The study is being conducted to evaluate the efficacy and safety of SHR-1701 with or without chemotherapy in the treatment of unresectable stage III non-small cell lung cancer

Inclusion Criteria:

• Voluntarily participate in the study and sign the informed consent form;
• 18 to 70 years old, both male and female;
• ECOG score: 0-1
• histopathologically or cytologically confirmed, inoperable stage III squamous cell or non-squamous cell lung cancer;
• subjects who can provide fresh or archival tumor tissue;
• Measurable lesions available;
• Major organ function is basically normal;
• Non-surgically sterile female subjects of childbearing age must have a negative serum HCG test before randomization;

Exclusion Criteria:

• histologically or cytologically confirmed mixed SCLC and NSCLC;
• subjects who have malignant pleural effusion;
• Previous systemic anti-tumor therapy for NSCLC;
• Previous thoracic radiotherapy;
• Subjects who participated in other clinical trials within 4 weeks or 5 drug half-lives(whichever is shorter) before the first dose.
• Systemic immunostimulant therapy before the first dose;
• Systemic immunosuppressive therapy before the first dose or were expected to require systemic immunosuppressive drugs during the study treatment;
• Subjects with autoimmune diseases;
• Other malignant tumors other than non-small cell lung cancer within 5 years before screening;
• Known or suspected interstitial pneumonia;
• Other moderate to severe lung diseases that may interfere with the detection or treatment of drug-related pulmonary toxicity and seriously affect respiratory function;
• Severe cardiovascular and cerebrovascular diseases;
• Clinically significant bleeding symptoms or significant bleeding tendency within 1 month before the first dose;
• Arteriovenous thrombotic events within 3 months before the first dose;
• Positive HIV test;
• Active hepatitis B or C;
• Evidence of active tuberculosis infection within 1 year before the first dose;
• Serious infection within 4 years before the first dose;
• History of attenuated live vaccination 28 days before the first dose or expected to receive attenuated live vaccination during the study;
• Major surgeries other than diagnosis or biopsy within 28 days prior to first dose;
• Previous or planned allogeneic bone marrow transplantation or solid organ transplantation;
• History of severe allergic reactions to other monoclonal antibodies/fusion proteins;
• Allergic to any component of the randomized treatment regimen;
• Female subjects who are pregnant, lactating, or planning to get pregnant during the study period;
• Subjects who has a known history of psychotropic drug abuse, alcoholism, or drug abuse
• Presence of other conditions that, in the opinion of the investigator, would make participation in this clinical trial inappropriate.