In an attempt to cushion the blow from generic competition for one of its top-selling medicines, French drug major Sanofi-Aventis has joined a growing list of pharmaceutical companies that are planning to launch cheaper generic versions of their own products in an effort to undermine rival drugmakers.

Sanofi-Aventis has signed a distribution and supply agreement with privately-held, US generics manufacturer Prasco Pharmaceuticals for its third-biggest selling Allegra (fexofenadine), the world's number one hayfever treatment. Under the terms of the deal, financial details of which were not disclosed, Prasco will launch cheaper versions of Allegra in the USA, in 30mg, 60mg and 180mg formulations.

The announcement closely follows last week’s news that Israel’s Teva Pharmaceutical Industries and the USA’s Barr Laboratories have formed a partnership to sell a copycat version of the agent in the USA, even without a court decision on their legal challenge against the product’s patents [[08/09/05e]]. According to industry observers, the introduction of a generic form of Allegra will eradicate the majority of its $1.7 billion annual revenues for the company, making a substantial hole in the group’s earnings.

According to Sebastian Berthon, analyst at Exane-BNP Paribas, Sanofi-Aventis’ launch of its own cheaper version of Allegra will “take the wind out of the sails” of its generic rivals, but he warns that it will not protect the firm’s own sales of the drug in the long term, the Financial Times reports.