Thomas Schröder, MD, Essen University Hospital, Essen, Germany, outlines treatment strategies used in patients with acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) who relapse following allogeneic hematopoietic stem cell transplantation (alloHSCT). These patients have a poor prognosis, and it is therefore essential to develop effective treatments. Dr Schröder describes how early treatment with azacitidine in combination with donor lymphocyte infusion has shown promising results in this patient population, and how measurable residual disease (MRD) monitoring can indicate when to initiate treatment. In addition, targeted therapies and alternative agents with anti-leukemic properties, such as lenalidomide or venetoclax, can also be beneficial. This interview took place at the 2021 Relapse After HSCT² Workshop in New York, NY.