Three Bird flu vaccine shows good results in early trial

[Angel]

An experimental vaccine for bird flu using new cell-based manufacturing methods showed promise at combating several strains of the virus in an early clinical trial, Baxter International Inc. (BAX.N: Quote, Profile, Research) said on Wednesday.

The health-care products maker said preliminary results from a 270-patient study suggest the vaccine was safe, well- tolerated and may provide wider protection against H5N1 -- the bird flu virus -- for a larger number of people.


Although early, Baxter's study suggests the vaccine could be stockpiled and used as a weapon against an emerging bird flu pandemic, said Hartmut Ehrlich, M.D., vice president of global R&D for Baxter's BioScience division.

Ehrlich said the early-stage study suggests the vaccine could offer cross-protection from similar strains of the H5N1 virus.

"We're seeing cross-neutralization, which of course we hope will be translated to cross-effectiveness in a pandemic situation," Ehrlich said in an interview.

H5N1 mainly affects birds, but experts fear it could mutate into a strain easily transmitted from person to person, capable of killing millions of people in a global pandemic.

Deerfield, Illinois-based Baxter said the results are the first data from any bird flu vaccine made using cell-based techniques, a new and better way for developing vaccines that holds the promise of producing much larger quantities of vaccine in much less time.

Vaccine makers currently rely on egg-based production methods, which require steady supplies of carefully grown eggs and months of cultivation. The new method grows the vaccines in labs, in batches of cells called cell cultures.

"Our system will allow us to begin vaccine production significantly earlier than the egg manufacturers," said Noel Barrett, Baxter's vice president of global research vaccines.

He said Baxter is the only vaccine maker using the highly virulent "wild type" strain of the virus, which is the authentic virus circulating in nature,

Baxter is also using the whole virus. Other companies must genetically manipulate the virus to make it less toxic to chicken eggs and must have its safety checked before vaccine production can start.


Because of those extra steps, Barrett estimates the company could have a seven to 10-week advantage over the egg-based manufacturers in the event of a pandemic.

LATE-STAGE CLINICAL TRIAL EARLY 2007

Ehrlich said the Baxter-funded study of healthy adults in Austria and Singapore suggested the vaccine had similar side effects to those reported for seasonal flu vaccines.

The preliminary results suggest the vaccine is highly capable of producing an immune response and can create antibodies to H5N1 even at the lowest dose level.

Serum samples from study subjects showed the vaccine was able to neutralize the virus contained in the vaccine as well as other diverse strains of the H5N1 virus.

Baxter plans to begin a late-stage clinical trial of the vaccine early next year and said it will present final results by the end of 2007.

Joy Amundson, president of Baxter's Bioscience business, said in an interview the company is in active discussions with ministers of health concerning bird flu preparedness.

"We've got a commercial scale facility that is able to produce product immediately," she said.

Baxter is under contract to supply bird flu vaccine to the U.S. and British governments.


Amundson said the company will deliver some 2 million doses to the British government in the fourth quarter and is in the process of delivering product to the U.S. government as well.

Europe's biggest drugmaker GlaxoSmithKline Plc in July said its egg-based vaccine could be mass produced in 2007.

French drugmaker Sanofi-Aventis and Swiss drugmaker Novartis AG are also working on an H5N1 vaccine.

The virus has killed at least 148 people since 2003, mostly in Indonesia, Vietnam, Thailand and China, according to the World Health Organization.