A Study of Imlunestrant (LY3484356) in Premenopausal Women With Estrogen Receptor-Positive (ER+) Human Epidermal Growth Factor Receptor 2 Negative (HER2-) Early Breast Cancer

Summary

This study will include two groups of patients: Cohort 1 and Cohort 2. Cohort 1: will help researchers learn how a medicine called imlunestrant (LY3484356) affects a specific type of breast cancer. Some patients will take both imlunestrant and another treatment to suppress their ovarian function. Some will take it without ovarian suppression. Researchers will compare the effects in breast cancer cells to those of another medicine called tamoxifen. All patients in this group will be premenopausal women who have a type of early breast cancer called estrogen receptor-positive, HER2-negative.

Shortened from the sponsor's brief summary. View official record on ClinicalTrials.gov

Conditions studied

• Breast Neoplasms

Eligibility basics and study details

Study type

Interventional

Phase

Phase 2

Ages

18 years and older

Sex

Female

Healthy volunteers

Not accepted

Sponsor

Eli Lilly and Company

Last updated on ClinicalTrials.gov

October 8, 2026

These are the basic criteria only. The full inclusion and exclusion criteria are on the official record, and the study team decides who can take part.

US recruiting sites