Cytokine-enhanced vaccine and suicide gene therapy as adjuvant treatments of metastatic melanoma in a horse

Abstract

We evaluated the safety, efficacy and anti-tumour effects of a surgery adjuvant treatment on an equine patient with metastatic malignant melanoma. This approach combined suicide gene therapy with a subcutaneous vaccine composed by formolized tumour cells and irradiated xenogeneic cells producing human interleukin-2 and granulocyte-macrophage colony-stimulating factor. The post-surgical margins of the cavities were infiltrated with lipid-complexed thymidine kinase suicide gene co-administrated with ganciclovir. In addition, subcutaneous lesions periodically treated with the suicide gene system objectively reduced their sizes or disappeared. Without any symptom of toxicity, this combined treatment abolished local recurrence and further metastatic spread of the disease. Therefore, this surgery adjuvant combined treatment controlled tumour growth and delayed or prevented post-surgical recurrence and distant metastasis while recovered the patient’s quality of life.