A Phase II, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study Evaluating the Efficacy and Safety of Inavolisib Plus Ribociclib Plus Fulvestrant Versus Placebo Plus Ribociclib Plus Fulvestrant in Patients With Endocrine- Resistant Hormone-Receptor-Positive, HER2-Negative Advanced Breast Cancer With Chromosome 8P Loss and Without a PIK3CA Mutation | Arctuva