This is a phase II randomized, control, multi-center study of recombinant humanized anti-PD-1 mAb for injection compared to high-Dose interferon in patients with mucosal melanoma that has been removed by surgery.

This is a multi-centre，open, randomized, parallel-group study of mucosal melanoma adjuvant therapy to evaluate the efficacy of recombinant humanized anti-PD-1 mAb for injection compared to high-Dose interferon in patients with mucosal melanoma that has been removed by surgery.There will be 220 subjects enrolling the study, and randomized 1:1 grouped into recombinant humanized anti-PD-1 mAb for injection group (experimental group) or interferon group (control group).Each group will have 110 subjects.Random stratification factor is the disease stage (I vs II vs III).The whole research lasts about 60 months.

Inclusion Criteria:

• Male and Female aged between 18 and 75 years are eligible;
• It was confirmed by histopathology that it was a mucosal melanoma;
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1;
• Complete excision of primary focal area, surgical incision; All patients must have disease-free status documented by a complete physical examination and imaging studies prior to registration;
• No adjuvant therapy was received;
• No treatment contraindication, peripheral blood, normal liver, kidney function and electrocardiogram are normal; WBC≥4.0×10^9/L,PLT≥100×10^9/L,Hgb≥90g/L; serum urea nitrogen, cr≤ULN; ALT,AST,TBI≤1.5*ULN,
• Males or female of childbearing potential must: agree to use using a reliable form of contraception (eg, oral contraceptives, intrauterine device, control sex desire, double barrier method of condom and spermicidal) during the treatment period and for at least 12 months after the last dose of study drug;
• FT3,FT4 and TSH is normal;
• Must have read, understood, and provided written informed consent voluntarily. Willing to adhere to the study visit schedule and the prohibitions and restrictions specified in this protocol.

Exclusion Criteria:

• Prior treatment with anti-PD-1/PD-L1/PD-L2 antibody;
• Hypersensitivity to recombinant humanized anti-PD-1 monoclonal mAb or its components;
• Skin melanoma, ocular melanoma, original unknown melanoma;
• The primary lesion was incomplete;
• The examination suggests that the tumor remains or metastases;
• Pregnant or nursing;Women with fertility but not contraception;
• There are severe acute infections that are not controlled;There is a suppurative and chronic infection, and the wound is deferrable;
• Those who had serious heart disease;
• Psychiatric medicines abuse without withdrawal, or history of psychiatric illness.
• Patients with other tumor;
• Participate in other clinical studies at the same time;
• Positive tests for HIV, HCV, HBsAg or HBcAb with positive test for HBV DNA (>500IU/ml);
• Patients with any active autoimmune disease or a documented history of autoimmune disease, or history of syndrome that required systemic steroids or immunosuppressive medications, such as hypophysitis, pneumonia, colitis, hepatitis, nephritis, hyperthyroidism or hypothyroidism;
• Prior live vaccine therapy within past 4 weeks;
• Underlying medical condition that, in the Investigator's opinion, would increase the risks of study drug administration or obscure the interpretation of toxicity determination or adverse events