Streamline: Retrospective Cohort Study of FMS-Like Tyrosine Kinase 3-Mutated Acute Myeloid Leukemia - Real-World Treatment Patterns and Clinical Outcomes of Patients in First Relapse or Refractory Diagnosis.

Introduction: Recent advances in genomic research have expanded the treatment landscape for acute myeloid leukemia (AML). This study examined treatment patterns and clinical outcomes among relapsed/refractory (R/R) FMS-like tyrosine kinase 3 (FLT3)-mutated AML patients.

Methods: This retrospective longitudinal study included patients with confirmed AML diagnosis, FLT3 mutation, and 1st R/R event from 1/1/2015 to 1/31/2023 in the ConcertAI Oncology Dataset. Treatment patterns, FLT3 testing rates, real-world overall survival (rwOS), and real-world time to next treatment (rwTTNT) were studied.

Results: Among the 336 treated patients, 50.6% received FLT3-tyrosine kinase inhibitors (FLT3-TKIs) as first treatment after R/R event, of which 51.8% received gilteritinib. High-intensity chemotherapy used as first treatment after R/R event decreased from 67.9% in 2015 to 20.0% in 2022, while FLT3-TKI utilization rose to 50% over the same period. Among the 246 patients tested for FLT3 at initial AML diagnosis, only 36% were retested at 1st R/R event. Median rwOS and rwTTNT among FLT3-TKI patients were 12.4 months and 2.9 months, respectively.

Conclusion: This study reveals a trend toward increasing FLT3-TKI use and highlights the need for repeated FLT3 testing among R/R AML patients. Real-world evidence is vital in understanding R/R AML patient care amidst emerging therapies.