A Trial of SHR-1316 Maintenance Therapy for Limited Stage Small Cell Lung Cancer

Inclusion Criteria: 1. The age is 18-75 years old (including both ends), regardless of gender; 2. Histologically confirmed limited stage small cell lung cancer ; 3. ECOG PS 0 \~ 1; 4. Patients received at least 2 cycles of platinum based chemotherapy and radiotherapy, and completed within 1 to 42 days before the first medication. 5. The last chemotherapy must be finished before or at the same time of radiotherapy. 6. The disease did not progress after concurrent chemoradiotherapy; 7. The expected survival time was more than 3 months; 8. Pulmonary function: FEV1 \> 70%; Exclusion Criteria: 1. The subjects volunteered to participate in the study, signed the informed consent form, had good compliance and cooperated with the follow-up. 2. Mixed SCLC or NSCLC confirmed by histology; 3. Locally advanced small cell lung cancer receiving sequential chemoradiotherapy; 4. Have received anti-tumor therapy of systemic immune checkpoint inhibitors for SCLC; 5. Extensive SCLC; 6. Operable SCLC (clinical stage T1-2N0, except for those who are contraindicated or refuse surgery); 7. Interstitial pneumonia 8. History of active, known or suspected autoimmune diseases and autoimmune diseases, including but not limited to myasthenia gravis, autoimmune hepatitis, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, etc. 9. HIV, active Hepatitis B or Hepatitis C infection