GDC-0587 + Giredestrant for Breast Cancer
What You Need to Know Before You Apply
What is the purpose of this trial?
This trial tests a new treatment for individuals with estrogen receptor-positive (ER+) and human epidermal growth factor receptor 2-negative (HER2-) breast cancer, specifically for those whose cancer has worsened after CDK 4/6 inhibitors. The study examines a drug called GDC-0587, both alone and with another drug, giredestrant, to assess their safety and effectiveness. Participants may qualify if they have advanced breast cancer that progressed after CDK 4/6 inhibitor therapy. As a Phase 1 trial, this research aims to understand how the treatment works in people, offering participants the chance to be among the first to receive this new therapy.
Is there any evidence suggesting that this trial's treatments are likely to be safe?
Research shows that GDC-0587, a new treatment being tested for breast cancer, is in its first human trials. No previous safety results from humans exist yet. The main goal of this early trial is to assess its safety for people, so researchers are still collecting safety information.
In contrast, giredestrant, used with GDC-0587 in some parts of the trial, has safety data from other studies. Giredestrant has helped certain breast cancer patients and is generally well-tolerated. While it has successfully reduced the return of the disease, specific safety details when used with GDC-0587 are still under investigation.
Since this trial is in an early phase, it primarily focuses on understanding safety and patient response to the treatment. Participants should expect close monitoring by the medical team as they gather more safety information.12345Why are researchers excited about this trial's treatments?
Researchers are excited about GDC-0587 and Giredestrant for breast cancer because these drugs offer a fresh approach compared to standard treatments like hormonal therapies or chemotherapy. Giredestrant is a selective estrogen receptor degrader (SERD) that directly targets and breaks down estrogen receptors on cancer cells, which is different from traditional hormone therapies that merely block estrogen. Meanwhile, GDC-0587 is being explored for its potential to enhance the effects of Giredestrant and may offer improved efficacy. Together, these treatments could offer a more targeted attack on cancer cells with the potential for fewer side effects and improved outcomes.
What evidence suggests that this trial's treatments could be effective for breast cancer?
Research shows that GDC-0587, a new drug known as a CDK4 inhibitor, targets proteins that aid cell division. This may help stop cancer cells from growing, particularly in breast cancer unresponsive to other treatments. However, specific data on its effectiveness in people is not yet available. In this trial, some participants will receive GDC-0587 as a monotherapy.
Conversely, giredestrant has shown promising results. Studies have found that it can significantly extend the time people with ER+/HER2- advanced breast cancer live without disease progression. It has also reduced the risk of disease progression or death by 44% in some patients. Current trials are testing whether using these two drugs together, as in the GDC-0587 + Giredestrant cohort, is more effective in treating breast cancer.12356Who Is on the Research Team?
Clinical Trials
Principal Investigator
Genentech, Inc.
Are You a Good Fit for This Trial?
This trial is for individuals with advanced or metastatic ER+/HER2- breast cancer who have progressed after CDK 4/6 inhibitor therapy. Participants must have a life expectancy of at least 6 months, adequate kidney function, and agree to contraception requirements. Pre-menopausal women and men must be on LHRH agonist therapy.Inclusion Criteria
Timeline for a Trial Participant
Screening
Participants are screened for eligibility to participate in the trial
Dose-Escalation
Participants receive GDC-0587 as a monotherapy to evaluate safety and pharmacokinetics
Combination Treatment
Participants receive GDC-0587 in combination with Giredestrant to evaluate safety and pharmacokinetics
Follow-up
Participants are monitored for safety and effectiveness after treatment
What Are the Treatments Tested in This Trial?
Interventions
- GDC-0587
- Giredestrant
Trial Overview
The study tests GDC-0587 alone and combined with giredestrant in patients whose breast cancer has worsened despite previous treatments. It's an early-phase trial to assess safety, how the body processes the drugs (pharmacokinetics), and their effectiveness against this type of cancer.
How Is the Trial Designed?
3
Treatment groups
Experimental Treatment
Participants will receive GDC-0587 and Giredestrant orally and also receive omeprazole for evaluating the effects of a proton pump inhibitor (PPI) and food on GDC-0587.
Participants will receive GDC-0587 and Giredestrant orally.
Participants will receive GDC-0587 orally.
Find a Clinic Near You
Who Is Running the Clinical Trial?
Genentech, Inc.
Lead Sponsor
Ashley Magargee
Genentech, Inc.
Chief Executive Officer since 2024
MBA from Harvard University, BA from Princeton University
Levi Garraway
Genentech, Inc.
Chief Medical Officer since 2021
MD, PhD
Citations
NCT07214662 | A Study to Evaluate the Safety, ...
This is a first-in-human, Phase Ia/Ib, dose-escalation and expansion study evaluating the safety, pharmacokinetics, and activity of GDC-0587 (cyclin-dependent ...
RGT-587 - Drug Targets, Indications, Patents
100 Clinical Results associated with RGT-587. Login to view more data. 100 Translational Medicine associated with RGT-587. Login to view more data.
GDC-0587 - Drug - TrialFetch
Efficacy · No clinical response data (e.g., ORR, CBR, PFS) have been publicly reported for GDC-0587 as of January 14, 2026. · The ongoing first-in-human study ...
4.
forpatients.roche.com
forpatients.roche.com/en/trials/cancer/bc/a-study-to-evaluate-the-safety--pharmacokinetics--and-a-70920.htmlClinical trial for Breast Cancer-ForPatients by Roche
This is a first-in-human, Phase Ia/Ib, dose-escalation and expansion study evaluating the safety, pharmacokinetics, and activity of GDC-0587 (cyclin-dependent ...
giredestrant (RG6171) News
Similarities and differences in practice patterns were observed between GMOs and breast cancer research leaders (data available separately) for a number of ...
6.
trialfetch.com
trialfetch.com/trial_match/view_trial/NCT07214662/?back=/trial_match/drug/3997/%3Fback%3D/trial_match/drugs/%253Fpage%253D5Trial: A Study to Evaluate the Safety, Pharmac… - TrialFetch
This is the first-in-human clinical study of GDC-0587; as of the latest public updates, no human efficacy or safety results have been posted.
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