On July 6, 2015 the Federal Court of Appeal released it decision on AstraZeneca’s appeal of Justice Rennie’s decision holding that the Canadian Patent No. 2,139,635 was invalid for lack of utility. The 635 Patent is generally directed to optically pure salts of esomeprazole. Below, Justice Rennie held that the 635 Patent promised compounds with an improved therapeutic profiles and that this utility had not been demonstrated or soundly predicted as of the Canadian filing date.
On appeal, AstraZeneca argued had erred by (1) not determining the promise on a claim-by-claim basis; and (2) construing the promised utility in a manner that was inconsistent with their inventive concept.
The Court of Appeal concluded that it was not open for AstraZeneca to argue the first point, as it had not asked Justice Rennie to construe the promise on a claim-by-claim basis. The Federal Court was entitled to rely on the lis as framed by the parties.
On the second alleged error, the Court of Appeal held that Justice Rennie had not erred in construing utility in a manner that was inconsistent with the inventive concept, holding:
 Again, I disagree that the Federal Court erred. The Court’s reasons show that the Federal Court directed itself to the correct legal tests applicable to claims construction, inventive concept and utility. In oral argument, AstraZeneca was unable to show that its submission was supported by the jurisprudence. While it pointed to an admittedly obiter passage in Canada (Attorney General) v. Amazon.com, Inc., 2011 FCA 328,  2 F.C. 49, at paragraphs 37 to 41, the obiter comments found there do not support AstraZeneca’s submission that a promise of utility must be construed to be virtually coterminous with the inventive concept of the relevant claim or claims.
A copy of the Court of Appeal’s Reasons for Judgment may be found here.