Molecular Testing and Therapeutic Sequencing in Relapsed NPM1-Mutated AML

Dr. Arana Yi addresses molecular testing importance at relapse, noting molecular persistence or re-emergence patterns that guide therapy selection. She specifically highlights NPM1 relapse cases associated with FLT3 mutations and their influence on treatment choices. Dr. Patel emphasizes AML's molecular heterogeneity, with patients often harboring multiple targetable mutations including IDH1, IDH2, FLT3, and menin inhibitor targets for NPM1-mutated or KMT2A-rearranged disease.

Prior venetoclax exposure represents a critical decision-making factor. Real-world data suggests IDH1 inhibitor ivosidenib and IDH2 inhibitor enasidenib demonstrate reduced effectiveness in venetoclax-exposed patients, whereas olutasidenib (IDH1 inhibitor) retains efficacy post-venetoclax exposure. Gilteritinib maintains efficacy in venetoclax-exposed patients, and menin inhibitors have been developed primarily in the venetoclax era with most clinical trials enrolling venetoclax-exposed patients.

Dr. Patel favors targeting FLT3 or NPM1 over IDH1 or IDH2 mutations when present. Variant allele frequency data guides selection decisions: predominant FLT3 clones in proliferative leukemias may warrant gilteritinib, whereas predominant NPM1 founder clones suggest revumenib or ziftomenib selection. These decisions remain dynamic with ongoing studies investigating multiple targeted therapy combinations including FLT3 plus menin inhibitors or menin plus IDH inhibitors. Outside clinical trials, sequential single targeted therapy approaches are typically employed, though combination data development continues progressing.