Baxter International Inc. (NYSE: BAX) announced final Phase I/II data for its adjuvant-free investigational pandemic H5N1 influenza vaccine and plans to initiate a Phase III clinical trial of the candidate vaccine in Europe to confirm the study results.
The Phase I/II study indicated that Baxter?s H5N1 candidate vaccine is highly immunogenic at low doses, and induces substantial levels of cross immunity against widely divergent H5N1 strains.
The open-label, multi-center Phase III trial is designed to evaluate the safety and efficacy of Baxter?s adjuvant-free, whole-virus candidate vaccine. Vaccinations will begin in the first half of this year and results of the Phase III trial are scheduled to be available by the end of 2007.
?The results of the Phase I/II clinical trial suggested that this candidate vaccine may provide protection against divergent strains of virus, even at low dose levels without an adjuvant,? said John Oxford, professor of Virology, The Queen Mary School of Medicine, London, United Kingdom. ?The Phase III clinical trial is designed to confirm these findings and provide a solid measure of the vaccine?s potential to protect a large number of people before and during a possible pandemic.?
Baxter?s candidate H5N1 vaccine is derived from H5N1 strain A/Vietnam/1203/2004. Its antigen composition and structure closely resembles the actual pathogen circulating in nature. The candidate vaccine induces an immune response (both cell and antibody mediated) that is similar to the body?s defense against a natural virus, without the need to incorporate additional agents (adjuvants) to enhance immune response. It is manufactured using the company?s proprietary vero cell technology, which produces high-yield vaccine more quickly than traditional approaches because it is not produced in eggs. Baxter?s candidate vaccine is the first cell-based candidate H5N1 pandemic vaccine to undergo clinical evaluation.