eligibility_summary
Eligible: ECOG 0–1, unresectable metastatic/locally advanced HER2+ PIK3CA-mutated breast adenocarcinoma, disease-free ≥6 months after (neo)adjuvant non-hormonal therapy, LVEF ≥50%, adequate hematologic/organ function. Exclude: prior PI3K/AKT/mTOR or systemic therapy for LA/M HER2+, IBD, progression ≤6 months on HER2 therapy, diabetes (T1 or T2 on meds), active HBV/liver disease, pneumonitis/ILD, leptomeningeal disease, recent serious infection, major ocular/uveitis.
trial_source
clinical_trials.gov from Dec 2, 2025
annotation_status
ai
ai_summary
Phase III maintenance study in HER2+ PIK3CA‑mutated advanced breast cancer testing inavolisib + Phesgo vs placebo + Phesgo after induction with Phesgo + a taxane, optional endocrine therapy allowed. Inavolisib: oral small‑molecule, selective PI3Kα inhibitor (targets PIK3CA‑mutant p110α) to block PI3K/AKT/mTOR signaling. Phesgo: fixed‑dose SC pertuzumab + trastuzumab (IgG1 anti‑HER2 monoclonal antibodies) with rHuPH20, pertuzumab blocks HER2 dimerization (HER2/HER3), trastuzumab inhibits HER2 signaling and mediates ADCC, rHuPH20 is a hyaluronidase that enhances SC absorption. Taxanes (e.g., docetaxel/paclitaxel): cytotoxic microtubule stabilizers causing mitotic arrest. Optional endocrine therapy: SERM (tamoxifen), AIs (anastrozole/letrozole/exemestane), SERD (fulvestrant), ± LHRH agonist to suppress ER signaling. Targets: HER2‑overexpressing, PIK3CA‑mutant tumor cells, HER2/HER3->PI3K/AKT/mTOR and ER pathways, microtubule dynamics, immune ADCC.