Treatment of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) relapsing after allogeneic hematopoietic cell transplantation (HCT).

Abstract

6539 Background: Disease relapse is a major cause of treatment failure after allogeneic HCT for AML and MDS. Therapeutic options after relapse are limited and the prognosis remains dismal. Methods: We analyzed 245 patients who received allogeneic HCT for MDS/AML using the conditioning regimen of fludarabine 40 mg/m2 and busulfan 130 mg/m2 for four days, between April 2001 and June 2008: 88 patients recurred. Results: Median age was 45 (range:18-66) years. Diagnosis was AML (n=72; 82%) or MDS (n=16; 18%). Donors were related (n=56) or unrelated (n=32). Relapse treatment: 21% (N=18) received supportive care only while 76% (N=67) received salvage (3 patients were lost to follow-up). Median complete remission (CR) duration after first HCT for the recurred group was 4 months; 67% of the patients relapsing <4 months received salvage treatment versus 90% of those that relapsed in >4 months (p=0.02). Salvage included: chemotherapy only (N=31), donor lymphocyte infusion (DLI) with or without chemotherapy (N=11), other (N=3), and second HCT with or without preceding salvage chemotherapy (n=22; 25%). Disease status at second HCT: CR2 (n=5) or active disease (n=17). Median survival after relapse was 3 months; 9 patients are alive (10%; 7 of 9 received second HCT. 2-year over all survival (OS) for second HCT and chemotherapy groups was 45% and 10%, respectively. Whereas 2-year OS was 0% for both DLI and supportive care only group. One-year OS was 45% (N=43) versus 10% (N=45) for patients whose post-transplant remission lasted >4 and <4 months, respectively (P=0.009). Conclusions: Survival after relapse is dictated primarily by post-transplant remission duration. A second HCT holds promise for long-term disease control in a subset of patients. 2-year OS 2-year OS Second allogeneic HCT 45% Chemotherapy 10% Donor lymphocyte infusion (DLI) 0% Supportive care only 0% CR duration after 1st HCT 1-year OS > 4 mo 45% < 4 mo 10% ü(p=0.009) No significant financial relationships to disclose.