District court invalidates patent covering micronization of Drospirenone and Ethinyl estradiol combination

Barr Pharmaceuticals, Inc. today announced that the U.S. District Court for the District of New Jersey has ruled in favor of its subsidiary, Barr Laboratories, Inc., in the challenge of the patent listed by Bayer Schering Pharma, AG in connection with Bayer Schering's Yasmin(R) (drospirenone and ethinyl estradiol) oral contraceptive. In his ruling, Judge Peter G. Sheridan found that the patent at issue was invalid, because it was obvious.Yasmin provides an oral contraceptive regimen consisting of 21 active tablets each containing 3 mg of drospirenone and 0.03 mg of ethinyl estradiol and 7 inert tablets. Yasmin is indicated for the prevention of pregnancy in women who elect to use an oral contraceptive. The product had annual sales of approximately $572 million for the twelve months ended December 2007, based on IMS sales data.Barr filed its Abbreviated New Drug Application (ANDA) containing a paragraph IV certification for a generic Yasmin product with the U.S. Food & Drug Administration (FDA) in January 2005, and received notification of the application's acceptance for filing in February 2005. Following receipt of the notice from the FDA, Barr notified Berlex, the New Drug Application (NDA) holder, and Schering AG, the patent owner. In April 2005, Schering AG and Berlex filed a patent infringement suit against Barr in the U.S. District for the District of New Jersey. In June 2006, Bayer AG acquired Schering AG. In November 2007, the patent infringement case was heard in front of Judge Sheridan. There are 3 orange book listed patents for Yasmin.
US5569652 (Expiry: OCT 29, 2013) – Covers Dihydrospirorenone method of use
US6787531 (Expiry: AUG 31, 2020)- Combination of Drospirenone and Ethinyl estradiol (Micronization technique)
US6933395 (Expiry: AUG 11, 2017)- Formulation and drospirenone intermediates as product
The patent in suit is micronization technique patent 531’. Barr argued that micronization technique is obvious as it increases dissolution of Drospirenone. Bayer argued that micronization without coating to reduce acid degradation in stomach is not obvious. Court decided in the light of KSR V/S Teleflex decision and concluded that person having ordinary skilled in the art would have known to test bioavailability of Drospirenone, and when choosing from finite number of methods for delivering oral contraceptive, micronized tablets without enteric coated would have been obvious to try.
Yasmin is part of a group of contraceptives that became the single biggest contributor to Bayer's pharmaceutical revenue last year, with 1.04 billion euros ($1.58 billion) in sales. The ruling may threaten the newer Yaz birth control pill, which is also protected by the patent. Bayer, which bought German rival Schering AG in 2006 to boost growth from pharmaceuticals, reduced the 2008 profitability goal for its health unit as a result of the Yasmin decision. Yasmin had sales of about $572 million in 2007.
The ruling increases the possibility that Barr will introduce a generic version sometime in the second half of the year. There are three patents on Yasmin, with the one invalidated yesterday considered among the strongest, he said.