Description:

Part A: The purpose of this part is to assess the safety of GEH200520 and GEH200521 (18F) when administered to patients with solid cancer. Subjects will be requested to complete 3 study visits: 1 screening visit, 1 imaging visit (over 24 hours) and 1 follow-up visit (7 days later). The estimated duration of Part A is 21 days. Part B: The purpose of this part of the study is to assess the imaging quality and findings as well as the safety and tolerability of GEH200520 and GEH200521 (18F) when administered to patients with cancer before and after immunotherapy treatment. Subjects will be requested to complete 7 study visits: 1 screening visit, the first imaging visit, followed by 2 immunotherapy immune-checkpoint inhibitor (ICI) treatment visits and 2 additional imaging and 1 follow-up visit . The estimated duration of Part B is approximately 64 days.