Moving to minimize the effect of generic competition for its blockbuster hypertension drug, Pfizer plans to authorize the sale of its own generic Norvasc, the company announced last week.

The announcement came immediately after Mylan Laboratories launched its generic version of Norvasc (amlodipine besylate), following a court ruling that invalidated a key patent covering the brand drug.

"We were certainly prepared to launch in that eventuality, but we were hopeful that we would prevail in federal court," Pfizer spokesman Bryant Haskins said.

Generic firm Apotex prevailed in its challenge to Pfizer's amlodipine besylate patent last week when the U.S. Appeals Court for the Federal Circuit ruled the patent invalid and unenforceable.

While Mylan had previously lost its own challenge to Pfizer's patent, the ruling in the Apotex case freed Mylan to move forward with an exclusive generic launch. Mylan was the first generic firm to win final FDA approval to market generic amlodipine besylate.

The authorized generic, available through Greenstone, a Pfizer subsidiary, will compete with the brand product, and both products will be on the market alongside Mylan's product until Pfizer "can persuade the courts" to reverse the ruling, Haskins said, adding that Pfizer is continuing to explore legal options toward securing pediatric exclusivity for its drug through September 2007.

( http://www.fdanews.com/did/6_61/ )