COURT INVALIDATES SYNTHON PATENTS, CITES INEQUITABLE CONDUCT

Manufacturing methods used by Pfizer to produce its top-selling hypertension treatment drug Norvasc do not infringe on patents held by Synthon, a federal district court has ruled.

In a decision handed down by the U.S. District Court for the Eastern District of Virginia invalidated Synthon's patents '481 and '738 related to the production of amlodipine besylate, the active ingredient in Norvasc.

The court said that Synthon obtained its patents through inequitable conduct because it used Pfizer's published process for manufacturing the brand drug but did not disclose that to regulators at the U.S. Patent & Trademark Office. "Synthon had claimed that Pfizer's process for manufacturing Norvasc, a process which we not only published, but had been using for more than 15 years, was infringing on their patents obtained in 2003 and 2005," Pfizer spokesman Bryant Haskins said.

The federal court sided with Pfizer on two positions, stating that its method of processing Norvasc does not infringe on Synthon's patent and that the patent in question was obtained through fraudulent means, Haskins said. Synthon had originally filed a patent infringement lawsuit against Pfizer, but Pfizer asked the court to find Synthon liable for inequitable conduct.

"We are very disappointed in the judge's decision, we believe it is incorrect and we are evaluating what our options are for responding," Synthon President Mark Buscher said. It is uncertain if the company is planning to appeal the ruling.