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GSK update on research suggesting association between Pandemrix and narcolepsy

25 January 2013

GSK initially became aware of possible cases of narcolepsy following vaccination with the adjuvanted H1N1 pandemic vaccine Pandemrix through adverse events reported in 2010. Since then we have been working hard to better understand the research emerging from a select number of countries suggesting an association between Pandemrix and an increased risk of narcolepsy.

In recent months there have been additional data showing that, in some countries, those vaccinated with Pandemrix appear more likely to develop narcolepsy than those not vaccinated. However, there is a need for further investigations, to disentangle the other factors (such as genetic, environmental, circulating infections) that we know are also associated with narcolepsy and may have played a role. As such we currently believe that the available data are insufficient to assess the likelihood of a causal association between Pandemrix and narcolepsy.

GSK remains committed to carrying out additional research into the potential role of Pandemrix in the development of narcolepsy. We are also supporting ongoing work from other experts and organisations investigating reported cases of the condition. We welcome any new data that could help in these investigations.

Narcolepsy is a complex disease and its causes are not yet fully understood but it is generally considered to be associated with genetic and environmental factors, including infections. It is crucial that we learn more about how narcolepsy is triggered and how Pandemrix might have interacted with other risk factors in affected individuals. The additional data becoming available will support our ongoing research efforts and, we hope, enable us to provide more answers.

Our pandemic vaccines went through a rigorous approval process, undergoing all the safety and efficacy testing required by regulatory authorities. Throughout development there was no data suggesting a potential for an increased risk of narcolepsy among those vaccinated.

GSK takes the safety of patients who entrust their health in our medicines very seriously and we are committed to the highest standards of patient safety.

We remain committed to pursuing additional research to understand the association between Pandemrix and narcolepsy and continue to support the research of others who are investigating reported cases.

Previous press releases regarding Pendemrix:

21 July 2011 - GlaxoSmithKline European regulatory update on Pandemrix

15 April 2011 - GSK European regulatory update on Pandemrix

18 February 2011 - GSK European regulatory update on Pandemrix

1 February 2011 - Update on Pandemrix and interim Finnish report on narcolepsy

23 September 2010 - GSK EU regulatory update on Pandemrix

2 September 2010 - Reports of narcolepsy in Europe following vaccination with Pandemrix