GlaxoSmithKline has announced the start of an international clinical trial program to test two pandemic vaccines against the H5N1 strain of the avian influenza virus in humans. This dual approach reflects the company’s commitment to provide health authorities with concrete options to face the threat of a pandemic.

A clinical trial just initiated in 400 healthy adult volunteers in Germany is testing a pandemic flu vaccine using a classic alum adjuvant to improve individuals’ immune response and possibly allow a lower amount of antigen to be used per dose. This trial supports a dossier GSK submitted to European regulators in December 2005. Should a pandemic flu strain be identified by the World Health Organization, a variation to the dossier would allow rapid European registration and production of a pandemic vaccine.

In parallel, a clinical trial conducted in Belgium in 400 healthy adults is testing a candidate pandemic flu vaccine that contains a novel adjuvant system. GSK is hopeful that a vaccine formulated with this novel adjuvant will further enable individuals’ immune system to respond to different H5N1 virus strains, offering a broader protection against the threat of a pandemic.

GSK novel adjuvant technology is also expected to further reduce the amount of antigen needed per dose, increasing the number of doses the company could make available worldwide. Such a vaccine would offer governments additional options of stockpiling and vaccinating ahead of a pandemic outbreak.

Both trials are testing the vaccine’s safety and ability to boost individuals’ immune response against H5N1. Tested vaccines are made from inactivated (killed) H5N1 virus. Different dose levels are being studied. Volunteers are to receive two vaccinations approximately three weeks apart. The studies will allow GSK to select an optimal dose and formulation for subsequent safety trials in groups at high risk of complications following influenza infection, such as children and the elderly.

Preliminary results from the clinical trials are expected in the third quarter of 2006. GSK plans to have a pandemic flu vaccine in production before the end of the year.

Jean Stephenne, President of GSK Biologicals, the vaccine division of GSK said: “We are moving forward with clinical trials of vaccines which could prove a vital part of the world’s response to a flu pandemic. While the first vaccine candidate aims at mounting a strong defense against a pandemic outbreak, the second vaccine may offer governments a preferred option to proactively stockpile and begin vaccination before the onset of a pandemic, significantly increasing the speed of a public health response in the event of an outbreak.”

Emmanuel Hanon, GSK head of Flu operations worldwide explained: “We believe that vaccinating populations with the appropriate H5N1 vaccine will help educate the body’s immune system and reduce expected morbidity and mortality associated with a pandemic. This means that if the current bird flu virus mutates to allow human-to-human transmission, a vaccinated person will be better prepared to combat the H5N1 pandemic flu virus.”

H5N1 avian influenza infections lead to severe disease in both birds and humans. Public health experts fear that the virus may evolve into a strain that is easily transmitted between people, triggering a worldwide pandemic. Influenza pandemics are global outbreaks that involve viruses to which humans have little or no immunity. H5N1 is one such flu virus strain.

GlaxoSmithKline, a leader in Flu treatment and preparedness

GlaxoSmithKline has an active research and development program targeted at both seasonal and pandemic influenza and has recently committed over a billion pounds ($2 billion) to expand capacity for manufacturing flu vaccine and its anti-viral influenza treatment Relenza(R) (zanamivir for inhalation).

GSK was the first company to submit a “mock-up” dossier for a pandemic vaccine with traditional alum adjuvant to European regulators in December 2005. Under new European rules, the vaccine was given accelerated review status. Should a pandemic flu strain be identified by the World Health Organization, a variation to the dossier would allow rapid registration and production of a pandemic vaccine more closely matched to the circulating pandemic strain.

In North America, GSK recently acquired a major influenza vaccine manufacturer, ID Biomedical Corporation. This acquisition provides GSK with a significant increase in flu vaccine manufacturing capacity. The production capacity of the newly acquired Canadian facilities - combined with GSK’s expanded vaccines manufacturing plant in Dresden, Germany - is expected to reach around 150 million doses per year by 2008. These numbers are based on production of trivalent seasonal influenza vaccine. The production capacity of a monovalent flu pandemic influenza vaccine can be expected to be significantly higher.

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