A Phase Ib Study of HS-10352 Plus Fulvestrant in Patients With Advanced Breast Cancer

"Drug: HS-10352 HS-10352 will be administered at escalating doses orally once daily on a continuous dosing schedule starting on Cycle 1 Day 1 (C1D1) in a 28 day cycle.~Drug: Fulvestrant Fulvestrant is administered at a dose of 500 mg intramuscular on Cycle 1 Day 1, Day 15, and Day 1 of every cycle thereafter (where a cycle is 28 days)."

"Drug: HS-10352 participants will be enrolled into Cohort 2 (endocrine therapy-resistant) and Cohort 3 (endocrine therapy-sensitive or naïve) respectively and HS-10352 will be administered at the recommended dose identified in Part 1.~Drug: Fulvestrant Fulvestrant is administered at a dose of 500 mg intramuscular on Cycle 1 Day 1, Day 15, and Day 1 of every cycle thereafter (where a cycle is 28 days)."