Study of Safety and Efficacy of Dapagliflozin + Metformin XR Versus Metformin XR in Participants With HR+, HER2-, Advanced Breast Cancer While on Treatment With Alpelisib and Fulvestrant

Alpelisib (tablets) administered at 300mg orally once daily on a continuous dosing schedule starting on Cycle 1 Day 8 in a 28 days cycle.

Fulvestrant (prefilled syringe) 500mg administered intramuscularly at Cycle 1 Day 1 and 15 after randomization and then at Day 1 of each subsequent cycle during the randomized treatment phase.

Metformin XR (tablets) administered at a starting dose of 500mg orally once daily on a continuous dosing schedule starting on Cycle 1 Day 1 in a 28 days cycle. Dose titration from 500 mg once a day to 2000 mg once a day.

Dapagliflozin + metformin XR administered as a single tablet combination at a starting dose of 5 mg dapagliflozin + 500 mg metformin XR orally once daily on a continuous dosing schedule starting on Cycle 1 Day 1 in a 28 days cycle. Dose titration from 5 mg dapagliflozin + 500 mg metformin XR orally once daily to 10 mg dapagliflozin + 2000 mg metformin XR once daily

Dapagliflozin (tablet) at a starting dose of 5mg orally once daily on a continuous dosing schedule starting on Cycle 1 Day 1 in a 28 days cycle. Dose titration from 5 mg to 10 mg once daily