“[Sound prediction’s] introduction into Canadian law was not, as I understand it, to give a crushing hammer to those who challenge patents.”

Snider J Gleevec

These words are part of a refreshing and practical approach that was adopted in a decision released February 19, 2013 by the Federal Court regarding utility and the promise of pharmaceutical patents.

By this decision, Justice Snider dismissed two impeachment actions brought by Teva and Apotex against Novartis relating to the compound patent for Novartis’ breakthrough cancer drug Gleevec® (imatinib mesylate). In dismissing the actions, Justice Snider tempered the approach taken in some recent cases which imposed very high standards of proof and knowledge to establish a demonstration and sound prediction of utility, including the disclosure requirement. This decision is also important in that it is the first to comment on the effect of the recent Supreme Court of Canada (SCC) Viagra decision.

The patent being attacked had a number of genus and species claims to novel compounds and also included some claims to the use of certain compounds, including imatinib, for chemotherapy of tumors. The Court found that the narrower genus claims, the species claims, the process and the use claims were all valid.

The overriding point of contention between the parties was whether the promise of the patent (and therefore the analysis on utility) varied depending upon whether one was looking at the compound claims or the use claims. In this regard, the Court agreed with Novartis’ position that the promise of the patent must be analyzed by focusing on the claims. Thus, the Court rejected the Plaintiffs approach that all claims have the same utility and that the entire patent should be treated as a use patent. On the contrary, the Court found that the patent makes it very clear that the compound claims are “the most important aspect of the patent, with the use claims, the process claims and the medicinal composition claims arising from the properties of the compounds.” Consequently, different “promises” applied to the different types of claims.  

Moreover, the Court emphasized the reasoning of the SCC in AZT that “the doctrine of sound prediction, in its nature, presupposes that further work remains to be done”.

Gleevec

One of the compounds claimed was imatinib, a selective kinase inhibitor which is the active ingredient in the drug Gleevec, a drug used, among other things, to treat Chronic Myleoid Leukaemia (CML). Until the approval of Gleevec, CML was a devastating cancer for which survival rates were dismal and life expectancy short. In the approximately 12 years that it has been on the market, life expectancy rates for people with CML are now dramatically improved such that they are not really distinguishable from the normal population.

The Court Proceedings

The Court in this case was faced with two impeachment actions and also two proceedings under the Patented Medicines (Notice of Compliance) Regulations. All four proceedings were heard together on common evidence. The validity attacks focused on lack of utility (either demonstrated or soundly predicted), overbreadth of claims, lack of sufficiency, and in the case of Apotex, ambiguity. Due to the impending expiry date, the proceedings were scheduled for trial just 20 months after the first action was started and 16 months after the second one.

Claim Construction

The Court acknowledged that claims are paramount in claim construction. This situates the claim construction and review of the promise of the patent squarely where the Supreme Court has repeatedly indicated: in the context of the state of the art and the invention made, viewed through the eyes of the person skilled in the art and with a mind willing to understand.

Utility/Promise of the Patent

  1. The Compound Claims

Based on the expert evidence, the Court found that the promise of the patent with respect to the compound claims was that the novel compounds have utility as selective kinase inhibitors and that there was no specific promise of therapeutic utility.  

Thus the promise of the compound claims was that the utility of the compounds were as selective kinase inhibitors. The evidence was that this property is established through in vitro studies alone, e.g. not through in vivo studies.

Based on this finding, the utility of the single compound claims were demonstrated as Novartis had done the appropriate in vitro studies before the patent was filed.

  1. The Genus Claims

Because Novartis did not make and test all of the compounds in the genus claims, it was necessary that their utility (as kinase inhibitors) be able to be soundly predicted.  In this regard, the narrower genus claims were upheld. The Court agreed one can extrapolate to the genus from the species within the genus so long as some compounds are made which are representative of the variables to the genus (the different “R groups”). In this case, 29 examples were made encompassing representative examples of the genus claims 5 and 7. In the case of claim 5, the 29 compounds made could still predict the class of millions of compounds.

  1. The Use Claims

For the use claims, the Court found that the promise was that a compound included in those claims could be used to treat the diseases or conditions specified in the claims. Because the Court found that this could not be established through in vitro studies alone, the Court considered the question of sound prediction.

In this regard, the Court noted that the Plaintiffs bore the burden of establishing that the prediction was not sound, and failed to do so. Indeed, the Court found that both the in vitro and in vivo studies performed pointed to a conclusion that the compounds would be useful in treating tumours in warm-blooded animals and that, in view of the knowledge in the field about the relationship between the inhibition of these kinases and CML, this lead to a strong inference that the compounds would have utility in the treatment of certain tumours.

  1. The Process Claims

Because the compounds whose manufacture the process claims were directed to were found to have utility, the processes directed to that manufacture were found to be useful as well.

Disclosure

The Court found that the fact that only some of the tests conducted were described in the patent was not fatal. The disclosure included both background information on the invention and on results of the more important tests carried out. In view of the common general knowledge available to the Person of Ordinary Skill (which included the “well known” link between kinase inhibition and potential to treat tumours), this was sufficient.

Sufficiency

As the SCC Viagra decision came down during the closing arguments of the trial, the Court considered the decision’s potential impact on the sufficiency of the disclosure.

In this regard, the Court set out the test for sufficiency as a three part test, the third aspect being a gloss on the Consolboard test which was cited in Viagra: (a) what is the invention, (b) how is the invention practised, and (c) having only the specification, can the person of ordinary skill in the art produce the invention using only the instructions in the disclosure.

The Court found that the disclosure of the ‘203 patent was not analogous to that in the Viagra disclosure because the ‘203 patent disclosed a class of compounds rather than describing that one compound - undisclosed - works. The overall inventive concept was that the compounds could selectively inhibit kinases. All of the six individually claimed compounds of “group 2” were tested and exhibited selective inhibition, and that information was not hidden from the public. Moreover, Novartis had not yet determined which inhibitor would be most appropriate for drug development. In addition, there is no requirement in law that a party disclose which compound has the “best” test results. As such, there was no basis to argue that Novartis “hid” anything. Finally, the Court rejected the argument that the data for the best compounds need be included and indeed noted that for the sufficiency requirement under s. 27(3) no data is required at all.

NOC Proceedings

As noted above, the case also comprised NOC proceedings. In addition to the question of whether the allegations of invalidity were justified, the applicant (Novartis) had raised the issue of whether the NOAs were improper and thus null and void. The question of the propriety of the NOAs related to the fact that in each case Apotex and Teva, respectively had first filed Form Vs agreeing to await expiry of the patent. Subsequently, and without filing a new drug submission, each had submitted different Form Vs. Thus, the question for the Court was whether a second person can file new Form Vs alleging invalidity and whether the NOA related to those new Form Vs is valid and proper. The court noted that in view of her findings on the impeachment actions and thus the allegations of invalidity that the question was obiter and thus declined to decide.

Conclusion

Overall, the case appears to provide more realistic approaches to patent construction, interpreting the “promise of the patent” and the application of sound prediction than approaches applied in some previous cases. The Court carefully applied the law by staying true to the principles of construction and not falling into the trap of microscopically analysing each word out of context of the invention made and without regard to the state of the art.