Sugemalimab as Consolidation Therapy in Patients With LS-SCLC Following cCRT or sCRT

This study is testing whether a drug called sugemalimab (an immunotherapy) helps prevent small cell lung cancer from coming back after patients complete chemotherapy combined with radiation. It is designed for people with limited-stage small cell lung cancer — meaning the cancer has not spread widely beyond the chest. **You may be eligible if...** - You are 18 or older with small cell lung cancer confirmed by biopsy - Your cancer is limited-stage (confined to a region that can be treated with radiation) - You have completed 4 cycles of chemotherapy (with etoposide and carboplatin or cisplatin) given together with or sequentially with radiation - Your cancer did not grow during that treatment - You are generally active and able to care for yourself (good performance status) **You may NOT be eligible if...** - Your cancer has spread widely (extensive-stage) - You have a mixed type of lung cancer or pleural/pericardial fluid from the cancer - You have had prior immunotherapy or any prior treatment for this cancer - You have an active uncontrolled infection, heart failure, or serious organ disease - You have a history of severe lung inflammation (interstitial lung disease) - You have had another cancer in the past 5 years (with minor exceptions) - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.