Baxter International, DVC present Phase III clinical efficacy data for PREFLUCEL

Baxter International Inc. (NYSE:BAX), in conjunction with DynPort Vaccine Company LLC (DVC), a CSC Company (NYSE:CSC), today presented Phase III study data measuring the clinical efficacy for PREFLUCEL, a trivalent seasonal influenza candidate vaccine. PREFLUCEL is made using Baxter’s Vero cell culture platform and does not contain an adjuvant or preservatives. The data were presented at the International Congress on Infectious Disease (ICID) in Miami, Florida.

“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.”

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.”

In the double-blind, placebo-controlled trial, the highly sensitive 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 (CHMP). For licensure of new influenza vaccines, CHMP mandates that at least one of these criteria are met for each of the three strains (H1N1, H3N2, B) included in the vaccine. The findings were also consistent with immunogenicity data from Baxter’s previous studies of PREFLUCEL in adults and the elderly.

The Phase III study also indicates that PREFLUCEL’s safety profile is similar to that of licensed egg-derived seasonal influenza vaccines. The most common side effects observed in the study were injection site reactions, myalgia, fatigue, headache and malaise.

Baxter and DVC plan to complete the PREFLUCEL Phase III clinical trial program in adults and elderly individuals in early 2010. Work on this vaccine is being completed as part of a U.S. Department of Health and Human Services (HHS) Office of Public Health and Emergency Preparedness contract awarded to DVC in May 2006. DVC is working in collaboration with Baxter to develop seasonal and pandemic influenza vaccines. Under this contract, DVC is managing the project and clinical trials. Baxter is manufacturing the vaccines and will serve as the FDA license-holder should the product be licensed in the United States.