Skip to main content

Viagra tablets are seen at Brooks Pharmacy in Montpelier, Vt., in this file photo.TOBY TALBOT/The Associated Press

The major drug company that markets Viagra has asked the Supreme Court of Canada to reverse the remedy it imposed a multimillion-dollar ruling it made last week against the company.

In a rare application for a rehearing, Pfizer Canada Inc. claims that the court exceeded its powers when it rendered the company's Viagra patent invalid, opening the market to generic manufacturers.

Last week's decision ended an 18-year monopoly Pfizer had enjoyed over the drug for impotence.

The unanimous ruling concluded that Pfizer improperly went to great lengths in its patent application to obscure the importance of a crucial ingredient – sildenafil.

In their fresh application, Pfizer alleges that the court accidentally went beyond its jurisdiction by wholly invaliding its Viagra patent.

Howard Knopf, an intellectual-property expert with the firm of Macera Jarzyna LLP, said it is the first time he has heard of the loser in an intellectual-property case at the Supreme Court trying to overturn the result.

"It would be very unusual for the Supreme Court of Canada to overrule itself days after its ruling."

Mr. Knopf noted that the Canadian patent on Viagra had not been due to expire until 2014.

"Viagra is what we call a blockbuster drug," he said.

"It's worth spending a lot of money on legal fees and they are going to pull out all the stops."

Susan Beaubien, another lawyer at the firm, said the new application revolves around the nature of the proceeding that the plaintiff – Teva Canada Inc. – originally launched.

Known as a "notice of compliance" proceeding, it fell short of being a full-blown hearing on the validity of the Viagra patent.

In the normal course of events, Ms. Beaubien said, a company that wins a notice of compliance battle can commence manufacturing the drug it sought to copy.

Simultaneously, however, the losing company can launch a second step – a full patent infringement hearing – which can theoretically result in it winning back the right to be the sole manufacturer of the product.

A notice of compliance hearing usually means that a company has merely lost the first stage of two-stage litigation process.

"You end up with a patent that has not been invalidated, but with a patent that has a cloud over it," Ms. Beaubien said.

Pfizer's objection to last week's Supreme Court decision is based on an argument that the court leapt over this second step and simply decided, without hearing from Pfizer, that its patent was invalid.

Interact with The Globe