Gedatolisib Toxicity and Treatment Education in HR+/HER2− mBC

The panel discusses the clinical and practical considerations surrounding the introduction of gedatolisib for patients with hormone receptor-positive, HER2-negative metastatic breast cancer (HR+/HER2− mBC), with particular emphasis on its mechanism, toxicity profile, intravenous administration, and patient education. Dr. Jennifer Hutchinson explains that gedatolisib provides broad inhibition across the PI3K/AKT/mTOR pathway by targeting all four PI3K isoforms and both mTOR complexes, resulting in a toxicity profile that incorporates adverse effects associated with both PI3K and mTOR inhibition, including hyperglycemia, diarrhea, rash, and mucositis. The panel discusses how intravenous administration may contribute to improved tolerability compared with earlier attempts at comprehensive pathway inhibition. NP Kathryn Post emphasizes evaluating individual patient factors, comorbidities, treatment preferences, and the increased visit burden associated with weekly infusions. The experts also stress the importance of distinguishing targeted IV therapy from traditional cytotoxic chemotherapy and providing proactive education on expected adverse effects, red-flag symptoms, self-management, and when to contact the care team.