Drug: sildenafil

The Court of Appeal upheld the decision of a Trial Judge granting a prohibition order preventing Novopharm from coming to market with a generic version of sildenafil until the expiry of the patent at issue. The appeal dealt with sufficiency of disclosure and utility.

The Court upheld its reasoning in previous decisions that where a single patent application separately claims a class of compounds and a single compound within that class, each claim discloses a separate invention. The Court also confirmed that the “best mode” obligation only arises in the case of a patent to a machine. Thus, the disclosure requirements are limited to the claim at issue. The patent need only describe what the invention is, which was found in the claim, and how it works, which was found in the rest of the patent.

With respect to utility, the Court of Appeal held that there is no requirement for a patent to demonstrate utility in the patent disclosure so long as it can be proven upon a legal challenge. There is nothing in the Patent Act which leads one to conclude that utility be demonstrated in the patent disclosure. The disclosure provides direction, not proof: it tells practitioners how to practice the invention, however, it does not prove to them its utility. Practitioners can require proof through invalidity proceedings.

The Court of Appeal confirmed that an inventor is not required to meet the regulatory testing standards in order to demonstrate utility, a mere scintilla of utility is all that is needed. Thus, the appeal is dismissed with costs.