This is a multicenter, prospective, randomized, open-label, parallel-group, phase II study to evaluate the potential incremental efficacy and safety of inavolisib in the neoadjuvant treatment of early-stage HER2-positive, HR-positive, PIK3CA mutant breast cancer.~170 patients with confirmed eligibility criteria and PIK3CA mutant breast cancer will be randomized in a 1:1 ratio to receive: Neoadjuvant endocrine therapy in combination with dual anti-HER2 blockade consisting of ready-to-use fixed-dose combination of pertuzumab and trastuzumab as subcutaneous (PH-FDC SC) formulation q3w for 6 cycles (18 weeks) with (6cycles) or without inavolisib. Endocrine therapy consists of either tamoxifen 20mg or an aromatase inhibitor +/- GnRH analogue for premenopausal women and men.~In both study arms, treatment will be given until surgery/core-biopsy, disease progression, unacceptable toxicity, or withdrawal of consent of the patient.~All patients will undergo surgery or biopsy after completing study therapy to assess pCR rate.
Evaluation of the potential incremental efficacy and safety of inavolisib in the neoadjuvant endocrine treatment of early-stage HER2-positive, HR-positive, PIK3CA mutant breast cancer.