Third parties frequently wish to challenge the validity of problematic patents or patent applications to secure freedom to operate, avoid potential infringement suits, or simply as a tactic in business negotiations. While it may be necessary to resort to court proceedings it is usually simpler and less costly to contest a patent at the appropriate patent office.

Standards for patentability, state of the art, and the legal basis for opposing patents can differ from country to country, so it is important to develop a cohesive approach to maximize chances of success. In this article, we review the ways patent rights may be challenged in Canada, Europe and the U.S.

Challenging Patent Rights in Canada

There are a number of ways to contest patent rights before the Canadian Patent Office. Before grant, a third party may file published prior art documents accompanied by an explanation of why the art is pertinent under section 34.1 of the Patent Act. In addition, they may file a protest pursuant to section 10 of the Patent Rules. A protest may extend beyond the mere submission of prior art and can include submissions questioning patentability on a variety of grounds.

Post grant, a request for re-examination under section 48.1 of the Patent Act may be filed, citing published prior art.

These procedures are ex parte and the third party is not permitted to communicate directly with the Examiner or Re-examination Board. Indeed the third party is not even informed of any actions taken as a result of their intervention. Consequently, these provisions are rarely used and it is more common for an interested party to attempt to impeach a patent under section 60 of the Patent Act or to make a counterclaim for invalidity when sued for infringement.

The European Perspective

Within nine months of the date of grant, a European patent may be opposed under Article 99 of the European Patent Convention (EPC). The grounds on which a patent may be opposed are laid out in Article 100 EPC and include lack of patentable subject matter, failure to sufficiently disclose the invention, and that the patent extends beyond that which was originally filed. Opposition proceedings are inter partes and any party may request an oral hearing by the Opposition Board. Frequently a decision is rendered at the conclusion of the oral hearing. On request, a decision of an Opposition Board may be subject to review by a Board of Appeal.

In addition to post-grant opposition, Article 115 EPC provides basis for a third party to make observations to the European Patent Office concerning the patentability of a patent or patent application. As in Canada, submitting observations does not make one a party to proceedings and consequently the process is less frequently utilized than opposition proceedings.

Patent Challenges in the U.S.

The Leahy-Smith America Invents Act proposes to expand the provisions on pre-grant third-party observations by encouraging third-party submissions of relevant documents to the U.S. Patent Office prior to issuance of a patent application filed on or after September 16, 2012. The prior art may now be accompanied by concise statements explaining each document, thus making the observations significantly more powerful than the current provisions. However, the opportunity for fi ling such observations is relatively curtailed in that observations may only be made prior to the notice of allowance and within six months of publication or the issuance of the first rejection.

The America Invents Act will also provide two new options for challenging the validity of a U.S. patent — post-grant and inter partes review.

Under the new post-grant review process, granted U.S. patents that have an effective filling date of March 16, 2013 or later may be challenged within nine months of grant or issuance of a re-issued patent.

A third party may request cancellation of one or more claims alleging invalidity based on any ground, with the exception of failure to comply with "best mode." Prior art is not limited to printed publications, and may include evidence of sales or public use, etc. Post-grant review may also be granted if the petition raises a new or unsettled legal question important to the patent system. After the Patent Trial and Appeal Board renders its final decision, the petitioner is estopped from asserting invalidity of any claim in the patent on any ground that the petitioner actually raised, or could reasonably have been expected to raise, before the board.

Inter partes review, which replaces the current "inter partes reexamination" proceeding, is intended to be a relatively quick proceeding for challenging a U.S. patent's validity in the Patent Office on the grounds of double patenting, anticipation, or obviousness on the basis of printed publications or patents. The new inter partes review procedure commences September 16, 2012.

In view of the variety of options available, and the differences in national laws, it is advisable to seek expert help when opposing a patent. In addition, patent owners should place a premium on high-quality prosecution so as to minimize the grounds available to a potential opponent.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.