Baxter Receives EMEA Positive Opinion for CELVAPAN, the First Cell Culture-Based Pandemic Flu Vaccine
News Dec 19, 2008
Baxter International Inc. announced that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMEA) has issued a positive opinion for the marketing authorization of CELVAPAN, the first cell culture-based H5N1 (avian flu) pandemic vaccine, in the European Union.
The positive opinion precedes the licensure of the “mock-up” vaccine, which allows CELVAPAN to be used if the World Health Organization (WHO) officially declares a pandemic. The positive opinion was based on results from a comprehensive clinical development program, including a Phase III clinical trial that demonstrated vaccines for two different H5N1 virus strains were well tolerated and generated a functional immune response.
“We are very pleased to receive the EMEA’s positive opinion for CELVAPAN,” said Hartmut Ehrlich, M.D., vice president, BioScience global research and development. “This is another step towards our goal of supplying a safe and effective vaccine to protect the population against a possible influenza pandemic.”
A “mock up” vaccine is identical to the future pandemic vaccine in composition and manufacturing; however, since the actual pandemic strain is not known, the vaccine contains another influenza strain not yet exposed to the general population. Once a pandemic is declared, this licensure allows for a fast track approval of the vaccine containing the actual pandemic strain.
CELVAPAN is made using Baxter’s proprietary Vero cell technology, which offers advantages against conventional egg-based vaccine technology. Baxter’s Vero cell manufacturing process is more rapid due to its ability to use the “native” virus that does not need to be modified in order to grow in chicken eggs. The shorter time for vaccine production is critical in accelerating vaccine supply in response to an influenza pandemic.
Baxter’s candidate avian flu vaccine is derived from the H5N1 strain A/Vietnam/1203/2004. Its antigen composition and structure are identical to the actual virus circulating in nature. This vaccine formulation alleviates the need to enhance the immune response by including adjuvants (additives) that may cause side effects. In the Phase III study, CELVAPAN induced an immune response that is similar to the body’s defense against a natural influenza virus infection.
The purpose of the randomized Phase III study was to evaluate safety and immune responses to 7.5 µg of the Vietnam strain vaccine in two age groups. The antibody persistence and immune response to a booster with either the same or a different strain was also measured. The study also investigated the ability of the vaccine to induce cross-immunity against divergent H5N1 strains.
Overall, the vaccine was well tolerated after the first and second vaccination as well as after the booster, with a safety profile similar to currently licensed seasonal influenza vaccines. The most common side effects were injection site pain and headache, fatigue or malaise.