Background: Relapse of primary hematologic disease constitutes an important reason for failure of allogeneic hematopoietic stem cell transplantation (alloHSCT). There are very few treatment modalities for this indications. Therefore, there is a need for novel effective therapies and even more for the prevention of relapse. There are scarce data that azacitidine can be used for these purposes.
Methods: At the Polish Adult Leukemia Group, we retrospectively analyzed the results of azacitidine treatment after alloHSCT. Relapsing patients, patients with minimal residual disease/mixed chimerism, and patients in complete remission with high risk of relapse were analyzed separately. There were 17 patients, 6 with myelodysplastic syndrome, 11 with acute myeloid leukemia, 8 male, and overall median age of 56 years (range, 15-78); 7 patients received donor lymphocyte infusion (DLI).
Results: Patients treated because of relapse received a median of 3 (range, 1-6) cycles of azacitidine, patients receiving preemptive treatment received a median of 4 cycles (range, 2-6), and those on maintenance received a median of 5 cycles (range, 3-5). Toxicity was considerable, especially in relapse-neutropenia (67%), anemia (67%), thrombocytopenia (100%), serious infections (78%)-and preemptive settings. Median overall survival of patients treated for relapse reached 6.8 months (95% confidence interval [CI], 0.7-∞), with better survival observed in patients with temporary disease control (7.7 vs 4.7 mo) and without previous exposure to azacitidine (7.7 vs 3.4 mo). One-year overall survival reached 75% (95% CI, 13%-96%) for preemptive and 50% (95% CI, 0%-91%) for maintenance treatment. DLI did not aggravate graft-versus-host disease.
Conclusions: Effectiveness of azacitidine in relapsing patients is disappointing. Azacitidine seems to be promising in preemptive and maintenance settings. Toxicity is considerable. Further research is needed.
Copyright © 2016 Elsevier Inc. All rights reserved.