive care.