Molecular measurable residual disease monitoring and transplant indications in NPM1 mutated acute myeloid leukemia

NPM1 mutated acute myeloid leukemia (AML) comprises roughly 30% of all AML cases and is mainly classified as favorable or intermediate-risk according to the European Leukemia Net stratification. Some patients, however, either have a poor response to initial intensive chemotherapy or ultimately relapse. NPM1 mutations are common, generally stable at early relapse and AML specific, features which make them ideal targets for measurable residual disease (MRD) monitoring. MRD monitoring via molecular analysis during the course of treatment can inform the role of allogeneic stem cell transplantation (HCT) in first remission in patients with NPM1 mutated AML with high-risk co-occurring mutations, particularly FLT3-ITD, and in favorable risk patients who do not achieve defined molecular milestones. In this review, we evaluate the prognostic role of MRD monitoring in NPM1 mutated AML and its use as a predictive biomarker to refine risk stratification and inform decision making regarding treatment. We explore the impact of pre-HCT MRD positivity on post-HCT outcomes in this AML subset, and how HCT-related factors such as conditioning intensity may influence this risk.