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

NCT ID NCT05304962

Recruiting now Disease control Sponsor: Regor Pharmaceuticals Inc. Source: ClinicalTrials.gov ↗

First seen Jun 27, 2026 · Last updated Aug 13, 2026 · Updated 2 times

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.

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

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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.

BREAST CANCER

Contacts and locations

Locations

Emory University
RECRUITING

Atlanta, Georgia, 30322, United States
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
Moffitt Cancer Center
RECRUITING

Tampa, Florida, 33612, United States
New York Cancer and Blood Specialists
RECRUITING

Port Jefferson Station, New York, 11776, United States
University California, Los Angeles
RECRUITING

Los Angeles, California, 90404, United States
University of California, San Diego
RECRUITING

La Jolla, California, 92037, United States
Washington University School of Medicine
RECRUITING

St Louis, Missouri, 63110, United States

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