The FDA is facing calls to reconvene an advisory panel to review a GlaxoSmithKline ($GSK) vaccine in light of data linking an adjuvant to narcolepsy. And the outcome could have implications for other next-generation adjuvants pharma hopes will supercharge vaccines.
GSK, Novartis ($NVS) and others have invested in adjuvants to boost vaccine potency and broaden the range of targets. Vaccines targeting rapidly mutating viruses like HIV are now possible, but many of the candidates use adjuvants. "The whole adjuvant story is an important one because there are going to be vaccines that we may be able to use to prevent diseases, if we are able to use adjuvants, that we could not prevent otherwise," Dr. Kathryn Edwards, director of the vaccine research program at Vanderbilt University, told Reuters.
Other vaccine manufacturers are now fending off questions about their adjuvants. Novavax, for example, was asked whether its pandemic flu vaccine candidate uses squalene--a component of GSK's adjuvant--during its fourth-quarter results call. VP Louis Fries declined to answer--and warned against jumping to conclusions about squalene--but speculation appears set to continue.
Adjuvants have been used to boost vaccine activity since the 1930s, but new formulations--like AS03 in the GSK vaccine--have emerged in the past decade. An FDA advisory panel unanimously endorsed a GSK bird flu vaccine featuring AS03 in November, but since then new evidence showing links to narcolepsy has been published. "I personally think the panel should be reconvened now that we have new data. This is an issue worth re-examining," FDA advisory panel member Dr. Ambrose Cheung said.
Given the high mortality rate of bird flu--it kills nearly 60% of infectees--the risk-reward balance could favor the vaccine even if a link to narcolepsy is proven. More data is due in 2014 when a Centers for Disease Control and Prevention-sponsored international study reports its findings.