INAVO120: This phase II/III trial is evaluating the safety and effectiveness of adding an oral targeted therapy to a standard chemotherapy/targeted therapy combination, in patients with hormone receptor positive, HER2-negative locally advanced or metastatic breast cancerA Phase III, Randomized, Double-Blind, Placebo-Controlled Study Evaluating the Efficacy and Safety of GDC-0077 Plus Palbociclib and Fulvestrant Versus Placebo Plus Palbociclib and Fulvestrant in Patients With PIK3CA-Mutant, Hormone Receptor-Positive, Her2-Negative, Locally Advanced or Metastatic Breast Cancer (WO41554)

Exclusion

• Metaplastic breast cancer
• Any history of leptomeningeal disease or carcinomatous meningitis
• Any prior systemic therapy for metastatic breast cancer
• Prior treatment with fulvestrant or any selective estrogen-receptor degrader, with the exception of participants that have received fulvestrant or any selective estrogen-receptor degrader as part of neoadjuvant therapy only and with treatment duration of no longer than 6 months
• Prior treatment with any PI3K, AKT, or mTOR inhibitor, or any agent whose mechanism of action is to inhibit the PI3K-AKT-mTOR pathway
• Type 2 diabetes requiring ongoing systemic treatment at the time of study entry; or any history of Type 1 diabetes
• Known and untreated, or active CNS metastases. Patients with a history of treated CNS metastases may be eligible
• Active inflammatory or infectious conditions in either eye, or any eye conditions expected to require surgery during the study treatment period
• Symptomatic active lung disease, or requiring daily supplemental oxygen
• History of inflammatory bowel disease or active bowel inflammation
• Anti-cancer therapy within 2 weeks before study entry
• Investigational drug(s) within 4 weeks before randomization
• Prior radiotherapy to >= 25% of bone marrow, or hematopoietic stem cell or bone marrow transplantation
• Chronic corticosteroid therapy or immunosuppressants
• Pregnant, lactating, or breastfeeding, or intending to become pregnant during the study or within 60 days after the final dose of study treatment
• Major surgical procedure, or significant traumatic injury, within 28 days prior to Day 1 of Cycle 1