A Phase 1/2, Open-label, Multicenter, FIH Study to Evaluate Safety, Tolerability, PK and Anti-tumor Activity of YH42946

This first-in-human study is testing a new drug called YH42946, which targets cancer cells with specific mutations in the HER2 or EGFR proteins. This early-phase trial is evaluating whether the drug is safe, how the body processes it, and whether it shows any early signs of fighting cancer in patients with solid tumors that have stopped responding to available treatments. **You may be eligible if...** - You are in good general health (ECOG score 0–1) - Your life expectancy is at least 3 months - You have a solid tumor that has progressed on or after all standard treatments, or for which standard treatment is not appropriate - You can provide a tumor tissue sample for HER2 or EGFR mutation testing - If you had brain metastases, they have already been treated - Your blood counts and organ function are within the required range **You may NOT be eligible if...** - You have active, untreated brain metastases - You have uncontrolled infections or serious autoimmune conditions - Your organ function does not meet required levels Talk to your doctor to see if this trial is right for you.