Introduction
Canada recently introduced patent rules related to excess claim fees and
continued examination fees that have the potential to
complicate conventional approaches to filing divisional patent
applications. This article reviews the requirements for filing a
divisional patent application in Canada, the impact of the new
claim fee and continued examination fee rules on divisional
practice and provides strategies for safely filing divisional
applications while minimizing patent prosecution costs.
Divisional application requirements in Canada
Canadian patent law provides for the filing of divisional
applications, consistent with Canada's obligations under
Article 4.G of the Paris Convention, as follows:
(1) If the examination reveals that an
application for a patent contains more than one invention, the
applicant may divide the application into a certain number of
divisional applications and preserve as the date of each the date
of the initial application and the benefit of the right of
priority, if any.
(2) The applicant may also, on his own initiative, divide a patent
application and preserve as the date of each divisional application
the date of the initial application and the benefit of the right of
priority, if any. Each country of the Union shall have the right to
determine the conditions under which such division shall be
authorized.
Paragraph (2) of Article 4.G does not limit the conditions under
which an applicant may "voluntarily" divide their patent
application. Any such restrictions are matters of national
law.
Divisional application filing formalities are much more flexible
in Canada than in many countries. A divisional application may be
filed at the applicant's initiative at any time, the sole
limitation being that the divisional application must be filed no
later than the day before grant of the parent application. There
are no formal limitations as to what may be claimed in a divisional
application, and the historical requirement that the subject-matter
claimed in the divisional application must have been claimed at
some point in the parent application was removed from the
Patent Act by amendments in force October 1, 1996.1 Furthermore, the Patent Office permits
divisional applications to be filed in a serial or
"cascading" manner, such that if a first application (the
"grandparent" application) leads to a first divisional
application (the "parent" application), a further
divisional application (the "child" application) may be
filed on the basis of either the parent or the grandparent
application.2
With respect to substantive matters, subsections 36(2) and (2.1)
of the Canadian Patent Act set forth the conditions under
which a divisional application may be filed:
Limitation of claims by
applicant
(2) Where an application (the
"original application") describes more than one
invention, the applicant may limit the claims to one invention
only, and any other invention disclosed may be made the subject of
a divisional application if the divisional application is filed
before the issue of a patent on the original application.
Limitation of claims on
direction of Commissioner
(2.1) Where an application (the
"original application") describes and claims more than
one invention, the applicant shall, on the direction of the
Commissioner, limit the claims to one invention only, and any other
invention disclosed may be made the subject of a divisional
application if the divisional application is filed before the issue
of a patent on the original application.
It means that the Patent Act permits the Patent Office
to require division only when an application "claims more than
one invention." Reciprocally, the applicant may voluntarily
file a divisional application that claims an invention
"other" than the invention claimed in the parent
application.
Divisional applications and double patenting
Although the Patent Act and Patent Rules
contain no unambiguous reference to the concept, the Canadian
courts have recognized a prohibition against "double
patenting"- i.e., the patentee obtaining a second patent
claiming subject matter that is "conterminous" with or
obvious over the claims granted in the first patent. This issue
does not arise in respect of divisional applications filed in
response to an objection for lack of unity of invention. While
there is no statutory safe harbour for a divisional application
filed at the direction of the Patent Office,3 the Supreme Court of Canada has held that
"[i]f patents are granted on divisional applications directed
by the Patent Office, none of them should be deemed invalid, or
open to attack, by reason only of the grant of the original
patent."4
But this judicially developed protection against double
patenting does not apply to a "voluntary" divisional
application filed at the initiative of the applicant. Accordingly,
it is generally preferable to file a divisional application only
after the Patent Office has objected for lack of unity of
invention. Consequently, proposed divisional claims are routinely
added to applications, often late in prosecution, for an assessment
by the Patent Office as to whether such claims properly should be
filed in a divisional application or retained in the original
application.
Excess claim fees and continued examination fees
As discussed in our previous
article, amendments to the Canadian Patent Rules came
into force recently and apply to any application in which
examination was not requested before October 3, 2022. The rules
introduce a fee of CAD $1005 for each
claim over 20. Claim fees are first calculated and payable when
examination is requested. They are calculated again when the final
fee (i.e., issue fee) is paid. The excess claim fee calculation is
based on the greatest number of claims pending in the application
at any time starting from the date examination is requested and
ending on the date the final fee is paid. The new rules also
introduced a continued examination scheme requiring a request for
continued examination (RCE) and payment of a CAD $8166 fee to continue examination and respond
to the third Examiner's Report and every second Examiner's
Report thereafter.
Cost implications for divisional applications
Prior to the October 3, 2022, rule change, it was common to
prosecute large claim sets with a view to obtaining an assessment
of unity of invention and to avoid filing voluntary divisional
applications. For instance, the claims from a series of foreign
counterpart continuation or divisional applications might be
consolidated in a single claim set. If the Patent Office were then
to object for lack of unity of invention, divisional applications
safely could be filed. No government fees were payable.
Similarly, it was common to re-open prosecution after allowance
to add claims for an assessment of unity of invention rather than
to file a voluntary divisional application upon allowance. If the
Examiner objected for lack of unity, the added claims could then
safely be cancelled and filed in a divisional application.
Alternatively, if the Examiner did not object for lack of unity,
the application might immediately again proceed immediately to
allowance or another Examiner's Report might be issued.7 The only government fee associated with
this practice was the CAD$407.18 fee for withdrawing the
application from allowance.
The introduction of the new excess claim fee and RCE rules have
the potential to add to the costs involved in ensuring that
divisional applications are safely filed without the risk of double
patenting.
Prosecuting large claim sets will incur excess claim fees, even
for claims that are ultimately cancelled for filing in a divisional
application. Adding claims later in prosecution may result in
issuance of a further Examiner's Report, potentially requiring
an RCE and CAD $816 fee. Re-opening prosecution after an
application is allowed to add further claims for an assessment of
unity of invention will also require an RCE and CAD $816 fee and
will similarly ultimately require payment of excess claim
fees.
By way of example, under the previous rules, if an application
was allowed with 20 claims, and 16 claims added after allowance for
an assessment of unity of invention, the only government fee
payable was the CAD$407.18 fee to withdraw the application from
allowance. Under the new rules (i.e., if examination was requested
on or after October 3, 2022), the government fees would instead be
CAD $2416 (the excess claim fees of $1600 and the RCE fee of $816).
Even if the 16 additional claims were added prior to allowance, it
would still be necessary to pay the excess claim fees of $1600,
whether or not those claims were later cancelled in response to an
objection for lack of unity of invention.
Strategies for cost-effective patent prosecution
Compact prosecution
These new requirements and fees for excess claims and requests
for continued examination will motivate applicants to prosecute
compact claim sets that do not require multiple rounds of
examination. This may involve limiting the scope of claims early in
prosecution to that of claims granted in other jurisdictions or
focusing on subject-matter of greatest importance. But at the same
time, claims to all subject-matter of interest ideally are
presented for an initial examination so that unity of invention can
be assessed early, and voluntary divisional applications
avoided.
Prior to or at the time of requesting examination, it may be
advantageous to reduce the number of claims (e.g., by cancelling
dependent claims) and at the same time to ensure that independent
claims to all important embodiments of the invention are presented
so that unity of invention can be properly assessed. There are no
additional fees for independent claims (provided the total number
of claims does not exceed 20) and unity of invention is more
readily assessed in the context of independent claims.
Claiming alternatives in a single claim for the
assessment of unity
As discussed in our previous
article, a claim reciting subject-matter in the alternative
counts as a single claim for fee calculation purposes. Such claims
have disadvantages - if one of the alternatives is unpatentable,
the entire claim is likely invalid. But they might be used
effectively to permit assessment of unity of invention in an
application covering numerous embodiments. For example, a claim
reciting "A compound selected from the group consisting of:
(a) a compound of Formula I; (b) a compound of Formula II; (c) a
compound of Formula III; (d) a compound of Formula IV; and (e) a
compound of Formula V" could take the place of five separate
independent claims yet be similarly useful for obtaining an
assessment of unity of invention in the first Examiner's
Report.
Outlook for the future: voluntary divisional applications and
double patenting considerations
Practice with respect to voluntary divisional applications at
the time of allowance may also evolve in view of increased costs
under the new claim fee and RCE rules. Although voluntary
divisionals have historically been avoided in view of potential
double patenting concerns, the application of double patenting
principles finds limited support in the case law. The Supreme Court
of Canada has explained that the prohibition against double
patenting addresses an "evergreen" problem - i.e., an
improper extension of patent term.8 The prohibition against double patenting
would therefore seem to have no application to divisional
applications filed under the post-October 1, 1989, Patent
Act, when the patent term changed from 17 years from grant to
20 years from the filing date. A parent and divisional patent now
both expire no later than 20 years from the original filing date,
such that there is no extension of the term of protection.
While there is one instance in which the Federal Court concluded that a voluntary divisional application under the current Patent Act could be invalid for obviousness double patenting, the "sin" of double patenting going beyond an evergreening problem,9 the Federal Court has more recently described parent/divisional double patenting under the current Patent Act, where there is no extension of term, as "somewhat academic."10 Nevertheless, the Patent Office takes the position that double patenting can apply in the modern parent/divisional context and may object to alleged double patenting in a voluntary divisional application or a divisional application in which the claims do not adhere to a claim grouping identified by the Examiner in an objection for lack of unity of invention in the parent application.11
"Obviousness" double patenting and Unity
of Invention
In any event, the principle of "obviousness" double
patenting does not rest easily with divisional practice under
section 36 of the Patent Act, an issue that the courts do
not appear to have addressed to date. The question to be answered
for obviousness double patenting is whether there is an
"inventive step" from the first patent to the second
patent.12 This is not the test
for filing a divisional application under section 36 of the
Patent Act. The Patent Rules provide that a
patent application claims only "one invention," and thus
does not require division, if the inventions are "linked in
such a manner that they form a single general inventive
concept."13 The
Patent Office considers this to be consistent with Rule 13.2 of the
Regulations under the PCT, which specifies that unity of
invention is present "only when there is a technical
relationship among those inventions involving one or more of the
same or corresponding special technical features," and that
"[t]he expression 'special technical features' shall
mean those technical features that define a contribution which each
of the claimed inventions, considered as a whole, makes over the
prior art."
Unity of invention thus requires a comparison of the claimed invention to the prior art, whereas double patenting instead requires a comparison between the claims in question of the earlier and later patent. Consider the following claims:
- An apparatus comprising elements A and B.
- The apparatus of claim 1, further comprising element C.
- The apparatus of claim 1, further comprising element D.
If each of elements A, B, C, and D is known in the art, but the
combination of A and B is nevertheless inventive, then claim 1 is
patentable, and claims 2 and 3 possess unity of invention as they
share the inventive concept of A+B. The Patent Office could not
properly object for lack of unity of invention in such
circumstances.
But if the combination A+B is not inventive, then claim 1 is
unpatentable. Claim 2 (A+B+C) and claim 3 (A+B+D) may or may not be
patentable (i.e., unobvious over the prior art), but they clearly
now lack unity of invention as they are not linked by a single
general inventive concept. The Patent Office could properly object
for lack of unity of invention under subsection 36(2.1) of the
Patent Act, obliging the applicant to prosecute claims to
an apparatus comprising A+B+C in the original application and
claims to an apparatus comprising A+B+D in a divisional application
(or vice versa). Likewise, pursuant to subsection 36(2) of the
Patent Act, the applicant properly could file a
"voluntary" divisional application, separating claims to
A+B+C from claims to A+B+D, as these subject matters lack unity of
invention.
Thus, pursuant to the express provisions of the Patent
Act, whether a voluntary divisional application properly
claims A+B+D when the parent application claims A+B+C fairly should
turn on whether there is a single general inventive concept linking
these two inventions (i.e. the same test that the Patent Office
uses to assess unity of invention) not whether A+B+D reflects an
"inventive step" over A+B+C, which is the test for
obviousness double patenting but clearly an irrelevant
consideration for unity of invention.
The Federal Court of Appeal has held that the
"improper" filing of a divisional application does not,
in the absence of double patenting, give rise to a loss of patent
rights. The principle of double patenting provides a sufficient
remedy.14 However, this was
decided in a case under the pre-October 1, 1989, Patent
Act such that a divisional patent could have a different term
(running 17 years from grant) than the parent. Moreover, it does
not follow that the applicant's entitlement to voluntarily file
a divisional application under subsection 36(2) of the Patent
Act requires that the claims of the divisional application
reflect an "inventive step" over the claims of the parent
application - rather, the statutory requirement is that the
divisional claim an invention "other" than the invention
claimed in the parent application, a matter of unity of invention,
not double patenting.
Clarification from the courts concerning the relevance of double patenting principles to divisional applications under the current Patent Act would be welcome. In any event, applicants will no doubt be scrutinizing their entitlement to file voluntary divisional applications more closely under the new excess claim fees and RCE rules, which will add to the cost of re-opening prosecution to add claims.
Applicants and foreign IP counsel seeking guidance on strategies
for Canadian patent prosecution can reach out to any member of the
Patents
group at Smart & Biggar.
Footnotes
1. Intellectual Property Law Improvement Act S.C. 1993 c.15 s. 39.
2. Canadian Intellectual Property Office Manual of Patent Office Practice ("MOPOP") §3.04.01.
3. cf. United States patent law wherein 35 U.S. Code § 121 provides "A patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement, shall not be used as a reference either in the Patent and Trademark Office or in the courts against a divisional application or against the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application." (emphasis added)
4. Consolboard Inc v MacMillan Bloedel (Sask.) Ltd, [1981] 1 SCR 504 at p. 537.
5. The CAD $100 excess claim fee is reduced by 50% to CAD $50 for small entities. In brief, a small entity is an entity having no more than 50 employees or that is a university, and that has not transferred or licensed any right or interest in a claimed invention to another entity that is not a small entity and has no obligation (other than a contingent obligation) to do so.
6. The CAD $816 continued examination fee is reduced 50% to CAD $408 for small entities.
7. Typically, objections would only be raised to newly added claims but as the application is subject to further examination it is possible that new objections would be made to previously allowed claims.
8. Whirlpool Corp v Camco Inc, 2000 SCC 67 at ¶37.
9. GlaxoSmithKline Inc v Apotex Inc, 2003 FCT 687.
10. MIPS AB v Bauer Hockey Ltd, 2018 FC 485 at ¶302.
11. MOPOP §18.06.04
12. See e.g. Mylan Pharmaceuticals ULC v Eli Lilly Canada Inc 2016 FCA 119 at ¶35
13. Patent Rules SOR/2019-251. s. 88.
14. Merck & Co, Inc v Apotex Inc 2006 FCA 323 at ¶50.
The preceding is intended as a timely update on Canadian intellectual property and technology law. The content is informational only and does not constitute legal or professional advice. To obtain such advice, please communicate with our offices directly.