New hope for advanced breast cancer: experimental drug combo enters human trials

NCT ID NCT07100106

Recruiting now Disease control Sponsor: Genentech, Inc. Source: ClinicalTrials.gov ↗

First seen Jun 27, 2026 · Last updated Aug 11, 2026 · Updated 4 times

Summary

This study tests a new drug called GDC-4198, alone or combined with another drug (giredestrant), against a standard treatment (abemaciclib plus giredestrant) in people with advanced ER+/HER2- breast cancer that has worsened after prior CDK4/6 inhibitor therapy. The trial has two phases: first to check safety and dosing, then to compare how well the new combination controls the cancer. About 285 participants will be enrolled.

What this could mean

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

Active substance: GDC-4198 (also known as RGT-419B) and giredestrant (also known as GDC-9545)
What this could lead to: If successful, this could offer a new treatment option for people with advanced ER+/HER2- breast cancer whose disease has worsened after standard CDK4/6 inhibitor therapy.
What could go wrong: This is an early-phase (Ib/II) trial with only 285 participants, so results may not confirm benefit or safety. The new drug combination might not work better than existing treatments and could have unexpected side effects.

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

Get updates

Get notified about this study

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 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

ASST degli Spedali Civili di Brescia - Spedali Civili di Brescia
RECRUITING

Brescia, Lombardy, 25123, Italy
Asan Medical Center.
RECRUITING

Seoul, 05505, South Korea
Barbara Ann Karmanos Cancer Institute
RECRUITING

Detroit, Maine, 48201-2013, United States
Cancer Research SA
RECRUITING

Adelaide, South Australia, 5000, Australia
Centre Eugene Marquis
RECRUITING

Rennes, 35042, France
Centre Francois Baclesse
RECRUITING

Caen, 14076, France
Centre Oscar Lambret
RECRUITING

Lille, 59020, France
City of Hope
RECRUITING

Duarte, California, 91010, United States
City of Hope - Orange County Lennar Foundation Cancer Center
RECRUITING

Irvine, California, 92618, United States
City of Hope® Cancer Center Chicago
RECRUITING

Zion, Illinois, 60099, United States
Fudan University Shanghai Cancer Center - Pudong Campus
RECRUITING

Shanghai, Shanghai Municipality, 201321, China
Gangnam Severance Hospital, Yonsei University Health System
RECRUITING

Seoul, Seoul Teugbyeolsi, 6273, South Korea
Gustave Roussy
RECRUITING

Villejuif, Val-de-Marne, 94805, France
Hospital Beata Maria Ana
RECRUITING

Madrid, 28007, Spain
Hospital Clinico Universitario de Valencia
RECRUITING

Valencia, 46010, Spain
Hospital General Universitario Gregorio Maranon
RECRUITING

Madrid, 28007, Spain
Hospital Universitario 12 de Octubre
RECRUITING

Madrid, 28041, Spain
Hospital de Clinicas de Porto Alegre (HCPA) - PPDS
RECRUITING

Porto Alegre, Rio Grande do Sul, 90560-030, Brazil
Hospital do Cancer de Pernambuco - HCP
RECRUITING

Recife, Pernambuco, 50040-000, Brazil
IRCCS Azienda Ospedaliero Universitaria di Bologna
RECRUITING

Bologna, Emilia-Romagna, 40138, Italy
Institut Jean Godinot
RECRUITING

Reims, Champagne-Ardenne, 51100, France
Instituto Do Câncer Do Estado de São Paulo Octávio Frias de Oliveira - ICESP
RECRUITING

São Paulo, 01246-000, Brazil
Instituto de Investigacion Oncologica Vall dHebron (VHIO) - EPON
RECRUITING

Barcelona, 08035, Spain
Irmandade Da Santa Casa de Misericordia de Porto Alegre
RECRUITING

Porto Alegre, Rio Grande do Sul, 90035-074, Brazil
Istituto Romagnolo per lo Studio dei Tumori Dino Amadori - IRST S.r.l - PPDS
RECRUITING

Meldola, Emilia-Romagna, 47014, Italy
KEM - Evang. Huyssens-Stiftung Essen-Huttrop
RECRUITING

Essen, North Rhine-Westphalia, 45136, Germany
Levine Cancer Institute
RECRUITING

Charlotte, North Carolina, 28204, United States
Maryland Oncology Hematology - Annapolis
RECRUITING

Annapolis, Maryland, 21401, United States
Moffitt Cancer Center
RECRUITING

Tampa, Florida, 33612, United States
Montefiore Einstein Cancer Center
RECRUITING

The Bronx, New York, 10461, United States
New York Cancer & Blood Specialists
RECRUITING

East Patchogue, New York, 11772, United States
Novant Health Cancer Institute
RECRUITING

Charlotte, North Carolina, 28204, United States
ONCOSITE Centro de Pesquisa Clínica Em Oncologia
RECRUITING

Ijuí, Rio Grande do Sul, 98700-000, Brazil
Oncology Associates of Oregon, P.C
RECRUITING

Eugene, Oregon, 97401, United States
Ospedale San Raffaele S.r.l. - PPDS
RECRUITING

Milan, Lombardy, 20132, Italy
Penn State Health Milton S. Hershey Medical Center
RECRUITING

Hershey, Pennsylvania, 17033-2360, United States
Princess Margaret Hospital
RECRUITING

Toronto, Ontario, M5G 2M9, Canada
Rutgers Cancer Institute of New Jersey
RECRUITING

New Brunswick, New Jersey, 08901-1914, United States
Samsung Medical Center
RECRUITING

Seoul, 06351, South Korea
Seoul National University Bundang Hospital
RECRUITING

Seongnam-si, 13620, South Korea
Seoul National University Hospital
RECRUITING

Seoul, 03080, South Korea
Severance Hospital, Yonsei University Health System
RECRUITING

Seoul, 3722, South Korea
Shandong Cancer Hospital
RECRUITING

Jinan, SD, 250117, China
St Vincent's Hospital Sydney
RECRUITING

Darlinghurst, New South Wales, 2010, Australia
Sylvester Comprehensive Cancer Center
RECRUITING

Miami, Florida, 33136-1002, United States
Texas Oncology (Worth) - USOR
RECRUITING

Dallas, Texas, 75246-2003, United States
The Catholic University of Korea, Seoul St. Mary's Hospital
RECRUITING

Seoul, 6591, South Korea
Tianjin Medical University Cancer Institute & Hospital
RECRUITING

Tianjin, Tianjin Municipality, 300060, China
UC San Diego Moores Cancer Center
RECRUITING

La Jolla, California, 92093-1503, United States
UCSF Helen Diller Family CCC
RECRUITING

San Francisco, California, 94158, United States
UPMC - Hillman Cancer Center
RECRUITING

Pittsburgh, Pennsylvania, 15213-3108, United States
Universitatsklinikum Hamburg-Eppendorf
RECRUITING

Hamburg, 20251, Germany
Universitatsklinikum Tubingen
RECRUITING

Tübingen, Baden-Wurttemberg, 72076, Germany
University of Arizona Cancer Center
RECRUITING

Tucson, Arizona, 85724-0001, United States
University of California San Diego Medical Center
RECRUITING

San Diego, California, 92103-1911, United States
University of Pennsylvania - Abramson Cancer Center
RECRUITING

Philadelphia, Pennsylvania, 19104, United States
University of Utah Huntsman Cancer Institute
RECRUITING

Salt Lake City, Utah, 84013, United States
Vanderbilt Breast Center at One Hundred Oaks
RECRUITING

Nashville, Tennessee, 37204-3609, United States
Virginia Oncology Associates (Norfolk) - USOR
RECRUITING

Norfolk, Virginia, 23502-2800, United States
Washington University Siteman Cancer Center
RECRUITING

St Louis, Missouri, 63110-1010, United States
Winship Cancer Institute of Emory University
RECRUITING

Atlanta, Georgia, 30322-1013, United States

More trials for these conditions

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