Barr Laboratories received a boost yesterday after it said that it had final US Food and Drug Administration clearance for its generic version of Sanofi-Aventis’ allergy drug, Allegra-D 12 Hour (fexofenadine and pseudoephedrine) extended-release tablets.

As the first firm to file for approval of a copycat version of the product, Barr says that it is entitled to 180 days of marketing exclusivity once it launches the drug. However, when this will ultimately take place remains to be seen as Sanofi-Aventis filed a patent infringement lawsuit against the firm, which still has to go to trial [[05/07/04d]]. The French company is seeking to block Barr’s sale of the product until after the expiration of various patents, the last of which expires in 2018.

Allegra-D 12 Hour is indicated for the relief of symptoms associated with seasonal allergic rhinitis in adults and children 12 years of age and older and generated annual sales of approximately $434 million dollars for the twelve months ended February 2005, according to IMS sales data.