Shares in GlaxoSmithKline were given a boost over the weekend on news that the Committee for Medicinal Products for Human Use has issued the thumbs up for its pandemic H1N1 swine flu vaccine, the newly christened Pandemrix.

The Committee’s recommendation for approval means that European regulators will now conduct an immediate review of the vaccine, which is specifically indicated for protection against pandemic H1N1 2009 influenza, in the hope that its speedy introduction will help to reduce the impact of the current pandemic.

“GSK will continue to work closely with regulators, governments and health authorities around the world so that they can determine the most appropriate strategy to address the H1N1 pandemic,” promised Jean Stéphenne, President GlaxoSmithKline Biologicals.

The CHMP nod is actually based on a “mock-up” registration file using the H5N1 antigen cleared by European regulators in August last year, which, the company stressed, was shown to be both effective and generally well-tolerated.

But the file also contained initial findings from clinical studies using the H1N1 strain, including data showing that just one dose of the vaccine provided a strong immune response “which exceeds the immunogenicity criteria as defined by international licensing authorities for a pandemic influenza vaccine”, according to the firm. And importantly, early evidence also suggests that the H1N1 vaccine has a similar tolerability profile as the already approved H5N1 vaccine.

The company says it is carrying out 16 clinical trials in over 9,000 subjects in Europe, Canada and the US to further assess the vaccine, and that data will be handed over to regulators a soon as it becomes available.

Sales potential?
GSK has several contracts to supply Pandemrix to governments in the bag, and is offering the vaccine under a tiered-pricing policy based on World Bank classification of countries and eligibility through the Global Alliance for Vaccines and Immunisation. But despite these pricing arrangements and strong competition, the vaccine is still expected to generate billions of dollars for the firm.

Earlier this month, the US Food and Drug Administration issued a green light for H1N1 vaccines produced by CSL of Australia, AstraZeneca’s MedImmune unit, Novartis and Sanofi Pasteur, which are all manufactured using the same processes, and is also expected to clear GSK’s product shortly.