For Adults With Advanced HR+ HER2- Breast Cancer, Not Yet Treated: Join the FourLight-3 Study

About the Study

The FourLight-3 clinical trial tests a study treatment, atrimociclib, plus letrozole against standard approved treatments plus letrozole. The clinical trial is for adults with advanced or metastatic HR-positive, HER2-negative breast cancer who have not received prior treatment for advanced disease. Participants will be randomly assigned to a treatment group, attend regular clinic visits, and have tests and scans to monitor their health and cancer response.

What the Study Involves

• This is a randomized, open-label Phase 3 clinical trial. Participants are randomly assigned to receive either the investigational treatment (atrimociclib plus letrozole) or standard approved therapy plus letrozole
• Interested individuals will complete screening tests to confirm eligibility, including medical history review, lab tests, and scans. Only adults with advanced HR-positive, HER2-negative breast cancer who have not received prior treatment for advanced/metastatic disease may qualify
• Participants receive either atirmociclib plus letrozole, or standard approved therapy plus letrozole. Treatment is given in cycles, with regular dosing and clinic visits. The exact dose and schedule are determined by the study protocol
• Regular clinic visits are required for monitoring, including blood tests, scans, and assessments of health and cancer response. Additional procedures, such as biopsies, may be needed
• Participants may receive reimbursement for treatment-related costs, such as travel
• The study includes follow-up visits and assessments, such as surveys or scans at set intervals (e.g., 6-month follow-up surveys, annual scans). Additional time commitment may be required beyond standard care, depending on the study arm and protocol.

People may be eligible to join the FourLight‑3 study if they are 18 or older and have been diagnosed with hormone receptor–positive (HR+) and HER2‑negative advanced or metastatic breast cancer. This study is designed for individuals whose cancer has spread beyond the breast or returned after earlier treatment, and who have not yet received systemic treatment for their advanced or metastatic disease.

Some people may not be able to join the FourLight‑3 study if certain health or treatment factors could affect their safety or the study results. Individuals may be excluded if they have received previous systemic treatment for advanced or metastatic breast cancer, or if they have other serious medical conditions that could interfere with participation, such as uncontrolled infections, significant heart or liver problems, or other active cancers. People may also be ineligible if they are unable to attend required study visits, complete medical tests, or safely undergo the procedures involved in the trial. Final eligibility decisions are made by the study team after reviewing each person’s medical history and overall health.