Phase 3 Randomized Study Comparing RLY-2608 plus Fulvestrant to Capivasertib plus Fulvestrant for Treatment of PIK3CA-Mutant HRHER2- Locally Advanced or Metastatic Breast Cancer After Progression on CDK46 Inhibitor Therapy

What this Trial Is About

Researchers are evaluating the effectiveness and safety of two combination treatments for adults with hormone receptor positive HR, human epidermal growth factor receptor 2 negative HER2- locally advanced or metastatic breast cancer that has a PIK3CA mutation. These patients have experienced recurrence or progression after treatment with a CDK46 inhibitor. This Phase 3, open-label, randomized study compares RLY-2608 zovegalisib plus fulvestrant against capivasertib plus fulvestrant to determine which treatment better controls the disease. Participants are assigned to one of two groups one group receives zovegalisib orally twice daily along with fulvestrant administered by injection on specific days during a 28-day treatment cycle the other group receives capivasertib orally twice daily on an intermittent weekly schedule plus fulvestrant injections on the same schedule. Treatment cycles repeat every 28 days. The study is conducted globally at multiple centers and continues until disease progression or other criteria are met. During the study, participants undergo regular assessments including scans reviewed by blinded independent central review to measure progression-free survival, as well as monitoring overall survival, response rates, quality of life questionnaires, and safety evaluations. Blood samples are taken periodically to measure drug levels. The study may last up to approximately 77 months for outcome measurements, with ongoing monitoring for adverse events and quality of life changes throughout this period.

Phase 3 Study of RLY-2608 + Fulvestrant vs Capivasertib + Fulvestrant as Treatment for Locally Advanced or Metastatic PIK3CA-mutant HR+/HER2- Breast Cancer