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