Clinical Research Directory

Inclusion Criteria: \- 1. Age: ≥18 years and ≤70 years, gender unrestricted. 2. Diagnosis: Histologically/pathologically confirmed metastatic nasopharyngeal carcinoma (NPC) that has failed at least one prior line of therapy (including cisplatin-containing regimens) or is intolerant to existing therapies (relapse within 6 months after completion of adjuvant/neoadjuvant concurrent chemoradiotherapy is eligible). 3\. Performance Status: ECOG performance status 0-1. Measurable Disease: At least one measurable lesion per RECIST 1.1 criteria. 4. Prior Immunotherapy: Patients who have received PD-1, PD-L1, PD-L2, or CTLA-4 inhibitors, or other therapies targeting T-cell co-stimulation/checkpoint pathways: Must have achieved complete response (CR), partial response (PR), or stable disease (SD) ≥6 months during treatment. Only one prior immunotherapy regimen is allowed (e.g., neoadjuvant and adjuvant regimens using the same immunotherapy are considered one regimen). Switching to a different immunotherapy regimen for non-immunotherapy-related progression is permissible if cumulative SD duration ≥6 months. 6\. Organ Function: Hematology: ANC ≥1.5×10⁹/L, PLT ≥75×10⁹/L, Hb ≥90 g/L. No blood product transfusion or growth factor support (e.g., G-CSF, EPO) within 2 weeks prior to screening. Hepatology: TBIL ≤1.5×ULN; ALT/AST ≤2.5×ULN (≤5×ULN if liver metastases present). Renal Function: Serum Cr ≤1.5×ULN or CrCl \>60 mL/min. Thyroid Function: TSH, FT4, FT3 within CTC AE Grade 0-1. 7. Survival Expectancy: ≥3 months. 8. Informed Consent: Voluntary participation and signed written informed consent. Exclusion Criteria: 1. Known severe hypersensitivity (≥Grade 3) to any monoclonal/polyclonal antibody, chidamide, or anlotinib components. 2. Necrotic lesions identified within 4 weeks prior to enrollment, with investigator-judged risk of major bleeding. 3. Chemotherapy, targeted therapy, or immunomodulatory agents (including thymosin, interferon, IL-2, etc.) within 2 weeks prior to enrollment. Washout period determined by clinical resolution of adverse events (AEs) and prior treatment regimens. 4. Palliative radiotherapy to localized lesions within 4 weeks prior to enrollment, unless the lesion is non-target and other measurable target lesions exist. 5. Grade ≥3 irAEs during prior immunotherapy. 6. Prior treatment with HDAC inhibitors or anti-angiogenic agents. 7. Urine protein ≥2+ or 24-hour urinary protein ≥1 g. 8. Systolic BP \>140 mmHg or diastolic BP \>90 mmHg despite treatment. 9. Persistent toxicity from prior antitumor therapy (per NCI CTCAE v5.0) \>Grade 1, excluding: alopecia, Grade 2 fatigue, Grade 2 anemia, or asymptomatic lab abnormalities. 10. Symptomatic CNS metastases (e.g., edema, steroid requirement) or leptomeningeal disease. 11. Systemic immunosuppressive drugs (excluding topical/inhaled corticosteroids or physiological doses ≤10 mg/day prednisone equivalent) or corticosteroids for contrast allergy within 4 weeks prior to enrollment. 12. Active autoimmune diseases (e.g., interstitial pneumonia, colitis, thyroiditis) or history of severe autoimmune conditions requiring systemic therapy. Exceptions: Vitiligo, childhood asthma (resolved without treatment), or mild asthma managed without bronchodilators. 13. Ongoing anti-tuberculosis therapy or treatment within 1 year prior to screening. 14. Conditions requiring long-term immunosuppressive therapy or systemic corticosteroids at immunosuppressive doses. 15. Severe Cardiac Disease or Significant Cardiac Symptoms. 16. Other Circumstances Deemed Unsuitable by the Investigator