Second Kick at the Can: Post-Grant Proceedings Involving Canadian Patents

September 09, 2020

Once a Canadian patent has issued, it can be the subject of various types of proceedings. This article will provide an overview of both proceedings that are adjudicated by the Patent Office (such as reissue and re-examination) and proceedings that are determined by the courts (such as declaratory actions in respect of infringement and validity).


A patentee who seeks to make amendments to its patent can request reissue of the patent within four years after grant. The patentee must satisfy the Commissioner of Patents that its patent is defective or inoperative by reason of insufficient description and specification, or by reason of the patentee claiming more or less than it had a right to claim as new.  The patentee must also establish that the error arose from inadvertence, accident or mistake, without any fraudulent or deceptive intention. 

If the Commissioner is satisfied that reissue is appropriate, it will issue a new patent containing the requested amendments for the then unexpired term for which the original patent was granted.  If the patentee subsequently commences an action for a cause accruing after reissue, then the trial shall be determined as if the amended description and specification had been originally filed in their corrected form before the issue of the original patent.  Additionally, if an action for infringement is pending at the time of reissue and the claims of the original and reissued patents are identical, then the reissue shall not have any negative impact on the patentee’s cause of action.

Correction of Obvious Errors

Another avenue for a patentee to make amendments to its patent is to file, within twelve months after issuance, a request to correct an error in the patent.  The patentee can, through this process, seek to correct an error: (a) in the name of the patentee or an inventor if the correction does not change their identity; or (b) in the specification or drawings if it would have been obvious to a person skilled in the art that something other than what appears in the patent was intended and that nothing other than the correction could have been intended.

If the Commissioner of Patents agrees to make the change requested by the patentee, such change is considered to have been made as of the date of grant of the patent.


A patentee can, at any time during the life of its patent, amend the patent to claim less than that which was claimed in the original patent. The patentee can take advantage of this disclaimer procedure where it has by any mistake, accident or inadvertence, and without any willful intend to defraud or mislead the public, made its specification too broad by claiming more than the inventor invented or subject-matter to which the patentee had no lawful right.

A disclaimer need not be limited to the entirety of one or more claims; a patentee can instead disclaim part of a claim provided that the disclaimer does not extend the scope of the claim or any dependent claim.

One scenario in which a patentee might choose to file a disclaimer is to narrow down a broad claim that, if challenged, would be at risk of being held to be invalid.


Re-examination of a patent may be requested by either the patentee or by a third party at any time during the term of the patent. 

A re-examination proceeding involves a reconsideration by the Commissioner of Patents of the validity of one or more claims of an issued patent in light of prior art that was publicly available before the relevant claim date.

A third party need not demonstrate the nature of its interest in the patent or re-examination in order to have standing.  However, once a re-examination request is filed, the Commissioner will only acknowledge receipt to the third party and all other communication will be held with the patentee.

The person who requests re-examination must file prior art consisting of patents, published patent applications and/or printed publications and explain the pertinency of the prior art and the manner of applying such art to the claims in respect of which re-examination is sought.

The matter is then turned over to a re-examination board established by the Commissioner to determine whether a substantial new question of patentability has been established.  The board’s decision in this regard is final and is not subject to appeal or judicial review.

If the board determines that no substantial new question of patentability has been established, then the re-examination comes to an end. If, on the other hand, the board concludes that a substantial new question of patentability has been established, then it will commence re-examination proceedings. 

During the re-examination proceedings, the patentee has the right to make submissions in support of patentability and to propose amendments to the existing claims and/or introduce new claims provided that they do not enlarge the scope of the claims of the patent as issued.

The re-examination board, after considering the patentee’s submissions and any proposed amendments, can cancel any claim as unpatentable, confirm any claim as patentable and/or incorporate into the patent any proposed amended or new claims that it holds to be patentable.

The principal advantages of re-examination are speed and cost.

There are, however, two important drawbacks to the use of re-examination by a party other than the patentee.

First, re-examination proceedings are not inter partes proceedings in that the third party is not entitled to participate beyond its submission of the request for re-examination.

Second, the fact that a patentee can propose amended or new claims during re-examination means that it can, through amendment, address the shortcomings in its patent that have been identified by the requesting party.

Given the above two limitations, it is relatively uncommon for a third party to seek to challenge a patent through re-examination.  Instead, most third parties will seek to challenge a patent through an impeachment proceeding where the party seeking impeachment can make a broader range of invalidity attacks and is entitled to participate as a full party and the patentee cannot amend its claims in an attempt to overcome the prior art.

Typically, re-examination will only be used by a party where cost or timing is an issue and the party has prior art that is of such impact that the patentee will either not be able to overcome the art through amendment of its claims or, alternatively, any claims as amended would not cover the third party’s activities.

The re-examination process may also be utilized by a patentee to amend one or more claims of its patent in view of any prior art not previously addressed during the examination phase of its application.


An “interested person” may commence an impeachment action in the Federal Court seeking to invalidate a patent or any claim in a patent.  The threshold to qualify as an “interested person” is low.  For example, a person who wishes to commence an impeachment action is not required to show that it has received a cease-and-desist letter from the patentee. 

A person who commences an impeachment action must provide security for the patentee’s costs of the litigation.  If, however, a person has been sued for patent infringement and counterclaims for a declaration of invalidity, it is not required to provide security for the patentee’s costs of the impeachment portion of the litigation.

Unlike a re-examination where the requesting party can only attack a patent’s validity based on prior art, an impeachment action may be based on any grounds of invalidity available under the Patent Act, such as: (a) the patent is not directed to patentable subject matter; (b) lack of utility; (c) ambiguity in the claims; (d) double patenting; and (e) the claims being broader than the invention made or disclosed.

As discussed above, the principal advantages of an impeachment action are that the challenger can attack a patent on a broad range of fronts and it has full rights as a participant in the proceeding such as the right to lead evidence, cross-examine on the patentee’s evidence and make written and oral arguments before the trier of fact. The biggest disadvantages of an impeachment action versus a re-examination proceeding are time and cost.

Declaration of non-infringement

Where a person has reasonable cause to believe that any process used or proposed to be used or any article made, used or sold or proposed to be made, used or sold by him might be alleged by any patentee to constitute infringement, such person may bring an action in the Federal Court against the patentee for a declaration that the process or article does not or would not constitute an infringement.

Compulsory Licensing

The Patent Act permits the granting of a compulsory license in the following circumstances: (a) the patentee has been abusing its patent rights; (b) the federal government or a provincial government requires authorization to use a patent; (c) a license is required to export pharmaceutical products for humanitarian reasons; or (d) a license is required in order to respond to a public health emergency.

Dealing first with scenario (a) above, the Attorney General of Canada or an interested person may, at any time within three years from the date of grant of a patent, apply to the Commissioner of Patents, alleging that there has been an abuse of the exclusive rights granted under the patent.  If abuse is established, one of the powers available to the Commissioner is to order the patentee to grant the applicant a licence on such terms as the Commissioner finds to be appropriate.  The most likely ground for establishing patent abuse would be a showing that the demand for the patented article in Canada is not being met to an adequate extent and on reasonable terms. 

In scenario (b), if the federal government or a provincial government can, upon application to the Commissioner, show that it has made unsuccessful efforts to obtain authorization from the patentee on reasonable commercial terms it may be able to obtain an order from the Commissioner authorizing the use of the patented invention by that government predominantly to supply the domestic market. The Commissioner would also have the power to assess an amount that it considers to be adequate remuneration in the circumstances.

Turning to scenario (c), the grant of a licence for the purpose of making, constructing and using a patented invention for export, has only rarely been used.

Scenario (d) relates to changes to the Patent Act, enacted in March 2020, for the purpose of addressing public health emergencies.  These changes are not expected to have long-term application beyond the COVID-19 outbreak.

Patent Term Restoration

As part of its obligations under the Canadian-European Union Comprehensive Economic and Trade Agreement (CETA), which entered into force on September 21, 2017, Canada introduced a form of patent term restoration, namely, a Certificate of Supplementary Protection (CSP).  This term restoration applies to patents relating to drugs containing a new medicinal ingredient, or a new combination of medicinal ingredients. 

To be eligible for a CSP, a patent must have been issued in respect of an application that was filed on or after October 1, 1989 and such patent must still be in force.  The patentee must also have had a Notice of Compliance (NOC) issued in Canada after September 21, 2017.  An application for a CSP must be filed within 120 days from the date on which the NOC was issued if the relevant patent has already been granted, or within 120 days from the date on which the relevant patent is issued, if it was pending when the NOC was granted.  A CSP allows for a patent term restoration of up to two years from the expiry date of a patent that meets the eligibility and timing requirements.

Disputes Over Ownership of a Patent

The Federal Court has jurisdiction, on the application of the Commissioner of Patents or of any person interested, to order that any entry in the records of the Patent Office related to the title of a patent be varied or expunged.  A third party who wishes to challenge the ownership of an issued patent may bring an action in the Federal Court seeking, among other things, an order recognizing its ownership rights in the patent.

Newsroom Articles

Choose Your Own Source: Adding A Trademark to Someone Else’s Goods

Antonio Turco

In a recent decision arising from an appeal of a decision of the Trademarks Opposition Board, the Federal Court commented on when a retailer can establish use of a trademark on goods when the retailer is not the “source” of the goods. Specifically, if a retailer simply affixes its own trademark to goods manufactured by a third party, does that constitute use of the retailer’s trademark in association with those goods.

Read more

Hot Dog!: Injunction Overturned in “Bombay Frankie” Case

Sarah O'Grady

Interlocutory injunctions in Canadian trademark cases are rare. The decision at first instance to grant a motion for an interlocutory injunction in a dispute related to the “Bombay Frankie” trademark therefore made headlines, at least in trademark circles, for two reasons. First, the fact that the injunction had been granted was in itself noteworthy. Second, many in the intellectual property bar were of the view that the decision misapplied certain fundamental principles of trademark law and therefore introduced uncertainty into the law.

Read more

I Can’t Wait! Speeding Up Processing of Your Canadian Trademark Applications

Anthony Prenol

Canada continues to make news (the wrong kind) when it comes to the slow pace of its examination of trademark applications. Despite repeated promises by the Canadian Intellectual Property Office (“CIPO”) to speed things up, the problem is only getting worse. However, there are some promising signs.

Read more

130 Queens Quay East, East Tower, Suite 809, Toronto, Ontario, M5A 0P6, Canada
Main: (647) 478-2425 | Fax: (647) 478-2438 |
© CPST Intellectual Property Inc.
All Rights Reserved. 2021 |
Legal | Terms of Use
Website Design by Clutch Marketing