A Study of GSK5764227 in Combination With Standard of Care (SoC) or Other Agents in Participants With Advanced Solid Tumors

Inclusion Criteria:

* Has an ECOG performance status of 0 or 1, with no deterioration in the 2 weeks before first dose.
* Has adequate organ function.
* Has histologically confirmed unresectable adenocarcinoma or unresectable metastatic adenocarcinoma of the colon or rectum. (Cohort A)
* Histologically or cytologically confirmed adenocarcinoma of the prostate (Cohort B)

Exclusion Criteria:

* Has a malignancy (except disease under study) that has progressed or required active treatment within the past 24 months except for basal cell or squamous cell carcinomas of the skin or in-situ carcinomas \[e.g., breast, cervix, bladder\] that have been resected with no evidence of disease.
* Has had any major surgery within 28 days prior to first dose.
* Has clinically significant bleeding symptoms or significant bleeding tendency within 1 month prior to the first dose.
* Has serious infection within 4 weeks prior to the first dose,
* Has untreated brain or central nervous system (CNS) metastases or brain/CNS metastases that have progressed
* Any evidence of current interstitial lung disease (ILD) or pneumonitis OR a prior history of ILD requiring high-dose glucocorticoids or non-infectious pneumonitis requiring high-dose glucocorticoids.
* Has a history of autoimmune disease that has required systemic treatments in the 2 years prior to screening.
* Has received immunosuppressive agents within 30 days prior to first dose of study intervention (or requires long-term \[30 days or longer\]). Low-dose corticosteroids (prednisone ≤10 milligrams (mg)/day or equivalent) may be administered.