The defendants brought a motion for leave to amend their Statements of Defence to plead that a patent previously declared invalid by the Federal Court was actually valid, relying on a recent Supreme Court of Canada decision that overturned the 'promise doctrine' used to invalidate it.
The Superior Court of Justice dismissed the motion, holding that the proposed amendments constituted an impermissible collateral attack and were barred by issue estoppel.
The court found no 'special circumstances' to justify re-litigating the patent's validity, noting that under section 62 of the Patent Act, the Federal Court's declaration rendered the patent void ab initio.
