Double Patenting in Canada

Double patenting, in other words an applicant obtaining more than one patent for their invention, is prohibited in Canada. The rule against double patenting prevents the grant of more than one patent for a single invention. Although “double patenting” is not an explicitly defined term in the Patent Act, section 36(1) of the Patent Act states that “A patent shall be granted for one invention only…” From this, it can be gleaned that the Patent Act contemplates a singular patent for each invention.

The rationale behind the prohibition of double patenting is explored at length in the case law. As articulated in Abbott Laboratories v. The Minister of Health, 2009 FC 648, a second patent cannot be justified unless its claims are novel over the claims of the first patent. In other words, further invention is required on the first invention, as to meet the novelty requirement of obtaining a patent, as to obtain a second patent. Another reason for the prohibition of double patenting is to prevent an applicant from “evergreening” their patent monopoly, thereby maintaining the patent bargain (i.e., the inventor is granted a limited monopoly in exchange for public disclosure of the invention).

During the patent prosecution process, the issue of double patenting may arise where two patent applications (or one patent application and one patent), belong to the same applicant. Applicant is defined in section 2 of the Patent Act to include “an inventor and the legal representatives of an applicant or inventor”, where legal representatives include “heirs, executors, administrators of the estate, liquidators of the succession, guardians, curators, tutors, transferees and all other persons claiming through applicants for patents and patentees of inventions or through holders of certificates of supplementary protection.”

It is also important to note that as established in Bayer Inc. v. Cobalt Pharmaceuticals Company, 2013 FC 1061, double patenting is only an issue when the first patent is not citable against the second patent for anticipation or obviousness under the Patent Act. As explained by the Court, “If the first patent was published sufficiently before the application for the further patent, then it will simply serve as a piece of prior art and the further patent may be invalid for lack of novelty or obviousness.” For more information on the requirements of patentability in Canada, including novelty and non-obviousness, you may wish to consult our article on this topic.

Types of Double Patenting in Canada

As articulated in Whirlpool Corp. v. Camco Inc., 2000 SCC 67, a leading authority on double patenting in Canada, although the prohibition against double patenting is judge made law, the SCC has articulated that there is an inherent prohibition against double patenting. In Whirlpool, the Court held that there are two branches of the prohibition of double patenting: (i) Same invention double patenting and (ii) obviousness-type double patenting. Same invention double patenting occurs when the two sets of claims that are being compared are “identical or conterminous”. In other words, the subject matter claimed is exactly the same. Obviousness-type double patenting occurs when the second, later set of claims are not “patently distinct” from the claims of the earlier patent.

A patent examiner will compare the claims to determine if double patenting is at issue. This comparison of claims is not literal, but rather, the claims are constructed in a purposive manner based on how a person skilled in the art would have understood the claims in light of their common general knowledge. Where the two sets of claims, constructed in a purposive manner, are such that that second, later set of claims is being anticipated or rendered obvious by the earlier set of claims, then the claims are not “patently distinct” from one another. Where the claims are not “patently distinct” from one another, the requirements for either type of double patenting is met.

In determining a claim of double patenting, the case law in Eli Lilly Canada Inc. v. Apotex Inc., 2015 FC 875 lays out a three-step inquiry, including:

• “First, it [the Court] must set out what is claimed in each of the patents, construing the claims, if necessary;
• Second, the court must determine if the claims in the two patents are identical. If they are and the same invention is claimed, the second patent will be void for same invention or coterminous double patenting; and
• Finally, if the inventions claimed in the two patents are not identical, the court must then go on to determine if the invention claimed in the later patent is inventive or patentably distinct from the invention claimed in the earlier patent. If not, then the second patent will be void for obviousness-type double patenting.”

How to Deal with Double Patenting Objections During The Patent Prosecution Process In Canada

Applicants may choose to pursue a proactive strategy and take steps at the filing stage to reduce the odds of receiving a double patenting objection. For example, applicants may choose to consolidate claims from all related patent applications into a single patent application. By doing so, applicants may increase the likelihood of obtaining a lack of unity of invention objection by the examiner. In turn, this objection will enable the applicant to elect and proceed with a subset of claims, and subsequently file a divisional application for the remainder of the claims. The advantage of this divisional application is that it will not be subject to a double patenting objection by the Patent Office or by a court. Prior to October 3, 2022, excess claims fee only applied at the time of allowance, making it feasible for applicants to employ the above strategy without having to pay the excess claims fee. After October 3, 2022, excess claims fees apply when the number of claims by the applicant exceeds 20, at any time during the examination process. In other words, applicants who choose to consolidate all the patent claims into a single application must pay excess claims fee if those claims exceed 20.

Applicants who receive a double patenting objection during the prosecution process may choose to respond by amendment, argument or abandonment. Applicants could amend either one of the patent applications such that the overlapping subject matter is only claimed in one application.

Alternatively, for an obviousness-type double patenting objection, applicants may advance arguments that the earlier set of claims do not render the second, later set of claims obvious. An obviousness-type objection is likely to be raised where, for example, the second, later set of claims is merely an aspect or embodiment of the first application. However, as in the case of many pharmaceutical patent applications, a second patent application that relates to a selection invention is not per se invalid for double patenting. Selection patents applications, which typically identify an advantageous narrow species of compounds, are filed following a first patent claiming a broad class of compounds (i.e., genus of compounds).

Another option is for applicants to abandon one of the two patent applications.

Comparison Of the Approach To Double Patenting In Canada And The United States

Similar to Canada, double patenting is not allowed in the United States. While both jurisdictions have similar approaches to double patenting, there are some key differences noted in the chart below.

Conclusion

If you would like assistance with overcoming a double patenting objection or have further questions on how to avoid double patenting, contact us today for a complimentary and confidential initial telephone appointment.