Systemic Safety of a Recombinant AAV8 Vector for Human Cocaine Hydrolase Gene Therapy: A Good Laboratory Practice Preclinical Study in Mice.

Cocaine addiction continues to impose major burdens on affected individuals and broader society but is highly resistant to medical treatment or psychotherapy. This study was undertaken with the goal of Food and Drug Administration (FDA) permission for a first-in-human clinical trial of a gene therapy for treatment-seeking cocaine users to become and remain abstinent. The approach was based on intravenous administration of AAV8-hCocH, an adeno-associated viral vector encoding a modified plasma enzyme that metabolizes cocaine into harmless by-products. To assess systemic safety, we conducted "Good Laboratory Practice" (GLP) studies in cocaine-experienced and cocaine-naive mice at doses of 5E12 and 5E13 vector genomes/kg. Results showed total lack of viral vector-related adverse effects in all tests performed. Instead, mice given one injection of AAV8-hCocH and regular daily injections of cocaine had far less tissue pathology than cocaine-injected mice with no vector treatment. Biodistribution analysis showed the vector located almost exclusively in the liver. These results indicate that a liver-directed AAV8-hCocH gene transfer at reasonable dosage is safe, well tolerated, and effective. Thus, gene transfer therapy emerges as a radically new approach to treat compulsive cocaine abuse. In fact, based on these positive findings, the FDA recently accepted our latest request for investigational new drug application (IND 18579).

Safety studies on intravenous administration of oncolytic recombinant vesicular stomatitis virus in purpose-bred beagle dogs.

VSV-IFNß-NIS is a novel recombinant oncolytic vesicular stomatitis virus (VSV) with documented efficacy and safety in preclinical murine models of cancer. To facilitate clinical translation of this promising oncolytic therapy in patients with disseminated cancer, we are utilizing a comparative oncology approach to gather data describing the safety and efficacy of systemic VSV-IFNß-NIS administration in dogs with naturally occurring cancer. In support of this, we executed a dose-escalation study in purpose-bred dogs to determine the maximum tolerated dose (MTD) of systemic VSV-hIFNß-NIS, characterize the adverse event profile, and describe routes and duration of viral shedding in healthy, immune-competent dogs. The data indicate that an intravenous dose of 10(10) TCID50 is well tolerated in dogs. Expected adverse events were mild to moderate fever, self-limiting nausea and vomiting, lymphopenia, and oral mucosal lesions. Unexpected adverse events included prolongation of partial thromboplastin time, development of bacterial urinary tract infection, and scrotal dermatitis, and in one dog receiving 10(11) TCID50 (10 × the MTD), the development of severe hepatotoxicity and symptoms of shock leading to euthanasia. Viral shedding data indicate that detectable viral genome in blood diminishes rapidly with anti-VSV neutralizing antibodies detectable in blood as early as day 5 postintravenous virus administration. While low levels of viral genome copies were detectable in plasma, urine, and buccal swabs of dogs treated at the MTD, no infectious virus was detectable in plasma, urine, or buccal swabs at any of the doses tested. These studies confirm that VSV can be safely administered systemically in dogs, justifying the use of oncolytic VSV as a novel therapy for the treatment of canine cancer.

Reduction of post-surgical pericardial adhesions using a pig model.

BACKGROUND: Post-surgical pericardial adhesions pose an increased risk of complications during redo sternotomies. Adhesive tissue formation is a normal response to tissue injury and involves complex patho-physiological processes including the actions of prostaglandins to cause plasma leakage and fibrin formation. The purpose of this study was to assess the ability of two non-steroidal anti-inflammatory agents (Indomethacin and Rofecoxib) and a barrier (Coseal, a polyethylene glycol) to limit adhesion formation following cardiac surgery in a pig model. METHODS: Forty-four piglets were allocated equally to four treatment groups: Group 1: Control, Group 2: intramuscular Indomethacin, Group 3: oral Rofecoxib and Group 4: Coseal sprayed on the heart. A full median sternotomy was performed on each animal and the heart exposed. Adhesions were induced by rubbing tissues with gauze, applying sutures and leaving blood in the pericardial sac before chest closure. Plasma inflammatory markers including prostaglandin E(2) and thromboxane B(2) were measured preoperatively and on Days 2, 5 and 10 after surgery. Eight animals from each group were slaughtered after 12 weeks and 3 after 25 weeks. Adhesions were assessed macroscopically and microscopically. RESULTS: Compared to the Control group, the extent of adhesions was significantly less in all other groups whilst adhesion density was least in the Indomethacin and Coseal groups. Indomethacin and less so Rofecoxib, inhibited the synthesis of prostaglandin E(2) and thromboxane B(2) but there were no significant changes in other inflammatory markers. CONCLUSIONS: We conclude that systemic Indomethacin, and locally applied Coseal are suitable methods to markedly reduce pericardial and retrosternal adhesions.