Treatment of Breast Cancer
“To Evaluate the Safety, Tolerability, and Pharmacokinetics of GDC-0077 Single Agent in Participants With Solid Tumors and in Combination With Endocrine and Targeted Therapies in Participants With Breast Cancer”
This is an open-label, multicenter, Phase I study designed to evaluate the safety, tolerability, and pharmacokinetics of GDC-0077 administered orally as a single agent in participants with locally advanced or metastatic Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Alpha (PIK3CA)-mutant solid tumors, including breast cancer, and in combination with standard-of-care endocrine and targeted therapies for the treatment of locally advanced or metastatic PIK3CA-mutant hormone receptor-positive (HR+)/human epidermal growth factor receptor 2 negative (HER2-) breast cancer. Participants will be enrolled in two stages: a dose-escalation stage (Stage I) and an expansion stage (Stage II). Participants will be assigned to one of six regimens: GDC-0077 as a single agent (Arm A), GDC-0077 in combination with palbociclib and letrozole (Arm B), GDC-0077 in combination with letrozole (Arm C), GDC-0077 in combination with fulvestrant (Arm D), GDC-0077 in combination with palbociclib and fulvestrant (Arm E), and GDC-0077 in combination with palbociclib, fulvestrant, and metformin (Arm F).
Drug - GDC-0077
Participants will receive oral GDC-0077 once daily on Days 1-28 of each cycle.
Drug - Fulvestrant
Participants will receive fulvestrant 500 mg, administered intramuscularly on Days 1 and 15 of Cycle 1. For subsequent cycles, participants will receive fulvestrant intramuscularly on Day 1 of each cycle.
Drug - Letrozole
Participants will receive once daily oral doses of letrozole 2.5 mg on Days 1âˆ’28 of each cycle.
Drug - Palbociclib
Participants will receive once daily oral doses of palbociclib 125 mg on Days 1âˆ’21 of each cycle.
Drug - Metformin
Participants will receive oral metformin once daily, starting on Cycle 1, Day 1, as tolerated.
A Phase I, Open-Label, Dose-Escalation Study Evaluating the Safety, Tolerability, and Pharmacokinetics of GDC-0077 as a Single Agent in Patients With Locally Advanced or Metastatic PIK3CA-Mutant Solid Tumors and in Combination With Endocrine and Targeted Therapies in Patients With Locally Advanced or Metastatic PIK3CA-Mutant Hormone-Receptor Positive Breast Cancer