Additional Study Information: The purpose of this study is to learn how well RP-1664 alone works to treat advanced solid tumor. RP-1664 has not been approved by the Food and Drug Administration (FDA). RP-1664 has not been given to humans prior to this study. Cancers include: bladder cancer, breast cancer, colon and rectal cancer, esophageal cancer, gynecologic cancers, head and neck/oral cancer, kidney cancer, liver cancer, lung cancer, skin cancer, pancreatic cancer, prostate cancer, stomach cancer, testicular cancer, and thyroid cancer.