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A Study to Evaluate the Effect of GDC-4198 Alone and in Combination With Giredestrant Versus Abemaciclib and Giredestrant in Participants With Locally Advanced or Metastatic Estrogen Receptor-Positive (ER+), Human Epidermal Growth Factor Receptor-Negative (HER2-) Breast Cancer

Testing new breast cancer treatments in a clinical trial.

Recruiting
18 years and older
All
Phase 1/2
  • Simplified description (AI rewritten)
  • Technical description (Original)

This study looks at the safety and effectiveness of a new drug, **GDC-4198**, for people with a type of breast cancer called *estrogen receptor-positive* (ER+) and *human epidermal growth factor receptor-negative* (HER2-) breast cancer. It will test GDC-4198 alone and with another drug called **giredestrant**. The study compares these with a known treatment, **abemaciclib** and giredestrant. The study has two parts: *Phase Ib*, focusing on safety and how the drug moves in the body, and *Phase II*, comparing how well the drugs work. Participants should have advanced cancer that has worsened during or after specific treatments.

  • Study has two parts: Phase Ib (safety) and Phase II (effectiveness).
  • Participants must have advanced ER+, HER2- breast cancer.
  • Cannot join if they had recent chemotherapy or poor vein access.
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Study details
    Breast Cancer

NCT07100106

Genentech, Inc.

4 April 2026

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What is a clinical trial?

A clinical trial is a study designed to test specific interventions or treatments' effectiveness and safety, paving the way for new, innovative healthcare solutions.

Why should I take part in a clinical trial?

Participating in a clinical trial provides early access to potentially effective treatments and directly contributes to the healthcare advancements that benefit us all.

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The duration of clinical trials varies. Some trials last weeks, some years, depending on the phase and intention of the trial.

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Compensation varies per trial. Some offer payment or reimbursement for time and travel, while others may not.

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Clinical trials follow strict ethical guidelines and protocols to safeguard participants' health. They are closely monitored and safety reviewed regularly.
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