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

Patients with recurrent or metastatic head and neck tumors, including nasopharyngeal carcinoma, have limited treatment options after failure of platinum-based therapy. Anti-programmed cell death protein 1 (PD-1) therapy is an established later-line treatment option in this setting. EDS01 is a recombinant human endostatin adenovirus injection designed for intratumoral administration. By delivering the human endostatin gene into tumor cells, EDS01 is intended to support sustained local expression of endostatin and inhibit tumor angiogenesis. Head and neck lesions are often accessible for direct intratumoral injection and serial local assessment, which makes this disease setting suitable for evaluation of this approach. Prior early-phase clinical experience with EDS01 in advanced head and neck tumors showed that the main observed toxicities were fever, injection-site pain, and flu-like symptoms, without dose-limiting toxicity or serious adverse events at the studied dose levels, and preliminary antitumor activity was observed. These findings support further evaluation of EDS01 in combination with PD-1 blockade.

This single-center Phase 1 study is designed to evaluate the safety, tolerability, and preliminary antitumor activity of EDS01 in combination with toripalimab in adults with recurrent or metastatic head and neck tumors who have previously received platinum-based treatment or demonstrated platinum insensitivity or intolerance, and who have an injectable tumor lesion. The study will explore planned EDS01 dose levels in combination with fixed-dose toripalimab in order to characterize the safety profile of the regimen and identify whether the combination is feasible for further clinical development.

Study evaluations include clinical assessments, physical examinations, laboratory testing, and monitoring of adverse events and serious adverse events. Tumor response will be assessed radiographically according to RECIST version 1.1, including evaluation of objective response, disease control, and time to progression. Additional translational and exploratory assessments include anti-adenovirus antibody testing, serum endostatin measurement, and selected monitoring related to environmental shedding after intratumoral administration. After treatment, participants will enter follow-up and be assessed every 3 months until disease progression or death.

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.