BLUE BELL, Pa., Jan. 23, 2014 /PRNewswire/ -- Inovio Pharmaceuticals, Inc. (NYSE MKT: INO) today unveiled that the company has developed a new DNA-based cytokine immune activator, interleukin -33 (IL-33), that in combination with optimized DNA vaccines delivered by electroporation increased the potency and efficacy of the therapeutic response to the DNA vaccines in a preclinical study. The findings of this study reveal that IL-33 could be an effective immune booster when used with Inovio's products to generate therapeutic immune responses against cancers and chronic viral infections in humans. Inovio has developed a portfolio of patent-protected IL-33 and other immune activators to form combination therapies with its DNA vaccines and immunotherapies with the goal of achieving the greatest possible efficacy against targeted diseases.
A therapeutic vaccine study treating HPV-16 based cancer-bearing mice demonstrated rapid and complete tumor regression after treatment with Inovio's HPV16 (human papillomavirus type 16) vaccine in combination with DNA-based IL-33. Both were delivered using Inovio's CELLECTRA® electroporation device. Previous studies have shown that the HPV 16 DNA vaccine alone was able to prevent tumor growth in mice and delay progression or cure mice of tumors. Addition of the IL-33 immune activator resulted in a more rapid and complete regression of established tumors in the mouse model.
The adjuvant/vaccine combination induced potent CD4 and CD8 T cells. Notably, inclusion of the DNA-based IL-33 immune activator significantly increased the magnitude of vaccine-specific CD8 T cell responses. Prior research has demonstrated that CD4 and CD8 T cells are both important in cellular immune responses; however, CD8 T-cells, or killer T cells, are considered especially integral to fighting cancers and chronic infectious diseases.
The peak vaccine-induced expansion of CD8 T cells at 14 days after vaccination correlated with complete tumor regression. This desirable outcome points to the important role IL-33 and other immune activators may play in combination with Inovio's cancer treatments in development.
The results of this study, conducted by Inovio scientists and collaborators, are detailed in a paper entitled: "Alarmin IL-33 acts as potent immunoadjuvant enhancing antigen-specific cell-mediated immunity and inducing potent anti-tumor immunity," published in Cancer Research.
Dr. J. Joseph Kim, Inovio's President and CEO, said: "To create the most effective arsenal of therapeutic products against cancer and infectious diseases, we are researching combination therapies using our DNA immunotherapies with checkpoint inhibitors and immune activators to optimize their therapeutic effects. While we have already reported best-in-class T cell responses from two DNA vaccines in human trials, this published study shows for the first time how DNA-based IL-33 can boost antigen-specific immune responses generated by our DNA immunotherapies and vaccines.
"We are developing multiple DNA plasmid based cytokine and chemokine genes as immune activators and I am proud to say that Inovio has more of these immune activators in its pipeline than anyone else in the world. We have initiated human studies using other DNA-based cytokines and look forward to moving IL-33 into clinical trials in combination with our DNA vaccines," Dr. Kim added.
About Inovio's Immune Activators
Immune activators can play a vital role in augmenting antigen-specific immune responses such as those generated by Inovio's DNA vaccines. Inovio's portfolio of patent-protected immune boosters vary in their ability to enhance (activate) therapeutic T cells or preventive antibodies, modulate the type of immune responses produced by the vaccine, impact durability of immune responses, and drive immune responses to sites of infection, e.g. mucosal surfaces. Different immune activators can therefore play unique roles in achieving desired immune responses generated by DNA immunotherapies and vaccines. Moreover, while some protein based cytokines and chemokines have been shown to have severe toxicity, likely due to their dosing and systemic delivery, Inovio's DNA-based cytokines and chemokines are delivered together with the vaccines as DNA plasmids and are produced locally at the injection site to drive the production of immune responses without systemic effects.
Inovio has deployed two different DNA immune activators in human studies with electroporation delivery. Inovio previously reported that in a published clinical study its DNA-based IL-12 immune activator enhanced antigen-specific T cell immune responses from its HIV DNA vaccine, PENNVAX®. In that study, 89% of the subjects who received IL-12 DNA together with the PENNVAX® DNA vaccine delivered with electroporation produced a vaccine specific CD4+ or CD8+ T cell response compared to 67% who received the DNA vaccine alone without the IL-12 DNA. To exploit these boosting properties, Inovio plans to test its cancer immunotherapy products in combination with DNA IL-12 in upcoming cancer trials. Additionally, a second cytokine based DNA immune activator, Inovio's DNA-based IL-28, in combination with its multi-antigen hepatitis C DNA vaccine, INO-8000, is being tested in a phase I study in HCV patients. Inovio has in its portfolio over ten (10) important cytokine and chemokine genes which have shown in preclinical studies to boost either T cell or antibody-based immune responses to the vaccines and therapies.
About Inovio Pharmaceuticals, Inc.
Inovio is revolutionizing vaccines to prevent and treat today's cancers and challenging infectious diseases. Its SynCon® vaccines, in combination with its proprietary electroporation delivery, are generating best-in-class immune responses, with therapeutic T-cell responses exceeding other technologies in terms of magnitude, breadth, and response rate. Human data to date have shown a favorable safety profile. Inovio's lead vaccine, a therapeutic against HPV-caused pre-cancers and cancers, is in phase II. Other phase I and preclinical programs target prostate, breast, and lung cancers as well as HIV, influenza, malaria and hepatitis. Partners and collaborators include Roche, the University of Pennsylvania, Merck, NIH, HIV Vaccines Trial Network, National Cancer Institute, U.S. Military HIV Research Program, 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, 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, 2012, our Form 10-Q for the quarter ended September 30, 2013, 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.