CASE: Pfizer Canada Inc. et al v. Pharmascience Inc.. (Federal Court)

DRUG:  XALATAN (latanoprost)

NATURE OF CASE: NOC Regulations: Prohibition proceeding - Section 6

SUCCESSFUL PARTY: Pfizer Canada Inc. et al

DATE OF DECISION: December 18, 2009


On December 18, 2009, the Federal Court granted an application by Pfizer Canada Inc. and Pharmacia Aktieblolag (“Pfizer et al”) for an order prohibiting the Minister of Health from issuing a notice of compliance to Pharmascience Inc. (“PMS”) in respect of a generic version of XALATAN® until the expiry of Canadian Patent No. 1,339,132 (“132 patent”). Ogilvy Renault LLP represented Pfizer et al.

PMS alleged that the 132 patent was invalid on the following grounds: anticipation, obviousness, insufficiency, lack of utility, lack of sound prediction and overbreadth. PMS also alleged that its proposed generic copy of XALATAN® would not infringe the claims on the basis of the Gillette Defence. The parties had agreed that only claims 12, 19, 31, 37 and 38 of the 132 patent would be subject to the invalidity and non-infringement allegations.

After construing the claims, Madam Justice Heneghan considered PMS’s non-infringement allegation. She noted that the evidence relied upon by PMS was rooted in an assumption that latanoprost was an old compound for an old use. Accordingly, Heneghan J determined that PMS’s Gillette Defence could only succeed if the allegations of anticipation and obviousness succeeded.

Heneghan J. proceeded to analyze the invalidity allegations and determined that each was not justified:

1. Anticipation – Disclosure requires that a single document disclose subject matter that, if performed, would result in infringement. If there is more than one possible result, there is no disclosure. The requirement of disclosure is not satisfied when the prior art teaches a broad class and the invention is a specific member of that class. Heneghan J. determined that no document listed in the Notice of Allegation disclosed the chemical composition of latanoprost and accordingly the disclosure requirement had not been satisfied. Thus, the Court did not consider enablement.

2. Obviousness – Heneghan J. held that the prior art established that there was a problem to be solved and that the solution was not obvious. She considered the testimony of the inventor who described the work done by a competitor performing similar experiments who was not led to latanoprost. Heneghan J concluded that there were an almost infinite number of changes possible to the natural molecule and one would not be able to predict the result of making changes. The allegation of obviousness was not justified.

3. Insufficiency – Heneghan J re-iterated the established test that a patent must describe the invention and how to work it. The 132 Patent satisfied this test.

4. Utility – Justice Heneghan determined that the 132 Patent showed utility and furthermore, publications between the filing date and issue date confirmed the utility of latanoprost. She concluded that the 132 patent offers the public a useful choice from what was offered as the state of the art at the filing date.

5. Sound Prediction – Heneghan J briefly considered this allegation in obiter despite her finding that the 132 patent has utility. She found that the data and examples in the 132 patent (which included testing in humans and animals) provided a sound line of reasoning and disclosure to satisfy the requirements of sound prediction.

6. Overbreadth – PMS alleged that the claims were overly broad because they did not include all the benefits of latanoprost. The Court found that a patentee is not obliged to claim a particular benefit and accordingly, there was no overbreadth.

Having found all the invalidity allegations not justified, PMS’s Gillette Defence failed and accordingly, its non-infringement allegation was also not justified.


This decision has not yet been posted on the Federal Court website. It will have the citation 2009 FC 1294.