The Federal Court Warns Against Using Sound Prediction as a “Crushing Hammer”

Paula Bremner
Published March 25th, 2013

Apotex/Teva v Novartis, 2013 FC 141 (Snider) (under appeal A-98-13 and A-100-13)

Summary – The Federal Court has arguably pleased the patentee side of the fence in its recent decision finding that Novartis’ tumour drug patent had the requisite utility.  Madam Justice Snider states that the “introduction [of sound prediction] into Canadian law was not, as I understand it, to give a crushing hammer to those who challenge patents.”  Overall though, the court’s detailed analysis generally applies Canada’s “utility law” developed over the past few years.  The decision is a good illustration that the two steps of (1) identifying the promise of the patent and (2) determining if it has been demonstrated or was soundly predictable – depends on the context.  Relevant factors include the particular wording of the patent, the court’s acceptance of expert reasoning, the specific understanding of the inventors and the general understanding of the skilled addressee of the applicable science at the time.  The court also applied the recent Supreme Court of Canada (“SCC”) test for sufficiency of disclosure.  Justice Snider found there was no requirement to disclose specific test results showing the basic enzymatic utility of the compounds – although this was “troubling” it was not “fatal”.

Analysis Novartis’ patent (CA Patent No. 2,093,203) relates to a number of new compounds that are stated to have activity as selective enzyme (kinase) inhibitors.  The patent states:

“Owing to their inhibiting activity towards [particular enzyme], the [compounds] . . . can be used as tumour-inhibiting …ingredients…” [emphasis added]

Significantly, the patent provides no specific test results.  The disclosure merely discusses general testing methodology and general ranges of enzyme inhibition results that were briefly referenced in the patent (over 2 paragraphs).  As is typical, the patent contains claims to several compounds (and separate claims to particular drugs including imatinib), use claims and process claims.  These different types of claims were central to the court’s analysis of both the promised utility and the nature of the invention that needed to be disclosed.  The court found there were 4 separate promises (largely taken from the first paragraph of the patent) for compounds, uses, processes and medical compositions.  A central theme of the decision is the court’s finding that it was improper to treat “the entire patent as a use patent” as the Plaintiffs’ expert did.  Instead the court found the patent is “primarily a compound patent; the potential uses [are secondary] and arise from the fact that selective inhibition of the identified kinases is a valuable pharmacological property that can lead to therapeutic use.”


The Plaintiffs Apotex and Teva argued the patent promised in vivo/therapeutic utility for all claims which was neither demonstrated nor soundly predictable.  The court disagreed and found the promised minimum utility of the compound claims was only in vitro selective enzymatic inhibition.  The patentee had actually secretly demonstrated that imatinib and the other specific compounds had in vitro utility (the court considered the patentee’s secret testing “holistically”).  The utility of claims to several other compounds was soundly predictable based on the Plaintiffs’ expert admission that the compounds were “reasonably predicted to exhibit the same properties as those of the tested compounds [in the patent]”.  (The patentee made no attempt to defend the utility of very broad claims directed at billions of compounds.)

The court proceeded to find the promise of the “use claims” was only “the potential of in vivo treatment of the named maladies or conditions” following analysis of the term “can be used” in the disclosure.  The Plaintiffs tried to argue the in vivo promise was a “guarantee”.  The court criticized the Plaintiffs for “reading … the patent characteristic of a mind unwilling to understand” and on a “quest to find fault with specific or omitted tests” that were done by the patentee before it filed its patent.  After finding the patentee’s secret mouse tests provided a “positive result” that pointed to usefulness of the compounds for treating tumours in warm blooded animals, the court reasoned there was “considerable knowledge” in the kinase/tumour area and concluded that enzyme inhibition “was the key to the treatment of [leukemia]”.  In vivo tests were not even needed to provide an articulable and sound line of reasoning.  As the patent contained both background information and “results of the more important tests carried out”, there was sufficient disclosure for a sound prediction.  The link between enzyme inhibition and tumour treatment was “notorious”.  The Plaintiffs’ questions regarding cell penetration etc. were “demanding much more from [the patent] … than is necessary to satisfy the doctrine of sound prediction”.  Significantly, the court stated that it was not necessary to be ready to go into clinical trials for a sound prediction – admittedly Novartis was still far from such a stage.


The court found that the patentee had not “gamed” the system (applying the approach from the SCC in Teva Canada Ltd v Pfizer 2012 SCC 60 (“Sildenafil”) summarized here where Pfizer failed to identify sildenafil in its patent as the only successful compound tested).  First, the court found the invention was in essence a class of compounds, each one a selective enzyme inhibitor.  The Plaintiffs were wrong to “leap immediately to the utility of the compound”.  There was no argument as to how the invention works.  Finally, the court seems to have been most persuaded by the Plaintffs’ arguments regarding the third requirement for proper disclosure – namely whether “Having only the specification, can the person of ordinary skill in the art produce the invention using only the instructions contained in the disclosure?”.  Justice Snider evaluated each argument in detail.  Although accepting that specific test results (for imatinib in particular) were missing from the patent, the court concluded the patentee was not compelled to provide this level of detail, including its “best compound” based on in vitro tests to date.  One important fact seemed to sway the court in Novartis’ favour – Novartis’ own secret testing, although showing imatinib as an impressive inhibitor, had not yet determined which compound was “the one” for future commercial development.  As the inventors had not distinguished between the compounds; “this distinction cannot be necessary for the skilled reader to use the invention in the same successful way as the inventor”.  As to certain problems the public would have in formulating imatinib (based on the inventors having such problems according to their secret tests) – the court found such work was “simple trial and error”.

Practice Point – This decision is one of the first to apply the SCC’s test for sufficiency in Sildenafil.  Arguably, Justice Snider’s analysis on this point suggests the court may now be undertaking a “heightened” evaluation of disclosure requirements.

From a procedural point, this is also an unusual case because both impeachment actions and Notice of Compliance (NOC) applications were consolidated such that the decision applies to both proceedings.  The trial took place just over 2 years after Teva started its impeachment claim, and lasted 18 days – suggesting greater efficiencies in such consolidation.

This decision highlights the importance of expert evidence in evaluating a patent.  The court clearly had a problem with the Plaintiffs’ expert who “ignores (or seriously discounts) the obvious utility of the compounds as selective kinase inhibitors”.  Although he was a “credible” witness, the court plainly disagreed with him regarding the promise of the patent, and found he failed to consider the total in vitro testing (showing enzymatic inhibition) provided by the patentee.

Readers should review pages 7 and 8 of the patent for themselves – to evaluate whether there really was enough for any sound prediction and sufficiency.  It is expected the Court of Appeal may provide further insight on these matters.

Finally, there is arguably a policy rationale underlying the decision.  Although not discussed directly, the court seems to be concerned about requiring too much from patentees who are at a very early stage of their research.  Such patentees are permitted to hold certain details back from the public, as long as they appear to reflect the bona fide dealings of the patentee at the time.  This is particularly the case where a patentee can make the argument that its invention at the time of filing is a “general” one – in this case several compounds, and not simply imatinib.  This will save a patentee from being accused of hiding its true invention and “gaming” the system.

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