Toripalimab and JS004 Combined With Platinum-based Chemotherapy for Relapsed and Extensive-stage Small Cell Lung Cancer

Inclusion Criteria: 1. The patient shall sign the Informed Consent Form; 2. Aged 18 ≥ years; 3. Histological or cytological diagnosis of SCLC by needle biopsy or EBUS, and extensive stage or recurrent confirmed by imageological examinations or relapsed within more than six months after radical treatment SCLC; 4. Eastern Cooperative Oncology Group (ECOG) performance-status score of 0 or 1; 5. Life expectancy is at least 12 weeks; 6. At least 1 measurable lesion according to RECIST 1.1; 7. Patients with good function of other main organs (liver, kidney, blood system, etc.); 8. Fertile female patients must voluntarily use effective contraceptives from the start of the trial to within 30 days after its completion, and urine or serum pregnancy test results within 7 days prior to enrollment are negative; 9. Unsterilized male patients must voluntarily use effective contraception during the trial period and for 30 days after its conclusion. Exclusion Criteria: 1. Patients with a malignancy other than SCLC within five years prior to the start of this trial; 2. Participants with any unstable systemic disease (including uncontrolled hypertension, severe arrhythmia, etc.); 3. With activate or suspectable autoimmune disease, or autoimmune paracancer syndrome requiring systemic treatment; 4. Participants who are allergic to the test drug or any auxiliary materials; 5. Participants with active hepatitis B, hepatitis C or HIV; 6. Participants with Interstitial lung disease currently; 7. Pregnant or lactating women; 8. Any malabsorption; 9. Participants suffering from nervous system diseases or mental diseases that cannot cooperate; 10. Other factors that researchers think it is not suitable for enrollment.