Inovio Pharmaceuticals' PENNVAX®-B HIV Vaccine Demonstrates Strong T-Cell Immune Responses in Therapeutic Vaccine Trial

BLUE BELL, Pa., March 13, 2012 /PRNewswire/ -- Inovio Pharmaceuticals, Inc. (NYSE Amex: INO)  announced today that it has achieved strong T cell immune responses in a Phase I clinical study of PENNVAX®-B, its product for the treatment of the HIV subtype prevalent in North America and Europe, in HIV-positive subjects. These interim results were presented by Dr. Niranjan Y. Sardesai, Inovio's Chief Operating Officer, at the Vaccine World Summit 2012 in Hyderabad, India in a talk titled, "New Development Paradigms and Vaccine Innovation for Infectious Diseases."

"We are particularly excited by the positive interim results of the HIV-001 study in HIV-positive subjects. This data is a first for DNA vaccines by yielding robust T cell immune responses in people chronically infected with HIV. Even though the HIV viral load of these volunteers was suppressed and brought under control by antiretroviral drugs, their immune systems are not normal and would typically have difficulty generating strong T cell responses to any immune stimulating approach. Coupled with positive data from two earlier trials, Inovio's results demonstrate the potency of our synthetic vaccine technology platform and raises the potential for the development of therapeutic vaccines against HIV and other chronic infections," said Dr. J. Joseph Kim, Inovio's President and CEO. "Together with our HIV prophylactic vaccine programs in collaboration with our partners at DAIDS and HVTN, this HIV therapy trial highlights our commitment to addressing one of the foremost global health issues of our time."

The HIV-001 open label, Phase I study enrolled 12 adult HIV-positive volunteers to assess safety and levels of immune responses generated by Inovio's PENNVAX®-B vaccine delivered with its CELLECTRA® electroporation device. PENNVAX®-B consists of SynCon® immunogens targeting HIV gag, pol, and env proteins from HIV subtype B commonly found in North America and Europe.

Study volunteers were required to be on a highly active antiretroviral therapy (HAART) regimen, have undetectable plasma viral load (<75 copies/mL), and have CD4 T lymphocyte counts above 400 cells/µL with nadirs over 200 cell/µL. Twelve (12) eligible subjects were administered a four dose series (day 0, weeks 4, 8 and 16) of PENNVAX®-B containing 3 mg of DNA/dose via intramuscular electroporation.

The study was sponsored by Inovio Pharmaceuticals and conducted at the University of Pennsylvania Medical Center. Dr. Pablo Tebas, Professor of Medicine and Director of AIDS Clinical Trials Unit (ACTU) of the University of Pennsylvania, is the Principal Investigator of the HIV-001 study.

All 12 subjects completed the four dose vaccination regimen. There were no significant adverse events or vaccine related grade 3 or 4 adverse events noted in the study and the vaccine was found to be generally well tolerated. Reported injection site reactions were mild to moderate and did not require treatment to resolve. T-cell responses were measured using a validated ELISpot assay at the U Penn Immunology Core Facility.

Overall, significant vaccine-specific T-cell responses were observed in 75% (9 out of 12) of subjects against at least one of the three vaccine antigens (gag. pol, or env) following vaccination. Fifty percent of the subjects (6 out of 12) had strong vaccine induced antigen-specific responses above the pre-vaccination levels to at least two of the antigens. Importantly, the responses induced by vaccination were predominantly antigen-specific (i.e. gag, pol and env) CD8+ T-cells, which are considered to be paramount in clearing chronic viral infections and an important measurement of the performance of a therapeutic vaccine. These results are in stark contrast to previously reported studies with other DNA vaccines delivered without electroporation that yielded poor overall T cell immune responses.

According to the Joint United Nations Programme on HIV/AIDS (UNAIDS), nearly 30 million people have died from HIV-related causes and roughly 34 million are living with HIV. Although a highly active antiretroviral therapy (HAART) regimen has dramatically transformed the treatment of the disease in developed countries, effective HIV vaccines are needed to stop the spread of disease and perhaps reduce the need for antiretroviral treatments, which generally have harsh side effects and which in many cases lose their efficacy over time. Inovio's PENNVAX®-B HIV vaccine is unique in the field in that it is designed to be used for both treatment and prevention.

Inovio previously reported best-in-class T cell immune responses to the PENNVAX®-B vaccine in healthy adults in a preventive setting. In that study (HVTN-080), three doses of the vaccine delivered together with an IL-12 cytokine plasmid via electroporation resulted in over 89% of the vaccinated subjects mounting an antigen-specific CD4+ or CD8+ T cell response against at least one of the vaccine antigens. The HIV-001 study did not include the IL-12 cytokine plasmid. Inovio plans to further study the impact of cytokines as well as the impact of therapeutic vaccination on HIV viral load in future clinical trials.

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 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, 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, 2010, our Form 10-Q for the quarter ended September 30, 2011, 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.

CONTACTS:

Investors: Bernie Hertel, Inovio Pharmaceuticals 858-410-3101 [email protected]

Media: Jeff Richardson, Richardson & Associates 805-491-8313 [email protected]

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SOURCE Inovio Pharmaceuticals, Inc.