On January 7, 2015, Justice de Montigny of the Federal Court released his judgment and reasons in Eli Lilly Canada Inc. v. Mylan Pharmaceuticals ULC, 2015 FC 17, allowing Lilly’s application for an order prohibiting the Minister of Health from issuing a Notice of Compliance to Mylan until the expiry of Canadian Patent No. 2,226,784 (the “‘784 Patent”). The patent relates to Lilly’s successful erectile dysfunction (“ED”) drug CIALIS® (tadalafil).

The Court found that Mylan’s allegations of invalidity on the basis of lack of utility and obviousness-type double patenting were unjustified. Justice de Montigny’s reasons signal the Court’s continuing hesitation to impute potentially invalidating promises of utility if they are not clearly and explicitly stated in the patent. Further, the case establishes that the relevant date for conducting the double patenting analysis is the earlier patent’s claim date.

Utility: Promise of the Patent

Lilly argued that the promise of the ‘784 Patent is the use of certain claimed compounds to treat ED. Mylan disagreed, asserting that the patent also promises that the compounds will be effective on oral administration and will not have severe side effects.

The Court preferred Lilly’s construction, holding that the promise of the ‘784 Patent does not relate to the specific route of administration, but rather to the effectiveness of the compounds to treat ED. Justice de Montigny explained that although oral administration is a preferred feature of the invention, it is not the promise of the entire patent. Additionally, he disagreed with Mylan’s assertion that the claim term “treatment” imports a consideration of side effects, holding that there is no reference to toxicity in the ‘784 Patent.

Utility: Sound Prediction

Since the utility of the claimed compounds to treat ED was not demonstrated prior to the filing date, the Court undertook an analysis of whether such utility could be soundly predicted. Justice de Montigny found that in light of the common general knowledge, the ‘784 Patent taught a skilled person that the claimed compounds potently and selectively caused penile erection. He further held that even if the promise of the patent was construed to included oral administration, such utility was also soundly predicted by the filing date.

Double Patenting

Mylan argued that if the promise of the ‘784 Patent does not include oral administration, it must be invalid for double-patenting over an earlier Canadian patent which claims the same compounds. The Court disagreed, holding that while both patents claim the same chemical compounds, the earlier patent does not contemplate use of the compounds to treat ED.

On the issue of the relevant date for an obviousness-type double patenting analysis, the Court explained that the key consideration is whether the claims in the later patent disclose novelty or ingenuity over the earlier patent. As such, “[o]ne cannot read into the claims of the first patent more than what would have been understood by the person skilled in the art at the claim date when comparing the claims of the second patent to those of the first patent” (at para. 134). On this basis, Justice de Montigny held that the correct date for determining the issue of double patenting is the priority date of the earlier patent.