The German drugmaker thought it had both its Yasmin and Yaz birth control products protected in the US until next year. Bayer had also agreed to supply an authorised generic of both pills to Teva in exchange for royalties. Teva in return had agreed not to launch its Yaz copy before July 2011, unless other companies got into the market earlier.

Yaz tablets contain an estrogen (ethinylestradiol) stabilized by β-cyclodextrin (‘betadex’) as a ‘clathrate’ (a protective molecular cage). Bayer claims that this improves stability and prolongs shelf life of the product.

Bayer believes that Teva is claiming that Gianvi contains ethinyl estradiol “stabilised by betadex as a clathrate”. Based on testing of Gianvi tablets now in the US market, Bayer believes that this is in fact not the case.

Bayer has filed a law suit to stop Teva from making false claims about its Gianvi product and from infringing Bayer’s patent. Bayer has also asked that Teva take action in the US market to correct any erroneous impression persons may have derived concerning the nature, characteristics or qualities of Gianvi.

Teva's launch of its Yaz copycat has “come as a surprise” to Deutsche Bank analysts as they “had previously expected Teva to launch generic Yaz in line with its agreement from July 2011". It is estimated that Bayer could lose Euros 200 million in sales of the drug this year and Euros 250 million next year.

Teva, on the other hand, obviously has plenty to gain, especially since they will have 180 days of market exclusivity – from its first-to-file status with the FDA. As long as there is no interference by a court in the US, Teva will have six months to take full advantage of this exclusivity.

(see also Teva gains approval for generic breast cancer and anti-depressant drugs, FDA ANDAs containing paragraph IV patent certifications and Teva changes generic Yaz contraceptive label)

Reference:

Bayer News Release, Bayer Sues Teva and Barr for False Advertising and Patent Infringement in Connection with Teva’s Generic Oral Contraceptive Gianvi, June 15, 2010