This clinical trial is for adults who have been diagnosed with advanced or metastatic colorectal cancer (CRC) OR advanced or metastatic pancreatic cancer (PDAC).

The purpose of this study is to evaluate how well a new investigational drug called GSK5764227 works to treat advanced or metastatic colorectal cancer (CRC) or advanced or metastatic pancreatic cancer (PDAC), whether GSK5764227 is safe and well-tolerated, and how the body handles GSK5764227.
  
“Investigational” means that GSK5764227 has not yet been approved by the United States Food and Drug Administration (FDA). GSK5764227 is only given to people who participate in clinical studies. 
   
This study is a part of a bigger study for gastrointestinal cancers, which will include participants in separate groups (also called cohorts) depending on the type of gastrointestinal cancer they have.
   
In Part 1 Cohort A (advanced or metastatic colorectal cancer), participants will receive the study drug, GSK5764227, alone by infusion into a vein (blood vessel) either every 3 weeks (21 days) or every 2 weeks (14 days). In Part 1 Cohort A, study treatment will continue as long as the study doctor feels it is safe for participants to continue or until their disease gets worse. The study will take approximately 3 years to complete for these participants.
   
In Part 1 Cohort B (advanced or metastatic pancreatic cancer), participants will receive the study drug, GSK5764227, alone by infusion into a vein (blood vessel) every 3 weeks (21 days). In Part 1 Cohort B, study treatment will continue as long as the study doctor feels it is safe for participants to continue or until their disease gets worse. The study will take approximately 4 years to complete for these participants.