The prognosis for patients with relapsed/refractory classical Hodgkin lymphoma (cHL) who refuse or are ineligible for transplant is poor. This open label, randomized, phase 2 study aims to evaluate the efficacy of Chidamide+Decitabine plus Anti-PD-1 Antibody and Brentuximab Vedotin plus Anti-PD-1 Antibody in transplant-ineligible or refused transplant diagnosedR/R cHL. The primary objective of the study is to evaluate progression-free survival.

The prognosis of refractory or early-relapsed lymphoma is poor, and it is even worse for those who are not eligible or refuse transplantation. Although many salvage regimens have been developed, there is no standard of care. Preliminary clinical observations have shown that Chidamide +Decitabine plus Anti-PD-1 Antibody might be beneficial for these patients. Brentuximab Vedotin plus Anti-PD-1 Antibody is a standard regimen . This open-label, randomized, phase 2 study aims to evaluate the efficacy of Chidamide+Decitabine plus anti-PD-1 antibody and Brentuximab Vedotin plus Anti-PD-1 Antibody, in patients with classical Hodgkin lymphoma who are transplant-ineligible or refused transplant . The primary objective of the study is to evaluate the progression free survival.The key secondary end points are complete response rate, objective response rate and the safety.

Inclusion Criteria:

1.18 to 75 years of age. 2.ECOG performance of less than 2. 3.Subjects must have histological confirmation classical Hodgkin lymphoma (cHL). 4. Patients must have at least two lines of antitumor therapy, those who were transplant-ineligible or refused transplant. 5.Life expectancy of at least 3 months. 6.Subjects with lymphoma must have at least one measureable lesion >1cm as defined by lymphoma response criteria. 7. Previous treatment must be completed for more than 4 weeks prior to the enrollment of this study, and subjects have recovered to ≤ grade 1 toxicity. 8.Subjects with autologous hematopoietic stem-cell transplantation are eligible which must be more than 3 months. 9.Subjects must have adequate marrow, live, renal and heart functions.

Exclusion Criteria:

1. Subjects have received the combination therapy of Chidamide+Decitabine and anti-PD-1 antibody or BV+ anti-PD-1 antibody.2.Subjects with any autoimmune disease or history of syndrome that requires corticosteroids or immunosuppressive medications. 3. Serious uncontrolled medical disorders or active infections, pulmonary infection especially. 4. Active alimentary tract hemorrhage or history of alimentary tract hemorrhage in 1 month. 5. Prior organ allograft. 6. Women who are pregnant or breastfeeding. 7. Women with a positive pregnancy test on enrollment or prior to investigational product administration. 8. Subjects who are compulsorily detained for treatment of either a psychiatric or physical illness.