The purpose of this study is to investigate the effects of an investigational medication, sacituzumab tirumotecan, on gastrointestinal cancers. These cancers include advanced or unresectable types, where the cancer has spread or cannot be surgically removed.

This study evaluates the safety and tolerability of sacituzumab tirumotecan, both alone and in combination with other treatments. Researchers will also observe how the cancer responds to the treatment, such as whether it becomes smaller or disappears.

• Who can participate: Adults with advanced or unresectable gastrointestinal cancers, including colorectal, pancreatic, and biliary tract cancers, may participate. Participants must have received prior therapy and recovered from side effects.
• Study details: Participants will receive either the investigational medication alone or with other treatments. The study will monitor safety and how well participants tolerate the treatments. A placebo may be used for comparison.