Docket: A-47-15
Citation:
2016 FCA 119
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CORAM:
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DAWSON J.A.
TRUDEL J.A.
RENNIE J.A.
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BETWEEN:
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MYLAN
PHARMACEUTICALS ULC
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Appellant
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And
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ELI LILLY
CANADA INC., ICOS CORPORATION and THE MINISTER OF HEALTH
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Respondents
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REASONS
FOR JUDGMENT
RENNIE J.A.
I.
Introduction
[1]
This is an appeal from a decision of the Federal
Court per Justice de Montigny (the judge) dated January 7, 2015 (2015 FC
17). In that decision, the judge allowed Eli Lilly’s application for an order
under section 6 of the Patented Medicines (Notice of Compliance) Regulations,
SOR/93-133 (Regulations) prohibiting a Notice of Compliance (NOC) from being
issued to Mylan. Mylan had alleged that Eli Lilly’s patent was invalid on the
basis of obviousness-type double-patenting and for lack of utility due to no
sound prediction. For the reasons that follow, I would dismiss the appeal.
II.
Background
[2]
The impugned patent (Canadian Patent No.
2,226,784 or the ‘784 patent) claims tadalafil and 3-methyl tadalafil (the two
compounds) for the treatment of erectile dysfunction (ED). The patent comprises
28 claims, a subset of which are disputed in this appeal. Saliently, claim 18
claims the use of the two compounds via oral administration for the treatment
of ED; claims 2, 4, 12, 14, and 15 (the remaining claims) are to the general
use of the two compounds to treat ED, with no mention of oral administration.
[3]
The impugned ‘784 patent had a priority date of
July 14, 1995, Canadian filing date of July 11, 1996, and a publication date of
February 6, 1997.
[4]
Tadalafil and 3-methyl tadalafil are PDE V
inhibitors. PDE V is an enzyme that breaks down the chemical cGMP (which causes
erections via triggering smooth muscle relaxation) into GMP (which does not).
Because PDE V prevents erections, a PDE V inhibitor has the effect of
stimulating erections.
[5]
Eli Lilly had previously acquired a patent that
claimed, among other compounds, tadalafil. This earlier patent (Canadian Patent
No. 2,181,377 or the ‘377 patent) had a priority date of January 21, 1994 and a
Canadian filing date of January 19, 1995. In the words of the judge, the ‘377
patent claimed “novel compounds, including tadalafil,
pharmaceutical compositions, and the use of tadalafil in the treatment of
various disorders where smooth muscle relaxation was thought to be beneficial,
including cardiovascular disorders.” The patent indicated that tadafafil
was bioavailable for reducing systemic hypertension. It did not mention ED
treatment specifically.
[6]
On December 22, 1994 (after the priority date of
the ‘377 patent, but before the priority date of the impugned ‘784 patent)
Pfizer’s American patent application WO 1994028902A1 (the ‘902 patent application)
for sildenafil (another PDE V inhibitor) was published. Notwithstanding criticism
of the equivalent Canadian patent (Patent 2,163,446) by the Supreme Court of
Canada in Teva Canada Ltd. v. Pfizer Canada Inc. 2012 SCC 60, [2012] 3 S.C.R.
625 for inadequate disclosure of the particular chemical claimed by the patent,
the ‘902 patent application did show that a PDE inhibitor could treat ED. There
was evidence before the judge, however, that the information in the ‘902 patent
application was a counterintuitive breakthrough and was initially met with
scepticism.
[7]
In early 1996 (after the priority date of the ‘784
patent, but a few weeks prior to its Canadian filing date) a study (the Boolell
study) provided robust evidence, based on clinical trials, that the PDE V
inhibitor sildenafil could be orally administered for effective treatment of
ED. The judge found that this study stood for the broader proposition that a
PDE V inhibitor could be administered orally for safe, effective treatment of
ED.
[8]
Eli Lilly applied for an order under subsection
55.2(4) of the Patent Act, RSC 1985, c P-4, and section 6 of the Regulations,
prohibiting the Minister from granting a NOC to Mylan for a generic version of
tadalafil. On December 21, 2012, Mylan filed a Notice of Allegation alleging
that the ‘784 patent was invalid for lack of utility and obviousness-type double-patenting.
III.
The decision below
[9]
Mylan alleged that the claims at issue were
invalid for obviousness-type double-patenting, and also that they were invalid
for inutility on the basis of a lack of sound prediction.
[10]
With regard to the double-patenting challenge,
the judge determined that the relevant date on which the impugned patent was to
be assessed was the priority date of the first (‘377) patent (January 21, 1994).
He found that the inquiry at the centre of obviousness-type double-patenting was
whether the second patent’s claims should have been included in the first
patent. He also found that while the double-patenting analysis was to be a
comparison of the claims of the two patents, the claims must be read in the
context of the full patent; consequently, he interpreted the ‘377 patent as
claiming tadalafil as a PDE V inhibitor even though its status as a PDE V
inhibitor was only made clear in the specification.
[11]
On the basis of this framework, the judge
determined that at the priority date of the ‘377 patent, the use of PDE V
inhibitors, such as the two compounds, to treat ED was patentably distinct from
the ‘784 patent. Indeed, he noted that this factual finding was uncontroversial
in the view of the parties’ witnesses. In the alternative, the judge found that
even at the priority date of the second patent, the ‘784 patent was
still patentably distinct from the ‘377 patent. The ‘902 patent application, which
had been published about six months prior to the ‘784 patent’s priority date,
did not sufficiently advance the common general knowledge held by the person
ordinarily skilled in the art (the skilled person) such that the ‘784 patent
was not patentably distinct.
[12]
The judge also rejected the challenge to the
utility of the patent. He concluded that the promise of the patent was the use
of tadalafil and 3-methyl tadalafil to treat ED without reference to any
particular mode of administration or the absence of toxicity or undue side
effects. The judge found that in light of the experiments taught in the patent’s
disclosure, the common general knowledge and the disclosure of the ‘377 patent,
there was a prima facie reasonable inference of utility for the claimed
compounds.
[13]
The judge also found that, in the alternative,
even if the promise of the patent includes oral administration it was still
soundly predicted. The judge determined that by combining the ‘377 patent’s
disclosure that demonstrated that tadalafil was an orally bioavailable PDE V
inhibitor with the Boolell study’s teachings that an orally bioavailable PDE V
inhibitor could be used to treat ED, there was a prima facie reasonable
inference of the utility of the oral administration of tadalafil. Having found
that claim 18 was soundly predicted with regard to tadalafil, the judge
determined that it was not necessary to make a similar finding with regard to
3-methyl tadalafil. The basis for this conclusion was that claim 18 was a Markush
claim, and that Markush claims to a class of compounds have utility as
long as at least one compound within the class has utility.
IV.
Positions of the parties
[14]
Mylan appeals the findings with regard to both
obviousness-type double-patenting and sound prediction, limiting its arguments
on appeal to the sound prediction of claim 18 and to obviousness-type
double-patenting of the remaining claims.
[15]
With regard to double-patenting, Mylan alleges
that the judge erred in law by conducting the analysis as of the priority date
of the ‘377 patent, and that Whirlpool Corp. v. Camco Inc., 2000 SCC 67,
[2000] 2 S.C.R. 1067 instead mandates using the publication date of the
later (in this case, ‘784) patent. Mylan also contends that the
judge committed a palpable and overriding error in finding that, at the ‘784
patent’s priority date, the impugned patent was not invalid for
obviousness-type double-patenting. Finally, Mylan argues that the nature of the
inquiry for obviousness-type double-patenting should be akin to obviousness.
[16]
Regarding sound prediction, Mylan argues that no
skilled person would draw the inference of oral utility without specific in
vivo tests on the two compounds which were claimed. Because there was no
testing of 3-methyl tadalafil’s oral bioavailability for any purpose, and no
testing of the oral use of either compound to treat ED, claim 18 was not
soundly predicted.
[17]
Eli Lilly contends that the judge ultimately
reached the correct conclusion on both challenges to the patent.
[18]
With respect to double-patenting, Eli Lilly
argues that because PDE V inhibition is only mentioned in the patent’s
specification rather than its claims, the judge erred in reading PDE V
inhibition into the claims of the ‘377 patent. Notwithstanding this alleged
error, however, Eli Lilly argues that the judge used the correct date for the double-patenting
analysis and properly concluded that the patent was not invalid on this ground.
[19]
Eli Lilly also submits that the obviousness-type
double-patenting inquiry cannot be conducted according to the obviousness framework.
It argues that to do so would make obviousness-type double-patenting a
surrogate of the obviousness doctrine and circumvent the protections of section
28.3 of the Patent Act. Subsection 28.3(a) excludes from the prior art,
which forms the basis of an obviousness challenge, any documents disclosed by
the patentee in the year prior to filing.
[20]
On the sound prediction issue, Eli Lilly’s
position is that the judge correctly concluded that the ‘902 patent application
and the Boolell study provided a factual basis for a sound line of reasoning to
predict the utility of claim 18 with regard to the two compounds.
V.
Standard of review
[21]
The standard of review established in Housen
v. Nikolaisen, 2002 SCC 33, [2002] 2 S.C.R. 235 applies to appeals of NOC
applications: Pfizer Canada Inc. v. Canada (Minister of Health), 2006 FCA
214, at para. 15, [2007] 2 F.C.R. 137. Findings of fact and mixed fact and law
can only be reversed if there is a palpable and overriding error. Findings of
law, including extricable questions of law on an issue of mixed fact and law,
are reviewed on a correctness standard.
VI.
Preliminary observations
[22]
Before examining the grounds of invalidity under
appeal, it is useful to briefly review three areas of patent law. The first is
the distinction between prior art and common general knowledge. The second is
the distinction between obviousness and double-patenting. Finally, a
recapitulation of the various dates that are engaged by the issues on appeal
completes the backdrop.
A.
Prior art and common general knowledge
[23]
Prior art is the collection of learning in the
field of the patent at issue. It comprises any publically available teaching,
however obscure or not generally accepted.
[24]
The common general knowledge, in contrast, is
the “knowledge generally known by
persons skilled in the relevant art [skilled persons] at the relevant time”:
Apotex Inc. v. Sanofi-Synthelabo Canada Inc., 2008 SCC 61, at
para. 37, [2008] 3 S.C.R. 265. Unlike the prior art, which is
a broad category encompassing all previously disclosed information in the
field, a piece of information only migrates into the common general knowledge
if a skilled person would become aware of it and accept it as “a good basis for further action”: General Tire
& Rubber Co. v. Firestone Tyre & Rubber Co., [1971] F.S.R. 417, (1972)
R.P.C. 457 at 483 (C.A.).
[25]
Prior art is used for specific purposes in
patent law, such as to found an allegation that prior art anticipated the
invention or rendered it obvious. The common general knowledge informs the way
in which the claims and specifications are read, because it is to the skilled
person that the patent is addressed. Any inquiry in patent law that is
performed from the perspective of a skilled person will import the common
general knowledge.
B.
Obviousness-type double-patenting
[26]
The double-patenting doctrine holds that a claim
is invalid if it constitutes patenting of an invention that has already been
claimed in a previous patent. It is aimed at the problem of evergreening;
extending the monopoly that was granted on the first patent by filing a new
patent that does not offer a new invention to the public. As such, the doctrine
of double-patenting prevents a patentee from violating the bargain at the heart
of the patent system.
[27]
In Whirlpool, the Supreme Court of Canada
recognised two types of double-patenting. The first is “same-invention”
double-patenting, which occurs when the claims of the second patent are
outright “identical or coterminous” to the
first. This is not alleged in this case. The second is “obviousness-type”
double-patenting, which occurs when the second patent is not identical to the
first, but is nonetheless not “patentably distinct”
from the first.
[28]
Invalidity on the basis of obviousness-type double-patenting
is not the same as invalidity on the basis of obviousness. Obviousness is
directed at the question of whether an “invention”
(in the legal sense) exists at all. Obviousness-type double-patenting has a
different policy justification; the prevention of evergreening an existing
patent through what would otherwise be a valid patent but is, in effect, an
extension of the patent that has already been granted: Merck & Co., Inc.
v. Pharmascience inc., 2010 FC 510, at para. 124, 368 F.T.R. 1. Some of the
differences are contested issues in this appeal, but a few uncontroversial
distinctions between the two variants of the doctrine can be noted.
[29]
In an obviousness challenge, any piece of prior
art, including a collection of works, can be cited as rendering the impugned
patent obvious and therefore not patentable: Sanofi-Synthelabo at paras.
67-71. By contrast, in an obviousness-type double-patenting challenge, only the
earlier patent can be cited as rendering the impugned patent not patentably
distinct; any other prior art is only relevant insofar as it contributes to the
common general knowledge of the skilled person.
[30]
Finally, in an obviousness challenge, subsection
28.3(a) of the Patent Act provides that any information disclosed by the
patentee within a year prior to the filing cannot be cited as prior art that
renders the patent obvious. This effectively gives the patentee a one-year
grace period before filing in which it can make disclosures without worrying
that those disclosures will be the basis of an obviousness attack. Double-patenting
is not subject to subsection 28.3(a), which is what allows the earlier patent
to be cited if it was published within a year of the filing date of the
impugned patent.
C.
The relevant dates
[31]
Borrowing in large measure from Hughes and
Woodley on Patents: The Honourable Mr. Justice Roger T. Hughes, Dino
Clarizio & Neal Armstrong, 2d ed, looseleaf, (Toronto: LexisNexis
Butterworths, 2005), it is useful to revisit some of the key terms on which
this appeal turns:
a)
The filing date is the date on which the patent
application is filed with the Canadian Patent Office.
b)
The priority date is the date on which an
earlier patent application disclosing the same invention was filed by the
patentee – either in Canada or (much more often) in a country that is party to a
relevant patent treaty or convention to which Canada is also a party. A
priority date only applies at the request of the patentee, and the patent must
be filed in Canada within 12 months of the priority date.
c)
The claim date is the priority date if
there is one; otherwise the claim date is the filing date.
(The above concepts (a and b) are governed
by section 28.1 of the Patent Act. Though the various iterations of the Patent
Act complicate matters slightly, a general statement can be made that
novelty and obviousness are both assessed as of the claim date).
d)
The publication date is the date on which
the application for a patent is first open to the public for inspection. The
prospective patentee has the right to delay this up to 18 months after the
claim date. This is governed by section 10 of the Patent Act. The patent
becomes citable prior art as of the publication date; the publication date is
also the date for claims construction.
VII.
Analysis
[32]
One issue in dispute between the parties is
whether the substance of the analysis of obviousness-type double-patenting is
the same as that for obviousness and what date is to be used for conducting the
analysis.
[33]
Mylan submits that the Court should apply the
well-settled test for obviousness, with the earlier patent taking the place of
the prior art. Under this construct, the question for the Court is whether a skilled
person would consider the impugned patent obvious in light of the earlier
patent, with the earlier patent taking the place of the prior art generally, or
whether there was an inventive step that makes the impugned patent non-obvious.
This approach differs from straightforward obviousness in terms of what prior
art is considered, but the central inquiry is the same.
[34]
Eli Lilly argues that this is incorrect, and
that the inquiry is instead whether the second invention constitutes an
improper extension of the original patent. For his part, the judge framed the
question as whether what was claimed in the second patent could or should have
been included in the first patent.
[35]
I do not see a substantive distinction between
the two approaches. They are not inconsistent and are, in effect,
reformulations of the same inquiry. When one says “the
second patent is an impermissible extension of the first” or “the claims of the second patent should have been included in
the first”, those statements, in essence, ask whether there is an
inventive step from the first patent to the second.
[36]
The Supreme Court of Canada in Whirlpool
indicated that the substance of a double-patenting inquiry – like obviousness –
is whether there is “invention” or “ingenuity” in the move from the first patent to the
second: Whirlpool at paras. 66-67. Moreover, because the doctrine exists
to prevent the evergreening of patents with uninventive additions, examination
of whether the changes in the second patent are or are not inventive is
directly linked to the policy considerations that underlie the doctrine.
Finally, while not dispositive, the use of the label “obviousness”
for this type of double-patenting indicates that a similar analytical process
is appropriate.
[37]
This, in execution, requires consideration of
the claims of the second patent against the claims of the first patent. The
distinction from an obviousness inquiry is nuanced, but doctrinally important.
As noted by Hughes J. in Merck v. Pharmascience, at para. 124:
What is important to keep in mind is that
the exercise required in the inquiry as to whether there is double patenting is
that the claims of the earlier patent owned by the same patentee as the
latter must be compared with the claims of the latter to see if they are
“identical or co-terminus”, or whether the latter is “obvious” in view of the
former. Therefore, the exercise is somewhat different than that of dealing with
obviousness of a patent having regard to the art that would have been known to
a person skilled in the art as of the relevant time. The exercise respecting
double patenting is to present the notional person skilled in the art with the
claims of the first patent and inquire whether what is claimed in the second
patent was “identical or co-terminus” with the first or would have been obvious
in light of the earlier patent. The inquiry must not bother with any inquiry as
to whether the earlier patent would have come to the attention of the notional
person skilled in the art. Nor does the inquiry extend to the validity or
otherwise of the claims of the earlier patent. Nor does the inquiry extend to
“prior art” beyond the earlier patent, as Binnie J. wrote at paragraph 67 of Whirlpool,
the inquiry is whether a second patent can be justified unless the claims
exhibit “novelty or ingenuity” over the first patent.
[Emphasis in original]
[38]
Although formulated in slightly different
language, this analysis may be traced back to, and is consistent with, Commissioner
of Patents v. Fabwerks Hoechst Aktiengeselschaft Vormals Meister Lucius &
Bruning, [1964] S.C.R. 49 and its focus on whether the second patent
contains a new or inventive element or process beyond that claimed in the
first.
[39]
In my view, the judge erred in referring to the
specification when construing the claims of the ‘377 patent. The rules of
patent construction preclude reference to the specification when the claims are
clear, and also improper if it varies the scope of the claims: Hughes and
Woodley on Patents, p. 312:
In construing a patent, the claims are the
starting point. The claims alone define the statutory monopoly and the Patentee
has a statutory duty to state, in the claims, what he invention is for which
protection is sought. In construing the claims, recourse to the rest of the
specifications is (1) permissible to assist in understanding the terms used in
the claims; (2) unnecessary where the words and plain and unambiguous and (3)
improper to vary the scope or ambit of the claims.
[40]
In this case, the ‘377 patent unambiguously
claims the compound tadalafil, without any comment on its use as a PDE V
inhibitor. In these circumstances, the judge’s reliance on Sanofi-Synthelabo, at paragraph 77 is misplaced. Rothstein J.’s comments
regarding the patent specification were in the specific context of construing
the inventive concept of a selection of patent for the purposes of an
obviousness analysis, not in the context of claims construction. Sanofi-Synthelabo makes it clear that construing the inventive concept is a distinct
analysis from claims construction.
[41]
Paragraphs 76-77 of Sanofi-Synthelabo
are helpful on this point. First, at paragraph 76, Rothstein
J. construed the claims of the patent and found that they constitute “the dextro-rotatory isomer”, a compound. Rothstein J.
then moved to the obviousness inquiry and the inventive concept of this
claim. It was only at this latter stage of the analysis that Rothstein J. referenced
the specification, observing that “[a] bare chemical
formula in a patent claim may not be sufficient to determine its inventiveness.”
[42]
Moreover, when Rothstein J. assessed
obviousness-type double patenting later in the judgment, he did not consider
the patent’s specification in construing the claims. At paragraph 108, he
stated:
Apotex argues that the focus in a double
patenting challenge is on the claims of the two patents rather than on the
disclosure. I agree. In Whirlpool, Binnie J. stated, at para. 63:
It is clear that the prohibition
against double patenting involves a comparison of the claims rather than the
disclosure, because it is the claims that define the monopoly.
[43]
To conclude, as there was no ambiguity in the
claims here, there could be no recourse to the specification. However, this
error is one of no consequence, as its effect was to impose a higher burden on
Eli Lilly. The judge came to the correct conclusion with respect to
obviousness-type double patenting.
[44]
Having settled on the essential methodology, I
turn to the question as to the date at which the inquiry is to be conducted.
The consequences associated with the selection of any date are considered by
Professor N. Siebrasse in “Sufficient Description,
Observations on Canadian patent case, Disagreement on Date for Assessing
Obviousness-type Double Patenting” (14 August 2015),: <http://www.sufficientdescription.com/2015/08/disagreement-on-date-for-assessing.html>,
where he concludes that the law is unsettled and that the point is a difficult
one, a proposition with which I agree.
[45]
There are three possible dates from which
obviousness-type double-patenting may be assessed. The first date is the
priority date of the first patent. The middle date is the priority date of the second
patent, which in this case is after Pfizer’s ‘902 patent application was
published. The last possible date is the publication date of the second patent,
by which point the Boolell study was also publically available and well-known.
The timeline, and choices, is reflected below:
[46]
The parties broadly agree on the consequences of
each date being the appropriate one. If the first date (the priority date of
the ‘377 patent) is correct, the respondent will almost surely succeed; Mylan
did not argue in its factum or oral argument that double-patenting could be
established based on the ‘377 patent alone. If the last date is correct (the
publication date of the ‘784 patent), the appellant will almost surely succeed,
as the Boolell study renders the contributions of the ‘784 patent non-inventive.
Eli Lilly, in oral argument, did not seriously contend otherwise. If the middle
date is correct (the ‘784 patent priority date), then there is an evidentiary
dispute as to whether the judge erred in finding no double-patenting.
[47]
I am convinced that the publication date of the
later patent (the last date) is not the appropriate one. Contrary to the
appellant’s submissions, I do not read Whirlpool as the controlling
authority on this point.
[48]
As noted by the judge, Whirlpool was an
obviousness case and did not turn on the correct date for a double-patenting
analysis. The Court found the expert evidence before the judge insufficient to
support a finding of obviousness-type double patenting. Further, the discussion
arose in the context of the date for construction of claims under the old act
and the Court settled on the publication date. Thus, while strictly obiter,
Binnie J.’s observation at paragraph 67 that the inquiry is whether a second
patent can be justified unless the claims exhibit “novelty
or ingenuity” over the first patent, places the focus on the publication
date of the first patent. At the risk of repetition, I note as well the
interpretation of Whirlpool by Hughes J. in Merck v. Pharmascience,
at para. 124, subsequent to Whirlpool, that:
The exercise respecting double patenting is
to present the notional person skilled in the art with the claims in the first
patent and inquire whether what is claimed in the second patent was “identical
or co-terminus” with the first or would have been obvious in light of the earlier
patent […] Nor does the inquiry extend to “prior art” beyond the earlier
patent.
[49]
The next question is therefore whether the
publication date of the later patent (the ‘784 patent) is nonetheless the
correct date in light of the principles underlying double-patenting doctrine. I
conclude that it is not. Specifically, it would be inappropriate to use any
date after the claim date of the second patent (whether in a particular case
the claim date is the same as the priority date – as it is here – or the filing
date).
[50]
As Professor Siebrasse notes, using a date after
the claim date would also mean that a court assessing an obviousness-type double-patenting
claim would consider prior art beyond what section 28.3 allows the Court to
consider when assessing classical obviousness. Contrast this with the fact that
the double-patenting doctrine allows a challenger to circumvent the one year
grace period in subsection 28.3(a). That circumvention is acceptable because a consideration
of the patentee’s prior patent documents is precisely what the doctrine
mandates the Court to undertake. However, there is no equivalent reason to
allow a challenger alleging obviousness-type double-patenting to point to prior
art after the claim date, while not allowing the same to a challenger alleging
obviousness.
[51]
This eliminates the possibility of the third
date – the ‘784 patent publication date – being correct. As such, the Boolell
study cannot be considered by the skilled person when assessing double-patenting.
The scenario in which the appellant Mylan succeeds uncontroversially should be
eliminated.
[52]
This leaves the first date, on which the
appellant Mylan uncontroversially fails, and the middle date, on which there is
an evidentiary dispute. It is not necessary to determine the question of which
of these dates is the appropriate one. This is because, on the facts of this
case, even if the correct date is the more appellant-friendly middle date, I
find that the judge did not err in finding that there was no double-patenting.
As I will explain, there was no change in the common general knowledge between
the first date and the middle date.
[53]
Specifically, I find that the judge committed no
reviewable error in concluding that the ‘784 patent was patentably distinct
even in light of the ‘902 patent application. I agree with the appellant that
the fact that the Supreme Court of Canada criticised the Canadian equivalent to
the ‘902 patent application for lack of disclosure of the specific compound
claimed (sildenafil) is irrelevant to the broader issue of what the ‘902 patent
application taught about PDE V inhibitors as a general class. However, the
judge accepted evidence that the ‘902 patent application’s teachings about the
use of PDE V inhibitors to treat ED were counterintuitive and met with initial
skepticism. As such, the skilled person would not have unhesitatingly accepted
the teachings of the ‘902 patent application as true; they were not part of the
common general knowledge. The judge correspondingly did not commit a palpable
and overriding error in concluding that, even as the common general knowledge
stood after the ‘902 patent application, the ‘784 patent was patentably
distinct over the ‘377 patent.
A.
Utility of claim 18
[54]
Mylan also challenges claim 18 on the basis that
it lacks utility. Specifically, Mylan alleges that while the oral
administration of tadalafil to treat ED may have been soundly predicted, the
oral administration of 3-methyl tadalafil was not. This is because while the ‘377
patent (demonstrating oral bioavailability and PDE V inhibition) could be
combined with the Boolell study (teaching that an orally bioavailable PDE V
inhibitor could treat ED) in the case of tadalafil, the ‘377 patent only showed
such oral bioavailability for tadalafil and not 3-methyl tadalafil.
[55]
Utility need not be demonstrated at the time a
patent is filed; it is enough for the claimed utility to be soundly predicted
by the filing date. Sound prediction has three requirements, a factual basis
for the prediction, an articulable and sound line of reasoning and proper
disclosure: Apotex Inc. v. Wellcome Foundation Ltd., 2002 SCC 77, at
para. 70, [2002] 4 S.C.R. 153. If all of these are present, a “prima facie reasonable inference of utility” can
be reached: Eli Lilly Canada Inc. v. Novopharm Limited, 2010 FCA 197, at
para. 85, [2012] 1 F.C.R. 349.
[56]
After finding that claim 18 with regard to
tadalafil was soundly predicted, the judge did not consider whether the use of
3-methyl tadalafil to treat ED orally was also soundly predicted. He reasoned
that the status of the claim as a Markush claim rendered it unnecessary
to determine whether each compound claimed would work. However, a Markush
claim requires that each compound in the claimed class, not merely one of the
compounds, have utility: Abbott Laboratories v. Canada (Minister of Health),
2005 FC 1095, at paras. 23-27, 30 C.P.R (4th) 20. Assuming, without
deciding, that claim 18 was indeed a Markush claim, the judge thus
erred, but it is an error of no consequence.
[57]
There was evidence before the judge which
indicated that 3-methyl tadalafil was soundly predicted. In particular, the
reply affidavit of Dr. Brock provided a factual basis and a sound line of
reasoning sufficient to ground a sound prediction. Dr. Brock noted both the
Boolell study’s demonstration that PDE V inhibitors could be used to treat ED
and also the broad variety of tetracyclic derivatives that were identified as
orally bioavailable PDE V inhibitors in the ‘377 patent. The latter fills in,
via a general statement, the factual premise (that 3-methyl tadalafil as a tetracyclic
derivative was an orally bioavailable PDE V inhibitor) which Mylan alleges is
missing. Dr. Brock further understood that a skilled person would be able to
infer the oral administration of both compounds to treat ED. There was no
guarantee of success, but the doctrine of sound prediction does not require
guarantees. A prima facie reasonable inference of success existed.
[58]
Finally, I note that even if a different view were
taken as to the validity of claim 18, it would have no effect on the disposition
of this appeal. Claim 18 is a dependent claim comprising a subset of the
subject matter claimed by the remaining claims. Because, as I have determined
above, the remaining claims survive the double-patenting challenge, claim 18
fences off no monopoly that is not entirely subsumed within their scope.
VIII.
Conclusion
[59]
In conclusion, the judge committed no reversible
errors in finding that the impugned patent was not invalid for either
obviousness-type double-patenting or a lack of utility. Accordingly, I would dismiss
the appeal with costs.
"Donald J. Rennie"
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“I agree
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Eleanor R. Dawson J.A.”
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“I agree
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Johanne Trudel
J.A.”
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