PIK3CB and triple-negative breast carcinoma: In the overall study population, numerically greater objective response rate (74% vs. 48%), clinical benefit rate (100% vs. 61%), and median PFS (13 vs. 7 months, HR 0.40) were observed among patients with PI3K pathway-activation compared to those without PIK3CA-activating or PTEN-inactivating mutations, leading to the design of an ongoing phase 3 randomized study of alpelisib or placebo plus albumin-bound paclitaxel as first- or second-line therapy for patients with PIK3CA-mutant or PTEN loss (without PIK3CA mutation) advanced triple-negative breast cancer (NCT04251533).