Barr Laboratories has filed a lawsuit against the US Food and Drug Administration challenging the latter’s policy of awarding generic exclusivity on a patent-by-patent basis, rather than solely to the first company to file an application to sell a copycat version of a given drug.

Barr believes it is entitled to sole exclusivity for its generic version of Aventis’ allergy drug, Allegra-D (fexofenadine and pseudoephedrine), having won the tentative green light from the agency last summer [[05/07/04d]], and notes that it originally filed an application with the FDA back in 2001 [[04/07/01b]]. Aventis – now part of Sanofi-Aventis – filed suit against Barr within the 45-days permitted under the Hatch-Waxman act. However, the following year, Aventis obtained and listed an additional patent in connection with Allegra-D and Barr fears that the FDA will conclude that another company filed for approval based on this patent and will force it to share its exclusivity with the other company.

“We believe that the exclusivity provisions of Hatch-Waxman are clear and that the first company to file a patent challenge is entitled to the 180-day incentive. We will seek all remedies to ensure that the incentive of 180 days of generic exclusivity is preserved as Congress intended,” said Barr’s chairman and chief executive, Bruce Downey.

Allegra-D is indicated for the relief of symptoms associated with seasonal allergic rhinitis in adults and children 12 years of age and older and brought in annual sales of approximately $444 million dollars in the twelve months to the end of November 2004.