Date: 20120411
Docket: A-344-11
Citation: 2012 FCA 109
CORAM: EVANS
J.A.
SHARLOW
J.A.
DAWSON J.A.
BETWEEN:
MYLAN PHARMACEUTICALS ULC
Appellants
(Respondent)
and
ASTRAZENECA CANADA, INC.
ASTRAZENECA UK LIMITED and
THE MINISTER OF HEALTH
Respondents
(Applicants, Respondent)
REASONS FOR JUDGMENT
EVANS J.A.
Introduction
[1]
This is an
appeal by Mylan Pharmaceuticals ULC (Mylan) from a decision of the Federal
Court, reported at 2011 FC 1023. In that decision, Justice Rennie (Judge)
granted an application by AstraZeneca Canada Inc. and AstraZeneca UK Limited
(collectively, AstraZeneca) under section 6 of the Patented Medicines
(Notice of Compliance) Regulations, SOR/93-133, for an order of prohibition.
[2]
The
Judge’s order prohibits the Minister of Health from issuing a Notice of
Compliance to Mylan to sell its version of the medicine anastrozole in Canada
until after the expiry of Canadian Patent No. 1,337,420 (420 patent) on October
24, 2012. The 420 patent relates to the compound anastrozole.
[3]
In its
Notice of Allegation Mylan alleged that its sale of a generic version of
anastrozole would not infringe the 420 patent because the patent was invalid
for lack of utility and obviousness. Mylan no longer challenges the patent on
the ground that the invention is obvious. The Judge held that AstraZeneca had
established that Mylan’s Notice of Allegation was not justified.
[4]
This
appeal turns principally on the construction of one sentence in the
specification of the 420 patent. At the outset, however, it is helpful to
identify two of the claims set out in the patent. Claim 14 claims a
pharmaceutical composition comprising an effective amount of anastrozole, and claim
15 relates to the use of anastrozole as an inhibitor of the enzyme aromatase. Neither
claim is in dispute in this appeal
[5]
An
aromatase inhibitor blocks the conversion of androgens to estrogens, which reduces
the availability of circulating estrogens in the body. The reduction of
estrogens has particular significance for the treatment of forms of breast
cancer that depend on estrogen for their growth.
[6]
It is
agreed that anastrozole is a new and useful compound, and is patentable under
section 2 of the Patent Act, R.S.C. 1985, c. P-4. It is also agreed that
the 420 patent demonstrated that, by June 15, 1988, the Canadian filing date,
anastrozole inhibited the enzyme aromatase, as claim 14 of the patent states,
and that the invention was therefore useful.
[7]
The law
sets the bar low for utility when the specification does not promise that the
invention will produce a specific result. Inventors are not required to make
such a promise. However, when they do, an invention that does not do what the
specification promises lacks utility for the purpose of section 2: Consolboard
Inc. v. MacMillan Bloedel (Saskatchewan) Limited, [1981] 1 S.C.R. 504 at
525 (Consolboard); Eli Lilly Canada Inc. v. Novopharm Limited,
2010 FCA 197, 85 C.P.R. (4th) 413 at para. 76 (Eli Lilly).
[8]
The
question in dispute in this appeal concerns the construction of the underlined
sentence in the following paragraph from the patent specification.
A variety of compounds
possessing aromatase inhibitory activity is known, of which the most important
clinically is aminogluthethimide [AG]. [AG], however, has the drawback that it
affects other aspects of steroid metabolism, with the consequence that its use
is often associated with undesirable side-effects. It is a particular object
of the present invention to provide aromatase inhibitory compounds with fewer
undesirable side effects than [AG].
[9]
Although
not relevant to the disposition of this appeal, I should add by way of
completeness that anastrozole has proved to be a highly effective clinical
treatment for estrogen-dependent breast cancer and a great commercial success
for AstraZeneca. It is both a potent inhibitor of aromatase and, because it is
highly selective in its inhibitory effects, it has much less toxicity than
earlier generations of aromatase inhibitors, including AG.
Mylan’s position
[10]
Mylan says
that the underlined sentence in the extract quoted above constitutes a promise
that anastrozole has fewer undesirable side effects than AG, the first
aromatase inhibitor to be used in the treatment of breast cancer. This first
generation drug effectively inhibited aromatase. However, because it was not
selective, AG inhibited other enzymes necessary for a healthy functioning body.
A focus of pharmaceutical research in the 1980s was to discover an aromatase
inhibitor that was both potent and selective in the enzymes that it inhibited.
[11]
Mylan
argues that by June 15, 1988, the inventors of anastrozole had not demonstrated
that it produced fewer side effects than AG. In any event, any utility with
respect to side effects was not sufficiently disclosed in the patent. Because
this promise of the patent was not demonstrated, the invention lacked utility
and the allegation that the patent was invalid was therefore justified.
[12]
Mylan
argued in the Federal Court that the patent also promised that anastrozole had
therapeutic utility in the treatment of breast cancer. Consequently, since it
had not been demonstrated that anastrozole produced fewer side effects than AG,
there was no basis for this promise and Mylan’s allegation of invalidity was
therefore justified.
[13]
The
Judge found that no such promise was made and dismissed the argument. Mylan
stated in its memorandum of fact and law (paragraph 30), and in oral argument,
that it is content to rest its utility argument solely on the unfulfilled
promise that anastrozole will produce fewer side effects than AG. Accordingly,
counsel said, the Court need not address whether the patent also promises
therapeutic utility.
AstraZeneca’s position
[14]
AstraZeneca’s
position on the construction of the disputed sentence in the specification is
that the “object of the invention” refers to the forward-looking or
aspirational aim of the invention. It is not a promise that anastrozole had
achieved this goal by the date of filing, but merely looks to its future
attainment. Hence, Mylan’s allegation was not justified in so far as it alleged
that the patent was invalid for lack of utility because it did not demonstrate
by June 15, 1988 that anastrozole had fewer side effects than AG.
[15]
In any
event, AstraZeneca argues, even if Mylan is correct to say that, properly
construed, the patent does promise fewer side effects than AG, it had been
demonstrated by the filing date of the 420 patent that anastrozole was a
selective enzyme inhibitor and thus produced fewer undesirable side effects
than AG. The invention therefore had utility because it did what it promised.
Federal Court’s decision
[16]
The Judge
agreed with the construction of the specification advanced by AstraZeneca and
therefore concluded that Mylan’s allegation that the 420 patent was invalid for
lack of utility was not justified. He approached the construction of the
promise on the basis of the following interpretative principles.
[17]
First,
both the disclosure of the patent as a whole and its specific language must be
examined (para. 88). Second, the promise of the invention must be construed
from the perspective of persons of skill in the art relevant to the invention
(POSITA). These include those with a medical degree or Ph.D. in a relevant
field, and two to three years’ experience in pharmaceutical research and drug
development. Third, the patent must also be construed in the light of the state
of scientific knowledge at the time of filing (para. 89). Fourth, patents
should be read neither too generously nor too strictly, but should be construed
with an eye to ensuring that an inventor is not deprived of any protection for
a useful invention (at para. 88): Consolboard at 520-21.
[18]
In the
alternative, the Judge held that if Mylan’s construction of the specification
is correct, it was not demonstrated in the patent that by June 15, 1988
anastrozole had fewer side effects than AG. Accordingly, on this construction
of the patent, the allegation of lack of utility was justified.
[19]
I am not
persuaded that the Judge erred in law in his construction of the patent’s
promise. Hence, I need not comment on his conclusion that, if the patent
promises fewer side effects than AG, it is invalid for
lack of utility because it refers to no study that demonstrates this. I would
leave this interesting question for another day.
Analysis
[20]
Standard
of review Since
the construction of a patent, including its specification, is a question of
law, correctness is the applicable standard of review: Eli Lilly at
para. 80. However, any assessment of the evidence (concerning the state of
scientific knowledge at the relevant time, or how a reasonable POSITA would
understand the patent, for example) made by the Judge in the course of reaching
his conclusion on the construction of the patent is reviewable for palpable and
overriding error.
[21]
Did the
Judge make an error of law?
Mylan does not disagree with the interpretative framework adopted by the Judge
for construing the promise of the 420 patent, but says that he erred in law by
giving more weight to some factors and not enough to others. I shall deal with
the errors that Mylan says are apparent in the Judge’s reasoning.
[22]
For
convenience, I set out again the one sentence in the 55-page patent on which
Mylan relies in order to show that anastrozole not only inhibits aromatase, but
also produces fewer side effects than AG.
It is a particular object of
the present invention to provide aromatase inhibitory compounds with fewer
undesirable side effects than [AG].
[23]
It will be
recalled that the question is whether the words “object of the present
invention” mean that anastrozole produces fewer effects than AG, as Mylan
argues, or whether, as AstraZeneca says, it means that this is what the
invention aims to do, without promising that it has succeeded.
(i) undue reliance on
dictionary definition
[24]
The Judge
stated (at para. 132) that the plain meaning of the word “object” suggests that
it means an aim to be fulfilled, and referred to the following part of the
definition of “object” given in the The Oxford English Dictionary. 3rd
ed., on line version:
A goal, purpose, or aim; the
end to which effort is directed; the thing sought, aimed at, or striven for.
[25]
Mylan
makes two points. First, the Judge put undue weight on the dictionary
definition of “object”, rather than considering its meaning in the context of
patent law. Counsel referred us to cases, including Amfac Foods Inc. v.
Irving Pulp & Paper, Ltd. (1986), 12 C.P.R. (3d) 193 (F.C.A.) at 199,
where the Court relied on an “object clause” to define the scope of the invention.
On the basis of these authorities, he argued that the “object of an invention”
was virtually a legal term of art and formed part of the definition of the
invention.
[26]
I do not
agree. Patents are not required to contain a clause describing the object of
the invention. When they do, the meaning of the object clause depends on the
specific context, including the wording of the particular clause in question
and its relationship to the rest of the patent. Indeed, in oral argument
counsel conceded that object clauses should not necessarily always be construed
as promises of the invention.
[27]
Second,
counsel for Mylan said that the Judge referred to only some of the dictionary
synonyms for, or definitions of, “object”; in particular, he omitted “purpose”,
a word that connotes what the invention does. In my view, however, this kind of
close semantic parsing of the Judge’s reasons in this case is not productive.
Reading them in their entirety, I am satisfied that the Judge placed relatively
little weight on the dictionary definitions in reaching his conclusion that the
patent does not promise that anastrozole has fewer side effects than AG. For
example, he said (at para. 139):
In sum, the plain language of the patent,
when read in the context of the patent as a
whole, does not support a promise of
fewer undesirable side effects. I accept AstraZeneca’s argument that not all
statements of advantage in a patent rise to the level of a promise. A goal is
not necessarily a promise. The third paragraph of the 420 Patent refers to a
forward looking goal, a hoped-for advantage of the invention.
[28]
A better
reading of the reasons, in my view, is that the Judge relied on the dictionary
definitions and synonyms to confirm that, in its ordinary usage, the word
“object” is capable of bearing the meaning that he had assigned to it on the
basis of other considerations: the evidence of Dr Dowsett discussed at
paragraphs 40-42 of these reasons, and his examination of the patent as a
whole.
(ii) context of the patent
[29]
In examining
the patent in its entirety, the Judge noted that, apart from the “object of the
invention” sentence in the specification, nowhere else in the patent is there
any indication that anastrozole has fewer side effects than AG. In contrast to
the statement of the invention’s object, the claims to the compound anastrozole
and its inhibitory effects on aromatase are precise and specific. For example,
Claim 13 covers “the compound [anastrozole]”, and Claim 15 relates to “The use
of the compound [anastrozole] as an inhibitor of the enzyme aromatase.”
[30]
Moreover,
it is agreed that the 420 patent would be valid if it only claimed the compound
anastrozole and its inhibitory effects on aromatase. It was thus unnecessary
for the patent also to promise fewer side effects than AG. Even though tests,
which AstraZeneca did not disclose, had been conducted showing that anastrozole
was selective, a promise in the patent to this effect would be entirely
gratuitous, and could only provide competitors with another basis for attacking
its validity.
[31]
Mylan
counters these arguments by saying that the word “provide”, which appears in
the object clause, is used elsewhere in the patent in connection with the
claims of the patent. Thus, by stating that “it is a particular object
of the invention to provide aromatase inhibitory compounds with fewer
undesirable side effects than [AG]”, the object clause should, counsel argues,
be interpreted as a promise.
[32]
I do not
agree. In my view, this microscopic approach to the construction of the provisions
of a patent is misguided. The fact that such an ordinary word as “provide” is
used in sentences containing the claims of the patent does not mean that when
used in other sentences, it should be construed as connoting a promise of the
patent.
[33]
I agree
with the Judge that an examination of the patent as a whole supports the
conclusion that, unlike the express claims of the patent, the object clause
contains no more than a forward-looking aim of the invention. In my view, the
fact that side effects are not mentioned elsewhere in the patent is telling.
(iii) state of existing
knowledge
[34]
The state
of scientific knowledge at the date of the Canadian filing of a patent is an
important aspect of the context within which a patent must be construed. Mylan
argues that in the 1980s the major problem with the aromatase inhibitors then
used to treat estrogen-dependent breast cancer was that they were not selective
in their inhibitory effects. In particular, AG, the most widely used drug for
this purpose, has the undesirable side effect of inhibiting cortisol synthesis.
Cortisol is essential to the body’s stress response and a cortisol deficiency
is potentially life-threatening.
[35]
In 1988,
scientists were searching for a compound that would selectively target aromatase
and thus not have this side effect. Hence, says Mylan, a reasonable POSITA
would interpret the statement in the 420 patent that the “particular object” of
anastrozole is to provide aromatase inhibitory compounds with fewer side
effects than AG as a promise that AstraZeneca had discovered what the industry
was looking for, namely, a compound that would not have the side effects of AG.
A compound that produced no fewer side effects than AG would not be
commercially and clinically useful.
[36]
I do not
agree with this argument. In my view, the fact that the pharmaceutical industry
was seeking a solution to a particular problem would not lead a POSITA to necessarily
think that the “particular object” of anastrozole was that it solved one of the
pressing research problems of the day. It is equally plausible to read the
object clause as simply stating that its aim is to solve the problem, without promising
that it had succeeded.
[37]
Further,
even if anastrozole would not be commercially or clinically useful if it
produced no fewer side effects than AG, it is agreed that it was patentable as
a novel and useful compound, and as an aromatase inhibitor. It would be
rational to seek patent protection for anastrozole on this basis, in case it
turned out to be selective, as AstraZeneca had good reason to believe at the
time of the Canadian filing of the 420 patent that it would, because of male
side effect (MSE) tests on rats that had been conducted prior to 1988, but were
not disclosed in the 420 patent.
(iv) expert evidence
[38]
The
subjective intention of the inventor counts for relatively little in construing
the provisions of a patent. Much more important is how its addressees, the
reasonable POSITA, would understand them: Consolboard at 521; Pfizer
Canada Inc. v. Canada (Minister of Health), 2005 FC 1725, 46 C.P.R. (4th)
244 at para. 28. Both parties produced expert witnesses who testified on the
issue of utility. Mylan’s expert was Dr Coombes, a medical doctor and a
professor of oncology who had been involved in the development of aromatase
inhibitors. He testified that, in his opinion, a POSITA would read the object
clause in the 420 patent as promising fewer side effects than AG.
[39]
Dr
Hartmann was AstraZeneca’s expert on obviousness. He was a professor of
pharmaceutical and medicinal chemistry, and had worked on aromatase inhibitors
in the treatment of breast cancer. He seems to have been of the view that a
POSITA would read the object clause in the 420 patent as saying that
anastrozole would result in fewer side effects. The Judge acknowledged this in
his reasons (at para. 124).
[40]
AstraZeneca’s
expert on utility was Dr Dowsett, a professor of biochemical endocrinology
whose research had focussed almost exclusively on breast cancer. The Judge
accepted Dr Dowsett’s evidence that a reasonable POSITA would read the object
clause as a mere statement of the inventors’ aim, not as a promise that
anastrozole achieved it.
[41]
Mylan
argues that the Judge’s conclusion on how a POSITA would understand the promise
of the patent was not supported by any of the experts. This is because he
failed to notice that Dr Dowsett admitted at one point in his cross-examination
that the object clause would cause a POSITA to construe the 420 patent as
promising fewer side effects.
[42]
I do not
agree. The trier of fact’s assessment of the evidence of a witness can only be
impeached on appeal on the basis of palpable and overriding error: Halford
v. Seed Hawk Inc., 2006 FCA 275, 54 C.P.R. (4th) 130 at para. 11.
[43]
In my
view, when Dr Dowsett’s alleged concession is read in the context of the entire
cross-examination, its meaning is far from clear. In fact, immediately before
and immediately after the alleged concession, Dr Dowsett clearly indicates that
he understands “object of the invention” to mean its goal.
[44]
It was thus
reasonably open to the Judge to base his conclusion on Dr Dowsett’s explicit
testimony that the object clause set out the long-term aim of producing fewer
side effects, and his doubt that “the patent is actually stating that this is
what they have achieved.” Hence, the Judge made no reversible error in assessing
the evidence and preferring that of Dr Dowsett (at para. 125).
(v) internal incoherence of the
Judge’s reasons
[45]
Mylan
submits that the Judge erred by inferring from the absence in the patent of any
description of clinical trials that the patent could not have promised
something only demonstrable by clinical trials. Counsel argues that the Judge
thereby confused the construction of the patent (the first step in the
analysis) with whether that promise was fulfilled. As a related point, Mylan
says that the Judge makes contradictory statements about whether clinical
trials were necessary to demonstrate that anastrozole produced fewer side
effects.
[46]
In my
view, neither of these arguments warrants the interference of this Court with
the Judge’s decision. Even if, as Mylan argues, the Judge appears at some
points to infer the meaning of the patent from the absence of clinical trials,
a reading of his reasons in their entirety shows that this played only a minor
role in leading him to conclude that the 420 patent does not promise that
anastrozole produces fewer side effects than AG.
[47]
Nor was
the Judge confused about the need for clinical trials to demonstrate fewer side
effects. It is clear from his reasons that he understood that the MSE test was
sufficient to show that anastrozole was selective and therefore did not give
rise to the main undesirable side effect of AG, namely cortisol deficiency. He
was equally alert to the fact that clinical tests were
needed to demonstrate that anastrozole produced other side effects, such as
rashes.
Conclusion
[48]
For all
these reasons, I would dismiss the appeal with costs.
“John M. Evans”
“I
agree
K.
Sharlow J.A.”
“I
agree
Eleanor
R. Dawson J.A.”
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