Canada’s Federal Court of Appeal Affirms Invalidity of Idenix Patent for Insufficient Disclosure

In their decision reported as 2017 FCA 161, the Federal Court of Appeal says s. 27(3) of the Patent Act requires the patent to disclose both the invention, and how to make the invention. Further, that a patent will not lack sufficient disclosure where routine experimentation is required of a skilled person. However, disclosure is insufficient if the specification “necessitates the working out of a problem”.

In this case, the patent did not teach a step necessary to synthesize the claimed compound. The issue was whether this gap could be filled by the common general knowledge of the skilled person or routine experimentation.

Idenix appealed from a Federal Court ruling that its 191 patent was invalid for lack of sufficient disclosure because the common general knowledge could not fill the gap nor could it be discerned through routine experimentation. In the court below, Gilead contended that the 191 patent failed to disclose important steps in the chemical synthesis of the claimed compound. Justice Annis found that these gaps could not be filled by the common general knowledge and/or routine experimentation such that the person skilled in the art could have made the invention.

The Court of Appeal did not interfere, holding that Justice Annis was “concerned with how the skilled person would have understood the patent”, and made no error in his appreciation of the expert evidence. The Court of Appeal drew an analogy to the Supreme Court’s decision in Viagra (2012 SCC 60), where the skilled person would have had to “undertake a minor research project to determine which claim is the true invention” in a patent where only one of the two disclosed compounds worked to treat erectile dysfunction. In this case, the Court of Appeal held that “since at the date of filing the skilled person would not have known which pathway, along with the associated choices of reagents and reaction condition, would successfully lead to the claimed invention, the skilled person was faced with a similar task, at a conceptual level, as in [Viagra].” Accordingly, the Court of Appeal found that the 191 patent specification necessitated the “working out of a problem” rather than leading the skilled person step by step through the synthesis of the claimed compound or within the skilled person’s common general knowledge / ability to discern through routine experimentation. As such, it failed to satisfy the disclosure requirements under s. 27(3) of the Patent Act and the appeal was dismissed.

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