ERBB2 and breast adenocarcinoma: PIK3CA-mutated, hormone sensitive patients with HER2-negative breast adenocarcinoma have significantly improved progression-free survival with the addition of the PI3K inhibitor alpelisib to fulvestrant, which is FDA-approved.33 The pan-AKT inhibitor capivasertib added to fulvestrant prolonged progression-free survival vs fulvestrant alone in tumors harboring AKT, PIK3CA, or PTEN alterations and is expected to receive FDA approval soon.