Sintilimab Plus R-GemOx as Second-line Salvage Therapy in Patients With R/R DLBCL

Inclusion Criteria:

1. Willingness to provide written informed consent.
2. Age range from 18 to 80 years;
3. Pathologically confirmed CD20+ diffuse large B-cell lymphoma
4. According to Lugano 2014, at least one measurable nodular lesion with a length of greater than 15 mm, or extranodal lesion greater than 10 mm, lesion on FDG-PET scan demonstrates uptake);
5. Diffuse large B-cell lymphoma patients failed to first-line rituximab based chemotherapy including anthracycline or anthracycline
6. Patients are allowed to receive palliative radiotherapy, but the last time radiotherapy cannot be within 7 days before the first study drug administration;
7. Eastern Cooperative Oncology Group (ECOG) performance status of 0-2;
8. Adequate organ function
9. Expectation survival time over 3 months;

Exclusion Criteria:

1. History of other malignancy within the past 5 years (except for 1. basal cell carcinoma of the skin and 2. carcinoma in situ of the cervix and 3. patients who had received treatment for the purpose of cure and had not developed a malignant tumor with a known active disease in the previous 5 years);
2. Patients who had received other antitumor therapy (including corticosteroid therapy, immunotherapy) or participated in other clinical studies within 4 weeks before the start of the enrollment (if patients received small-molecule targeted drug therapy, they could be included in the study if the drug was discontinued for more than 5 half-lives), or had not recovered from the previous toxicity;
3. Previous treatment with anti-PD-1 antibody, anti-PD-L1 antibody or other medications that stimulates or collaboratively inhibits T cell receptors
4. Patients previously received anti-CD20 antibody combined GemOx regimen;
5. Evidence of central nervous system invasion;
6. Patients received systemic treatment of traditional Chinese herb with anti-tumor indications or immunomodulatory drugs (including thyroxin, interferon and interleukinin, except for local use to control pleural effusions) within 2 weeks before first administration;
7. Patients with autoimmune diseases requiring treatment or with a history of syndrome requiring systemic use of steroid immunosuppressive agents, such as hypophysitis, pneumonia, colitis, hepatitis, nephritis, hyperthyroidism, hypothyroidism, etc;
8. Patients received systemic glucocorticoid therapy (excluding nasal spray, inhaled or other topical glucocorticoids) or any other form of immunosuppressive therapy within 7 days prior to the first administration;
9. Clinically uncontrollable pleural effusion/peritoneal effusion (patients who do not need drainage effusion or do not significantly increase the effusion after 3 days of drainage can be enrolled);
10. Patients who have had previous organ transplants (except autologous hematopoietic stem cell transplants);
11. Patients are allergic to sintilimab, CD20 monoclonal antibody and GemOx regimen
12. Patients has not fully recovered from toxicity and/or complications due to any intervention prior to initiation of treatment (i.e., ≤ grade 1 or baseline, excluding fatigue or hair loss);
13. A confirmed history of human immunodeficiency virus (HIV) infection (i.e. HIV 1/2 antibody positive);
14. A confirmed history of Novel Coronavirus infection;
15. Patients with hepatitis B (HBV HBsAg positive and HBV-DNA≥105), hepatitis C (HCV) infection (HCV antibody positive and HCV-RNA detectable); And subjects with other acquired or congenital immune deficiency diseases, including but not limited to hiv-infected;
16. Patients who received the live vaccine within 4 weeks of the start of the enrollment;
17. Pregnant or lactating women;
18. Patients who have received grade II or above surgery within 3 weeks before enrollment;
19. Patients with significant coagulation abnormality;
20. Other serious, uncontrolled concomitant diseases that may affect protocol compliance or interfere with results interpretation, including uncontrolled diabetes, or pulmonary disease (a history of interstitial pneumonia, obstructive pulmonary disease, and symptomatic bronchospasm);
21. Patients who received the live vaccine within 4 weeks of the start of the enrollment;
22. Severe or uncontrolled infections;
23. Patients with history of severe neurological or psychiatric illness, including dementia or epilepsy;
24. Patients with drug abuse, medical, psychological or social conditions that may interfere with the study results or the assessment of the study results;
25. Patients are unsuitable for the enrollment according to investigator's judgement.