Cantabria

Researchers are evaluating treatments for advanced breast cancer characterized by estrogen receptor-positive, HER2-negative, and ESR1-mutated tumors. This study focuses on patients whose cancer has progressed despite previous endocrine therapy and CDK4/6 inhibitor treatment. The goal is to determine the effectiveness of combining elacestrant, a selective estrogen receptor degrader, with everolimus, a kinase inhibitor, compared to elacestrant with a placebo. This phase 3 trial aims to assess how well these treatments prolong the time patients live without disease progression or unacceptable side effects. A total of 240 patients will be randomly assigned to one of two groups: one receiving 345 mg of elacestrant plus 7.5 mg of everolimus daily, and the other receiving 345 mg of elacestrant plus a placebo daily. Treatment cycles last 28 days and continue until disease progression, unacceptable toxicity, death, or other reasons for stopping. Patients will be grouped based on the presence of visceral metastases and prior duration of CDK4/6 inhibitor therapy. After stopping treatment, patients enter a follow-up period where survival and new cancer therapies are tracked every three months for up to 12 months after the last patient is enrolled. Participants will undergo regular assessments including imaging scans to monitor cancer status and safety evaluations. The main measure is progression-free survival, defined as the time from treatment start until tumor progression, death, or discontinuation for other reasons, monitored on average for 12 months. Safety and treatment effectiveness will be closely followed throughout the study, with additional tumor assessments for those who stop treatment for reasons other than progression until new cancer therapy begins, death, or disease progression occurs.