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Supreme Court Breaks The “Promise Doctrine” In NEXIUM Patent Dispute

On June 30, 2017, the Supreme Court of Canada released its judgment in AstraZeneca v. Apotex, a case dealing with the utility requirements under the Canadian Patent Act.

Section 2 of the Patent Act requires that an invention be useful, and the main issue before the Court was “useful for what?” The Promise Doctrine, as developed in the Federal Court and the Court of Appeal, held that while a patent need not promise any specific use, where an express promise of a specific result is made, that promise has to have been demonstrated or soundly predicted as of the Canadian filing date, absent which the patent would be invalid for inutility.

Background – 653 Patent

AstraZeneca’s 653 Patent is generally directed to optically pure salts of omeprazole. At trial, Justice Rennie had held that the claimed subject matter would be useful as a proton pump inhibitor and would provide an improved pharmacokinetic and metabolic profile that would result in lower inter-individual variation. While there was no dispute that the 653 Patent met the first promise, the same was not true for the second, and Justice Rennie held that the 653 patent “promised more than it could provide” and accordingly held the 653 Patent invalid for lack of utility. AstraZeneca’s appeal of Justice Rennie’s judgment was dismissed by the Federal Court of Appeal. AstraZeneca then obtained leave to appeal to the Supreme Court of Canada.

Supreme Court’s decision

Justice Rowe, writing for a unanimous Court, held that utility is not to be addressed by reference to statements made in the disclosure. Justice Rowe also held that the “Promise Doctrine” is neither supported by the language of the Act and improperly conflates the utility requirement under section 2 with the disclosure requirement under section 27:

[24] I conclude that the Promise Doctrine is not the correct method of determining whether the utility requirement under s. 2 of the Patent Act is met. Given the correct approach, as set out below, the drug for which the ‘653 patent was granted is useful as a PPI; thus, it is an “invention” under s. 2 of the Act. The ‘653 patent is therefore not invalid for want of utility.

[44] The Promise Doctrine effectively imports s. 27(3) into s. 2 inappropriately, by requiring that to satisfy the utility requirement in s. 2, any disclosed use (by virtue of s. 27(3)) be demonstrated or soundly predicted at the time of filing. If that is not done successfully, the entire patent is invalid, as the pre-condition for patentability — an invention under s. 2 of the Act — has not been fulfilled.

Justice Rowe held that where the claimed subject matter is disclosed to have multiple uses, it is sufficient for the purpose of section 2 that the claimed subject matter have real world utility for any one of the disclosed uses. In coming to this conclusion, the Court noted that a patent should not be invalidated solely on the basis of an “unintentional overstatement” in the disclosure:

[51] The effect of the Promise Doctrine to deprive such an invention of patent protection if even one “promised” use is not soundly predicted or demonstrated is punitive and has no basis in the Act. Furthermore, such a consequence is antagonistic to the bargain on which patent law is based wherein we ask inventors to give fulsome disclosure in exchange for a limited monopoly (British United Shoe Machinery Co. v. A. Fussell & Sons Ltd. (1908), 25 R.P.C. 631(C.A.), at p. 650). To invalidate a patent solely on the basis of an unintentional overstatement of even a single use will discourage a patentee from disclosing fully, whereas such disclosure is to the advantage of the public. The Promise Doctrine in its operation is inconsistent with the purpose of s. 27(3) of the Act which calls on an inventor to “fully describe the invention and its operation or use”. Thus, the Promise Doctrine undermines a key part of the scheme of the Act; it is not good law.

Instead, the Court provided the following two-part test for assessing utility under section 2:

[54] To determine whether a patent discloses an invention with sufficient utility under s. 2, courts should undertake the following analysis. First, courts must identify the subject-matter of the invention as claimed in the patent. Second, courts must ask whether that subject-matter is useful — is it capable of a practical purpose (i.e. an actual result)?

Since the rationale behind the utility requirement is to prevent prematurely granting patents for fanciful, speculative or inoperative inventions, the Court held that a single use related to the claimed subject matter is sufficient to support the validity of a claim and that use need only show a “scintilla” of utility:

[55] The Act does not prescribe the degree or quantum of usefulness required, or that every potential use be realized — a scintilla of utility will do. A single use related to the nature of the subject-matter is sufficient, and the utility must be established by either demonstration or sound prediction as of the filing date (AZT, at para. 56).

Although section 2 is not the proper provision to assess promises made in the specification, the Court recognized that overpromising is a “mischief” and that validity consequences may flow from overpromises made in the disclosure. For example, a disclosure that states an unsubstantiated use of the invention may not “fully and correctly” describe the invention as required by subsection 27(3). Further, where the statements of unsubstantiated use are willfully made for the purpose of misleading, the patent may run afoul of section 53 of the Act.

Here, since it was undisputed that the utility of the claimed subject matter as a proton pump inhibitor was soundly predicted, the Court held that this was sufficient to support the utility of the claims and allowed AstraZeneca’s appeal.

A copy of the Supreme Court’s Reasons for Judgment is available here.

Aitken Klee LLP represented the intervenor, the Canadian Generic Pharmaceutical Association, before the Supreme Court of Canada in this matter.