PIK3CA and MAP3K1 alterations imply luminal A status and are associated with clinical benefit from pan-PI3K inhibitor buparlisib and letrozole in ER+ metastatic breast cancer.

Clinical trials have demonstrated the efficacy of combining phosphoinositide 3-kinase (PI3K) inhibitors with endocrine therapies in hormone therapy-refractory breast cancer. However, biomarkers of PI3K pathway dependence in ER+ breast cancer have not been fully established. Hotspot mutations in the alpha isoform of PI3K (

Déclaration de conflit d'intérêts

Competing interestsJ.M.B. receives consulting fees from Novartis (not pertaining to alpelisib or buparlisib), and research support from Genentech and Incyte Pharma. M.B. receives consulting fees from Roche and research support from Illumina. I.A.M. receives research funding from Novartis, Pfizer, and Genentech and adboards/consulting fees from Novartis, Genentech, Lilly, Astra-Zeneca, GSK, Immunomedics, Macrogenics and Seattle Genetics. C.L.A. receives research funding from Pfizer, Lilly, Radius, and PUMA Biotechnology, stock options from Provista, and holds advisory roles with Daichii Sankyo, TAIHO Oncology, Novartis, Merck, and Lilly. D.S. has received consulting fees from Pfizer, Loxo Oncology, Lilly Oncology, Vivideon Therapeutics and Illumina. L.C.C. owns equity in, receives compensation from, and serves on the scientific advisory board of Agios Pharmaceuticals. He is also a founder of and receives laboratory support from Petra Pharmaceuticals and receives compensation for being on the scientific advisory board of Petra Pharmaceuticals. No drugs from these companies were involved in this study. S.J.I. receives research funding support (to his institution) from Genentech, PharmaMar, AstraZeneca, and Merck and receives consulting fees from Genentech, Hengrui, Puma, Immunomedics, and Myriad Genetics. The remaining authors declare no competing interests.