Sanofi-Aventis says it has agreed to settle patent infringement suits in the USA with Barr Laboratories and Teva Pharmaceutical Industries over generic versions of the allergy drugs Allegra and Nasacort.

The French drugmaker noted that in exchange for payment of royalties, it has agreed to grant both firms certain patent rights to continue selling generic versions of Allegra (fexofenadine) 30mg, 60mg and 180mg tablets in the USA. Barr has also been given a licence to to sell generic versions of Allegra D-12 (fexofenadine/pseudoephedrine) and Nasacort (triamcinolone acetonide) AQ across the Atlantic at a future date.

In each case, Sanofi noted that the licence is to be non-exclusive and will allow generic entry prior to the patent expirations. The deal, which will result in the end of all litigation or any damage claims between the three firms and is subject to review by the Federal Trade Commission and US state Attorneys General, does not preclude the Paris-headquartered group from selling its own versions of these products.

The financial details of the settlement were not disclosed but Sanofi noted that royalties are to be retroactively applied to past sales of generic Allegra by Barr and Teva.

In 2007, US sales of Nasacort AQ, on which two patents will expire in 2016, reached $301 million, while Allegra D-12 turnover, which will lose patent protection from 2012 to 2018, was $276 million. Sanofi added that it continues to be involved in ongoing US patent litigation against other parties, notably Novartis’ Sandoz unit, in relation to Allegra and Allegra D-12.

The respnse to the settlement from analysts was generally positive and Natixis analyst Philippe Lanone issued a research note saying it is "better to have a good agreement than a bad trial”. The drugs in question are not seen by some observers as major growth drivers for Sanofi moving forward.