A Phase Ib/II Multicenter, Open-Label, Randomized Study Evaluating the Safety, Pharmacokinetics, and Activity of GDC-4198 Alone and in Combination With Giredestrant in Comparison With Abemaciclib and Giredestrant in Participants With Locally Advanced or Metastatic Estrogen Receptor-Positive, HER2-Negative Breast Cancer Who Have Previously Progressed During or After a CDK4/6 Inhibitor

Genentech, Inc.

Summary

The purpose of this study is to assess the safety of GDC-4198 alone and in combination with giredestrant and also the efficacy of GDC-4198 + giredestrant versus abemaciclib + giredestrant in participants with locally advanced or metastatic ER+, HER2- breast cancer. The study consists of 2 phases: Phase Ib and Phase II. Phase Ib will evaluate the safety and pharmacokinetics (PK) of GDC-4198 alone and in combination with giredestrant. Phase II stage will compare the activity and safety of GDC-4198 and giredestrant with abemaciclib and giredestrant.

Eligibility

Age range: 18+ years
Sex: All
Healthy volunteers

Detailed criteria

Inclusion Criteria: * Histologically and/or cytologically confirmed adenocarcinoma of the breast that is locally advanced or metastatic. * Previously documented ER+ and HER2- tumor according to American Society of Clinical Oncology (ASCO)/ College of American Pathologists (CAP) or European Society of Medical Oncology (ESMO) guidelines or any national guidelines with criteria conforming to ASCO/CAP or ESMO guidelines. * Disease progression during or after treatment with an approved cyclin-dependent kinase 4/6 (CDK4/6) inhibitor and approved endocrine therapy (ET) in the locally advanced or met…

Interventions

Drug
GDC-4198
GDC-4198 will be administered orally.
Drug
Giredestrant
Giredestrant will be administered orally.
Drug
Abemaciclib
Abemaciclib will be administered orally.

Locations (64)

University of Arizona Cancer Center
Tucson, Arizona
City of Hope
Duarte, California
City of Hope - Orange County Lennar Foundation Cancer Center
Irvine, California
UC San Diego Moores Cancer Center
La Jolla, California
University of California San Diego Medical Center
San Diego, California
UCSF Helen Diller Family CCC
San Francisco, California