NCT07222800 · Pfizer
Symbiotic-GI-03: A Study to Learn About the Study Medicine Called PF-08634404 in Combination With Chemotherapy in Adult Participants With Metastatic Colorectal Cancer
What this study is about
The purpose of this study is to learn more about a new medicine called PF-08634404, and how well it works in people with cancer of the colon or rectum (CRC)). The goal is to understand if the new study medicine, combined with chemotherapy that is approved for colorectal cancer, can help people whose cancer has spread or returned after treatments taken before.
View original scientific description
The purpose of this study is to learn more about a new medicine called PF-08634404, and how well it works in people with cancer of the colon or rectum (CRC)). The goal is to understand if the new study medicine, combined with chemotherapy that is approved for colorectal cancer, can help people whose cancer has spread or returned after treatments taken before. To join the study, participants must meet the following conditions: * Be 18 years or older. * Have colorectal cancer that has spread to other parts of your body. * Be in good enough health to receive study treatment. * Should not be pregnant before starting treatment. Participants will be randomized (like flipping a coin) to one of 2 different treatment arms. The first arm (Arm A) will include the new medicine PF-08634404 in combination with chemotherapy that is approved for colorectal cancer, and the second arm (Arm B) will include an approved medicine for colorectal cancer, called Bevacizumab, in combination with chemotherapy that is approved for this type of cancer. Participants and their doctors will not know which arm they are being assigned to. Participants will receive all the study medications through intravenous (IV) infusions, which means the medicine is given directly into a vein. The treatment will be given in cycles, and participants may continue receiving it if it is helping and they are not experiencing serious side effects. The medicine will be given at a clinical site, where trained medical staff will check participants during and after each treatment. * The study is expected to last approximately 33 months for each participant. * Participants will have regular visits to the study site for treatment, health checks, and tests. * After stopping treatment, participants will return for a final visit about 30 to37 days later to check their health and review any side effects. * Follow-up will continue every 12 weeks by phone or in person or by reviewing health records to check on health status and any new treatments.
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
- Histological or cytological confirmed colorectal adenocarcinoma.
- Evidence of Stage IV metastatic disease.
- No prior systemic therapy for metastatic disease.
- Eastern Cooperative Oncology Group performance status (ECOG) 0-1
- At least one measurable lesion according to RECIST 1.1 per Investigator assessment.
- Adequate hepatic, liver, and renal function
Exclusion criteria
- Participants are excluded from the study if any of the following criteria apply:
- Locally confirmed BRAF V600E mutation
- Locally confirmed microsatellite instability (MSI)-high or DNA mismatch repair deficiency (dMMR) colorectal cancer
- Participants with known active symptomatic CNS lesions, including leptomeningeal metastasis, brainstem, meningeal, or spinal cord metastases or compression
- Clinically significant risk of hemorrhage or fistula
- Major surgery or severe trauma within 4 weeks prior to the first dose, or planned major surgery during the study
- History of allogeneic organ transplantation and allogeneic hematopoietic stem cell transplantation
- Any Grade ≥3 bleeding/hemorrhage events within 28 days of Cycle 1 Day 1, or prior history of clinically significant bleeding events
- Clinically significant cardiovascular disease, or other comorbidities, within 6 months prior to first dose
- Participants with active autoimmune diseases requiring systemic treatment within the past 2 years
- Evidence of non-infectious or drug-induced interstitial lung disease (ILD) pneumonitis
Where
- Chandler, Arizona
- Gilbert, Arizona
- Glendale, Arizona
- Goodyear, Arizona
- Mesa, Arizona
- Phoenix, Arizona
- Scottsdale, Arizona
- Fayetteville, Arkansas
- Rogers, Arkansas
- Springdale, Arkansas
- Berkeley, California
- San Francisco, California
And 129 more locations — see the full list below.
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 Jul 6, 2026 · Source of record for eligibility and locations