On February 4, 2013 Justice Hughes of the Federal Court of Canada released his Reasons for Judgment dismissing a prohibition application involving Pharmascience in relation to Canadian Patent No. 2,255,652 listed against LYRICA, Pfizer’s pregabalin product. The 652 Patent is generally directed to the use of certain compound for the treatment of pains and contains results of experiments where pregabalin was tested in rats. The inventive concept of claim 3, the only claim at issue, was that pregabalin or its racemate can be used to treat a variety of types of pain.
Following the Supreme Court of Canada in Free Word Trust, Justice Hughes construed the word “pain” broadly to include all of the specific pains claimed in claims 4 to 16. Justice Hughes noted that the summary of the invention described a variety of pains, including acute herpetic and postherpetic neuralgia, that could be treated by the claimed compounds.
Claims Broader than Invention Made or Disclosed
Justice Hughes cited the following passage from Leithiiser v. Penga Hydra Pull as the classic statement of the law:
The first is whether the claims of the appellant’s patent claim more than he invented. The second is whether the claims are broader than the invention which is described in the specification. If the answer to either question is in the affirmative, as I understand the law, the claims are invalid.
Justice Hughes relied on evidence from the inventor that the objective was to test pregabalin for chronic or persistent pain. The inventor admitted that pregabalin was not effective for acute pain and no one had ever thought of testing the racemate. Justice Hughes rejected the Applicants’ submission that the effectiveness of the racemate could be inferred form the patent disclosure. Based on the inventive concept and construction of Claim 3, Justice Hughes concluded that Pharmascience’s allegation of claims broader was justified
Sound Prediction for Pharmaceutical Patents
After providing an extensive history of the development of the theory of sound prediction, Justice Hughes concluded that decision of the Supreme Court of Canada in AZT and the cases that have followed it are still good law: for pharmaceuticals, the basis for sound prediction must be disclosed in the descriptive part of the patent.
Pharmascience challenged the utility of pregabalin, or it racemate, in treating a different types of pain in humans based only on the rat data reported in the 652 Patent. More specifically, Pharmascience alleged (1) that pregabalin does not treat all types of human pain; and (2) that the 652 patent fails to disclose any data on the racemate form which the utility of the racemate in all or s even some types of pain could be soundly predicted.
All types of pain
Justice Hughes found that neither pregabalin nor it racemate had been tested in humans as of the Canadian filing date. Based on the evidence before him, Justice Hughes concluded the that pregabalin does not, in fact, treat certain types of acute pain described in the 652 Patent and that animal model would not not have been accepted as predictive of treatment for all of the different types of pains described in the 652 Patent. Claim 3, which embraces pain which cannot be treated, as well as pain which, as of 1997, could not have been predicted as treatable by pregabalin, was held invalid.
Justice Hughes also concluded that there was not basis to soundly predict the utility of the racemate:
 I have read and considered not only the evidence of Drs. Hayes and Jamali, but also that of the other experts; including Drs. McCarson, McMahon and Cowan. I am satisfied that, as of the relevant date and even as of today, there is no factual basis from which a sound prediction as to the effectiveness of the racemate could be made.
 Further, and in any event, there is no factual basis and no line of reasoning set out in the ‘652 patent from which a person skilled in the art could make a sound prediction that the racemate would be useful in treating the variety of pain encompassed by claim 3 or even some of them.
Justice Hughes held that it would not be more or less self-evident that pregabalin and its racemate could be used to treat some types of pain. Justice Hughes, mindful of his finding on utility, addressed the relationship between his findings as follows:
 I am mindful, in coming to this conclusion, that I have concluded that it was not obvious to use pregabalin for a variety of pains, including some acute pains, and that likewise the racemate was not obvious for such uses. I am mindful, as well, as to my findings in this respect as to utility and sound prediction. The questions are different. For instance, it may not be obvious that the racemate can treat a variety of pain, but it may not be useful for that purpose.
A copy of Justice Hughes’ reasons for Judgment may be found here.