Apotex v. Pfizer Ireland

Drug: sildenafil

The Court of Appeal heard an appeal from the Motions Judge where the majority of impugned paragraphs in the Statement of Defence were allowed to stand. The decision of the Motions Judge is summarized here.

In the underlying action, Apotex has started a proceeding to impeach the validity of Pfizer’s patent. Apotex brought the within motion to strike part of Pfizer’s pleadings relating to issue estoppel, collateral estoppel, comity and abuse of process. Pfizer’s pleadings in these areas assert that Apotex is precluded from re-litigating issues relating to the validity of the patent because of these principles.

The Court of Appeal summarized the history of law relating to the re-litigation of issues decided in NOC proceedings in subsequent actions. The Court of Appeal held that res judicata does not apply to the determination of validity and infringement in an action following a NOC proceeding. If a party introduces new evidence or new argument in a subsequent action, the trial judge should reconsider the issue in light of the full record before him or her. However, if a witness gives exactly the same evidence in both proceedings and the judge found the witness not to be credible in the NOC proceeding it may be open to the judge to bar re-litigation of the witness’ credibility through issue estoppel or abuse of process.

The Court of Appeal held that it is plain and obvious that Pfizer’s defence of issue estoppel, collateral estoppel, comity and abuse of process cannot apply to bar litigation of the validity issue. Thus, those paragraphs were struck from the Statement of Defence. However, statements relating to other subsidiary findings of the applications judge were allowed to stand so that the trial judge has the discretion to evaluate whether these findings may be relitigated in light of evidence and arguments at trial.