Sanofi loses appeal over Taxotere patents in US

Sanofi has been unsuccessful in its bid to overturn a 2010 court decision to invalidate two patents on Taxotere, its big-selling cancer drug.

The US Court of Appeals for the Federal Circuit has upheld a lower court ruling that the two patents ('561 and '512) were unenforceable on the grounds that the invention was 'obvious' and that Sanofi had engaged in 'inequitable conduct' in obtaining them.

"We have considered Sanofi's additional arguments for reversing the district court's decision and conclude that they similarly lack merit," says the decision document.

The decision is a victory for generic drugmakers Hospira and Apotex, the defendants in the case and the first companies to market generic versions of Taxotere (docetaxel) in 2010, after the patents were invalidated by the lower court.

Sanofi started legal proceedings against the two firms in 2008 when they filed for approval of their generic versions of the drug.

Both patents relate to a formulation of docetaxel that does not make use of Cremophor, a solvent used in early formulations of the drug that was associated with side effects including hypersensitivity reactions, and a lower amount of ethanol.

They would have provided protection from generic competition until July 3, 2012.

Taxotere sales have been hit hard by generic competition in the US and elsewhere in the world, plunging 57 per cent last year to reach $1.2bn across the globe. In 2010, the company made $1.2bn in Taxotere sales from the US market alone.

Sanofi said in a statement that it was disappointed by the latest ruling and that it was evaluating its options. The company sells Taxotere in more than 100 countries to treat lung, prostate, gastric and head and neck cancer.