Evaluation of Lasofoxifene Combined With Abemaciclib Compared With Fulvestrant Combined With Abemaciclib in Locally Advanced or Metastatic ER+/HER2- Breast Cancer With an ESR1 Mutation

Summary

The goal of this clinical trial is to assess the efficacy, safety and tolerability of the combination of lasofoxifene and abemaciclib compared to fulvestrant and abemaciclib for the treatment of pre- and postmenopausal women and men who have previously received ribociclib or palbociclib-based treatment and have locally advanced or metastatic estrogen receptor positive (ER+)/human epidermal growth factor 2 negative (HER2-) breast cancer with an estrogen receptor 1 (ESR1) mutation.

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

Conditions studied

• Metastatic Breast Cancer

Eligibility basics and study details

Study type

Interventional

Phase

Phase 3

Ages

18 years and older

Sex

All

Healthy volunteers

Not accepted

Sponsor

LeonaBio

Last updated on ClinicalTrials.gov

June 22, 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