Intratumoral Injection of Recombinant Human Endostatin Adenovirus (EDS01) for the Treatment of Recurrent or Metastatic Head and Neck Tumors

Inclusion Criteria: Adults aged 18 to 65 years. Histologically or cytologically confirmed recurrent or metastatic head and neck tumor. Previously received at least 1 standard platinum-based systemic chemotherapy regimen for recurrent/metastatic disease, or had platinum-insensitive or platinum-intolerant disease after prior curative-intent treatment. Not suitable for surgery or radiotherapy. At least 1 target lesion suitable for intratumoral injection of recombinant human endostatin adenovirus injection. At least 1 measurable lesion with diameter ≥2 cm on imaging, according to RECIST version 1.1. No chemotherapy, radiotherapy, biologic antitumor therapy, or antiviral therapy within 4 weeks before enrollment. Estimated life expectancy of at least 12 weeks. ECOG performance status 0 to 1. Male or female participants of childbearing potential must agree to use reliable contraception during treatment and for at least 6 months after treatment. Recovery of prior treatment-related toxicities to NCI CTCAE grade 1 or baseline, with screening laboratory results within 1 week before enrollment meeting protocol requirements: ANC ≥1.5×10\^9/L, platelet count ≥80×10\^9/L, total bilirubin ≤1.5 × ULN, ALT and AST ≤2 × ULN, and coagulation parameters ≤1.25 × ULN. Willing and able to provide written informed consent. Exclusion Criteria: Known allergy to the study drugs. Lesions involving major blood vessels or nerves and therefore unsuitable for local injection. Receiving radiotherapy to the study lesion at the same time. Prior anti-angiogenic therapy. Receiving immunosuppressive therapy or systemic corticosteroids for immunosuppressive purposes at a dose greater than prednisone 10 mg/day (or equivalent) within 2 weeks before enrollment. Active autoimmune disease or history of autoimmune disease. Congenital or acquired immunodeficiency. Risk of major nasopharyngeal hemorrhage or deep nasopharyngeal ulceration. Severe coagulation disorder or bleeding tendency. Severe uncontrolled medical disease or myocardial infarction within 3 months before enrollment. Acute infection. Pregnant or breastfeeding women. Any condition that, in the investigator's judgment, makes the participant unsuitable for enrollment.