MERIDEN, Conn., June 14 /PRNewswire/ -- Protein Sciences Corporation announced today preliminary results from its first field efficacy study of FluBlOk(TM), a patented influenza vaccine that is produced in insect cells without live influenza viruses, eggs or preservatives such as thimerosal. The study enrolled 460 healthy subjects aged 18 to 49 into three equal arms at three sites in the United States during the 2004/05 influenza season. Subjects received one of the two different doses of FluBlOk (the concentration of the H1 and B antigens was different and the H3 antigen the same in the two FluBlOk formulations) or placebo. The study subjects were followed for influenza-like illnesses (ILI) and those who developed ILI were cultured to confirm that their illness was influenza. The study met its primary endpoints by showing safety and inducing strong titers against influenza in all vaccinated subjects that correlate with protection. FluBlOk containing higher amounts of the H1 and B antigens was 100% efficacious in preventing culture positive influenza illness, the FDA standard measure of efficacy. This was statistically significant compared to placebo (p=0.0146). FluBlOk also significantly reduced the overall occurrence of CDC-defined ILI compared to placebo, the established measure of vaccine effectiveness. FluBlOk was more than 85% efficacious against culture positive influenza illness in the combined vaccine group (2/301 vs. 7/153 placebo), which also was statistically significant relative to placebo (p=0.0083). A comparison group using the 2004/05 egg-grown vaccine could not be included in the study because of the vaccine shortage, but the results with FluBlOk are as good as or better than what would be expected with the licensed vaccine. Final immunologic laboratory assessments and full clinical data audits are still in progress. "We are extremely pleased with these results that matched even our most optimistic scenario," said Daniel D. Adams, Protein Sciences President and CEO. "We showed that FluBlOk provides a clear dose-response effect for the H1 and B antigens, which we demonstrated previously for the H3 antigen. It is especially significant that in such a small study the results show that FluBlOk is protective under field conditions and strongly suggest that FluBlOk can provide protection that is superior to the licensed influenza vaccines." He added, "It is now reasonable to think in terms of applying for licensure of FluBlOk in the next few years." The Principal Investigator of the study, Dr. John Treanor, Professor of Medicine, Infectious Disease Unit, University of Rochester Medical Center, said, "The results of this study are very impressive and clearly show that FluBlOk had a protective effect against culture-positive illness meeting the CDC-ILI case definition." He added, "The study shows that the baculovirus expressed hemagglutinin induces a high level of protective immunity in humans and that the lack of a neuraminidase in FluBlOk does not compromise the protective effect. This represents an important validation of the baculovirus approach for the next generation of flu vaccine. The FluBlOk approach is also uniquely well suited for the challenges that pandemic influenza poses, so the results of this study are especially important as we consider our responses to this looming threat." In addition to Dr. Treanor, the clinical investigators included Dr. Gilbert Schiff at the University of Cincinnati Children's Hospital and Dr. Frederick Hayden at the University of Virginia. Eight previous clinical trials under which approximately 1,200 healthy adult and elderly and immunocompromised subjects were vaccinated with various formulations of FluBlOk have been conducted Division of Microbiology and Infectious Diseases (DMID), a division of the National Institute of Allergy and Infections Diseases, National Institutes of Health. These studies all show that FluBlOk is safe and that vaccinees develop antibodies that are believed to be protective against influenza. A DMID trial in the elderly in 2003 showed that higher doses of FluBlOk can be safely administered to elderly subjects, generate antibody titers that are significantly more immunogenic than licensed vaccines and could protect up to 97% of the elderly against influenza. Two DMID clinical trials of monovalent FluBlOk designed to protect against an H5N1 potential pandemic influenza strain were conducted in over 200 subjects. A high percentage of subjects receiving two doses of vaccine generated antibodies that are believed to be sufficient to protect against the lethal virus. We plan to conduct further studies in the United States and elsewhere in all age groups including "at risk" populations such as young children and asthmatics with the expectation of applying for licensure in the United States in the next few years. Protein Sciences is a world leader in developing recombinant human and veterinary vaccines, therapeutics and diagnostics using its proprietary baculovirus expression vector system technology.
SOURCE Protein Sciences Corporation