A Phase II Study to Evaluate the Safety and Efficacy of TQB2450 Injection in Relapsed or Refractory Classical Hodgkin's Lymphoma

Inclusion Criteria: 1. Subject has voluntarily agreed to participate by giving written informed consent.; 2. Histopathological confirmed classical Hodgkin's lymphoma; 3. Relapsed/refractory cHL include：a)subject with relapse and progression after salvage chemotherapy followed by autologous stem cell transplantation(ASCT); b) subject with no ASCT: The first-line chemotherapy must be systemic multi-drug combination chemotherapy and subsequent chemotherapy requires at least one first-line chemotherapy must be systemic multi-drug combination chemotherapy; subject which is refractory didn't achieve PR after 2 cycles or didn't achieve CR after 4. Age ranged from 18 to 75 years; 5. At least one measurable disease ; 6. Patients must have ECOG performance status of 0-2; 7. Subject must have adequate organ functions ：Count of Blood Cells:hemoglobin content(HB)≥80g/L; absolute neutrophil count (ANC) ≥ 1.0 × 10\^9 / L; platelet count (PLT) ≥ 75 × 10\^9 / L;; Biochemical examination: serum total bilirubin (TBIL) ≤ 1.5 × normal upper limit (ULN), with the exception of patients with hepatic metastases and Gilbert's syndrome(TBIL≤3×ULN） ; alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3 × ULN，with the exception of patients with hepatic metastases (ALT and AST ≤ 5 × ULN) , serum creatinine (Cr) ≤ 1.5 × ULN or Creatinine clearance rate（CCR）≥50 mL/min；Serum amylase and lipase ≤ 1.5 x ULN Blood coagulation function:International standardized ratio(INR)≤1.5×ULN、Activation partial thrombin time(APTT)≤1.5×ULN、Prothrombin time≤1.5×ULN；Doppler ultrasound evaluation：Left ventricular ejection fraction（LVEF)≥50%×MLN; Exclusion Criteria: * 1、Nodular lymphocyte-predominant Hodgkin lymphoma or gray zone lymphoma； 2、 Prior exposure to any anti-PD-1, anti-PD-L1 ， anti-CTLA-4 antibody or CAR-T cell treatment(Any other antibody that has been applied to a T cell synergistic stimulus or checkpoint pathway); 3、Need to therapy with other anticancer during the study; 4、Received allogeneic organ transplantation or allogeneic hematopoietic stem cell transplantation;