The data show that two 0.6 microgram doses of Novavax's virus-like particle (VLP) H5N1 vaccine -- without the addition of an adjuvant -- protected ferrets from challenges with live H5N1 bird flu viruses. This dose is 25 fold lower than the average human dose for most seasonal flu vaccines and more than 100 times lower than other H5N1 vaccines against avian influenza. Novavax plans to submit an investigational new drug application to the U.S. Food and Drug Administration in mid-2007 to commence human clinical trials with the novel H5N1 influenza vaccine.
"We are extremely encouraged that even very low doses of our vaccine are proving to be effective in pre-clinical models without the need for adjuvants," said Dr. Rick Bright, Novavax's Vice President of Global Influenza Programs. "This may be important in a pandemic, where the vaccine supply could possibly need to be 'stretched' to meet the significant global demand."
In the study, ferrets were inoculated with a range of doses of the company's VLP vaccine made from an Indonesian strain of H5N1 avian influenza. The ferrets, which represent the most relevant influenza animal model for humans, were then challenged with live H5N1 virus, and all survived. The typical human dose of a seasonal influenza vaccine is 15 micrograms. Other pandemic vaccines with no adjuvant have shown only modest levels of immunogenicity in humans with doses as high as 90 micrograms. In this study, ferrets received either 15, 3 or 0.6 micrograms of Novavax's vaccine, and all immunized animals had similar survival results.
In addition, ferrets were protected not only against the Indonesian strain of avian flu but were cross-protected against a separate challenge strain originating in Vietnam. Again, all ferrets that received the Novavax vaccine survived, even those that received the lowest 0.6 microgram dose.
The International Conference on Avian Influenza in Humans brings together leading bird flu experts at the Pasteur Institute to review and discuss the latest scientific advances in vaccine prevention strategies and treatments designed to stem a pandemic.
The U.S. Centers for Disease Control and Prevention currently is testing antibodies from these animals against a number of additional strains of H5N1 that have been detected in recent years to establish whether the vaccine is even more broadly cross-protective.
"We are eager to begin our human clinical trials so that we can continue to evaluate the immunogenicity of our vaccine," Dr. Bright said. "The goal of prevention in a pandemic setting is to be prepared with a vaccine that can protect against varying strains of the virus that mutate as they travel around the globe, and to have enough supply to protect vulnerable populations. We believe our VLP vaccine may provide a unique solution to this potential public health threat."
VLPs mimic the three-dimensional structure of a virus but do not contain genetic material, so they cannot replicate or cause infection. As VLPs maintain functional properties of both influenza surface proteins (hemagglutinin and neuraminidase), they have been shown to activate multiple arms of the immune system to generate a broadly protective immune response.
"We continue to learn more about the potency of our VLP based flu vaccines, which have been shown to induce broadly reactive antibodies, provide efficacy against drifted flu strains, and elicit both B cell and T cell responses," Dr. Bright said. "This information is being used to design clinical studies that have the potential to demonstrate the advantages of the VLP flu vaccines in humans."
About Novavax Inc.
Novavax Inc. (Nasdaq: NVAX) is committed to leading the global fight against infectious disease by creating novel, highly potent vaccines that are safer and more effective than current preventive options. Using the company's proprietary virus-like particle (VLP) and Novasome(R) adjuvant technologies, Novavax is developing vaccines to protect against H5N1 pandemic influenza, seasonal flu and other viral diseases. Novavax's particulate vaccines closely match disease-causing viruses while lacking the genetic material to cause disease, which provides potential for greater immune protection at lower doses than current vaccines. With an exclusive portable manufacturing system that allows for rapid mass-production of vaccines, Novavax is uniquely positioned to meet global public health needs.
Statements herein relating to future financial or business performance, conditions or strategies and other financial and business matters, including expectations regarding clinical developments, safety, efficacy and potency of our vaccines, and supply availability are forward-looking statements within the meaning of the Private Securities Litigation Reform Act. Novavax cautions that these forward-looking statements are subject to numerous assumptions, risks and uncertainties, which change over time. Factors that may cause actual results to differ materially from the results discussed in the forward-looking statements or historical experience include risks and uncertainties, including the failure by Novavax to secure and maintain relationships with collaborators; risks relating to the early stage of Novavax's product candidates under development; uncertainties relating to commencing clinical trials and their outcome; risks relating to the supply and commercialization, if any, of Novavax's proposed product candidates; dependence on the efforts of third parties; dependence on intellectual property; competition for clinical resources and patient enrollment from drug candidates in development by other companies with greater resources and visibility, and risks that we may lack the financial resources and access to capital to fund our operations. Further information on the factors and risks that could affect Novavax's business, financial conditions and results of operations, is contained in Novavax's filings with the U.S. Securities and Exchange Commission, which are available at http://www.sec.gov. These forward-looking statements speak only as of the date of this press release, and Novavax assumes no duty to update forward- looking statements.