On July 24, 2017, in Idenix Pharmaceuticals, Inc v Gilead Pharmasset LLC (2017 FCA 161), the Canadian Federal Court of Appeal (FCA) dismissed the appeal of Idenix Pharmaceuticals, Inc (Identix) from a Federal Court (FC) decision finding Idenix's Canadian Patent No 2,490,191 ('191 Patent) invalid for insufficiency and inutility.  The '191 Patent relates to the compound sofosbuvir (Gilead's SOVALDI®) for the treatment of Hepatitis C viral (HCV) infections. 

The FCA noted that this case raised no new issues of principle or novel applications of established principles to the facts.  The FCA affirmed the FC's finding that the '191 Patent failed to sufficiently disclose how to synthesize the claimed compound. 

Notably, the FCA held that the sufficiency of a patent disclosure was determined as of the date of filing and, as a result, anything which occurred subsequent to that date was of no relevance.  The FCA also agreed with the FC that "the fact that, in hindsight, individual steps in a chemical synthesis have some precedent in the literature does not mean that the overall sequence of steps for making a new compound was easy to determine".  In this case, the FCA found that, rather than leading the skilled person step by step through the synthesis of the claimed compound, the specification necessitated the working out of a problem.  The FCA held that, in the absence of any teaching from the patent, this "constituted a burden beyond that borne by" paragraph 27(3)(b) of the Patent Act.  

The FCA held that it was not necessary to deal with the inutility issue given its finding on insufficiency.

The FC decision (2015 FC 1156) was previously reported in E-TIPS® Newsletter here.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.