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Federal Court invalidates Idenix patent, dismisses attacks on Gilead patent for SOVALDI

On October 9, 2015, the Federal Court ruled on the validity of two patents relating to Gilead’s SOVALDI (sofosbuvir) in Gilead Sciences, Inc v Idenix Pharmaceuticals, Inc, 2015 FC 1156 (public judgment and reasons were issued on November 2, 2015). The Court declared Idenix’s Patent No. 2,490,191 (‘191) invalid and dismissed Idenix’s counterclaims for infringement of the ‘191 patent and a declaration of invalidity of Gilead’s Patent No. 2,527,657 (‘657).

All claims of Idenix’s ‘191 patent declared invalid

Gilead sought to invalidate Idenix’s ‘191 patent on the grounds of (i) inutility, (ii) insufficient disclosure, and (iii) overbreadth.

On the issue of utility, the parties agreed that the patent promised that the claimed compounds are useful in the treatment of Flaviviridae infections, including hepatitis C virus (HCV) infections, in humans and other hosts, which required “effectiveness in combination with low toxicity as measured in accordance with the therapeutic index.” The Court held that the patent did not promise any specific result or level of treatment and Gilead therefore had to prove that Idenix did not demonstrate or soundly predict a scintilla of such utility. It was common ground that there was no demonstrated utility at the filing date since Idenix had not synthesized the claimed compounds. Thus, Idenix sought to rely on the doctrine of sound prediction. The Court held that the skilled person could not soundly predict any antiviral activity of the claimed compounds prior to synthesis, finding “the evidence bordering on overwhelming that it would not have been possible to soundly predict in advance the therapeutic advantages of substituting a fluoride for the hydroxyl on the 2’-C-Me/OH nucleoside … the only way to find the … therapeutic value was to make it and discover what its therapeutic characteristics are by reliable and valid testing.” The Court therefore invalidated the claims for lack of utility.

The Court, however, made further findings in the event of an appeal. Regarding the disclosure requirement for sound prediction, the Court adopted the reasoning of Justice Rennie in AstraZeneca Canada Inc v Apotex Inc, 2014 FC 638, and held that this requirement only applied to new use patents. Nonetheless, the Court noted that the jurisprudence was “contentious” and found that if disclosure of the factual basis and sound line of reasoning is required then the ‘191 patent also failed to meet this requirement.

On the second issue of insufficient disclosure, the Court held that the ‘191 patent did not sufficiently disclose how to synthesize the claimed compounds and was therefore invalid. As the patent did not expressly disclose all of the steps for synthesizing the claimed compounds, Idenix sought to rely on common general knowledge to meet the burden of disclosure. However, the Court held that the evidence did not establish this knowledge and commented that for a statement in a published article to be common general knowledge in relation to the synthesis of a compound, “the statement must possess some fore-ordained degree of near-certainty, to be confirmed, not proven, by routine experimentation.” Moreover, section 27(3)(b) of the Patent Act “requires that the description of how to make the compound be almost certain, with some scope for routine experimentation to make the invention work.”

On the final issue of overbreadth, Gilead made a “novel” argument that since Idenix had been unsuccessful in making a compound within the scope of the claims and had no way of making the compounds, it did not complete the act of invention at the date of filing, thereby rendering any claim to such compounds by definition overbroad. The Court rejected this submission, noting that it would open the “floodgates somewhat to new challenges requiring a means to make the inventions for all unmade inventions relating in timing to disclosure, but affecting soundly predicted inventions.”

The Court also commented on the procedural issue of conducting testing before trial. Idenix sought to introduce the results of certain experiments to show that one of its employees had unknowingly synthesized the compound in question. It conducted a first experiment in “secrecy behind the cloak of its litigation privilege” and later invited Gilead to observe a second experiment. The Court noted that the secrecy of the first experiment and the lack of transparency regarding the testing protocol was a factor undermining the probative value of the second test. The Court suggested that a better solution would be for the party seeking to rely on testing to retain a mutually agreed-upon outside testing agency, be transparent in working up a protocol that replicated all of the relevant steps, and allow the other party to participate fully in all testing. In these circumstances, even if the offers for testing were rejected, the results would “serve considerable probative value.”

Idenix’s ‘191 patent infringed (if valid)

In its counterclaim, Idenix claimed that Gilead infringed its ‘191 patent by Gilead’s production and sale of sofosbuvir.

The Court concluded that sofosbuvir and/or Sovaldi, including in their metabolized forms, and a purported manufacturing intermediate fell within the scope of the claims of the ‘191 patent.

Invalidity attacks on Gilead’s ‘657 patent rejected

In its counterclaim, Idenix also sought to invalidate Gilead’s ‘657 patent on the grounds of anticipation based on its own (earlier) ‘191 patent and under section 53 of the Patent Act for wilful misrepresentation by “knowingly omitting naming Dr. Lieven Stuyver as inventor.”

On anticipation, the Court found that the same invention of the ‘657 patent was disclosed in the ‘191 patent but that there was no enablement of the claimed subject matter as the ‘191 patent failed to disclose how to synthesize the compounds as discussed above. Therefore, the ‘657 patent was not invalid for anticipation.

Finally, the Court dismissed Idenix’s counterclaim for invalidity of Gilead’s ‘657 patent under section 53 of the Patent Act. With respect to inventorship, the Court noted that this referred to the person(s) responsible for the inventive concept and a person who contributed to the idea would be a co-inventor. The Court concluded that the alleged co-inventor, who was initially named on a provisional patent application but was later removed, did not contribute to the invention and was therefore not a co-inventor even though he oversaw some testing in relation to the claimed compounds. The Court also commented in obiter that Idenix did not, in any event, establish how failure to name a co-inventor was a “material” untrue allegation.

Idenix may appeal as of right to the Federal Court of Appeal.


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