A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Efficacy of AST2303 Tablets (ABK3376 Tablets) in Patients With Advanced or Metastatic Non-Small Cell Lung Cancer

This study tests a new targeted drug for people with non-small cell lung cancer (NSCLC) whose tumor has a specific genetic mutation called C797S in the EGFR gene — a mutation that commonly develops as resistance to previous EGFR-targeted therapies. This drug is designed to overcome that resistance and re-control the cancer. **You may be eligible if...** - You are 18 or older with confirmed non-small cell lung cancer - You have at least one measurable tumor that has not been locally treated - Your tumor has the C797S EGFR mutation or another specific EGFR change that makes you likely to respond to this drug - Your overall health (ECOG score 0 or 1) is good enough to tolerate the study drug - Your expected survival is at least 12 weeks **You may NOT be eligible if...** - You have previously received a drug targeting the C797S mutation - Your cancer has other known driver gene mutations that would indicate a different treatment - You received another cancer drug within the past 2 weeks or within 5 half-lives of that drug - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.