Interferon-γ (IFN-γ) With Donor Leukocyte Infusion to Treat Relapsed Acute Myeloid Leukemia and Myelodysplastic Syndromes Post Allogeneic Hematopoietic Stem Cell Transplantation

This novel regimen has the potential to address a significant unmet need for this high-risk population of patients who have few, if any, effective therapeutic options. In Cohort 1, if this trial confirms the clinical efficacy of IFN-γ/DLI in patients with relapsed AML/MDS after HLA-matched alloSCT, it may establish a new therapeutic approach for post-transplant AML/MDS relapse. Cohort 2 will further evaluate the safety and potential efficacy of IFN-γ/DLI in patients with relapsed AML/MDS after haploidentical alloSCT, where treatment options are also limited and the risk of GVHD requires careful assessment. Together, these cohorts would provide a rationale to explore additional indications for IFN-γ in the context of alloSCT, including 1) IFN-γ/DLI for relapsed disease after haploidentical alloSCT; 2) pre-emptive post-alloSCT treatment of patients transplanted with measurable residual disease (MRD) or with poor-risk AML/MDS, such as disease with TP53 mutations; and 3) prevention of relapse in patients who can only tolerate reduced-intensity conditioning regimens, which in most studies are associated with higher rates of post-alloSCT AML/MDS relapse than intensive conditioning regimens. Collectively, this work may allow more patients with AML/MDS to be referred for and ultimately benefit from alloSCT.