A Study of Ipatasertib Plus Palbociclib and Fulvestrant Versus Placebo Plus Palbociclib and Fulvestrant in Hormone Receptor Positive and HER2 Negative Locally Advanced Unresectable or Metastatic Breast Cancer

A Phase Ib/III Study of Ipatasertib Plus Palbociclib and Fulvestrant Versus Placebo Plus Palbociclib and Fulvestrant in Hormone Receptor Positive and HER2 Negative Locally Advanced Unresectable or Metastatic Breast Cancer

The open-label Phase Ib portion of this study will evaluate the safety and pharmacokinetics of ipatasertib in combination with palbociclib and fulvestrant to identify a dose of ipatasertib that can be combined with palbociclib and fulvestrant in the Phase III portion. The randomized Phase III portion of this study will evaluate the efficacy, safety, and patient-reported outcome (PRO) objectives of ipatasertib + palbociclib + fulvestrant compared with placebo + palbociclib + fulvestrant in patients with HR+ HER2-, locally advanced unresectable or metastatic breast cancer who had relapsed during adjuvant endocrine therapy or progressed during the initial 12 months of first-line endocrine therapy in locally advanced unresectable or metastatic breast cancer.

Inclusion Criteria:

• HR+ HER2- adenocarcinoma of the breast that is locally advanced unresectable or metastatic
• For women of childbearing potential: agreement to remain abstinent or use contraception, and agreement to refrain from donating eggs
• For men: agreement to remain abstinent or use contraceptive methods, and agreement to refrain from donating sperm
• Radiologic/objective relapse during adjuvant endocrine therapy or disease progression during the initial 12 months of 1L endocrine therapy in locally advanced unresectable or metastatic breast cancer
• At least one measurable lesion via Response Evaluation Criteria in Solid Tumors, Version 1.1
• Phase III only: Tumor specimen from the most recently collected, available tumor tissue

Exclusion Criteria:

• Pregnant or breastfeeding, or intending to become pregnant
• Prior treatment with fulvestrant or other selective estrogen receptor down-regulator
• Prior treatment with PI3K inhibitor, mTOR inhibitor or AKT inhibitor
• Phase III only: Prior treatment with CDK4/6 inhibitor for locally advanced unresectable or metastatic breast cancer
• Prior treatment with a cytotoxic chemotherapy regimen for metastatic breast cancer
• History of Type I or Type II diabetes mellitus requiring insulin
• History of or active inflammatory bowel disease or active bowel inflammation
• Lung disease: pneumonitis, interstitial lung disease, idiopathic pulmonary fibrosis, cystic fibrosis, Aspergillosis, active tuberculosis, or history of opportunistic infections