Azacytidine in the Management of Myelodysplastic Syndrome: A Single Institutional Retrospective Review of Responses and Tolerability.

Twenty two patients (pts) with primary or therapy-related MDS were treated with 5-azayctidine (AZA) at the Kellogg Cancer Care Centers (KCCC) from July 2004–May 2006. We retrospectively reviewed all consecutive patients with myelodysplastic syndrome treated at the KCCC who received this agent. Charts were reviewed for response, time to response, duration of response and rate of hospitalization with complications of therapy or disease during AZA therapy. Treated patients had Refractory Anemia with Excess Blasts-type 1 (RAEB-1, n=6), RAEB type-2 (RAEB-2, n=3), Chronic Myelomonocytic Leukemia (CMMoL, n=4) or Refractory anemia (RA, n=6). Median age at study entry was 80 yrs (range, 58–95). Patients were treated with azacytidine 75mg/m2 daily for seven consecutive days or five days followed by a two day break and an additional two days of treatment. Patients were treated until best response and treatment frequency was decreased to every 6–8 weeks once a response had occurred.

Responses were as follows: Complete response (CR) with normalization of cytopenias, marrow dysplasia and blasts (as defined in IWG criteria by Cheson et al) occurred in 2 pts (9%). Complete hematologic response (CHR) meeting all of the peripheral blood criteria but without a confirmation bone marrow performed was noted in 4 pts (18%) while hematologic improvement (HE) major (>2 gm rise in Hgb) occurred in 1 pt (5%) and HE minor (1–2 gm rise in Hgb or 50% decrease in RBC requirements) occurred in 2 pts (9%). Thus, a response using the IWG criteria was seen in 9/22 pts yielding an overall response rate of 41%. The median time to response was 3 cycles (range, 1–4). The median duration of response was 8 months (range, 3–18+). Responses are ongoing in 4/9 of the responders. One of the complete response patients had a complex karyotype (5q-, 7q-, del (18p)) that was not present on follow-up marrow after response was noted. Though treatment related cytopenias did occur frequently in the first two cycles of therapy, there were no treatment related hospitalizations for neutropenic patients in this consecutive cohort of patients and no deaths due to therapy. Azacytidine is a well tolerated agent with responses occurring with a significant rate and duration in MDS.