HSV1716 in Patients With Non-Central Nervous System (Non-CNS) Solid Tumors

Patients with relapsed solid tumors such as sarcomas and neuroblastoma have a poor survival, generally \< 20%. There is an urgent need for new treatments that are safe and effective. HSV1716, an oncolytic virus, is a mutant herpes simplex virus (HSV) type I, deleted in the RL1 gene which encodes the protein ICP34.5, a specific determinant of virulence. Mutants lacking the RL1 gene are capable of replication in actively dividing cells but not in terminally differentiated cells - a phenotype exploited to selectively kill tumor cells. In previous clinical studies, HSV1716 has been shown to be safe when injected at doses up to 10\^5 plaque forming units (pfu) directly into human high-grade glioma and into normal brain adjacent to tumour, following excision of high-grade glioma. In an extension study, HSV1716 has been shown to be safe when injected at a dose of up to 10\^6 pfu directly into brain tumours. Replication of HSV1716 in human glioblastoma in situ has been demonstrated. Following a single administration of HSV1716 by direct injection into active recurrent tumor or brain adjacent to tumor, some patients have lived longer than might have been expected. This study seeks to evaluate the safety of a single injection of HSV1716 in the treatment of extracranial solid tumors in adolescents and young adults. HSV1716 has also proved safe when given by direct intra-tumoural injection in patients with squamous carcinoma of the head and neck, and in patients with malignant melanoma. Replication of HSV mutants in human sarcomas and neuroblastoma in cultured cells and human xenograft models has been demonstrated. This study is designed in two parts. PART 1 of the study specifies a single dose of virus. Participants who experience at least stable disease or relapse following a determination of stable disease, may qualify for subsequent doses in PART 2. PART 2 requires signing of a separate consent. Funding Source - FDA OOPD