Phase 3 Study Comparing Gedatolisib Plus Palbociclib and Endocrine Therapy With Ribociclib Plus Endocrine Therapy for HR-Positive, HER2-Negative Advanced or Metastatic Breast Cancer

What this Trial Is About

Researchers are evaluating the efficacy and safety of combining gedatolisib and palbociclib with endocrine therapy compared to endocrine therapy and ribociclib in adults with hormone receptor-positive, HER2-negative advanced breast cancer. This Phase 3, open-label, randomized clinical trial involves patients with locally advanced or metastatic breast cancer who have either endocrine-resistant or endocrine-sensitive disease. The study aims to explore treatment options for this specific breast cancer subtype to improve outcomes for patients. Participants are assigned to one of two studies based on their endocrine sensitivity status. Study 1 includes patients with endocrine-resistant cancer who will receive either intravenous gedatolisib combined with oral palbociclib and intramuscular fulvestrant or oral ribociclib with fulvestrant. Study 2 includes endocrine-sensitive patients who will receive intravenous gedatolisib with oral palbociclib and letrozole or oral ribociclib with letrozole. Treatments are administered in cycles with specific dosing schedules, including weekly intravenous infusions and oral medications over 28-day cycles. During the trial, participants will undergo screening to confirm eligibility before randomization. Researchers will monitor progression-free survival for up to 48 months as the primary outcome, along with secondary outcomes such as overall survival, response rates, duration and time to response, clinical benefit, quality of life, and adverse events. Safety follow-up will occur 30 days after treatment, and ongoing assessments will include imaging, tumor biopsies, laboratory tests, and quality of life questionnaires. The study is expected to last several years with continuous monitoring of patient health and treatment effects.

Phase 3 Study of Gedatolisib as First-Line Treatment for Patients With HR-Positive, HER2-Negative Advanced Breast Cancer (VIKTORIA-2)