Inovio Biomedical Corporation, a leader in enabling the development of DNA vaccines using electroporation-based DNA delivery, announced that its partner, Tripep AB of Sweden, has filed an application for a phase I clinical study with the Swedish Medical Products Agency. The application is designed to permit initial clinical testing of Tripep's proprietary DNA vaccine, ChronVac, administered using Inovio's MedPulser DNA Delivery System. This combination is designed to activate a T-cell response capable of clearing hepatitis C virus. Tripep intends to conduct a phase I clinical study in healthy volunteers at the Center for Gastroenterology at Karolinska University Hospital in Sweden beginning in early 2007.
"Our partnership with Tripep has rapidly moved this vaccine from concept to initial clinical evaluation in less than a year," stated Avtar Dhillon, MD, Inovio's president and CEO. "This vaccine trial represents the first study in man of an infectious disease vaccine delivered with electroporation and we are excited about the product's potential."
DNA vaccines have the potential to by-pass the numerous problems that plague conventional vaccines. For example, DNA vaccines may be better in stimulating cellular immunity necessary to fight chronic infection or diseases such as cancer. Despite this promise, vaccination using DNA plasmids alone, without enhanced delivery, has not been shown to reach the threshold for clinical benefit.
Intramuscular delivery of DNA vaccines using Inovio's proprietary electroporation technology has been shown in primate studies to boost the immune response by orders of magnitude over DNA plasmid alone. Plasmid-based vaccines induced higher levels of antibodies and T-cell responses when delivered via electroporation, suggesting the potential to provide better protection from infectious diseases such as HIV and hepatitis C.
Hepatitis is a disease characterized by inflammation of the liver. Hepatitis C virus (HCV) is a major cause of acute hepatitis. HCV is spread primarily by direct contact with human blood, the major causes worldwide being the use of unscreened blood transfusions and re-use of needles and syringes that have not been adequately sterilized. As many as 70 per cent - 90 per cent of newly infected patients may progress to develop chronic infection (WHO: 2002). Of those with chronic liver disease, 5 per cent - 20 per cent may develop cirrhosis. About 5 per cent of infected persons may die from the consequences of long-term infection (due to liver cancer or cirrhosis). Globally, an estimated 170 million people are chronically infected with HCV, which represents a reservoir sufficiently large for HCV to persist, and 3 to 4 million persons are newly infected each year. In the US, while new incidences of HCV have dropped dramatically, an estimated 4.1 million (1.6 per cent) Americans have been infected with HCV, of whom 3.2 million are chronically infected (Centers for Disease Control and Prevention: 2006).
HCV infections in the liver do not trigger an immune response very effectively. Certain antiviral therapies, while expensive, are somewhat effective in treating hepatitis C, but there is no vaccine currently available to prevent hepatitis C. ChronVac is designed to be a therapeutic DNA vaccine that can stimulate the body's immune system. Animal experiments have demonstrated that ChronVac vaccination activated B-cells and T-cells (the latter being regarded as the most significant to clearing the chronic infection relating to hepatitis C) that killed cells producing HCV protein. In humans, the ChronVac DNA plasmid will be injected into muscle tissue, where vaccinations are usually given, and taken up by muscle cells with the assistance of Inovio's electroporation-based DNA delivery system. These muscle cells would be expected to then produce predetermined proteins that may activate the body's immune system to attack all cells producing HCV proteins.
Tripep AB is a Swedish biotechnology research company that develops and commercializes candidate drugs based on patented and proprietary technologies. Its main focuses are research and clinical development of ChronVac, a therapeutic vaccine against hepatitis C; preclinical research focusing on the development of therapeutic and prophylactic vaccines against influenza A and HIV; and the RAS technology platform.