A Phase II, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study Evaluating 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

What this Trial Is About

Researchers are evaluating the effectiveness and safety of a combination treatment including inavolisib, ribociclib, and fulvestrant compared to placebo with ribociclib and fulvestrant. This study focuses on adults with hormone receptor-positive, HER2-negative advanced breast cancer that is resistant to endocrine therapy. Participants must have specific genetic markers, including chromosome 8p loss and no PIK3CA mutation, and have not received prior systemic therapy for advanced disease. Participants are randomly assigned to receive either the combination of inavolisib, ribociclib, and fulvestrant or placebo with ribociclib and fulvestrant. The study is double-blind, meaning neither participants nor researchers know which treatment is given. Treatments are administered according to a set schedule detailed in the study protocol. This phase II trial will compare the impact of these treatments over approximately two years. During the study, participants will undergo regular assessments including tumor measurements based on RECIST criteria, safety monitoring, and patient-reported evaluations of treatment side effects and daily function. Researchers will track confirmed objective response rates as the primary outcome and also measure progression-free survival, overall survival, duration of response, and clinical benefit. Safety and quality of life impacts will be closely monitored through adverse event reporting and patient questionnaires throughout the study period.

A Phase II Study Evaluating the Efficacy and Safety of Inavolisib Plus Ribociclib Plus Fulvestrant Versus Placebo Plus Ribociclib Plus Fulvestrant in Participants With Advanced Breast Cancer