Efficacy of alpelisib with rational use of metformin in HR+/HER2- advanced breast cancer patients with PIK3CA mutations (M): retrospective analysis in routine practice of several Russian centers

Background. Hyperglycemia (HG) is an on-target effect of ALP, and prophylactic with metformin was shown to decrease the rate and severity of HG. Here we present efficacy and safety of ALP in a large cohort of patients with rational approach to metformin usage based on risk factors of HG. Material and Methods. Patients (pts) with HR+/HER2- PIK3CA mut ABC were treated with ALP 300 mg orally and FUL 500 mg IM until disease progression or intolerance. The primary endpoints were progression free survival (PFS) and rate of grade 3/4 HG in different risk groups. Pts were stratified to risk groups of HG based on the algorithm before starting ALP and received MET for prevention of HG.