Phaes Ⅱ Study of Golidocitinib-Pegaspargase-PD-1 Antibody First-Line for Advanced ENKTL

Inclusion Criteria: 1. Voluntarily provides written informed consent (ICF) and agrees to comply with study procedures. 2. Histopathologically confirmed ENKTL per the 2022 WHO Classification of Lymphoid Neoplasms, with no prior systemic anti-lymphoma therapy. 3. At least one measurable or evaluable lesion per 2014 Lugano Classification: Measurable lesion: Lymph node ≥1.5 cm (long axis) × ≥1.0 cm (short axis); extranodal lesion ≥1.0 cm (long axis); if the only measurable lesion was previously irradiated, radiological progression after radiotherapy is required. Evaluable lesion: FDG-PET uptake higher than liver in lymph nodes or extranodal sites, consistent with lymphoma. 4. Age ≥18 years at ICF signing. 5. Estimated life expectancy ≥12 weeks. 6. ECOG performance status 0-2. Adequate organ and bone marrow function (without supportive care within 14 days): 7. Hematology: Absolute Neutrophil Count (ANC) ≥1.5×10⁹/L (≥0.5×10⁹/L with bone marrow involvement); Platelet (PLT) ≥100×10⁹/L (≥50×10⁹/L with bone marrow involvement); Hemoglobin (HGB) ≥8.0 g/dL. Liver function: Total Bilirubin (TBIL) ≤1.5×ULN (≤3.0×ULN for Gilbert syndrome or liver involvement); Alanine Aminotransferase (ALT)/Aspartate Aminotransferase (AST) ≤2.5×ULN (≤5.0×ULN for liver involvement). Renal function: Serum Creatinine (Cr) ≤1.5×ULN or Creatinine Clearance Rate (Ccr) ≥50 mL/min (Cockcroft-Gault method). Coagulation: International Normalized Ratio (INR) ≤1.5×ULN; Prothrombin Time (PT)/Activated Partial Thromboplastin Time (APTT) ≤1.5×ULN (unless on anticoagulants with stable levels). Thyroid function: Thyroid Stimulating Hormone (TSH), Free Thyroxine (FT4), Free Triiodothyronine (FT3) within ±10% of normal range (non-autoimmune TSH abnormalities allowed). 8. Left Ventricular Ejection Fraction (LVEF) ≥50% by MUGA or echocardiogram. 9. Resolution of acute toxicities from prior therapies to ≤Grade 1 (CTCAE v5.0) or baseline; irreversible Grade 2 toxicities (e.g., neuropathy, alopecia) are allowed if not worsening. 10. Women of Childbearing Potential (WOCBP) must have negative serum pregnancy test within 7 days of first dose; WOCBP and male partners must use effective contraception from ICF signing to 6 months after last study drug dose. Exclusion Criteria: 1. Aggressive NK-cell leukemia or ENKTL in leukemic phase. 2. Concurrent hemophagocytic syndrome. 3. Lymphoma involvement of central nervous system (CNS) or meninges. 4. History of other malignancies within 5 years (except cured localized tumors: e.g., basal/squamous cell skin cancer, in situ prostate/cervical/breast cancer). 5. Prior therapy: Allogeneic hematopoietic stem cell transplantation (HSCT) within 5 years (allowed if \>5 years with no graft-versus-host disease). Autologous HSCT within 3 months. Prior JAK/STAT3 inhibitors. Concurrent use of strong CYP3A inducers/inhibitors (unable to discontinue 1 week before first dose). Concurrent vitamin K antagonists, antiplatelet agents, or anticoagulants (unable to discontinue 1 week before first dose). Systemic glucocorticoids or immunosuppressants within 14 days (local/ocular/inhaled/nasal glucocorticoids or short-term ≤7 days for prophylaxis allowed). Cytotoxic chemotherapy within 21 days. Systemic anti-tumor therapy (including mAbs, immunotherapy) within 4 weeks. Major surgery within 6 weeks or radiotherapy within 90 days. Toxin/isotope-antibody conjugates within 10 weeks. Investigational drugs within 30 days. Active infections: Active/latent tuberculosis (PPD positive with induration \>10 mm or radiological evidence). HIV infection. Active chronic hepatitis B (HBsAg positive with HBV DNA \>2500 copies/mL or 500 IU/mL) or hepatitis C (HCV RNA positive). HBV carriers with controlled HBV DNA and cured HCV are allowed; HBsAg-positive patients require monthly HBV DNA monitoring and prophylactic entecavir until 12 months after anti-tumor therapy. 6. Active viral infections (e.g., herpes zoster) or bacterial infections requiring IV/oral antimicrobials within 30 days (including pneumonia). 7. Active autoimmune diseases requiring systemic therapy within 2 years (allowed if inactive for 2 years; hormone replacement therapy for hypothyroidism/diabetes is allowed). 8. Uncontrolled cardiac disease: NYHA Class \>2 heart failure, unstable angina, myocardial infarction within 1 year, clinically significant arrhythmias requiring treatment. 9. Prior interstitial lung disease (except radiation-induced asymptomatic disease). 10. Unresolved Grade \>1 AEs (except alopecia) from prior therapies. 11. Hypersensitivity to golidocitinib, pegaspargase, anti-PD-1 mAb, or excipients; history of Grade ≥3 hypersensitivity to mAbs or uncontrolled allergic asthma. 12. Refractory nausea/vomiting, chronic gastrointestinal disease, dysphagia, or prior bowel resection affecting drug absorption. 13. Pregnant or lactating women; unwilling to use contraception. 14. Psychiatric illness or inability to provide informed consent. 15. Investigator-determined unsuitability for study participation.