NCT07361562 · Cogent Biosciences, Inc.
A Study of a Selective ERBB2 Inhibitor (CGT4255), in Patients With Advanced Solid Tumors
What this study is about
This is an where both patients and doctors know the treatment given, phase 1/1b study evaluating the safety, tolerability, how the drug moves through the body (what the body does to the drug), how the drug affects the body (what the drug does to the body), and antitumor activity of CGT4255 in adult participants with advanced solid tumors with ERBB2 alterations or HER2 overexpression.
View original scientific description
This is an open-label, phase 1/1b study evaluating the safety, tolerability, pharmacokinetic (what the body does to the drug), pharmacodynamic (what the drug does to the body), and antitumor activity of CGT4255 in adult participants with advanced solid tumors with ERBB2 alterations or HER2 overexpression.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Have histologically confirmed diagnosis of:
- Part A: Locally advanced, metastatic, and/or unresectable solid tumor with documented ERBB2-activating alteration or NRG1 gene fusion in blood and/or tumor or HER2 overexpression in tumor
- Part B: Locally advanced, metastatic, and/or unresectable NSCLC with documented ERBB2 mutation in blood and/or tumor
- Part C: Locally advanced, metastatic and/or unresectable breast cancer with documented ERBB2 mutation in blood and/or tumor or HER overexpression in tumor
- Have measurable disease per RECIST v1.1.
- Eastern Cooperative Oncology Group (ECOG) Performance Status 0 to 1 for Part A. For Parts B and C, ECOG Performance Status must be 0 to 2.
- Have clinically acceptable local laboratory screening results (clinical chemistry and hematology) within certain limits.
Exclusion criteria
- Received small molecule chemotherapy or anticancer therapies or radiotherapy within certain timeframes before first dose of study drug.
- Major surgeries (eg, craniotomy and thoracotomy) within 4 weeks of the first dose of study drug.
- Treatment with palliative focal radiotherapy (cranial or extracranial) (eg, stereotactic radiosurgery or intensity-modulated radiation therapy) ≤2 weeks before the first dose of study drug; treatment with whole-brain radiotherapy ≤4 weeks before the first dose of study drug.
- Clinically significant cardiac disease.
- Resolution of toxicities from prior therapy to ≤Grade 1 (or baseline), including resolution of clinically significant laboratory abnormalities, before the first dose of study drug.
- Restrictions on use of corticosteroid use to manage neurologic symptoms in different parts of the study.
Where
- Grand Rapids, Michigan
- New York, New York
- Nashville, Tennessee
- Austin, Texas
- West Valley City, Utah
- Fairfax, Virginia
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Feb 27, 2026 · Source of record for eligibility and locations