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.

This phase I trial studies the side effects and best dose of CA-4948 when given together with fluorouracil, leucovorin, oxaliplatin (FOLFOX) plus bevacizumab in treating patients with colorectal cancer that has spread from where it first started (primary site) to other places in the body (metastatic). CA-4948 may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. The chemotherapy drugs used in FOLFOX, fluorouracil and oxaliplatin, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Leucovorin is used with fluorouracil to treat colorectal cancer. Bevacizumab is in a class of medications called anti-angiogenic agents. It works by stopping the formation of blood vessels that bring oxygen and nutrients to the tumor. This may slow the growth and spread of the tumor. Giving CA-4948 with FOLFOX plus bevacizumab may be safe, tolerable and/or effective in treating patients with metastatic colorectal cancer.