Date: 20070607
Docket: A-500-06
Citation: 2007 FCA 217
CORAM: NADON
J.A.
SHARLOW
J.A.
MALONE
J.A.
BETWEEN:
NOVOPHARM LIMITED
Appellant
and
JANSSEN-ORTHO INC. and
DAIICHI PHARMACEUTICAL CO., LTD.
Respondents
REASONS FOR JUDGMENT
SHARLOW J.A.
[1]
This is an
appeal by Novopharm Limited from a judgment of Justice Hughes of the Federal
Court (2006 FC 1234) declaring claim 4 of Canadian Letters Patent No. 1,304,080
(the “080 patent”) to be valid. Novopharm admitted that if claim 4 was valid,
it was infringed.
The 080 patent
[2]
The 080
patent is governed by the provisions of the Patent Act, R.S.C. 1985, c.
P-4, pertaining to patents applied for prior to October 1, 1989. The
application for this patent was filed in Canada on June 19, 1986 and claims
priority from patent applications filed in Japan on June 20, 1985, October 11, 1985 and
January 28, 1986.
[3]
The 080
patent was granted to the respondent Daiichi Pharmaceutical Co., Ltd. on June
23, 1992, which stills owns the 080 patent and has licensed it to the other
respondent, Janssen-Ortho Inc. The 080 patent will expire on June 23, 2009
unless it is held to be invalid.
Construction of Claim 4
[4]
In any
case in which the validity or infringement of a patent claim is in issue, it is
necessary to construe the claim: Whirlpool Corp. v. Camco Inc., [2000] 2
S.C.R. 1067 at paragraph 43. The relevant date for the construction of the 080
patent is the date of its issuance, June 23, 1992. The patent must be
understood as being addressed to a person skilled in the art, taking into
consideration the knowledge that such a person is expected to possess on that
date. The construction of a patent claim is a task for the Court and must be
based on the whole of the disclosure and the claim, assisted by expert evidence
as to the meaning of certain terms and the knowledge that a person skilled in
the art is expected to possess on the relevant date.
[5]
Novopharm
does not list an error of patent construction as one of its grounds of appeal.
However, one of its arguments relating to obviousness includes, as one step in
the analysis, the assertion that the construction of claim 4 adopted by Justice
Hughes improperly reads in a purity claim where none is expressed or implied.
Janssen and Daiichi responded to that point as a challenge to the correctness
of the construction of claim 4 adopted by Justice Hughes.
[6]
Claim 4 of
the 080 patent reads as follows:
4. S(-)-9-fluoro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-
de][1,4]benzoxazine-6-carboxylic acid.
That is the chemical name of the compound that may be called
either levofloxacin or S(-) ofloxacin. (For the purposes of this appeal, those
two terms are treated as synonymous.)
[7]
Justice
Hughes, after reviewing and analysing the relevant portions of the disclosure
and the claims of the patent, concluded (at paragraph 95 of his reasons) that
claim 4 should be construed as follows:
S(-)
ofloxacin, different from that contained in the racemate, obtained in a
reasonably pure state.
[8]
Before
embarking on a consideration of the issues raised in this appeal in relation to
the construction of claim 4, it is necessary to understand what levofloxacin
is.
[9]
Levofloxacin
is one of the two enantiomers of ofloxacin. The invention of ofloxacin was
disclosed in Canadian Letters Patent No. 1,167,840 issued on May 22, 1984.
[10]
It is
undisputed that persons skilled in the art would have known well before 1992 that
ofloxacin is a racemate with a single chiral centre. The chiral centre of a racemate
may be envisioned as a junction in the molecule at which a joined element may
be oriented in one of two opposite directions. The two variations, called
enantiomers, are mirror images of each other.
[11]
An enantiomer
is said to be “optically active” if it rotates a plane of polarized light. By
convention, if the rotation is clockwise, the enantiomer is a “right”
enantiomer and is represented in a chemical formula by a “+” symbol. If the
rotation is counter clockwise, the enantiomer is a “left” enantiomer and is
represented in a chemical formula by a “-” symbol. Within a given quantity a racemate,
there will be equal amounts of left and right enantiomers. A racemate will not
rotate a plane of polarized light because the rotations caused by the left and
right enantiomers cancel each other out.
[12]
Extracting
one enantiomer of a racemate is called “resolving” the racemate. Each of the
two enantiomers of a racemate is a different compound than the racemate, and
may have different properties, including different medicinal properties. A
sample produced by the separation process will have an excess of one enantiomer
over the other. That is referred to as the enantiomeric excess and is a measure
of the purity of the sample. Referring to the example given by Justice Hughes
in paragraph 36 of his reasons, if a sample contains 95% of the left enantiomer
and 5% of the right enantiomer, the enantiomeric excess (the difference) is
90%. In certain cases, the repetition of a particular technique for resolving a
racemate may produce samples of greater purity after each repetition, but the
evidence does not establish that continuous repetitions of a particular
technique will necessarily achieve a desired level of purity.
[13]
If claim 4
is construed simply as “levofloxacin”, it could be argued that the claim must
be obvious because the existence of levofloxacin is disclosed in the ofloxacin
patent and is necessarily present in ofloxacin. Novopharm does not propose that
interpretation. I conclude that Novopharm would agree with Justice Hughes that
claim 4 includes a claim for levofloxacin different from that contained in
ofloxacin.
[14]
Novopharm
takes issue with the qualifying phrase “in a reasonably pure state”, arguing
that no standard of purity is expressed or implied in the patent specification
or in the patent claim. Novopharm’s argument is supported by the evidence of their
expert Professor John Caldwell. His written expert statement (Appeal Book,
Volume 34, page 9549) says that a person skilled in the art would not read into
the claims of the 080 patent any limitation as to purity. He cited, by way of
contrast, a number of patents in which a “substantially pure” limitation was expressed
in a patent claim for an enantiomer.
[15]
Claim 4 does
not expressly refer to a degree of purity. However, the specification in the
patent indicates that levofloxacin obtained by the method described in example
6 (page 27 of the patent) results in levofloxacin with a 90% enantiomeric
excess.
[16]
In support
of the construction of claim 4 adopted by Justice Hughes, Janssen and Daiichi
cite the evidence of Professor Alexander Klibanov. He says in his written
expert report (Appeal Book, Volume 14, pages 3487-8), that a person skilled in
the art would have understood claim 4 of the 080 patent to claim an “optically
pure” form of the S(-) ofloxacin, that “practically all” of the molecules would
be S(-) ofloxacin, and that the compound would be “substantially free” of the
opposite enantiomer. He did not attempt in his initial report to quantify any
of these expressions. Rather, he seemed to be responding to statements in
Novopharm’s pleadings that he interpreted as an assertion that the language of
claim 4 (the chemical name of levofloxacin or S(-) ofloxacin) would include a
compound with any amount of levofloxacin. That construction of claim 4 would
include the ofloxacin (which contains 50% left and 50% right enantiomers) and
would also include a compound containing only a slight excess of the left
enantiomer over the right enantiomer. Professor Klibanov rejected that asserted
and stated that a person skilled in the art would understand that a purity
limitation is implicit in claim 4.
[17]
Professor
Klibanov’s reply expert report (Appeal Book, Volume 15, at pages 4046-8)
discusses the degree of purity that he suggests is implicit in the 080 patent.
Although he does not express an opinion on a precise number, he points out that
examples 7, 11 and 16 in the 080 patent use different methods of obtaining
levofloxacin, each yielding a similar high [α]D value, which he
describes as a measure of “optical
purity” which reflects enantiomeric excess. He also cites the method in example
6 of the patent specification, which indicates that levofloxacin obtained by
that method results in levofloxacin with a 90% enantiomeric excess. Some
support for Professor Klibanov’s understanding of the language of claim 4 is
provided in the oral testimony of Professor Caldwell (Appeal Book, Volume 3,
page 781).
[18]
The
conclusion of Justice Hughes as to the construction of claim 4 is supported by
the preponderance of the relevant expert evidence, and the record does not
compel a different construction. For the purposes of this appeal, I accept the
construction of claim 4 determined by Justice Hughes.
[19]
I would
add only that it is not clear whether Justice Hughes, in construing claim 4 to
include the qualifying phrase “in a reasonably pure state”, was paraphrasing
the various expressions used by Professor Klibanov or was choosing a less
exacting purity standard. It may be necessary in another case to clarify the
meaning of the phrase “in a reasonably pure state” as used by Justice Hughes,
but it is not necessary to do so in this appeal.
Is Claim 4 ambiguous?
[20]
Novopharm
argues that if claim 4 is properly construed to include the qualifying phrase
“in a reasonably pure state”, then the claim is ambiguous because there is no
way of knowing whether a given sample would fall inside or outside the claim: Hoffmann-La
Roche Ltd. v. Apotex Inc. (1989), 24 C.P.R. (3d) 289 (F.C.A.) at page 299. Justice
Hughes rejected this argument on the basis that a person skilled in the art
would understand the qualifying phrase “in a reasonably pure state” to refer to
the degree of purity required for the substance “to [do] its job for instance
as an antimicrobial agent” (paragraph 119 of his reasons).
[21]
There is a
conflict in the evidence as to what degree of purity is required to meet this
functional test, a conflict that Justice Hughes did not consider it necessary
to resolve. Novopharm cannot succeed on this point in the absence of evidence
establishing that a resolution of the conflict is not reasonably possible. In
my view, the evidence falls considerably short of that.
[22]
I conclude
that Justice Hughes did not err when he concluded that claim 4, as he construed
it, is not ambiguous.
Obviousness
[23]
The
accepted legal test for obviousness is stated as follows in the leading case of
Beloit Canada Ltd. et al. v. Valmet OY (1986), 8 C.P.R. (3d) 289 (F.C.A.)
at page 294, per Hugessen J.A.:
The
classical touchstone for obviousness is the technician skilled in the art but
having no scintilla of inventiveness or imagination; a paragon of deduction
and dexterity, wholly devoid of intuition; a triumph of the left hemisphere
over the right. The question to be asked is whether this mythical creature
(the man in the Clapham omnibus of patent law) would, in the light of the
state of the art and of common general knowledge as at the claimed date of
invention, have come directly and without difficulty to the solution taught
by the patent. It is a very difficult test to satisfy.
|
[24]
The
inquiry mandated by the Beloit test is factual and
functional, and must be guided by expert evidence about the relevant skills of
the hypothetical person of ordinary skill in the art, and the state of the art
at the relevant time. The expert evidence must be carefully assessed as to its
credibility and reliability. The classic warning from Beloit about hindsight must always
be borne in mind (at page 295, per Hugessen J.A.):
Every invention
is obvious after it has been made, and to no one more so than an expert in the
field. Where the expert has been hired for the purpose of testifying, his
infallible hindsight is even more suspect. It is so easy, once the teaching of
a patent is known, to say, "I could have done that"; before the
assertion can be given any weight, one must have a satisfactory answer to the
question, "Why didn't you?"
[25]
There is
no single factual question or a set of questions that will determine every
case, or any particular case. Justice Hughes, at paragraph 113 of his reasons,
proposes a list of factors to be considered when the validity of patent is
challenged on the basis of obviousness. The list is apparently derived from a survey
of numerous cases from Canada, the United States and the United Kingdom. In my view, despite the continual
debate as to whether the legal test for obviousness is the same in all of those
countries, the list of factors proposed by Justice Hughes is helpful to guide
the required factual inquiry, and as a framework for the factual analysis that
must be undertaken. What follows is an edited version of his list:
Principal factors
|
1.
|
The invention
What is in issue is the patent claim as
construed by the Court.
|
2.
|
The hypothetical skilled person
referred to in the Beloit quotation
It is necessary to identify the skills
possessed by the hypothetical person of ordinary skill in the art.
|
3.
|
The body of knowledge of the person of
ordinary skill in the art
The common knowledge of the hypothetical
person of ordinary skill in the art includes what the person may reasonably
be expected to know and to be able to find out. The hypothetical skilled
person is assumed to be reasonably diligent in keeping up with advances in
the field to which the patent relates (Whirlpool at paragraph 74). The
presumed knowledge of the hypothetical skilled person undergoes continuous
evolution and growth. Not all knowledge is found in print form. On the other
hand, not all knowledge that has been written down becomes part of the
knowledge that a person of ordinary skill in the art is expected to know or
find.
|
4.
|
The climate in the relevant field at
the time the alleged invention was made
The general state of the art includes
not only knowledge and information but also attitudes, trends, prejudices and
expectations.
|
5.
|
The motivation in existence at the time
the alleged invention to solve a recognized problem
“Motivation” in this context may mean the
reason why the claimed inventor made the claimed invention, or it may mean
the reason why one might reasonably expect the hypothetical person of
ordinary skill in the art to combine elements of the prior art to come up
with the claimed invention. If within the relevant field there is a specific
problem that everyone in the field is trying to solve (a general motivation),
it may be more likely that the solution, once found, required inventive
ingenuity. On the other hand, if there is a problem that only the claimed
inventor is trying to solve (a unique or personal motivation), and no one
else has a reason to address that problem, it may be more likely that the
solution required inventive ingenuity. However, if commonplace thought and
techniques can come up with a solution, there may be a reduced possibility
that the solution required inventive ingenuity.
|
6.
|
The time and effort involved in the
invention
The length of time and expense involved
in the invention may be indicators of inventive ingenuity, but they are not
determinative because an invention may be the result of a lucky hit, or the
uninventive application of routine techniques, however time consuming and
expensive they may be. If the decisions made in arriving at the solution are
few and commonplace, that may indicate that no inventive ingenuity was
required to arrive at the solution. If the points for decision were many and
choices abundant, there may be inventiveness in making the proper decisions
and choices.
|
Secondary factors
These factors may be relevant but
generally bear less weight because they relate to facts arising after the
date of the alleged invention.
|
7.
|
Commercial success
Was the subject of the invention
quickly and anxiously received by relevant consumers? This may reflect a fact
that many persons were motivated to fill the commercial market, which may
suggest inventive ingenuity. However, it may also reflect things other than
inventive ingenuity such as marketing skills, market power and features other
than the invention.
|
8.
|
Meritorious awards
Awards directed to the alleged
invention may be recognition that the appropriate community of persons
skilled in the art believed that activity to be something of merit. That may
or may not say anything about inventive ingenuity.
|
[26]
Justice
Hughes included as a secondary factor “subsequently recognized advantages”,
referring to the advantages of the claimed invention that are perceived only
after the date of the invention. Justice Hughes said that this factor is of
limited usefulness in considering inventive ingenuity, and should be given
little weight. I find it difficult to envisage a situation where a subsequently
recognized advantage to a claimed invention would be of any assistance in
determining whether inventive ingenuity was required to make it. I can imagine
a situation where the commercial success of an invention is attributable to a
subsequently recognized advantage, but that would not assist the inquiry as to
inventive ingenuity. I recognize that it is impossible to imagine every
possible situation, but given the current state of the jurisprudence I would be
inclined to give this factor no weight except in the most extraordinary case.
[27]
I
emphasize that this list is a useful tool, but no more. It is not a list of legal
rules to be slavishly followed; nor is it an exhaustive list of the relevant
factors. The task of the trial judge in each case is to determine, on the basis
of the evidence, sound judgment and reason, the weight (if any) to be given to the
listed factors and any additional factors that may be presented.
[28]
I would
also repeat the caution of Justice Hughes that catchphrases derived from this
list or from the jurisprudence are not to be treated as though they are rules
of law. I agree with the following comment of Justice Hughes from paragraph 113
of his reasons:
In this
regard phrases such as "worth a try" and "directly and without
difficulty" and "routine testing" have been used by the courts.
It is not useful to use such phrases as they tend to work their way into
expressions of law or statements of expert witnesses. Sachs L.J. deprecated the
coining of such phrases in General Tire & Rubber Company v. Firestone
Tyre & Rubber Company Limited, [1972] R.P.C. 195 at pages 211-12.
[29]
I turn now
to the specific grounds of appeal raised by Novopharm in relation to
obviousness.
Were conventional prior art methods used
to produce the claimed invention in 1982?
[30]
Novopharm
argues that Justice Hughes erred in ignoring uncontroverted evidence that
conventional prior art methods had been used to produce the claimed invention
in 1982. This argument refers to evidence that Daiichi, the employer of the
claimed inventor Dr. Hayakawa, used known techniques to successfully resolve
the (+) and (-) enantiomers of ofloxacin in 1981 and 1982. However, that
evidence does not establish that the levofloxacin produced at that time met an
acceptable level of purity. Justice Hughes found as a fact that the first
isolation of substantially pure levofloxacin did not occur until 1985. That
conclusion was open to him on the evidence.
Purity and quantities
[31]
Novopharm
argues that Justice Hughes (a) improperly grafted onto the test for obviousness
a “minimum quantity” and “minimum purity” requirement, (b) made a palpable and
overriding error in finding as a fact that known techniques could produce only
minute quantities of material, and (c) made a palpable and overriding error in
finding as a fact that known techniques could produce only impure material.
[32]
These
grounds of appeal refer to a statement made by Justice Hughes at paragraph 115
of his reasons that, prior to 1985, known techniques for the separation of a racemate
into its enantiomers produced, when applied to ofloxacin, “only minute
quantities of impure material, scarcely enough to interest anyone in activity”.
This is a factual conclusion that was open to Justice Hughes on the evidence.
It is relevant to the question of whether the invention is obvious, and Justice
Hughes made no error in taking it into account as a fact that weakens Novopharm’s
argument that claim 4 is invalid for obviousness.
The Gerster posters
[33]
Novopharm
argues that Justice Hughes misapplied the test for obviousness (a) by failing to
find claim 4 invalid because the “Process C” described in the patent
specification as being the preferred method of obtaining levofloxacin was
copied from and was a straightforward application of a process disclosed in the
1985 Gerster poster, (b) by disregarding the 1985 Gerster poster as relevant
prior art because it was not mainstream or commonplace, (c) by applying a
novelty standard that has no relevance to the determination of obviousness, and
(d) by failing to find the 1982 Gerster poster was relevant prior art.
[34]
The
evidence is that in the early 1980s Dr. Hayakawa, the inventor named in the 080
patent, tried without success to obtain levofloxacin of an acceptable level of
purity. It is undisputed that in the fall of 1985, Dr. Hayakawa attended a
conference at which Professor John Gerster made a presentation relating to
flumequine, an antimicrobial compound that is structurally similar to
ofloxacin. His presentation included a poster illustrating a method obtaining
S(-) flumequine from a racemic intermediate compound. Dr. Hayakawa made notes
of the poster, tried the technique, and employed the same method to produce
levofloxacin with an acceptable level of purity. That method is substantially
the same as Process C as described in the patent specification.
[35]
Dr.
Hayakawa is not only a person skilled in the art, but a person who is an
acknowledged inventor. Therefore, the manner in which Dr. Hayakawa used the
knowledge obtained from the 1985 Gerster poster cannot, by itself, establish
that an uninventive person of ordinary skill in the art could be expected to
have used the same knowledge to the same effect.
[36]
The
evidence is that at the relevant time, chirality was a relatively new field,
but Daiichi was doing considerable work in that area. Only Dr. Hayakawa was
trying to obtain levofloxacin from ofloxacin, and his efforts in the early
1980s had not met with sufficient success to satisfy his objectives. Justice
Hughes characterized the technique described in the 1985 Gerster poster as not
mainstream or commonplace. As I read that comment, he did not intend to exclude
the 1985 Gerster poster from consideration as prior art. He was merely
recognizing that, considered against the general state of the art, the 1985 poster
had special significance to Dr. Hayakawa because of his specialized work and
the particular problem that was occupying him. The evidence discloses no sound
basis for concluding that a person of ordinary skill in the art with knowledge
of the 1985 Gerster poster would have made the same connections as Dr. Hayakawa.
[37]
The
evidence cited by Novopharm on this point is the evidence of Professor Michael
Chong, whose evidence dealt with a poster prepared by Professor Gerster in 1982.
Although that poster is similar to the 1985 Gerster poster, it is directed to
flumequine itself whereas the 1985 paper is directed to a flumequine derivative.
Justice Hughes found as a fact that at the relevant time, the 1982 poster was
not in the public domain and was not accessible through diligent research.
There is no basis for disturbing that finding of fact.
[38]
The
suggestion that Justice Hughes applied a “novelty” standard appears to be based
on a misinterpretation of his statement (at paragraph 114 of his reasons) that
there is no evidence that Professor Gerster or anyone else had applied the
technique in the 1985 Gerster poster to ofloxacin. That was a factual statement
that correctly reflects evidence in the record. It may be an observation of
only marginal relevance, but that does not mean that Justice Hughes was wrong
to say it. I do not read this statement as an attempt to change or embellish
the legal test of obviousness.
Motivation
[39]
Novopharm
argues that Justice Hughes erred in the weight he gave to “motivation” in the
test for obviousness. As I read the reasons of Justice Hughes, he gave
significant weight to that factor in dismissing Novopharm’s challenge to the
validity of claim 4 on the basis of obviousness.
[40]
The
motivation of Daiichi to obtain the enantiomers of ofloxacin explains the
activities of Dr. Hayakawa during the relevant period. The business objective
of Daiichi was to produce patentable substances with useful medicinal
properties. Daiichi owned the patent for ofloxacin. Because it was thought that
the enantiomer of an antimicrobial racemate such as ofloxacin may prove to have
antimicrobial properties superior to that of the racemate, Daiichi was
motivated to isolate the enantiomers of ofloxacin. That motivation would have
been reinforced by the fact that American drug regulators and clinicians were
pressing Daiichi for information about the enantiomers of ofloxacin. The interests
and focus of other researchers in the field during the same period were not on
ofloxacin at all, indicating that others skilled in the art were not motivated
to work on the same problem that was occupying Dr. Hayakawa. Justice Hughes
found as a fact that, during the relevant period, Daiichi was motivated to
obtain levofloxacin from ofloxacin, and no one else was. That was a factual
conclusion that was reasonably open to him on the record.
[41]
Novopharm
does not and could not reasonably suggest that motivation is irrelevant in this
case, but argues that Justice Hughes gave motivation undue weight. That is an
allegation of a factual error. A factual conclusion must stand absent palpable
and overriding error. I can find no basis in the record for concluding that
such an error was made in this case.
Predictability
[42]
Novopharm
argues that Justice Hughes erred in applying a requirement for “predictability with
certainty” to the determination of obviousness.
[43]
As I read
the decision of Justice Hughes, he found that a person of ordinary skill in the
art would have known that ofloxacin is a racemate and that each enantiomer
would possess properties different from the racemate, but would not know the
degree of difference, and in particular would not be able to predict the degree
to which a particular enantiomer would have different properties of
antimicrobial activity. These are factual conclusions that were open to Justice
Hughes on the record. As factual statements, they are not to be considered in
isolation, but rather as one part of the entire factual picture that is
relevant to the question of obviousness in the particular circumstances of this
case. Read in context, these statements do not and are not intended to change the
legal test for obviousness or to make it more onerous.
The cross appeal
[44]
The
respondents filed a notice of cross-appeal, but the cross-appeal was abandoned.
Conclusion
[45]
For the
reasons stated above, I would dismiss this appeal with costs.
“K. Sharlow”
“I
agree
M.
Nadon J.A.”
“I
agree
B.
Malone J.A.”