175P Alpelisib (ALP) + endocrine therapy (ET) in patients (pts) with PIK3CA-mutated, hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (ABC): Subgroup analyses from the BYLieve study

The phase 2, noncomparative BYLieve study showed efficacy of ALP (PI3K-α inhibitor and degrader) + ET in pts with PIK3CA-mutated, HR+, HER2– ABC progressing on/after (Cohort A) cyclin-dependent kinase 4/6 inhibitor (CDKi) + aromatase inhibitor (AI), (Cohort B) CDKi + fulvestrant (FUL), or (Cohort C) AI followed by chemotherapy or ET as immediate prior treatment (Tx). Here we report efficacy for subgroups of interest.