Palbociclib for HR Positive / HER2-negative Isolated Locoregional Recurrence of Breast Cancer

POLAR is a phase III clinical trial, which will test the safety and efficacy of an investigational combination of drugs to learn whether the combination of drugs works for a specific cancer. Palbociclib (Ibrance®) is the name of the investigational agent, which is assessed together with standard anti-hormone therapy in this study. Palbociclib is used to treat patients with hormone receptor-positive / HER2-negative breast cancer which has spread beyond the original tumor and/or to other organs. During this study, anti-hormone therapy will consist of either a selective estrogen receptor modulator (such as tamoxifen) or an aromatase inhibitor (anastrozole, letrozole, exemestane) or fulvestrant (Faslodex®). Premenopausal women and men may also receive a drug called an LHRH (luteinizing hormone-releasing hormone) agonist by injection. It is standard of care for people with hormone receptor positive breast cancer to take anti-hormone therapy. The study doctor will determine the type of standard anti-hormone therapy that will be given during this trial. The purpose of the POLAR study is to compare the effect of using 3 years of palbociclib in combination with standard anti-hormone therapy with standard anti-hormone therapy alone and to evaluate the time until the breast cancer returns, if it does return.

NCT Number	NCT03820830
Lead Sponsor	ETOP IBCSG Partners Foundation Collaborators: Pfizer
Conditions	Breast Cancer Recurrent
Enrollment	405 participants
Start Date	2019-08-27
Primary Completion	2026-07-27 (estimated)
Study Completion	2029-01-01 (estimated)
Updated on ClinicalTrials.gov	2026-04-09