A Short-term Preoperative, Evaluating Activity and Safety of Elacestrant Monotherapy as Compared to Elacestrant + Ovarian Function Suppression (LHRH Agonist) in Premenopausal Patients With Stage I-II ER+/HER2- Breast Cancer

A prospective randomized trial designed to evaluate the mean decrease in Ki67 after 4 weeks of elacestrant monotherapy and in combination with leuprorelin in patients with early-stage HR+ BC. This preoperative study will enroll consecutive patients with early stage HR+ BC who are not candidates for neoadjuvant chemotherapy but are eligible for short-term preoperative treatment with elacestrant, with or without leuprorelin, followed by breast surgery. A total of three dedicated Formalin-fixed paraffin embedded (FFPE) samples (mandatory for all patients), along with two frozen biopsy (only for participants at Gustave Roussy), are planned to be collected at the time of inclusion from the biopsy sample and from the surgical specimen. Blood samples will also be collected throughout the study.

NCT Number	NCT07159451
Lead Sponsor	Gustave Roussy, Cancer Campus, Grand Paris Collaborators: Menarini Group
Conditions	Breast Cancer
Enrollment	140 participants
Start Date	2025-10-06
Primary Completion	2027-01-29 (estimated)
Study Completion	2027-05-29 (estimated)
Updated on ClinicalTrials.gov	2025-12-01