In a patent impeachment proceeding, the Court considered an appeal of a motion refusing to strike certain defences from the statement of defence. Pfizer was successful in a proceeding under the Patented Medicines (Notice of Compliance) Regulations. Apotex then started an action to impeach the patent.

Pfizer argued, as part of its statement of defence, that by reason of res judicata, issue estoppel, collateral estoppel, comity and abuse of process, Apotex is precluded from contesting the validity of the patent, as it raised many of the same grounds as to invalidity in the NOC Proceeding.

Pfizer agreed, during the hearing of the motion, that “res judicata” should be removed from the pleading. However, Pfizer argued that the other issues had not been raised or fully argued in any previous case, thus should remain. The Court agreed and refused to strike the pleadings.