PF-07248144, a first‐in‐class KAT6 inhibitor, achieves optimal 5 mg dose with fulvestrant in ER+/HER2– metastatic breast cancer

In phase 1 expansion, 5 mg PF-07248144 plus fulvestrant demonstrated an ORR of 37.2% (vs 24.1%) with a median duration of response of 15.8 months (vs 4.8 months at 1mg) and median PFS of 10.7 months (vs 3.6 months at 1mg). Safety was manageable with the most common TRAE being taste alteration in 83.7% of patients, while the most common G≥3 TRAE was reversible neutropenia in 46.5% of patients, managed with dose changes.