A Study to Learn About Study Medicine ALTA3263 in Adults With Advanced Solid Tumors With KRAS Mutations

This Phase I study tests ALTA3263, a new oral drug designed to block KRAS — one of the most common cancer-driving mutations — in patients with various advanced solid tumors that have not responded to standard treatments. **You may be eligible if...** - You have been diagnosed with a solid tumor (any type) that has a KRAS mutation, confirmed by approved genetic testing - Your cancer is unresectable (cannot be removed surgically) or has spread to other parts of the body - You have progressed on, cannot tolerate, or have declined standard treatment options - You have a good performance status (ECOG 0 or 1) - You have adequate organ function **You may NOT be eligible if...** - You have received a prior KRAS inhibitor (with some exceptions) - You have a condition that prevents you from swallowing or absorbing oral medication - You have uncontrolled brain metastases Talk to your doctor to see if this trial is right for you.