**HRS-4642 Study with Immunotherapy and Chemotherapy for Pancreatic Cancer** This study is investigating a new drug, HRS-4642, combined with **immunotherapy** (treatment that helps your immune system fight cancer) and **chemotherapy** (a type of cancer treatment using drugs). It aims to see how safe and effective this combination is for people with certain types of pancreatic cancer. People eligible to join must be 18 or older and have a specific type of pancreatic cancer that is measurable. They also need to be in good health, with a performance status score of 0 or 1 (showing how well they can do everyday activities) and a life expectancy of at least 6 months. Participants must not have received certain treatments before or have other serious health conditions. **Key Points:** - **Study Length**: Participation may involve regular check-ups and treatments over a few months. - **Eligibility**: You must have certain types of pancreatic cancer, be generally healthy, and agree to use birth control. - **Exclusions**: You cannot join if you've had previous treatments for cancer or have other serious health issues.