L’arrêt Lilly Canada Inc. c. Apotex Inc., 2009 FCA 97, (25 mars 2009) comprend un résumé de l’état actuel du droit canadien quant au principe de “sound prediction” (selon lequel des revendications sont valides même si elles ne sont appuyées que par une prédiction d’un résultat, si celui est fondée toutefois…).
Le juge de la cour fédérale d’appel précise toutefois que lorsque le brevet est basé sur une prédiction, la divulgation doit inclure la prédiction.
 In my respectful view, the Federal Court Judge proceeded on proper principle when he held, relying on AZT, that when a patent is based on a sound prediction, the disclosure must include the prediction. As the prediction was made sound by the Hong Kong study, this study had to be disclosed.
 Absent a legal error, a decision as to whether or not a prediction is sound gives rise to a question of fact which cannot be overturned in the absence of a palpable and overriding error.
 In this respect, the appellant properly accepted that the Hong Kong study was required in order to make the prediction underlying the â€˜356 Patent sound. After taking all of the relevant evidence into consideration, it was open to the Federal Court Judge to find that as of the priority date the prior art Jordan article and the disclosure of the â€˜356 Patent were at the same point given that both studies demonstrated positive effects in respect of bone loss in rats and both concluded that human studies were warranted. In particular, the â€˜356 Patent did not disclose any more than the Jordan article did, and as such, the person skilled in the art was given, by way of disclosure, no more than such a person already had available in the prior art.
 The appellant argues that in requiring the complete disclosure of the factual basis underlying the sound prediction (i.e. requiring data to substantiate the invention), the Federal Court Judge has changed the disclosure requirements as set out in subsection 27(3) of the Patent Act, R.S.C. 1985, c. P-4. I respectfully disagree. In AZT, the Supreme Court, with obvious reference to subsection 34(1) of the Patent Act (the predecessor to subsection 27(3)), held that where the claimed invention had not yet actually been reduced to practice, the patent must provide a disclosure such that a person skilled in the art, given that disclosure, could have as the inventors did, soundly predicted that the invention would work once reduced to practice. Significantly, in AZT, the Court went on to state that the disclosure requirements had been met given that both the underlying facts (the test data) and the sound line of reasoning (the chain terminator effect) were in fact disclosed (AZT, para. 70).
 The appellant further argues that requiring the complete disclosure of the factual basis underlying the sound prediction is inconsistent with the Patent Cooperation Treaty, 1970, 28 U.F.T. 7647 (Treaty). However, this Treatyspecifically contemplates the supremacy of national law in setting the rules for substantive conditions of patentability (see article 27(5) of the Treaty). We are concerned here with substantive conditions of patentability.