Sep 8, 2011 (GlobeNewswire via COMTEX) -- VLP vaccine candidate was well-tolerated, immunogenic and generated cross-reactive neutralizing antibodies
ROCKVILLE, Md., Sept. 8, 2011 (GLOBE NEWSWIRE) -- Novavax, Inc. /quotes/zigman/55054/quotes/nls/nvax NVAX +8.00% announced today the publication of an article that reported new safety, immunogenicity and cross-reactivity results from a Phase I/IIa clinical study of the company's H5N1 influenza virus-like particle (VLP) vaccine candidate that was conducted in 2008. According to the report in the current issue of Journal of Virology, Novavax's VLP-based vaccine targeted against a highly pathogenic avian H5N1 influenza virus was well-tolerated, produced no vaccine-related serious adverse events and induced neutralizing antibodies that were cross-reactive with different avian A/H5N1 influenza viruses. This is the first report of a unadjuvanted vaccine inducing cross-reactive neutralizing antibodies against multiple clades of H5N1 influenza virus.
Novavax's A/H5N1 VLP influenza vaccine candidate was administered to 230 adults immunized with two injections of 15, 45 or 90 micrograms of vaccine; the 2008 study was blinded, randomized and placebo-controlled. Recent analyses show that there was a dose-related immune response and 40%, 57% and 61% of the subjects developed a four-fold or higher increase in hemagglutination inhibition (HAI) and 39%, 52% and 76% of the subjects developed a four-fold rise in microneutralizing (MN) antibodies to the 15, 45 and 90 microgram dose, respectively.
Scientists at the FDA's Center for Biologics Evaluation & Research (CBER) developed new molecular tools for in depth analyses of antibody targets and affinity maturation. Novavax entered into a separate collaborative study with CBER using these tools to analyze a subset of serum samples representative of each vaccine dose for cross-reacting and binding specificity. These studies revealed a broad repertoire of antibody binding to hemagglutinin (HA) and neuraminidase (NA) that map to regions important for proper folding and critical for virus neutralization and protection. Importantly, the VLP vaccine induced antibodies with preferential binding of HA trimers (similar to those present on virions), and this binding correlated with virus neutralization titers. Serum samples with strong titers against the vaccine strain (A/Indonesia clade 2.1) also had high levels (70-90%) of cross-reactive neutralizing antibodies to clade 2.2 and 2.3 H5N1 viruses.
Dr. Greg Glenn, Chief Medical Officer of Novavax, stated: "We are excited about these results and insights into the quality of neutralizing and cross-protective antibody responses produced in the study volunteers by our H5N1 VLP vaccine candidate. Transmission of the highly pathogenic avian H5N1 flu virus in domestic poultry and humans is continuing in many countries and remains a serious pandemic threat with the potential to evolve into new strains where cross-protection and induction of neutralizing antibodies will be essential. The antibodies induced by this vaccine candidate without the use of an adjuvant indicate that the VLP is immunogenic relative to egg-based or cell-culture-derived H5N1 vaccines. These data suggest that VLPs can induce robust and functional responses and warrant further development as a pandemic vaccine. This is an important avenue of research which we are now actively pursuing under our advanced development vaccine contract with the U.S. Department of Health and Human Services' Office of Biomedical Advanced Research and Development Authority."
Novavax, Inc. /quotes/zigman/55054/quotes/nls/nvax NVAX +8.00% , a clinical-stage biopharmaceutical company, employs its cutting-edge technology to create next-generation vaccines to prevent serious infectious diseases, such as pandemic and seasonal influenza and respiratory syncytial virus (RSV). The company's proprietary VLP technology and single-use bioprocessing system enables rapid vaccine development and production where and when it's needed, worldwide. The company has formed a joint venture with Cadila Pharmaceuticals, named CPL Biologicals, to develop and manufacture vaccines, biological therapeutics and diagnostics in India. Additional information about Novavax is available on the company's website: www.novavax.com .