Two Pfizer Canadian patents were at issue in India-based Ranbaxy knocking on Lipitor's door: 1,268,768 & 2,021,546. Ranbaxy wants to cash in with a generic version to the cholesterol-lowering drug.

Justice von Finkenstein presided over what came down to a battle of expert witnesses on '768, and Pfizer held its ground.

Teva subsidiary Novopharm, another generic drug maker, had gone after '546 with invalidity due to anticipation, obviousness, and double patenting. A ruling two months ago against that assertion had Pfizer breath a sigh of relief. Ranbaxy added insufficiency to the list of bad patent ju-ju.

But '546 was, ultimately, a specification story.

Insufficiency is the Canadian equivalent of enablement.

The provisions of s. 27(3) have been described as technical. Justice Layden-Stevenson observed in AB Hassle v. Genpharm Inc., 2003 FC 1443, at para. 76:

An allegation of insufficiency of disclosure is a technical attack that should not operate to defeat a patent for a meritorious invention. An insufficiency attack will succeed where a specification fails to disclose the invention such that a person skilled in the art could not put the invention into practice.

Justice von Finkenstein opined:

While these cases undoubtedly set the bar for section 27(3) very low, Pfizer in this case has not vaulted over that low bar. In essence, the 546 Patent makes two assertions, one as to activity the other as to the preferred salt. The first assertion is that there is an unexpected and surprising inhibition of cholesterol biosynthesis because of the ten-fold increase in activity between atorvastatin calcium and the racemic calcium salt. However, from the evidence presented, this statement is incorrect. The only reliable data available, the AICS data, suggests an increase in activity barely over the expected two-fold when the racemate is resolved into its individual enantiomers. This is not anywhere close to ten-fold.

Here we clearly have an assertion of a ten-fold increased activity on the face of the specification. This false suggestion of a ten-fold increase in activity cannot be backed up by the data provided. Accordingly, I find the 546 Patent to be invalid for failing to meet the requirements of s. 27(3) of the Patent Act.

Ranbaxy was not able to dent '768, and Pfizer pinned infringement. But '768 expires in May, whereas '546 provided coverage until 2010.

$800 million worth of Lipitor is sold in Canada annually, while the U.S. market nets $7.85 billion. Pfizer's fright is over illicit cross-border sales.

As reported in the Wall Street Journal: Lehman Brothers pharmaceuticals analyst Tony Butler wrote in a note to investors Friday that "Lipitor is such a staple of so many Americans' daily therapeutic regime that its availability [as a generic] across the border could facilitate pricing pressures in the U.S. to prevent widespread trafficking from Canada, beyond direct purchasing by U.S. citizens."

Pfizer's attorneys at Torys are clocking heart-breaking billable hours preparing an appeal.