Phase I/IIa Trial Follows Preclinical Study Demonstrating for First Time that a Multi-Antigen HCV Vaccine Can Generate Potent T-Cell Response in Liver
Jan 9, 2013
BLUE BELL, Pa., Jan. 9, 2013 /PRNewswire/ -- Inovio Pharmaceuticals, Inc. (NYSE MKT: INO) and its development partner VGX International, Inc. (KSE: 011000) will move Inovio's hepatitis C (HCV) DNA vaccine into a phase I/IIa clinical trial by the end of 2013. This advancement is based on outstanding results of a preclinical study which demonstrated for the first time that a multi-antigen SynCon® HCV vaccine can generate robust T-cell responses not only in the blood but, more importantly, in the liver, an organ known to supress T-cell activity. VGX International is funding all preclinical and clinical development.
In preparation for entering clinical trials with its HCV vaccine (INO-8000), Inovio has completed manufacturing of its multi-antigen HCV vaccine and is performing IND (Investigational New Drug application)-enabling toxicity testing in animals. INO-8000 is a SynCon HCV therapeutic vaccine targeting NS3/4A, NS4B, and NS5A proteins of HCV. INO-8000 was designed with Inovio's SynCon process to broadly cover HCV genotypes 1a and 1b, the types that have been most difficult to treat with drug therapies.
It is estimated that more than 5 million people in the United States are infected with hepatitis C, and perhaps as many as 200 million around the world. This makes HCV one of the greatest public health threats of this century.
HCV vaccine research to date has mostly focused on one area of the virus (the NS3/4A proteins) to induce T-cell responses; however, there has been little research aimed at elucidating whether vaccines targeting proteins other than NS3/4A can induce potent T-cell responses within the liver. In this study, Inovio and its collaborators developed SynCon antigen constructs that targeted three other areas of the HCV virus (NS4B, NS5A and NS5B) and then demonstrated that each vaccine construct expressed its respective protein and that all three constructs induced potent HCV-specific T-cells in mice.
Prior research has also identified that a successful HCV vaccine must be able to induce not only strong HCV-specific T-cell responses that target several components of the virus but that these cells must migrate to the liver and remain activated. In this study, Inovio researchers observed in the liver not only NS4B-, NS5A- and NS5B-specific CD4+ and CD8+ (or killer T-cell) responses, but also a large pool of vaccine-specific T-cells. This pool of vaccine-specific T-cells was shown to be fully functional in an environment in which T-cell activity is usually suppressed. In fact, using a transient HCV infection model in mice, therapeutic immunization with INO-8000 was able to clear HCV antigens from the liver, demonstrating the therapeutic potential of this vaccine.
The pioneering preclinical research appears in the peer-reviewed journal Plos One in an article entitled: "Induction of Intrahepatic HCV NS4B, NS5A and NS5B Specific Cellular Immune Responses following Peripheral Immunization."
In addition to moving forward with INO-8000, Inovio has a long-standing partnership with ChronTech Pharma, which is developing its NS3/4A-based HCV DNA vaccine using Inovio's proprietary delivery technology. Interim results of ChronTech's open-label, randomized phase II trial are expected later in the first quarter of this year.
Dr. J. Joseph Kim, Inovio's President and CEO, said, "Inovio is a leader in developing therapeutic vaccines for HCV and HBV. The major hurdle to developing therapeutic vaccines for these ailments has been the inability to generate a functional T-cell response in the liver. The fact that our preclinical model demonstrated functional T-cells in the liver in this published study suggests that INO-8000 has the capacity to clear that hurdle. There have been important recent drug therapy advances for HCV; however, a safe and effective therapeutic vaccine could play a vital role in enhancing the potency of HCV treatments, especially for genotype 1, while achieving the desired goal of eliminating the use of interferon/ribavirin and their undesirable side effects."
About Hepatitis C and Inovio's SynCon® Vaccines
Hepatitis C is an infectious disease affecting primarily the liver, caused by the hepatitis C virus (HCV). The infection is often asymptomatic, but chronic infection can lead to liver failure or liver cancer. Approximately 80% of people who become infected with hepatitis C virus develop chronic infection.
The major obstacle to HCV vaccine development has been the extensive genetic variation between different strains and genotypes, and even the significant antigenic variation among virus within individual patients. In addition, the absence of a clearly defined protective immune response after natural infection has historically complicated the prospects of developing a vaccine against HCV infection.
However, unlike traditional vaccines constrained by the paradigm of matching a preventive or therapeutic vaccine to a single pathogen strain or strains, Inovio's SynCon vaccines are based on genetic code for a specific antigen from multiple strains of the target pathogen. Thus, while the SynCon antigens may not be perfectly (100%) matched to the pathogenic strains, they are designed to protect against multiple existing strains as well as changing strains of a virus. Extensive preclinical data has validated their ability to protect against many strains of a disease; initial human data for our influenza vaccine has also provided evidence of this capability.
About Inovio Pharmaceuticals, Inc.
Inovio is revolutionizing vaccines to prevent and treat today's cancers and challenging infectious diseases. Its SynCon vaccines are designed to provide universal cross-strain protection against known as well as newly emergent unmatched strains of pathogens such as influenza. These synthetic vaccines, in combination with Inovio's proprietary electroporation delivery, have been shown in humans to generate best-in-class immune responses with a favorable safety profile. Inovio's clinical programs include phase II studies for cervical dysplasia, leukemia and hepatitis C virus and phase I studies for influenza and HIV. Partners and collaborators include the University of Pennsylvania, Merck, ChronTech, National Cancer Institute, U.S. Military HIV Research Program, NIH, HIV Vaccines Trial Network, University of Southampton, US Dept. of Homeland Security, University of Manitoba and PATH Malaria Vaccine Initiative. More information is available at www.inovio.com.
This press release contains certain forward-looking statements relating to our business, including our plans to develop electroporation-based drug and gene delivery technologies and DNA vaccines and our capital resources. Actual events or results may differ from the expectations set forth herein as a result of a number of factors, including uncertainties inherent in pre-clinical studies, clinical trials and product development programs (including, but not limited to, the fact that pre-clinical and clinical results referenced in this release may not be indicative of results achievable in other trials or for other indications, that the studies or trials may not be successful or achieve the results desired, that pre-clinical studies and clinical trials may not commence or be completed in the time periods anticipated, that results from one study may not necessarily be reflected or supported by the results of other similar studies and that results from an animal study may not be indicative of results achievable in human studies), the availability of funding to support continuing research and studies in an effort to prove safety and efficacy of electroporation technology as a delivery mechanism or develop viable DNA vaccines, the adequacy of our capital resources, the availability or potential availability of alternative therapies or treatments for the conditions targeted by the company or its collaborators, including alternatives that may be more efficacious or cost-effective than any therapy or treatment that the company and its collaborators hope to develop, evaluation of potential opportunities, issues involving product liability, issues involving patents and whether they or licenses to them will provide the company with meaningful protection from others using the covered technologies, whether such proprietary rights are enforceable or defensible or infringe or allegedly infringe on rights of others or can withstand claims of invalidity and whether the company can finance or devote other significant resources that may be necessary to prosecute, protect or defend them, the level of corporate expenditures, assessments of the company's technology by potential corporate or other partners or collaborators, our ability to secure new partnerships and collaborations, capital market conditions, the impact of government healthcare proposals and other factors set forth in our Annual Report on Form 10-K for the year ended December 31, 2011, our Form 10-Q for the quarter ended September 30, 2012, and other regulatory filings from time to time. There can be no assurance that any product in Inovio's pipeline will be successfully developed or manufactured, that final results of clinical studies will be supportive of regulatory approvals required to market licensed products, or that any of the forward-looking information provided herein will be proven accurate.
SOURCE Inovio Pharmaceuticals, Inc.