Tislelizumab Combined With Chemotherapy and Relayed Radiotherapy in First-line Treatment of ES-SCLC

This trial tests whether adding tislelizumab — an immune checkpoint inhibitor that helps the immune system fight cancer — to standard chemotherapy, followed by radiation to the chest, can improve survival in people with extensive-stage small cell lung cancer (ES-SCLC), a fast-growing and aggressive cancer. **You may be eligible if...** - You are 18 or older with a confirmed diagnosis of extensive-stage small cell lung cancer - You have not received any prior treatment for this cancer - You have at least one measurable chest tumor that can be safely treated with radiation - You have a good performance status (ECOG 0 or 1) - Your blood counts and organ function are within acceptable ranges **You may NOT be eligible if...** - You have uncontrolled brain metastases - You have previously received immunotherapy (checkpoint inhibitors like anti-PD-1 or anti-CTLA-4) - You received a live vaccine within 4 weeks before treatment - You have an active autoimmune disease Talk to your doctor to see if this trial is right for you.