Phase II Study of Golidocitinib and Benmelstobart in Patients with R/R ENKTL (JACKPOT50)

Inclusion Criteria: 1. Subjects fully understand and voluntarily participate in this study and sign informed consent. 2. Pathologically confirmed extranodal natural killer/T cell lymphoma (ENKTL). 3. Age ≥18, no gender limitation. 4. Treatment failure to at least one line of asparaginase-based therapy. 5. Eastern Cooperative Oncology Group performance status of 0-2 6. Expected survival ≥ 3 months. 7. At least one measurable lesion that meets Lugano 2014 criteria. 8. Sufficient organ function. Exclusion Criteria: 1. Invasive NK-cell leukemia or NKTCL that has progressed to leukemia. 2. Accompanied by hemophagocytic lymphohistiocytosis. 3. NKTCL with central nervous system invasion. 4. Previously treated with JAK inhibitors. 5. The patients have contraindications to any drug in the combined treatment. 6. Patients with the infection of human immunodeficiency virus (HIV) and/or acquired immunodeficiency syndrome. 7. Inability to swallow tablets, presence of malabsorption syndrome, or any other gastrointestinal disease or dysfunction that may affect the absorption of the study drug. 8. Pregnant and lactating women and subjects of childbearing age who do not want to use contraception. 9. Mentally ill persons or persons unable to obtain informed consent. The investigators think that the patient is not suitable for the study.