New hope for Hard-to-Treat breast cancer: experimental drug ARV-471 shows promise

NCT ID NCT04072952

Completed Disease control Sponsor: Arvinas Estrogen Receptor, Inc. Source: ClinicalTrials.gov ↗

First seen Jun 27, 2026 · Last updated Jun 27, 2026

Summary

This trial tests an experimental drug called ARV-471, alone or with another drug (palbociclib), in 217 people with advanced ER+/HER2- breast cancer that has stopped responding to standard treatments. The goal is to see if it is safe and can shrink tumors or slow the disease. The study is completed, but results are not yet widely available.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance: ARV-471 (a drug that breaks down estrogen receptors) and palbociclib (a targeted cancer drug)
What this could lead to: If it works, this could offer a new treatment option for people with advanced ER+/HER2- breast cancer who have run out of standard therapies.
What could go wrong: This is an early-phase trial (Phase 1/2) with a small number of participants, so safety and effectiveness are not yet proven. Side effects or lack of benefit could limit its use.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Get updates

Get notified about this study

Sign up to get updates when this study changes or when new studies for BREAST CANCER are added.

Our safety recommendation!

By submitting, you agree to our Terms of use

Conditions

The condition(s) this trial relates to.

breast cancer breast neoplasm estrogen-receptor positive breast cancer

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

BREAST CANCER

Contacts and locations

Locations

Clinical Trial Site

Palo Alto, California, 94304, United States
Clinical Trial Site

San Francisco, California, 94158, United States
Clinical Trial Site

Santa Monica, California, 90404, United States
Clinical Trial Site

Norwalk, Connecticut, 06856, United States
Clinical Trial Site

Fort Myers, Florida, 33901, United States
Clinical Trial Site

Tampa, Florida, 33612, United States
Clinical Trial Site

Chicago, Illinois, 60637, United States
Clinical Trial Site

Boston, Massachusetts, 02114, United States
Clinical Trial Site

Boston, Massachusetts, 02215, United States
Clinical Trial Site

Ann Arbor, Michigan, 48109, United States
Clinical Trial Site

St Louis, Missouri, 63110, United States
Clinical Trial Site

East Brunswick, New Jersey, 08816, United States
Clinical Trial Site

The Bronx, New York, 10461, United States
Clinical Trial Site

Charlotte, North Carolina, 28204, United States
Clinical Trial Site

Nashville, Tennessee, 37203, United States
Clinical Trial Site

Seattle, Washington, 98109, United States

More trials for these conditions

Other studies related to the condition(s) this trial covers.