Brief Summary
This study will evaluate the efficacy and safety of inavolisib in combination with Phesgo (pertuzumab, trastuzumab, and rHuPH20 injection for subcutaneousunder the skin use) compared with placebo in combination with Phesgo, as maintenance therapy, after induction therapy in participants with previously untreated HER2-positive advancedat a late stage, far along breast cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs (ABC).
Intervention / Treatment
- Drug: Inavolisib
- Drug: Phesgo
- Drug: Placebo
- Drug: Taxane-based Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells
- Drug: Optional Endocrine Therapy of Investigator’s Choice
Inclusion Criteria:
- Eastern Cooperative Oncologythe study, diagnosis and treatment of cancer Group (ECOG) Performance Status 0 or 1
- Histologically or cytologically confirmed and documented adenocarcinomacancer arising from mucus-producing glands in organs of the breast with metastatic or locally advanced disease not amenable to curative resectionsurgical removal of tissue or part/all of an organ
- Confirmation of HER2 biomarker eligibility based on valid results from central testing of tumor tissuea group of cells that work together to perform a function documenting HER2-positivity
- Confirmation of PIK3CA-mutation biomarker eligibility based on valid results from central testing of tumor tissue documenting PIK3CA-mutated tumor status
- Disease-free interval from completion of adjuvant or neoadjuvant systemic non-hormonal treatment to recurrenceto occur or happen again of >= 6 months
- LVEF (left ventricular ejection fraction) of at least 50% measured by echocardiograma type of ultrasound that uses sound waves to create detailed images of the heart to assess heart structure, function and blood flow (ECHO) or multiple-gated acquisition scan (MUGA)
- Adequate hematologic and organ function prior to initiation of study treatment.