Real-World Outcomes of Midostaurin Plus Intensive Chemotherapy in FLT3-Mutated AML: The PETHRATIFY Study

Mutations in FLT3 are present in approximately 30% of patients with AML. The addition of midostaurin (MIDO) to intensive chemotherapy (IC) became standard of care following the RATIFY trial, but comprehensive real-world data spanning the full adult age spectrum and including both FLT3-ITD and FLT3-TKD mutations remain limited. We retrospectively analyzed 1658 adults aged 14-85 years with newly diagnosed FLT3-mutated AML from 129 PETHEMA registry centers: 469 received IC + MIDO and 1189 IC alone. Composite complete remission was higher with IC + MIDO than IC (81.4% vs. 71.7%; p < 0.001) and Day 30 mortality was substantially lower (2.1% vs. 7.1%; p < 0.001). Median overall survival was 47.2 versus 19.3 months (HR 0.64; 95% CI, 0.53-0.76; p < 0.001), and the benefit was sustained after multivariable adjustment (HR 0.73; p = 0.017). In 261 propensity score-matched pairs, the effect was attenuated, remaining significant for event-free survival (HR 0.77; p = 0.029) and showing a nonsignificant trend for OS (HR 0.77; p = 0.06). Allogeneic hematopoietic stem cell transplantation in first remission was more frequent in the IC + MIDO cohort (48.9% vs. 41.3%; p = 0.023). Time-dependent analyses showed the largest MIDO effect among autologous and non-transplanted patients (OS HR 0.45; p = 0.138, and HR 0.69; p = 0.014, respectively). The benefit of MIDO was consistent irrespective of FLT3 mutation type, FLT3-ITD allelic burden, cytogenetic risk, and gender, while less improvement occurred among NPM1 wild type and secondary AML patients. This large real-world cohort confirms the survival benefit of MIDO plus IC across the full adult age spectrum, supporting its standard-of-care status in FLT3-mutated AML.