Maintenance with Hypomethylating Agents after Allogeneic Stem Cell Transplantation in Acute Myeloid Leukemia and Myelodysplastic Syndrome: A Systematic Review and Meta-Analysis

Review question / Objective: P: Patients with AML or MDS after allo-SCT; I: Hypomethylating agents after allo-SCT; C: Observation after allo-SCT; O: Overall survival rates. Condition being studied: Hypomethylating agents (HMAs) seem to have a range of properties favorable to post-allogeneic hematopoietic stem cell transplantation (allo-SCT) maintenance in acute myeloid leukemia (AML) patients. This meta-analysis was performed to review all relevant studies to compare the outcomes of patients undergoing allo-SCT for AML or MDS receiving HMA maintenance therapy with observation only. Information sources: The systematic search of the Embase and MEDLINE databases identified 4,416 articles, from which 512 duplicates were removed. This resulted in 3,904 articles available for title and abstract review. Subsequently, 3,875 articles were excluded as the article type and study design did not fulfill the inclusion criteria, or there was no report on a primary outcome of interest. The remaining 29 articles underwent full-length review and 18 of those were excluded for the aforementioned reasons. Ultimately, the eligibility criteria for our meta-analysis were met by 11 studies: 2 RCTs, 1 prospective cohort study, and 8 retrospective cohort studies.