ERBB2 and breast cancer: The phase 3 CAPItello-291 Trial demonstrated that capivasertib, combined with fulvestrant, significantly improves PFS (7.3 months versus 3.9 in the placebo group) and shows a favorable safety profile in patients with HR+, HER2-advanced BC after relapse under aromatase inhibitor treatment and prior therapy with CDK4/6 inhibitors.