Indian drugmaker Dr Reddy's Laboratories says it will immediately launch its generic version of Sanofi-Aventis' allergy drug Allegra after securing US approval.

Dr Reddy's said it would launch its generic even though patent litigation with Sanofi-Aventis has not been resolved. Meanwhile, rival generics house Barr Laboratories and partner Teva have been marketing fexofenadine since September 2005, with their product enjoying six-months' exclusivity in accordance with the first-to-file legislation in the USA. This exclusivity period has now expired.

Dr Reddy's approval is for 30 milligram, 60mg and 180mg fexofenadine tablets, used to treat seasonal allergic rhinitis.

IMS data reveals that Allegra had sales of $1.4 billion in the USA last year, but has already been hit hard by the availability of the Barr/Teva generics, according to prescribing data released by pharmacy benefit manager Medco Health Solutions in January.

- Meanwhile, Mylan Laboratories said yesterday it has also been granted tentative approval from the US Food and Drug Administration to sell a generic version of Allegra.