Genentech’s Phase III results show that the Inavolisib (GDC-0077) treatment meets the primary end point in hormone receptor (HR)-positive, HER2-negative, PIK3CA-mutated Breast Cancer. The combination of Inavolisib with Palbociclib and fulvestrant improves the progression-free survival (PFS) in the first line. Inavolisib is a potent selective inhibitor of PI3K alpha (PI3Kα) that binds to the ATP-binding site of p110α, and promotes the degradation of mutated p110α.