What is the Correct Date for Assessing Sufficiency?

Idenix Pharmaceuticals, Inc v Gilead Pharmasset LLC 2017 FCA 161 Rennie JA: Pelletier, Near JJA aff’g 2015 FC 1156 Annis J
            2,490,191 2,527,657 / sofosbuvir / SOVALDI
            FC Overview FC Sufficiency FC Inventorship FC ToC

At trial Annis J held the Idenix’ ‘191 patent invalid for lack of utility and insufficiency: see my posts on sufficiency and utility. Idenix appealed on both issues. The FCA affirmed on sufficiency [50], and consequently it was unnecessary to address utility [52]. As the Court noted, Idenix’s appeal “raises no new issues of principle or novel application of established principles to the facts” [3]. Idenix made the usual valiant attempt to unearth errors of law, but the FCA held either that the putative errors where not errors when read in context, or that they were inconsequential, or that were really an attempt to reargue the facts.

One point that caught my eye is the Court’s statement that sufficiency of disclosure is determined “as of the date of filing” [46], citing Viagra 2010 FCA 242, [79] (rev’d on other grounds 2012 SCC 60]. However, in Zoledronate 2013 FC 283, Hughes J, after consideration of the case law, held that the appropriate date for consideration of sufficiency was the date of publication, not the filing date [179]-[188] (aff’d 2013 FCA 244 without discussing this point). Kelen J 2009 FC 638, [108] in his Viagra decision held the same, relying on an earlier decision by Hughes J 2007 FC 596, [140-41] – though just as noted, on the same case on appeal, Viagra 2010 FCA 242, [79], the FCA held the correct date was the date of filing. (In that paragraph the FCA stated that some of Kelen J’s comments were “misguided” but it is not clear to me that the FCA was referring to his comments regarding the date for assessing sufficiency.) Hughes J’s logic in Zoledronate was that the purpose of the sufficiency requirement is to ensure that the invention is given to the public, and since it is directed at the public there is no point in considering a date before the public can actually see it. On the same logic, the SCC has held that the date for construing the claims, and more generally “the language of a patent” is is the date of publication: Free World 2000 SCC 66, [52]; Whirlpool Corp v Camco Inc 2000 SCC 67 [56]. It seems a bit odd to say that the words are construed at the date of publication, yet sufficiency is assessed at the same of filing, in light of how the words would be understood at the publication date, but it is perhaps not logically inconsistent, though there is the unifying point of principle that both are addressed to the public. I suppose the argument for using the filing date (which was not articulated in either FCA decision), is that the disclosure is not just addressed to the public, but also to the patent examiner; an application for a patent which does not sufficiently describe how to make the invention can be refused for that reason, and it seems wrong to hold the patent valid after it is granted, just because it slipped through the cracks on examination. That is particularly because if the patent was insufficient as of the date of filing, but sufficient at the date of publication, that will usually be due to the efforts of some party other than that patentee that has become common general knowledge.

I’m not really sure what to make of this. The decision of Hughes J in Zoledronate is the most fully considered decision on the issue, and the FCA holdings were stated without analysis of the case law. Moreover, in this case, nothing turned on the difference between the filing date and the publication date, and I believe the same was true in Viagra. But of course, the FCA is the higher authority. It’s probably a rare case in which the outcome turns on whether sufficiency is assessed at the claim date or the publication date, but it would be nice to have an FCA decision on this point which directly discusses Hughes J’s Zoledronate analysis, and so resolves the issue one way or the other.