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Summary Judgment for Impeachment Action of Viagra Patent Upheld by FCA

January 24, 2014

By Andrea Berenbaum

On January 22, 2014 the Federal Court of Appeal (“FCA”) in Pfizer Ireland Pharmaceuticals v. Apotex Inc, dismissed an appeal from the judgment of the Federal Court which granted Apotex’s motion for summary judgment in its action to impeach Pfizer’s Canadian Patent No. 2,163,446 (“the ‘446 Patent”).

Background

The ‘446 Patent was previously the subject of an application brought by Pfizer under the Patented Medicines (Notice of Compliance) Regulations (“PM(NOC) Regulations”) for an order prohibiting the Minister of Health from granting authorization to Teva (then Novopharm) to market generic sildenafil for the use claimed in the ‘446 Patent. Those proceedings ultimately resulted in the Supreme Court of Canada (“SCC”) in Teva Canada Ltd v. Pfizer Canada Inc (“Sildenafil”) dismissing Pfizer’s application because of its finding that Teva’s allegation of invalidity on the basis of insufficient disclosure was justified. In the decision which was initially released, the SCC had held the ‘446 Patent to be “void” but the original reasons and formal order were subsequently amended in response to a motion brought by Pfizer. (Please click here and here for further details.)

The basis of the SCC’s finding in Sildenafil was that the disclosure of the ‘446 Patent was insufficient because it did not disclose that sildenafil, the active ingredient in ViagraTM, was the compound that had been demonstrated to work in patients.

Motion for Summary Judgment

After the SCC had released its initial decision in Sildenafil, Apotex filed a motion in the Federal Court seeking summary judgment of its action to impeach the ‘446 Patent.

The motion for summary judgment in the present case was granted by the Federal Court prior to the amendment to the Sildenafil reasons and formal order detailed above was made. In granting the motion, the Federal Court concluded that the determination by the SCC in Sildenafil that the ‘446 Patent fails to meet the requirement of sufficient disclosure is a legal determination binding on the Federal Court and was dispositive of Apotex’s claim in the impeachment action that the ‘446 Patent is invalid due to insufficiency even if the SCC grants Pfizer’s motion and deletes the declaration of invalidity from its judgment. The issue on appeal to the FCA was whether the Federal Court erred in law or misapplied the test for summary judgment in so concluding.

FCA Decision

Following the “long and consistent” line of jurisprudence to the effect that an application for a prohibition order under the PM(NOC) Regulations cannot, as a matter of law, result in a final determination as to the validity or infringement of a patent, the FCA agreed with Pfizer’s argument in the present appeal that Sildenafil is based on a particular construction of the ‘446 Patent which cannot be conclusive for all purposes.

However, the FCA held that Pfizer failed to present evidence establishing a genuine issue for trial as is required of a respondent opposing a motion for summary judgment.

The FCA held in its reasons that

… to establish that there is a triable issue with respect to the construction of the 446 patent, it was incumbent on Pfizer to adduce evidence or to refer to evidence already adduced in this matter. In particular, Pfizer should have adduced or referred to evidence that addresses how the skilled reader would construe the specification, and why that construction casts doubt on the correctness of the construction adopted in [Sildenafil]. The record contains no such evidence.(paragraph 25)

The claims of the ‘446 Patent included a claim relating to the use of sildenafil for the treatment of erectile dysfunction (ED) and another claim relating to the same use of a compound designated as UK-114,542. In the present case, Pfizer pointed to evidence that UK-114,542 was in fact tested before the Canadian filing date and found to be useful for treating ED. However, the FCA asserted that

… what the patent discloses is that as of the filing date studies had confirmed that one of the compounds in the especially preferred group induces penile erection in important (sic) males. There is no disclosure that UK-114,542 was tested, and Pfizer has adduced no evidence that is capable of establishing that the skilled reader should have discerned from the specification that it was tested. (paragraph 26)

Accordingly, the FCA concluded the evidence that UK-114,542 was tested is not capable of establishing a genuine issue for trial on the question of the sufficiency of the disclosure.

In the present decision, the FCA also declined to resolve the debate regarding whether the relevant date for determining the sufficiency of the disclosure is the filing date of the Canadian patent application or the date on which the patent application becomes public. Accordingly, it appears there is presently still uncertainty as to this issue in Canada.

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