On Sept. 25, 2019, Justice Manson of the Federal Court of Canada summarily dismissed a patent infringement action brought by CanMar Foods Ltd. against TA Foods Ltd.

This case is important for two reasons. First, it is the first time a Canadian court has interpreted the file wrapper estoppel rule added to Canada's Patent Act in December 2018. In a 2000 decision, the Supreme Court held that prosecution file histories are inadmissible for the purpose of construing patent claims because to do so would interfere with the public notice function of claims. The Supreme Court reasoned that the public should be able to ascertain the scope of claims in a patent without having to review extraneous documents such as negotiations between the patentee and the Patent Office. In 2018, Parliament statutorily overturned the Supreme Court on the basis that subject matter voluntarily given up to obtain a patent should not be capable of being recaptured in Court by a generous claim construction. To support the policy rationale of his decision, Justice Manson looked to US decisions because file wrapper estoppel has a long history in that country. CanMar Foods v. TA Foods is now a leading case in Canada for claims construction.

Secondly, CanMar Foods v. TA Foods now provides defendants with a viable and relatively inexpensive procedural route to exit patent actions where clearly there is no infringement. For decades, the Federal Court has been reluctant to use the summary judgment procedures in patent matters. Referencing the Supreme Court's dicta discussing the benefits of clearing out cases that do not need to go to trial, Justice Manson dismissed the action summarily. It is the first summary judgment decision of this type from the Federal Court in well over a decade.

Gowling WLG represented TA Foods in this action with a team that included Patrick Smith, Sarah Li and Jeffrey Coles.