A selective inhibitor of PI3Kα that is equipotent against both wild type and several mutant isoforms (IC₅₀s = 4.0-4.8 nM); dose-dependently inhibits the growth of PI3Kα-dependent xenograft tumors in mice, alone or in combination with other kinase inhibitors.

BYL-719 is an ATP-competitive oral PI3K inhibitor selective for the p110a isoform that is activated by a mutant PIK3CA gene in HER2+ breast cancers and gastric cancers. BYL-719 exhibits anticancer chemotherapeutic activity and inhibits proliferation in a variety of cell lines. IGF1 and neuregulin 1…