Washington -- A Food and Drug Administration advisorycommittee on Monday failed to endorse Warner-Lambert Co.'sproposal to expand access to the company's controversialCognex drug for Alzheimer's disease and asked the company todo more efficacy studies.
Members of the Peripheral and Central Nervous System DrugsAdvisory Committee proposed that expanded access be tied toa carefully controlled study of the efficacy of medium to highdosages of Cognex, also known as tacrine or THA. The newstudy could take from 18 to 30 months, according to a panel ofexperts who advise the committee.
The company had hoped for a clear recommendation for its planto expand patient access during continued testing of the drugprior to gaining marketing approval.
Warner-Lambert will now begin discussions with the FDA todetermine the parameters of a new efficacy study and whetherthe company wants to conduct it. "The ball is in our court now,"said company spokesman E. Peter Wolf.
Cognex is one of the first drugs to treat the cognitivesymptoms of Alzheimer's disease, and estimates of the marketfor the drug range from $500 million to $1 billion annually.Groups representing Alzheimer's victims are pressuring theFDA to approve THA, which is available in other countries, formore widespread testing and eventual marketing in the UnitedStates.
Committee members said Warner-Lambert demonstrated that40 and 80 mg. dosages of Cognex produced clinical effects, butthat the effectiveness of the drug was slight. The committeesaid studies of the efficacy of medium to high dosages of 120and 160 mg. are "desperately needed." Given only slightevidence of efficacy, committee members said they wereforced to weigh the consequences of exposing patients to therisk posed by a side effect that causes elevated liver enzymes.
Members also expressed concern that responding to pressurefrom consumer groups could set a precedent for weakeningapproval standards designed to protect consumers. Acommittee member noted that any further distribution ofCognex, even in a tightly controlled efficacy study, could helpgenerate irresistible pressure to give marketing approval.
-- Kris Herbst BioWorld Washington Bureau
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