Bayer files lawsuit against Teva over Yaz

Bayer has filed a patent-infringement lawsuit against Teva Pharmaceuticals over a generic version of birth-control pill, Yaz (drosperinone and ethinyl estradiol).

Israel-based Teva has announced in a statement the commercial launch of Gianvi, its generic version of Yaz – the drug which made total US sales of approximately $782m in 2009.

This introduction to the market is over a year ahead of schedule, with an earlier agreement between the two companies delaying a launch of any authorised generic competition from Teva until July 2011.

As part of the launch statement, Teva, the world's largest generics manufacturer, also announced a 180-day period of marketing exclusivity for the product as the first company to have an Abbreviated New Drug Application (ANDA) approved by the US Food and Drug Administration (FDA).

The suit was filed in the federal court in Delaware, US, with Bayer claiming Teva's version of the drug infringes three patents that expire in 2014.

As reported by the Associated Press, Germany-based Bayer said that the early launch "constitutes an act of infringement of the relevant intellectual property".

In 2008, Bayer signed an agreement with Barr Laboratories - a wholly owned subsidiary of Teva - giving the company the right to sell a generic version of oral contraceptive, Yasmin, a sister drug of Yaz, with Bayer receiving royalty payments.

This was to protect the product from cheaper generic competition with the impending expiry of the brand.

It was as part of this deal that Teva/Bell agreed to keep a generic version of Yaz off the market until July 2011 unless other generic makers managed to enter the market earlier.

Bayer is also involved in a lawsuit with Biogen Idec over patent infringement of multiple sclerosis therapy, Avonex (Interferon beta-1a).