New hope for Hard-to-Treat breast cancer: first human trial begins

NCT ID NCT05304962

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

Summary

This early-stage trial tests a new oral drug called RGT-419B, given alone or with hormone therapy, in 64 adults with a specific type of advanced breast cancer (HR+/HER2-) that has worsened after prior treatment. The main goal is to check safety and find the right dose, while also looking for early signs that the drug might slow or shrink the cancer.

What this could mean

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

Active substance

RGT-419B (oral drug) alone or with hormonal therapy

What this could lead to

If successful, this could point toward a new treatment option for people with advanced breast cancer that has stopped responding to current therapies.

What could go wrong

This is a very early Phase 1 trial with only 64 participants, so safety and effectiveness are not yet known. The drug may cause side effects or fail to shrink tumors.

Disclaimer Read more

This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.

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 hormone receptor-positive breast cancer

As listed by the trial registrant

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

Contacts and locations

Study contacts

  • Contact

    Phone: •••-•••-•••• Email: •••••@•••••

  • Contact

    Phone: •••-•••-•••• Email: •••••@•••••

Locations

  • Emory University

    RECRUITING

    Atlanta, Georgia, 30322, United States

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact

  • Hem-Onc Associates of the Treasure Coast

    ACTIVE_NOT_RECRUITING

    Port Saint Lucie, Florida, 34952, United States

  • Massachusetts General Hospital

    RECRUITING

    Boston, Massachusetts, 02142, United States

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact

  • Moffitt Cancer Center

    RECRUITING

    Tampa, Florida, 33612, United States

    Contact

    Contact Phone: •••-•••-•••• Email: •••••@•••••

  • New York Cancer and Blood Specialists

    RECRUITING

    Port Jefferson Station, New York, 11776, United States

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact

  • University California, Los Angeles

    RECRUITING

    Los Angeles, California, 90404, United States

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact

  • University of California, San Diego

    RECRUITING

    La Jolla, California, 92037, United States

    Contact

    Contact Phone: •••-•••-•••• Email: •••••@•••••

  • Washington University School of Medicine

    RECRUITING

    St Louis, Missouri, 63110, United States

    Contact

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact Phone: •••-•••-•••• Email: •••••@•••••