Manning

Researchers are evaluating the effectiveness and safety of combining ribociclib with standard adjuvant endocrine therapy (ET) in patients with hormone receptor-positive (HR+), HER2-negative early breast cancer. This study focuses on patients with Anatomic Stage Group III, IIB, and certain cases of Stage IIA breast cancer. It is a phase IIIb, open-label, multicenter, single-arm trial aiming to measure invasive breast cancer-free survival over three years. Participants who complete screening will receive ribociclib at 400 mg orally once daily for 21 days followed by 7 days off, in 28-day cycles, alongside daily endocrine therapy for 36 months, roughly 39 cycles. Endocrine therapies may include letrozole, anastrozole, exemestane, or hormone-suppressing drugs like goserelin or leuprolide, administered as per standard dosing schedules. After treatment, there is a 30-day safety follow-up and a longer follow-up period lasting until death, withdrawal, loss to follow-up, or up to 48 months after the last participant's first dose. During the study, participants will be monitored for safety and treatment efficacy through regular assessments including heart monitoring via ECG, performance status checks, and laboratory tests to ensure organ function. The main outcome is the rate of invasive breast cancer-free survival at three years. Safety follow-up calls occur 30 days after the last treatment dose, and participants are followed long-term to observe any disease recurrence or other health outcomes.