A Study to Evaluate Safety, Efficacy, and Pharmacokinetics in Participants With Advanced Solid Tumors

This study tests a new drug combination in people with advanced solid tumors, including colorectal cancer, gastric cancer, and other tumors that no longer respond to standard treatments. It looks at safety, dosing, and early signs of effectiveness. **You may be eligible if...** - You have a confirmed advanced or metastatic solid tumor and have run out of standard treatment options - For colorectal cancer: you must have progressed on all standard therapies including fluorouracil, oxaliplatin, and irinotecan - For gastric or other cancers: specific criteria apply based on prior treatment history - You are in good general health (ECOG 0 or 1) with adequate organ function **You may NOT be eligible if...** - Your cancer is localized and potentially curable by surgery - You have serious ongoing infections or autoimmune conditions - You have had more than 5 prior treatments for metastatic disease - You have active brain metastases requiring treatment - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.