Phase 1b/2 Study of TTI-101 in Combination for Patients With Metastatic Hormone Receptor-Positive and HER2-Negative Breast Cancer

The primary objective of Phase 1b will be to evaluate the safety and tolerability of TTI-101 when added to palbociclib and AI or fulvestrant administered orally to participants with hormone receptor-positive (HR+) human epidermal receptor 2-negative (HER2)- palbociclib-resistant breast cancer, and to determine the recommended Phase 2 dose (RP2D) for TTI-101 when added to palbociclib and AI or fulvestrant. The primary objective of Phase 2 will be to evaluate anti-tumor activity in participants who receive TTI-101 added to palbociclib or ribociclib and AI or fulvestrant.