RecruitingEarly Phase 1Drug trialA Study to Evaluate the Human Biodistribution and Dosimetry of the Radionuclide Labeled IR199 in Patients With Gastric Cancer and Pancreatic CancerThis study is to evaluate the safety, biodistribution, radiation dosimetry and tumor uptake of the \[68Ga\]/ \[131I\]-IR199 in patients with Claudin 18.2 positive gastric cancer and pancreatic cancer.