On March 11, 2005, a judge of the Federal Court prohibited the Minister of Health (the "Minister") from issuing a Notice of Compliance (NOC) to Pharmascience Inc. for a generic ramipril product (Aventis Pharma v. Pharmascience (2005 FC 340)) in an application under the Patented Medicines (Notice of Compliance) Regulations ("Regulations").
Pharmascience had alleged:
(i) non-infringement of Canadian Patent No. 1,246,457 ("457"), and
(ii) invalidity of Canadian Patent No. 1,341,206 ("206"), owned by the respondent Schering and listed by Aventis on the patent register.
The 457 patent covered the use of ramipril for the treatment of cardiac insufficiency (heart failure). Justice Snider of the Federal Court found Pharmascience's non-infringement allegation insufficient, noting it amounted to "a bald assertion of non-infringement". She reinforced the importance of the Notice of Allegation (NOA) in informing the patentee of the case to be met, stating: "there was nothing in the NOA that would enable Aventis to understand why a pill that looks and acts identically to its patented cardiac insufficiency medicine would not be used for such a purpose."
The allegation of invalidity was premised on the fact that the 206 patent, covering a genus of compounds including ramipril, had issued after Canadian Patent No. 1,187,087 ("087"), which included claims to ramipril only and was owned by Aventis. However, despite issuing later, the application for the 206 patent had actually been filed before the application for the 087 patent. Due to delays in the Canadian Patent Office during prosecution, including conflict proceedings, the 206 patent had not issued until 2001, some 16 years after the issuance of the later-filed 087 patent. Hence, Pharmascience was arguing that the earlier-filed 206 patent was invalid as a result of the grant of the later-filed, but earlier-granted, 087 patent. As noted by Justice Snider, the 087 patent was a "selection patent covering only a portion or a selection of the chemicals claimed in the genus patent".
Justice Snider rejected Pharmascience's double patenting argument. Two legal findings are noteworthy:
- First, she noted that the focus of the analysis must be the claims that form the invention and not the persons or parties that advance them. Where the two patents at issue have neither common inventors nor owners (as in this case), double patenting can apply.
- Second, she determined that the proper date to assess obviousness in the context of double patenting is the date of invention and not the date of grant.
On the facts of the case, Justice Snider ruled that, given the significantly increased activity of ramipril as compared to its stereoisomers, there was no obviousness and that the 087 and 206 patents were patentably distinct. Justice Snider also reaffirmed the validity of selection patents, specifically rejecting the notion that selection patents constitute evergreening.
This decision clarifies the scope of double patenting in Canada and reinforces the importance of the notice function of an allegation. Pharmascience has not yet appealed this decision.