Participants were women (aged ≥18 years) with histologically confirmed advanced breast cancer...cohort D comprised patients with AKT1 mutations and oestrogen receptor-negative cancer or PTEN mutation (treated with oral capivasertib 480 mg)...Two (33%, 95% CI 4–78) of the six patients with AKT1 mutations responded, and there were two further unconfirmed responses in these patients.