JAB-30355 in Patients With Advanced Solid Tumors Harboring TP53 Y220C Mutation

This study is testing a new drug called JAB-30355 in people with advanced solid tumors that carry a specific genetic mutation called TP53 Y220C — a mutation that disrupts the body's normal tumor-suppressing mechanism. This drug is designed to restore the function of the mutated p53 protein. **You may be eligible if...** - You are 18 or older - You have confirmed advanced solid tumor cancer with a TP53 Y220C mutation - You have already received at least one previous line of treatment - You are in generally good health (ECOG 0–1) - You have at least one measurable tumor - You can swallow and absorb oral medication **You may NOT be eligible if...** - You have active brain or spinal cord metastases - You have an active serious infection requiring treatment - You have active hepatitis B or C - You have a reduced heart pumping function (LVEF 50% or below) - You have a prolonged heart QT interval on ECG Talk to your doctor to see if this trial is right for you.