Prostate Cancer DNA Vaccine Results in Higher T-Cell Response When Delivered via Inovio Biomedical's Electroporation Delivery System

Inovio Biomedical Corporation (AMEX:INO), a leader in enabling the development of DNA vaccines using electroporation-based DNA delivery, announced today that the team of Dr. Christian H. Ottensmeier, MD, PhD, Cancer Research UK Senior Clinical Research Fellow at the University of Southampton, will present interim data from a clinical study of an experimental DNA-based prostate cancer vaccine at the American Association for Cancer Research meeting in San Diego, USA, April 12 – 16, 2008. The data indicates that the combination of this DNA vaccine and electroporation DNA delivery was safe and well-tolerated. Patients treated using electroporation also displayed higher levels of antibody and anti-DOM CD4 responses. This academic study is a phase I/II study in 30 HLA A2+ patients with biochemical failure of prostate cancer. The study is testing a DNA fusion vaccine developed at Southampton. The vaccine encodes an immunostimulant sequence from tetanus linked to a sequence from prostate specific membrane antigen (PSMA27). PSMA is an attractive antigen as it is found in the vast majority of prostate cancers and its expression is increased after standard anti-androgen treatment. The study is also evaluating electroporation as a novel delivery strategy for DNA vaccines compared to DNA delivered without electroporation. The study has completed recruitment of 30 patients and vaccination is ongoing at the third (highest) dose level. Monitoring of antibody responses has been completed for the 20 patients at the first and second dose levels to week 16. Monitoring of CD4 cellular immunity has been completed for the 10 patients at the lowest dose. These 10 patients have additionally been assessed for CD8 T-cell responses. Interim results to date include: --   Vaccination with and without electroporation has been safe and well tolerated.   -- The tetanus sequence induced strong antibody responses and cellular immunity. The PSMA27 antigen induced CD8+ cytotoxic T-cells in a substantial number of the patients.   --   13 of 20 patients developed increases in anti-DOM (the immunostimulant sequence from tetanus) antibody by week 16 after three vaccinations. Of these increased responses, 4 of 10 were in the DNA arm; 9 of 10 were in the electroporation arm.   -- In 9 of 10 patients in the low dose cohort, increases in CD4 responses were observed.   -- 6 of 10 subjects in the low dose cohort developed PSMA27-specific CD8 responses not detected before vaccination.   -- Antibody responses were generally higher in patients treated using electroporation compared to those treated with the DNA vaccine alone (without electroporation). The use of electroporation-based DNA delivery appears to also increase the level of anti-DOM CD4 responses. "We are extremely pleased with these observations that our electroporation delivery technology is enhancing the level of antibody and T-cell responses from this novel DNA vaccine against prostate cancer,” said Avtar Dhillon, MD, president and CEO of Inovio. "Apart from assessing the safety and tolerability of electroporation, being able to also detect increased levels of immune response is one of the important outcomes that we are aiming to achieve with all of our five current clinical studies for DNA-based immunotherapies and DNA vaccines that are being advanced by our partners.” The development of this DNA vaccine was supported by the UK cancer charities the Leukemia Research Fund and Cancer Research UK, and rights to the vaccine are owned by Cancer Research Technology Limited. The study was supported by Cancer Research UK funding, the Allan Willett Foundation, Inovio Biomedical Corporation, and the Experimental Cancer Medicine Centre in Southampton. The clinical study is a collaborative project between the University of Southampton/Southampton University Hospitals and the Institute of Cancer Research/Royal Marsden Hospital, Sutton, Surrey. An abstract of the presentation (Abstract Number 2843) including CD8+ response data for the first three patients is now available at www.aacr.org. The presentation during the conference will include the data from the first ten patients referenced above. About Inovio’s Immunotherapy Products DNA-based immunotherapy products have the potential to by-pass inherent scientific obstacles of conventional vaccines that prevent their development for cancer and chronic infectious diseases such as HIV and hepatitis C. Pre-clinical and clinical data have indicated the potential ability of Inovio’s technologies to safely and effectively deliver and significantly enhance the potency of such immunotherapies. Inovio’s DNA-based immunotherapy products consist of DNA plasmids and its electroporation-based intratumoral and intramuscular DNA delivery systems. A DNA plasmid is designed to express an antigen that can induce an immune response specific to a cancer or infectious disease-causing organism. The plasmid is synthetically created and readily manufactured using well-established bacterial fermentation and purification technology. After a plasmid is delivered into tumor or muscle cells, production of the antigen may then induce a preventive or therapeutic immune response against the targeted disease. Inovio’s advanced electroporation devices facilitate delivery and expression of such immunotherapies and have been shown in primate and human studies to safely and efficiently generate immune responses. Breast cancer, prostate cancer, melanoma, HIV and hepatitis C virus are among the current targets of therapies employing Inovio technology. Inovio is poised to deliver advanced DNA-based immunotherapies, devices and know-how in this rapidly advancing field. The company is actively licensing its technology to pharmaceutical and biotechnology companies and supporting early stage clinical studies arising from its own research efforts or through academic collaborations. About the University of Southampton The University of Southampton is a leading UK teaching and research institution with a global reputation for leading-edge research and scholarship. It is one of the UK’s top 10 research universities, offering first-rate opportunities and facilities for study and research across a wide range of subjects in humanities, health, science and engineering. The University has over 22,000 students and 5000 staff. Its annual turnover is in the region of £325 million. www.soton.ac.uk About Royal Marsden Hospital The Royal Marsden Hospital was the first hospital in the world dedicated to cancer treatment and research into the causes of cancer. Today the hospital with its academic partner, The Institute of Cancer Research, forms the largest comprehensive cancer centre in Europe with over 40,000 patients from the UK and abroad seen each year. It provides inpatient, day care and outpatient services for all areas of cancer treatment. About Cancer Research Technology Cancer Research Technology Limited (CRT) is a specialist commercialization and development company, which aims to develop new discoveries in cancer research for the benefit of cancer patients. CRT works closely with leading international cancer scientists and their institutes to protect intellectual property arising from their research and to establish links with commercial partners. CRT facilitates the discovery, development and marketing of new cancer therapeutics, vaccines, diagnostics and enabling technologies. CRT is wholly owned by Cancer Research UK, the largest independent funder of cancer research in the world. Further information about CRT can be found at www.cancertechnology.com. About Cancer Research UK Together with its partners and supporters, Cancer Research UK's vision is to beat cancer. The charity carries out world-class research to improve understanding of the disease and find out how to prevent, diagnose and treat different kinds of cancer. It ensures that its findings are used to improve the lives of all cancer patients. Cancer Research UK helps people to understand cancer, the progress that is being made and the choices each person can make. The charity works in partnership with others to achieve the greatest impact in the global fight against cancer. For further information about Cancer Research UK's work or to find out how to support the charity, visit www.cancerresearchuk.org. About Leukaemia Research Leukaemia Research is the only national UK charity devoted exclusively to improving treatments, finding cures and learning how to prevent leukaemia, Hodgkin's lymphoma and other lymphomas, myeloma and the related blood disorders. Leukaemia Research receives no government grants and urgently needs to raise over £100 million in the next five years to commit to new research. From basic laboratory research to clinical trials with patients, Leukaemia Research is committed to saving lives by funding high quality, carefully selected research throughout the UK. Further information, including patient information booklets, is available at www.lrf.org.uk. Leukaemia Research currently supports 30 Specialist Programmes in which the groups undertake long-term intensive research into relevant areas of leukaemia and the related diseases, often working closely with diagnosis and treatment; more than 200 project grants, which provides short-term funding, usually two-three years, for work on a specific problem; 25 clinical fellowships for the training of outstanding junior doctors in both the treatment and research of leukaemia and more than 20 studentships, lectureships and senior fellowships. About Inovio Biomedical Corporation Inovio Biomedical (AMEX: INO) is focused on developing multiple DNA-based immunotherapies and DNA vaccines. Inovio is a leader in developing human applications of electroporation using brief, controlled electrical pulses to increase cellular uptake of a useful biopharmaceutical. Human data has shown that Inovio’s electroporation-based DNA delivery technology can significantly increase gene expression and immune responses from DNA vaccines. Immunotherapy partners include Merck, Wyeth, Vical, University of Southampton, Moffitt Cancer Center, the U.S. Army, National Cancer Institute, and International Aids Vaccine Initiative. Inovio’s technology is protected by an extensive patent portfolio covering in vivo electroporation. More information is available at www.inovio.com. This press release contains certain forward-looking statements relating to our plans to develop our electroporation drug and gene delivery technology. Actual events or results may differ from our expectations as a result of a number of factors, including the uncertainties inherent in clinical trials and product development programs (including, but not limited to, the fact that clinical results referenced in this release may not be indicative of results achievable in other trials or for other indications and that results from one study may necessarily not be reflected or supported by the results of other similar studies), the availability of funding to support continuing research and studies in an effort to prove safety and efficacy of Inovio’s technology as a delivery mechanism, the availability or potential availability of alternative therapies or treatments for the conditions targeted by Inovio or its collaborators, including alternatives that may be more efficacious or cost-effective than any therapy or treatment that Inovio and its collaborators hope to develop, evaluation of potential opportunities, issues involving patents and whether they or licenses to them will provide Inovio 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 Inovio can finance or devote other significant resources that may be necessary to prosecute, protect or defend them, the level of corporate expenditures, assessments of our technology by potential corporate or other partners or collaborators, capital market conditions, and other factors set forth in our Annual Report on Form 10-K for the year ended December 31, 2007, and other regulatory filings from time to time. There can be no assurance that any product in our product 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 proved accurate.