Wednesday, February 27, 2008

GSK's Secret Vaccine Engine: What Drives Prepandrix and Pandermrix?

Hey, what are theses guys hiding in there?

GlaxoSmithKline has taken a lesson from the secrecy and protection of the new model as a way to stimulate excitement and curiosity. They have taken auto industry marketing skills into the usually mundane world of vaccines.

Two GSK pandemic vaccines passed major regulatory milestones at the end of last week: Prepandrix (the pre-pandemic vaccine for use on high risk groups prior to an outbreak) and Pandemrix (the mock-up vaccine for use during an outbreak) received positive opinions from the European Medicines Agency on Thursday, February 21.

Each vaccine is described as an “adjuvanted” product but the adjuvant remains unidentified: GSK’s secret system to drive efficacy at a low antigen dose.

GSK has been assiduously protecting information about its proprietary adjuvant for the pandemic flu vaccines throughout development. They have scrubbed their communications about the product to keep its description off the internet. Clinical trial results were reported on the vaccine with an oil-in-emulsion adjuvant in The Lancet in August 2007.

Against the backdrop of mystery, GSK has emphasized that adjuvants hold the key to reducing the amount of antigen necessary to permit large-scale production for a pandemic situation and to give the company’s product a proprietary niche.

The company’s refrain: “adjuvants will play a key role in improving pandemic preparedness.” The positive actions on GSK’s pandemic flu vaccines in Europe come as a positive piece of news to offset the slowdown of another of the company’s major adjuvant vaccine candidates in the US: the HPV adjuvanted vaccine (Cervarix) which is stalled at FDA. (See here for a full discussion of the Cervarix delay and its meaning to the onset of the age of adjuvants in the US.)

But the secrecy will have to end soon. If not with the final approval documents around the EMEA filing, the formula for the adjuvant will have to be revealed in the future in the US where the company is working under a January 2007, $63 million contract with the Department of Health and Human Services to support pandemic vaccine research. Novartis and IOMAI also are working under research contracts at the same time.

The HHS contracts call for the companies to provide their adjuvants to HHS for consideration with other antigens. A member of the HHS National Vaccine Advisory Committee, Cornelia Dekker (Stanford Medical School) explained that the HHS contract offers the first step towards a “mix-and-match” approach to building adequate pandemic vaccine supply, using one company's adjuvant to stretch another company's antigen. As part of that, GSK will have to share the adjuvant with the government (if not the other manufacturers). The loss of secrecy is part of the deal that GSK will have to accept to keep in the HHS development effort.

But FDA can help GSK in this development effort. Where the agency's review has slowed down Cervarix, its review procedures will provide an extra layer of proprietary protection to the pandemic flu projects. Even if GSK won't be able to keep the adjuvant under wraps for ever, FDA's review of vaccines as the full product of all ingredients and delivery systems will provide a further proprietary cover.

While HHS and EMEA may pull back the sheet, GSK should be able to keep use of the engine to itself.

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