The purpose of this research study is to test the safety of PRT3789 at different dose levels to find out what effects, good and/or bad, PRT3789 has on you and your type of cancer. The information collected from you and from other participants in this study will be used to decide the most appropriate dose of PRT3789 that should be used for studies that may be conducted in the future. The study drug, PRT3789, is a SMARCA2 degrader meaning that it helps break down the protein called SMARCA2. This protein is part of a cell life cycle that allows tumor cells to grow and spread. When SMARCA2 breaks down, it causes tumor cells to stop progressing through their life cycle and die. Studies done in animals have shown that PRT3789 can help break down this protein and induce cancer cell death, but PRT3789 has not yet been tested in humans. This is a Phase 1 study, which means this is a first study of the safety and efficacy (whether a drug works) in humans using the study drug, PRT3789. This study will be the first time PRT3789 is used in humans.