Molecular MRD is strongly prognostic in patients with NPM1-mutated AML receiving venetoclax-based non-intensive therapy

Abstract

Assessment of measurable residual disease (MRD) by RT-qPCR is strongly prognostic in patients with NPM1-mutated AML treated with intensive chemotherapy, however there are no data regarding its utility in venetoclax-based non-intensive therapy, despite high efficacy in this genotype. We analysed the prognostic impact of NPM1 MRD in an international real-world cohort of 76 previously untreated patients with NPM1-mutated AML who achieved CR/CRi following treatment with venetoclax and hypomethylating agents (HMA) or low dose cytarabine (LDAC). 44 patients (58%) achieved bone marrow (BM) MRD negativity and a further 14 (18%) a reduction of ≥4 log10 from baseline as their best response, with no difference between HMA and LDAC. The cumulative rate of BM MRD negativity by the end of cycles 2, 4 and 6 was 25%, 47% and 50%. Patients achieving BM MRD negativity by the end of cycle 4 had 2-year overall (OS) of 84% compared to 46% if MRD positive. On multivariable analyses MRD negativity was the strongest prognostic factor. 22 patients electively stopped therapy in BM MRD negative remission after a median of 8 cycles with 2-year treatment-free remission of 88%. In patients with NPM1-mutated AML attaining remission with venetoclax combination therapies, NPM1 MRD provides valuable prognostic information.