Despite statements by the Supreme Court of Canada1
("SCC") that patent law is entirely statutory, it has
been recognized by the SCC and other levels of the Federal Court
that double patenting is judge-made law. The SCC in fact refers to
the decision in Whirlpool Corp. v. Camco Inc2.,
and not a section of the Patent Act, as support for the concept
that there may only be one patent covering an invention.
Section 36(1) of the Patent Act is often cited as support for
the concept of double patenting but this section states only
a patent shall be granted for one invention only but in an
action or other proceeding a patent shall not be deemed to be
invalid by reason only that it has been granted for more than one
This section discusses "a" or one patent, not the two
patents required for an assessment of double patenting and appears
instead to be addressing the opposite problem to double patenting,
namely multiple inventions claimed in one patent. This
interpretation accords with the consideration of section 36(1) in
the Manual of Patent Office Practice ("MOPOP") in Chapter
144, the section relating to unity of invention. This
interpretation also accords with the remainder of section 36 that
addresses procedurally how to limit claims in an application that
describes more than one invention. Section 36 does not address the
procedure to follow if more than one patent claims the same
invention, providing further support that this section was not
intended to address this situation.
As a result of being judge-made, the law has evolved in a
fractional manner, with each decision addressing only the issues
before the Court in a given case. Accordingly, many questions
remain. Further problems arise as a result of case law that
developed in the context of patents filed and issued pursuant to
the "old" Patent Act 5, wherein the term of
the patent commenced at the date of issuance of the patent and
continued for 17 years. Thus, situations could and did arise in
which earlier filed patents issued after later filed patents and
thus expired after the later filed patents. The applicability of
such case law, particularly in light of the broad language used by
the Court in discussing the "earlier" and
"later" patents, is unclear.
The Court and practitioners alike require guidance with respect
to this concept in order to properly advise clients, consider
whether an allegation of double patenting is warranted in
litigation, and make a proper determination on the merits of any
case. Much as the concept of obviousness began in common law, and
was ultimately included as section 28.2 of the Patent Act
6, if the concept of double patenting continues to exist
in Canadian patent law, legislative consideration may be
1 Apotex Inc. v. Sanofi-Synthelabo Canada Inc. 2008 SCC
61 at para. 12
2 Ibid. at para. 95, citing Whirlpool Corp. v. Camco
Inc., 2000 SCC 67 at para. 63.
3 Patent Act, R.S.C. 1985, c. P-4, as am., s.
A recent Saskatchewan Court of Queen's Bench decision allowed a court-appointed receiver to sell and transfer intellectual property rights free and clear of encumbrances, finding that a license to use improvements of an invention was a contractual interest and not a property interest.
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