DEERFIELD, Ill. — Baxter International Inc., in conjunction with DynPort Vaccine Co., announced Phase III study data measuring the clinical efficacy for its trivalent seasonal influenza candidate vaccine on March 11 in Miami.
The data on Preflucel were presented at the International Congress on Infectious Disease.
The Phase III clinical study found a 78 percent overall protection rate against culture-confirmed influenza from influenza strains that matched those in the vaccine and a 71 percent rate of prevention of influenza from all circulating strains. The study was conducted during the 2008/2009 influenza season in the United States in more than 7,000 healthy clinical trial participants ages 18 to 49.
"We are pleased that these data suggest Preflucel elicits a strong immune response and may prevent influenza disease in vaccinated individuals," said Hartmut J. Ehrlich, M.D., vice president of Global Research and Development for Baxter's BioScience business. "This is a landmark study assessing the efficacy of a cell culture-based, non-adjuvanted and preservative-free vaccine in the prevention of seasonal influenza."
Preflucel is made using Baxter's Vero cell culture platform and does not contain an adjuvant or preservatives.
In the double-blind, placebo-controlled trial, the nasopharyngeal fluid test was used to detect the presence of influenza infection in any of the 7,243 trial participants who presented with clinical symptoms suggestive of influenza disease at least 21 days after vaccination.
The study also assessed the immunogenicity of Preflucel by determining the rates of seroprotection and seroconversion, as well as geometric mean titer increases, in vaccinated study participants.
Immunogenicity results met all of the requirements for each of these criteria set forth by the European Medicines Agency's Committee for Medicinal Products for Human Use.
For licensure of new influenza vaccines, CHMP mandates that at least one of these criteria is met for each of the three strains.