Pandemic 2009 Influenza Update: Pandemrix™ data in children and adolescents from 3 to 17 years of age

London UK - GlaxoSmithKline (GSK) today announced that over 40 million doses of its adjuvanted pandemic H1N1 vaccine have been distributed to countries globally for use in government-initiated vaccination programmes. GSK also announced new results from the clinical trial assessing the use of Pandemrix™ in children and adolescents aged 3 to 17 years of age. The trial, which is ongoing, shows that after the first dose of adjuvanted vaccine, a strong immune response was demonstrated in all age groups. The immune response elicited by Pandemrix exceeded the immunogenicity criteria, as defined by international licensing authorities for a pandemic influenza vaccine. All study participants in this trial received 3.75 micrograms of GSK’s adjuvanted H1N1 vaccine which is equivalent to the full adult dose.

"These results complete GSK’s initial post first dose data across all age ranges, from infants through to the elderly. In response to discussions with regulatory authorities and public health authorities, GSK has conducted a clinical programme designed to provide data in all age groups.” said Jean Stéphenne, President of GSK Biologicals. “We are making this information available in as short a time as possible. This allows authorities to have a more complete understanding of how the vaccine can be used in all age groups.”

In this study, children and adolescents aged 3 to 17 years were stratified into 3 age cohorts (3-5 years; 6-9 years; 10-17 years). These results show that 100% of children in all 3 cohorts demonstrated responses above the regulatory threshold of 1:40 seroprotection, which is considered indicative of protection in adults.

The tolerability of the vaccine in this study was again shown to be in line with that observed in the previously EMEA-approved H5N1 adjuvanted vaccine, as well as in the other pandemic H1N1 trials to date. Local reactions such as pain, redness, and swelling at the site of injection were observed in this trial. General reactions such as fatigue, low grade fever, headache, and muscle ache were also observed in this trial, and were reported at rates in line with or slightly higher than reported with GSK’s current unadjuvanted seasonal influenza vaccines. To date, the adverse events being reported to GSK by countries who have started vaccination programmes are also aligned with what has been seen in these clinical trials.

Further information on GSK’s development of a vaccine to protect against pandemic 2009, including explanation of the vaccine development process and background information on adjuvants is available on: www.gsk.com/media/pandemic-flu.htm

GlaxoSmithKline – one of the world’s leading research-based pharmaceutical and healthcare companies – is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For further information please visit www.gsk.com

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Under the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995, GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Factors that may affect GSK’ s operations are described under ’Risk Factors’ in the ’Business Review’ in the company’ s Annual Report on Form 20-F for 2008.

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