Novavax Study Published in Vaccine

RSV F-Protein Nanoparticle Vaccine Induces Antigenic Site II Antibodies

• Vaccinated Animals Generated a Broad Spectrum of Protective Antibodies
• Vaccine Induces Antibodies that are at Least as Protective as Palivizumab
• Palivizumab Competing Antibody Response from Vaccine Protects Against Both Homologous and Heterologous Disease Strains

GAITHERSBURG, Md., Oct. 15, 2014 (GLOBE NEWSWIRE) -- Novavax, Inc. (Nasdaq:NVAX), a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of recombinant nanoparticle vaccines and adjuvants, today announced that its RSV F-protein nanoparticle vaccine candidate (RSV F Vaccine) evoked a polyclonal antibody response to antigenic site II, the same site targeted by the monoclonal antibody palivizumab (Synagis^®), resulting in protection from an RSV challenge in an animal model. Researchers at Novavax reported these findings in an online paper published by Vaccine titled: "An insect cell derived respiratory syncytial virus (RSV) F nanoparticle vaccine induces antigenic site II antibodies and protects against RSV challenge in cotton rats by active and passive immunization."

"This study further characterizes the immune response to our RSV F Vaccine, including the production of both polyclonal palivizumab competing antibodies that target antigenic site II, as well as other neutralizing antigenic sites on the F-protein," said Greg Glenn, SVP, Research and Development at Novavax. "In addition, our ability to assess the safety of our RSV F Vaccine relative to Lot 100 formalin inactivated vaccine, which is known to cause disease enhancement, and to demonstrate that our vaccine's efficacy is equivalent or better than palivizumab, gives us greater confidence that our RSV vaccine candidate will be both safe and effective."

RSV is the number one cause of hospitalization in infants ages 0 to 12 months in the U.S. and is a significant cause of infant morbidity and mortality globally. The only approved product in the U.S. for the prevention of RSV disease in this population is palivizumab, marketed as Synagis^® by MedImmune/AstraZeneca. Palivizumab binds to a specific domain on the RSV F-protein known as antigenic site II, blocking viral fusion and preventing infection. Novavax has developed a novel RSV vaccine candidate based on the expression of a mature form of the RSV F-protein, which exposes the antigenic site II for processing by the immune system. The resulting immune response produces polyclonal antibodies that have been shown to compete with palivizumab for the antigenic site II binding domain, referred to as palivizumab-competing antibodies or PCA.