Measurable residual disease intervention in AML: a new therapeutic horizon

ABSTRACT: Acute myeloid leukemia (AML) is a polyclonal malignancy marked by high relapse rates despite initial morphologic remission. Although measurable residual disease (MRD) is an established prognostic tool, increasing evidence supports a role for preemptive, MRD-directed therapy. AML monitoring is hampered by the absence of a universal MRD marker, necessitating a more personalized approach. NPM1 is suited to an MRD-directed strategy because the mutation is AML defining and the monitoring methods are highly sensitive. Critically, rising NPM1mut levels portend clinical relapse with high fidelity, and recent studies demonstrate that venetoclax-based regimens induce rapid and deep MRD responses in a high proportion of patients with NPM1mut MRD relapse. The range of MRD-directed treatment options is expanding and includes FLT3 and menin inhibitors for MRD relapse driven by FLT3-ITD, NPM1mut and KMT2A rearrangements, respectively. To overcome the logistical issue of multiple MRD markers and associated therapies, we have developed a multitarget, multiarm platform trial named INTERCEPT. Novel features include the potential to adaptively expand the range of MRD markers and directed therapies, seamless transition of patients from a local to centralized MRD monitoring framework, a clinical decision rules approach to allocate treatment in a hierarchical and prespecified manner, creation of parallel protocol appendices to enable multiple industry partners to coexist with commercial independence, and development of approaches to minimize the time interval from "MRD relapse to treatment." The future success of MRD-directed therapy will depend on rapid diagnostic turnaround, coordinated logistics, and innovative clinical trial designs able to keep pace with advances in MRD detection technologies and associated targeted therapies.