Date: 20061207
Docket: T-560-05
Citation: 2006
FC 1471
OTTAWA, ONTARIO, December
7, 2006
PRESENT: The
Honourable Mr. Justice von Finckenstein
BETWEEN:
PFIZER CANADA INC.
and WARNER-LAMBERT COMPANY, LLC
Applicants
and
THE MINISTER OF HEALTH
and NOVOPHARM LIMITED
Respondents
REASONS FOR ORDER AND ORDER
[1]
This is an application pursuant to
s. 6(1) of the Patented Medicines (Notice of Compliance) Regulations, 1993,
SOR/93-133 (“NOC Regulations”), for an Order prohibiting the Minister of
Health (the “Minister”) from issuing a Notice of Compliance (“NOC”) under the Food and Drug Regulations,
C.R.C. c. 870, to the Respondent,
Novopharm Limited (“Novopharm”), with respect to atorvastatin calcium, 10 mg, 20 mg, 40 mg, or 80 mg strength
tablets until after the expiration of
Canadian Patent 2,021,546 (the “546 Patent”).
Procedural Background
[2]
The Applicants, Pfizer
Canada Inc. and Warner-Lambert Company, LLC (collectively, “Pfizer”),
manufacture and sell an anti-cholesterol drug under the trade name LIPITOR,
which is contained in the 546 Patent. The active ingredient of LIPITOR is the atorvastatin
calcium, a salt.
[3]
The 546 Patent was
filed with the Canadian Patent Office on July 19, 1990, and published on
January 22, 1991. It is based on a priority filing of U.S. Patent 384,187 filed
on July 21, 1989, but which has since been abandoned and is now continued under
U.S. Patent 5,273,995. Accordingly, the patent is governed by the Patent Act,
R.S.C. 1985, c. P-4 and the relevant date upon which the patent will be
interpreted is the date of publication, i.e., January 22, 1991. (Whirlpool
Inc. v. Camco Inc., [2000] 2 S.C.R. 1067 at para. 56).
[4]
The 546 Patent was
issued to Warner-Lambert Company, a predecessor of the Applicant Warner-Lambert
Company, LLC on April 29, 1997, and it expires on July 19, 2010. The only claim
in dispute is claim 6.
[5]
Novopharm is seeking an
NOC to allow it to produce a generic version of atorvastatin calcium. In making
its application, Novopharm sent a Notice of Allegation (“NOA”) in a letter
dated February 3, 2005, to Pfizer comparing its drug to LIPITOR and referencing
the 546 Patent. The NOA alleges that the 546 Patent is invalid for three
reasons: anticipation, obviousness, and double patenting. The relevant portions
of the NOA are attached hereto as Annex 1.
[6]
Pfizer
disputes these allegations and brought this application seeking an order
prohibiting the Minister from issuing an NOC to Novopharm prior to the
expiration of the 546 Patent.
Chemical Background - Underlying Concepts
[7]
In order
to provide a context to the discussion that follows, I will briefly describe
the underlying concepts and what the invention involves.
[8]
First,
cholesterol is synthesized in most body tissues and is necessary for normal
body functions. Cholesterol is carried throughout the body on two types of
particles: low density lipoproteins (LDL) and high density lipoproteins (HDL).
[9]
Cholesterol
biosynthesis is the process of producing cholesterol in the body. Cholesterol
is synthesized through a biochemical pathway made up of a number of steps
(between 20-40).
[10]
Many
different enzymes (proteins that control biochemical reactions) are involved in
cholesterol biosynthesis. One of the early steps in the cholesterol
biosynthesis pathway involves an enzyme called HMG-CoA reductase. This step is
often called the “rate limiting step” in the pathway.
[11]
Drugs that
prevent HMG-CoA reductase from performing its functions in the cholesterol
biosynthesis pathway are called HMG-Co-A reductase inhibitors. By inhibiting
cholesterol biosynthesis, these drugs decrease the production of cholesterol.
[12]
Statins
are drugs which function as HMG-CoA reductase inhibitors. There are two kinds
of statins: those derived from natural products (i.e., natural statins) and
those produced synthetically (i.e., synthetic statins). Natural statins are
derived from fungal fermentation. Synthetic compounds are produced by medicinal
chemists. LIPITOR is a member
of a class of synthetic statins.
[13]
Pfizer made the
following statements regarding LIPITOR:
LIPITOR® is a blockbuster, but not in the traditional sense: it was
not the first drug in its class. Rather, it was the fifth in the
commercial statin marketplace. However, it is one of a kind and the first of
its kind: it is a novel compound; it is the first statin to be formulated as a
calcium salt (all previous statins were formulated as sodium salts); it is the
first synthetic statin to be marketed in a form other than as a racemate.
LIPITOR® has become a commercial success because of the advantageous
properties of atorvastatin calcium. It has dominated the market: it has become
the first drug ever to reach over a billion dollars in sales in its first year,
is currently the largest selling drug in every country in which it is sold, and
is the largest selling drug of all time.
Not surprisingly, Novopharm wants to take as large a share of the
valuable LIPITOR® market as it can by selling its own atorvastatin calcium, a
generic copy. To do so, it must invalidate the single patent claim, claim 6, to
the most successful salt in pharmaceutical history.
(A.R. Vol. 29 at 9940.)
Prior Patents
[14]
The 546 Patent is based
on the prior art of U.S. Patent 4,681,893 (“893 Patent”). The 893
Patent was filed with the U.S. Patent Office on May 30, 1986, and issued on
July 21, 1987. It describes a class of statins, including natural statins which
were commercialized as lactones and compounds. The 893 Patent includes
individual enantiomers and mixtures, including racemic mixtures.
[15]
“Enantiomers” are a
pair of isomers that are non-superimposable mirror images of one another. The
most common analogy for enantiomers is a pair of hands. “Racemate”, also known
as a “racemic mixture”, is a 50/50 mixture of enantiomers.
[16]
The invention of the
893 Patent provided for compounds with the structural formula:
Wherein X is –CH2—,
--CH2CH2—, --CH2CH2CH2—
or –CH2CH(CH3)—
[17]
It also provides a list
of substituents for R1 to R4, including substituents
making up the atorvastatin racemate.
[18]
Thus, the 893 Patent
describes a broad class of compounds including the 4-hydroxypyran-2-ones and
the corresponding ring-opened acids, and the pharmaceutically acceptable salts
thereof.
[19]
These compounds are in
practice used in its salt form. The salt most commonly used was the sodium
salt, although any number of salts may be used. In describing what
“pharmaceutically acceptable metal salt” meant, the 893 Patent includes the
following salts: sodium, potassium, calcium, magnesium, aluminium, iron, and
zinc ions, but it did not draw special attention to the calcium salt
specifically.
[20]
The 893 Patent gave a
detailed description of the racemic mixture by stating [emphasis added]:
This asymmetry gives rise to four possible isomers, two of which are
the R-cis and S-cis-isomers and the other two of which are the R-trans and
S-trans-isomers. This invention contemplates only the trans- form of the
compounds of formula I above.
[21]
“Cis” and
“Trans” are terms which imply relative stereochemistry. Cis means that two chemical groups in a
molecule are on the same side of a plane, but it does not tell you which side
of the plane the groups are on. Trans means that two chemical groups in a
molecule are on opposite sides of a plane.
[22]
This might be a good
point to say a few words about the nomenclature of this case to clear up any possible
confusion. The compound from which the enantiomers are resolved has no name of
its own. It is called the atorvastatin racemate or atorvastatin racemic
mixture. The R- trans enantiomer of the atorvastatin racemate is called the atorvastatin.
The S- trans enantiomer has no name of its own and is always referred to as the
S-trans enantiomer. LIPITOR contains the calcium salt of atorvastatin
(the R-trans enantiomer).
[23]
The 893 Patent
corresponds to the Canadian Patent 1,268,768 (“768 Patent”). The 768 Patent was
filed on May 7, 1987, and issued on May 8, 1990.
[24]
Approximately
three years after the 893 Patent was filed, the Applicants filed another
patent, this time a process patent with the Canadian Patent Office on February 7, 1989. This was
the Canadian Patent 1,330,441 (“441 Patent”).
[25]
The 441 Patent
discloses and claims chemical processes that can be used to make chemical
compounds. This includes processes used in the production of atorvastatin.
Issue
[26]
Are
Novopharm’s allegations (that the 546 patent is invalid on the basis of
anticipation, obviousness and double patenting) justified?
Applicable Jurisprudence
[27]
The
jurisprudence regarding NOCs is extensive. It is best set out by Stone J.A. in Hoffman-La
Roche Ltd. v. Canada (Minister of National Health & Welfare) (1996),
205 N.R. 331 at para. 8, 70 C.P.R.
(3d) 206 (F.C.A.):
It seems to me that
the core guidance of these decisions, insofar as it is applicable to the case
at bar, may be summarized as follows:
1.
Applications made pursuant to subsection 6(1) of the Regulations are governed
by the procedural rules contained in Part V.1 of the Federal Court Rules,
[C.R.C. 1978, c. 663] - "Applications for Judicial Review".
Bayer AG, supra, per Mahoney J.A., at page 336 [C.P.R.];
2. The
initiator of a section 6 proceeding, being the person having the carriage of
the litigation, bears "the initial burden of proof" which is a
difficult burden because "it must be to disprove some or all of the
allegations in the notice of allegation which, if left unchallenged, would have
allowed the Minister to issue a notice of compliance". Merck Frosst,
supra, per Hugessen J.A., at page 319 [C.P.R.];
3. This
burden, known in a civil case as either the "persuasive burden" or
the "legal burden", is the burden of establishing a case to the civil
standard of proof. By contrast, the "evidential burden" consists of
the burden of putting an issue in play and means that a party has the
responsibility to ensure that there is sufficient evidence of the existence or
non-existence of a fact or an issue on the record to pass the threshold for
that particular fact or issue. Nu-Pharm, supra, per Stone J.A., at page 197
[N.R.].
4.
Where the notice of compliance of a second person alleges non-infringement, the
court should start from the proposition that "the allegations of fact in
the notice of allegation are true except to the extent that the contrary has
been shown by the applicant". Merck Frosst, supra, per Hugessen
J.A., at page 319 [C.P.R.];
5. In
determining whether or not the allegations are "justified" "the
court must then decide whether, on the basis of such facts as have been assumed
or proven, the allegations would give rise in law to the conclusion that the
patent would not be infringed by the respondent". Merck Frosst,
supra, per Hugessen J.A., at page 319 [C.P.R.];
6. The
Minister's decision of whether to issue a notice of compliance must turn on
whether the allegations of the second person are "sufficiently
substantiated to support a conclusion for administrative purposes ... that the
applicant's patent would not be infringed if the generic's product is put on
the market". Pharmacia, (A-332-94) supra, per Strayer J.A., at page
216 [C.P.R.];
7.
Where second persons fail to file notices of allegation or adequate notices of
allegation they "must assume their own risk when it comes to attacks on
the adequacy of such allegations once prohibition proceedings are commenced".
Bayer AG, (A-669-93) supra, per Strayer J.A., at page 134 [C.P.R.].
8. The
requirement in s. 5(3)(a) of the Regulations that a second person
provide a detailed statement "seems intended ... [to make] the patentee
... fully aware of the grounds on which the applicant seeks issuance of a NOC
[that will not lead to infringement of the patent] before the patentee decides whether
or not to apply to a court for a determination. Such disclosure would define
the issues at a very early stage." Bayer AG, (A-389-93) supra, per
Mahoney J.A., at pages 337-338 [C.P.R.];
9. A
bald statement of non-infringement in a detailed statement without any factual assertion
in support thereof does not meet the requirements of s. 5(1)(b)(iv) of the Regulations.
Nu-Pharm, supra, per Stone J.A., at page 199 [N.R.];
10. A
common law presumption that a second person's process would infringe the patent
applies where: that person has asserted no facts to support his allegation of
non-infringement; the evidence of non-infringement lay peculiarly within his
knowledge; no evidence of non-infringement has been presented by that person;
and the first person has no other available means of accessing such evidence. Nu-Pharm,
supra, per Stone J.A., at page 200 [N.R.].
Burden of Proof
[28]
Pfizer in its factum
states at para. 122:
Facts that are
set out in the Notice of Allegation in relation to allegations of invalidity
are not presumed to be true. A presumption that facts in a Notice of
Allegation are true arises only with respect to allegations of
non-infringement. The only allegations in this case are allegations of
invalidity. As a result, no facts set out in Novopharm’s Notice of Allegation
are presumed to be true.
(A.R.
Vol. 29 at 9972.)
[29]
This
is not a correct reflection of the law on this point. The issue of the
interaction of s. 43(2) of the Patent Act and the NOC Regulations has
been dealt with on numerous occasions by this Court (see Pfizer Canada Inc.
v. Apotex Inc., 2002 FCT
1138, (2002), 22
C.P.R. (4th) 466 at paras. 82-83, 225 F.T.R.
1, Dawson J.; Abbott Laboratories v.
Canada (Minister of Health), 2004 FC 1349, (2004), 36
C.P.R. (4th) 437 at paras. 103-106, 260 F.T.R.
276, Gibson J.; aff'd 2005 FCA 250, (2005),
339 N.R. 277; GlaxoSmithKline Inc. v. Genpharm Inc., 2003 FC
1248, (2003), 30
C.P.R. (4th) 360 at para. 45, 241 F.T.R.
42,
Heneghan J.; Janssen-Ortho Inc. v. Novopharm Ltd. 2004 FC
1631, (2004), 35
C.P.R. (4th) 353, at paras. 13-21, 264 F.T.R.
202,
Mosley J.; Sanofi-Synthelabo Canada Inc. v. Apotex Inc., 2005 FC
390, (2005), 39
C.P.R. (4th) 202 at 209, 271 F.T.R.
159,
Shore J.).
[30]
All these cases stand for the
proposition that the applicant must demonstrate on a balance of probabilities,
that the respondent's allegations of non-infringement or invalidity of the
patent are not justified. As Shore J. stated in Sanofi-Synthelabo, supra at
para. 9:
The applicant has the overall legal burden of proof. Nevertheless,
the Respondent, as the entity which has made its allegations in the NOA, has
the obligation to put these allegations "in play", i.e. to ensure
there is sufficient evidence of these allegations by which to present issues
for examination (Eli Lilly & Co. v. Nu-Pharm Inc. (1996), 69
C.P.R. (3d) 1, [1996]
F.C.J. No. 904 (F.C.A.) (QL)).
[31]
It is thus the duty of the Court
to consider each of the allegations of invalidity, and in view of the evidence
submitted by the Respondent, determine whether the evidence submitted was
sufficient to rebut the statutory presumption of validity. If the evidence was
sufficient, the Court then considers the evidence as a whole to determine
whether the Applicant had satisfied its burden of disproving the Respondent's
allegation of invalidity.
Findings Required
[32]
Given the nature and structure of NOC proceedings, in order
to grant the requested prohibition order, the Court must come to the conclusion
that Novopharm’s allegations are not justified. Conversely, in order to not
grant a prohibition order, the Court must make a determination that the patent
is invalid.
Experts
[33]
Both parties called a host of experts. Attached as Annex 2
is a list of the experts called by each side. The experts differed in their
testimony. Particularly, their evidence differs on what a person skilled in the
art would have known or assumed. Their evidence will be extremely helpful in
dealing with the issues of anticipation and obviousness. These issues however,
are ultimately questions for the Court to decide in light of the expert
testimonies received. Accordingly, I will treat the expert evidence in the same
way as Campbell J. in AB Hassle v. Apotex Inc., 2003 FCT
771, (2003), 27
C.P.R. (4th) 465 at para. 16:
16 Each of
the expert witnesses to the present case have sworn that the evidence they have
provided is true. On this basis, an evaluator of the evidence must start from
the proposition that the witnesses are credible unless good cause is shown, and
can be articulated, to the contrary (for an example of this general principle
see: Maldonado v. Canada (Minister of Employment and Immigration), [1980] 2
F.C. 302 (C.A.). That is, while they might hold differing views on a
given topic, it must be assumed that they are not just saying things to bestow
a benefit on the party who is relying on their evidence. In my opinion, it is
unfair to the witnesses and, accordingly, to each of the parties, to make
negative credibility findings in the guise of findings of weight without seeing
and hearing each witness testify.
Patent
Construction
[34]
Any case involving patents starts with construction of the
patent. In Biovail Pharmaceuticals Inc. v. Canada (Minister of National
Health and Welfare), 2005 FC 9,
(2005), 37
C.P.R. (4th) 487, 267 F.T.R.
243, Harrington J. succinctly summarized the jurisprudence on
the rules for patent construction at paragraph 15 which I intend to follow:
It is a pre-requisite
to considerations of both patent validity and infringement that the language of
what is claimed in the patent be properly considered. The Court can do no
better than to take the same approach in an NOC proceeding, keeping in mind the
restricted purpose of the proceeding. The Supreme Court has done much to codify
and clarify patent claim construction in two recent cases handed down the same
day: Free World Trust v. Electro-Sante Inc., [2000] 2
S.C.R. 1024, 9 C.P.R. (4th) 168 and Whirlpool Corp. v. Camco Inc.,
[2000] 2
S.C.R. 1067, 9 C.P.R. (4th) 129. The reasons in both were given by
Mr. Justice Binnie. I take the following principles as having particular
relevance to this case:
1. A patent is
construed as a bargain between the inventor and the public. In consideration of
disclosing the invention, the inventor is given a temporary monopoly to exploit
it.
2. It
is a statutory requirement that the patent contain a specification and end with
a claim or claims "defining distinctly and in explicit terms the
subject-matter of the invention for which an exclusive privilege or property is
claimed". The specification must be sufficiently full, clear, concise and
exact "as to enable any person skilled in the art or science to which it pertains,
or to which it is most closely connected, to make, construct, compound or use
it". (Patent Act, R.S.C. 1985, c. P-4, as amended, s. 27)
3. The
patent is notionally addressed to a person skilled in the art or science of the
subject-matter and is to be read as such a person would have read it when it
first became public. (More will be said about this skilled reader.)
4. The
claims are to be read in an informed and purposive way to permit fairness and
predictability and to define the limits of the monopoly "[I]ngenuity of
the patent lies not in the identification of the desired result but in teaching
one particular means to achieve it. The claims cannot be stretched to allow the
patentee to monopolize anything that achieves the desired result" (Free
World Trust, paras. 31, 32).
5. The
claim portion of the patent specification takes precedence over the disclosure
portion in the sense that the disclosure is read to understand what was meant
by a word in the claims "but not to enlarge or contract the scope of the
claim as written and thus understood" (Whirlpool, para. 52).
6. It
is only such novel features that the inventor claims to be essential that
constitute the "pith and marrow" of the claim. "The key to
purposive construction is therefore the identification by the Court with the
assistance of the skilled reader, of the particular words or phrases in the
claims that describe what the inventor considered to be the
"essential" elements of his invention" (Whirlpool, para.
45).
7. Some
elements of the claimed invention are essential and others are not, based
either on common knowledge when the patent was published or according to the
intent of the inventor, expressed or inferred from the claims. This lies at the
heart of Biovail's position that Novopharm's allegation that it will not
infringe the '320 patent is not justified. Put another way, was it obvious at
the time the patent was published that the substitution of a variant would make
a difference?
8. To
overclaim is to lose everything. If the inventor underclaims, the court will
not broaden the monopoly in the interests of the "spirit" thereof.
This often, as in this case, results in layers of claims, each limitation
serving as a potential safety net so that if the broadest claims fall, the monopoly
may be saved in part by the more modest claims.
9. Yet
a patent is not an ordinary writing. It meets the definition of a
"regulation" in the Interpretation Act, and must be read to assure
the attainment of its objects. "Claims construction is a matter of law for
the judge, and he was quite entitled to adopt a construction of the claims that
differed from that put forward by the parties." (Whirlpool, para.
61.)
Patent Construction in This Case
[35]
The relevant claims
in the 546 Patent, claims 1,
2, and 6 read as follows:
Claim 1:
[R-(R*,R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-((1-
methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid or (2R-trans)-5-(4-fluorophenyl)-2-(1-methylethyl-N,4-diphenyl-1-[2-
(tetrahydro-4-hydroxy-6-oxo-2H-pyran-2-yl)ethyl]-1H-pyrrole-3-carboxamide;
and pharmaceutically acceptable salts thereof.
Claim 2:
A compound of
Claim 1 which is [R-(R*R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-((1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrole-1-heptanoic
acid.
Claim 6:
The
hemicalcium salt of the compound of Claim 2.
Fortunately,
these complex formulae have been given simpler names such that Claims 1, 2, and
6 can be read more easily as follows:
Claim 1: Atorvastatin acid or atorvastatin lactone; and
pharmaceutically acceptable salts thereof.
Claim 2: Atorvastatin acid.
Claim 6: The hemicalcium salt of the compound of Claim 2.
[36]
The only claim in
issue in these proceedings is Claim 6. It claims the hemicalcium salt of
atorvastatin.
[37]
Dr. Roush for Pfizer made
the following remarks regarding a person skilled in the art:
57. I understand that the person of
ordinary skill in the art is one who would share the expected common knowledge
of competent ordinary workers within the field of the 546 Patent as of July 21,
1989. The “art” in this case is that of medicinal chemist, an important branch
of organic chemistry that deals with the development of new drugs, typically by
generating SAR data sets based on hard work and long hours in the laboratory.
58. The person of ordinary skill in the
art would have at least a Bachelor of Science degree in organic chemistry,
medicinal chemistry or related chemistry, coupled with several years of recent
experience in synthesizing organic molecules.
(A.R. Vol. 3 at 441.)
[38]
Dr. Heathcock for
Novopharm stated with respect to a person skilled in the art:
22. It is my opinion that one of the
people to whom the ‘546 patent is directed is an organic chemist who is
involved in the development and synthesis of complex organic molecules,
including pharmaceutical active ingredients.
23. This person would have at least a
Bachelor of Science degree, and more likely a post-graduate degree, in organic
chemistry or medicinal chemistry along with several years of experience in
synthesizing organic compounds.
(A.R. Vol. 14 at 4661.)
[39]
In other words,
both parties generally agree that a person skilled in the art would be an organic or medicinal chemist – a person
with at least a Bachelor of Science degree and with experience conceiving,
creating, synthesizing and testing compounds to be used as medicines.
[40]
Expert witnesses
called as persons skilled in the art who attempted to interpret the patent were
Dr. Roush, Dr. Spargo and Dr. Heathcock.
[41]
Dr. Roush for Pfizer
states the following:
63. The 546 Patent specifically discloses
and claims atorvastatin calcium. The 546 Patent specifically discloses that
atorvastatin has unexpected and surprising activity to inhibit cholesterol
biosynthesis. In particular, the 546 Patent specifically discloses that
atorvastatin has ten times the inhibitory activity (of the biosynthesis of
cholesterol) as compared to a racemic mixture of atorvastatin and its
corresponding S-trans enantiomer.
64. This increase in activity of
atorvastatin over the racemic mixture is unexpected and surprising. A person
of ordinary skill in the art would expect, at most, a two-fold increase in
activity upon separation of the enantiomers from the racemic mixture. This
two-fold activity increase assumes, however, that all of the activity of the
racemic mixture resides in one of the enantiomers, the other one being totally
inactive. In the case of atorvastatin, the S-trans enantiomer is not
inactive. The data on page 8 of the 546 Patent shows that the S-trans
enantiomer has activity. As such, the actual expected activity increase that a
person of ordinary skill would anticipate for the more active enantiomer over
the racemic mixture containing it would be less than two-fold. In this
context, the ten-fold increase in activity is surprising and more certainly
unexpected.
65. The 546 Patent identifies
atorvastatin calcium as the most preferred embodiment of the invention at page
4 lines 21 to 24 wherein it states: “The most preferred embodiment of the
present invention is
[R-(R*,R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid, hemicalcium salt”.
(A.R. Vol. 3 at 442.)
[42]
Dr. Heathcock for
Novopharm essentially concurs:
94. The ‘546 patent suggests that the
3R,5R isomer (also referred to as the 3-(R)-trans isomer when in the lactone
form) is 10-fold more effective in inhibiting HMGR than atorvastatin racemate.
It further states that this “surprising inhibition” is “unexpected,” and states
that “an ordinarily skilled artisan may not predict the unexpected and
surprising inhibition of cholesterol biosynthesis of the present invention.”
In support of these assertions, the ‘546 patent provides on page 8 the
following table of biological data:
Compound
|
IC50, μM/liter
|
[R-(R*R*)]
isomer (3R,5R)
|
0.0044
|
[S-(R*R*)]
isomer (3R,5R)
|
0.44
|
Racemate
|
0.045
|
95. As expected, the assay shows that the
3R,5R enantiomer is the active enantiomer. On the basis of this data, the
bioactivity of the 3R,5R enantiomer would appear to be 10-fold greater than
that of the racemate. A person of ordinary skill in the art would typically
only expect an improvement of up to 2-fold when comparing the active enantiomer
to the corresponding racemate (that is, if all of the biological activity
resides in the 3R,5R enantiomer and none in the 3R,5R).
(A.R. Vol. 14 at 4284.)
[43]
In addition Dr.
Spargo on behalf of Pfizer asserts:
30. The 546 Patent states (on page 3)
that the invention provides for compounds consisting of atorvastatin, its
lactone form, and pharmaceutically acceptable salts of atorvastatin. It is
stated at page 4 of the 546 Patent that “the most preferred embodiment of the
present invention is [atorvastatin] hemicalcium salt.”
31. This would teach a person skilled in
the art reading the 546 Patent that the hemicalcium salt of atorvastatin is
preferred over all other salts. The 546 Patent therefore teaches persons
skilled in the art to preferably use atorvastatin calcium.
32. The 546 Patent states that the
atorvastatin enantiomer has approximately ten times the inhibitory activity of
a racemic mixture. Any salts of atorvastatin would be expected to have the
higher inhibitory activity than salts of the racemic mixture. Thus, when the
patent states that the calcium salt is preferred, a person skilled in the art
would understand that the preference necessarily refers to that salt’s superior
physical properties over the other salts of atorvastatin.
(A.R. Vol. 8 at 2393.)
[44]
Upon reading the patent, and
taking into account the expert advice so as to read it through the eyes of a
person skilled in the art, the Court reads the disclosure as explaining the
following:
- atorvastatin
in its lactone form, its corresponding ring-opened acid form, and the
pharmaceutically acceptable salts thereof is useful for lowering cholesterol
levels in mammals, including humans.
- atorvastatin
in its lactone form, its corresponding ring-opened acid form, and its
pharmaceutically acceptable salts thereof provides an unexpected and surprising
inhibition of cholesterol biosynthesis; unexpected in that it is ten-fold increase
over the inhibition provided by the racemic mixture. The data for this ten-fold
increase comes from a CSI screen disclosed in the 893 Patent. All compounds for
the CSI screen were prepared as described in the 893 Patent.
- the most
preferred embodiment of the invention described in the 546 Patent is the hemicalcium
salt of the atorvastatin acid.
- the
compounds of the lactone form, the corresponding ring-opened
acid form, and the pharmaceutically acceptable
salts thereof all have generally equivalent utility.
Selection
Patent
[45]
Pfizer claims that
the 546 Patent is a selection patent. Specifically, Pfizer asserts in its
factum:
2.
The claim at issue in this proceeding is a claim to a selection invention. The
claim to atorvastatin calcium (also called the hemicalcium salt of
atorvastatin) is a selection of a compound having advantageous improvements
from a broad class of thousands of compounds and salts described in a prior
Pfizer patent (Canadian Patent 1,268,768 (the “768 Patent”)). The invention is
the selection of one specific compound, atorvastatin calcium, from that broad
class of compounds and the recognition of its preferred physical properties and
unexpected and surprising activity of atorvastatin calcium.
21.
A person of ordinary skill would read and understand the 546 Patent as
disclosing atorvastatin calcium as the particular salt form that exhibits the
unexpected and surprising inhibition of cholesterol biosynthesis and having the
most preferred physical properties. In terms of formulation, “most preferred
properties” would be understood by persons of ordinary skill to represent the
salt form with the best combination of physical properties -- including
solubility, hygroscopicity, stability and processability.
37.
… Thus, atorvastatin calcium not only has surprising and unexpected biological
activity, it also has the best set of physical properties, which was also
surprising and unexpected. In fact, it was the selection of the calcium
salt which made atorvastatin a commercially feasible product for the first
time.
(A.R. Vol. 29 at 9940, 9945, 9950 [underlining added].)
[46]
According to Pfizer, the 546 Patent reveals two special
advantages of the hemicalcium salt of the atorvastatin acid over the rest of
the group (in this case the racemic mixture of the atorvastatin and the S-trans
enantiomer of the atorvastatin), namely:
a.
an unexpected ten-fold increase in activity when a person skilled
in the art would have only expected a two-fold one, and
b.
the best combination of physical properties of this salt -- including
solubility, hygroscopicity, stability and processability, over all the other
salts mentioned in the 893 Patent.
[47]
Novopharm
disputes both of these claims. It alleges that the data regarding the ten-fold
advantage is unreliable (more about that later) and that no special advantage
regarding the hemicalcium salt of atorvastatin is provided within the 546
Patent.
[48]
The rules for selection patents are well
known and have
their origin in I.G. Farbenindustrie A.G.’s Patents (1930), 47 R.P.C. 289
at 322 (High. Ct. Ch.) where Maugham J. observed:
Three general propositions may,
however, I think, be asserted as true: - First, a selection patent to be valid
must be based on some substantial advantage to be secured by the use of the
selected members. (The phrase will be understood to include the case of a
substantial disadvantage to be thereby avoided.) Secondly, the whole of the
selected members must possess the advantage question. Thirdly, the selection
must be in respect of a quality of a special character which can fairly be said
to be peculiar to the selected group.
[49]
The rationale
for such policy can be found in Lord Glaisdale’s observation in E.I. du Pont
de Nemours & Co. (Witsiepe’s) Application, [1982] F.S.R. 303 at 313
(H.L.) [underlining added]:
The type of invention which the
law of selection patents was designed to foster appears from the speech of my
noble and learned friend, Lord Diplock, in Beecham Group Ltd. v. Bristol
Laboratories International S.A. [1978] R.P.C. 521, 579:
“The inventive step in a
selection patent lies in the discovery that one or more members of a previously
known class of products possess some special advantage for a particular
purpose, which could not be predicted before the discovery was made (In re I.G.
Farbenindustrie A.G.’s Patents (1930) 47 R.P.C. 283 per Maugham J. at pp.
322/3.) The quid prop quo for the monopoly granted to the inventor
is the public disclosure by him in his specification of the special advantages
that the selected members of the class possess.”
[50]
I propose to deal
with these propositions in the reverse order. In light of the above
jurisprudence, I have some trouble agreeing with the second proposition that
the 546 Patent selects the hemicalcium salt of the atorvastatin acid from all
the other pharmaceutically acceptable salts. Admittedly, the disclosure of the 546
Patent states at page 4, lines 21-24:
The most preferred embodiment of
the present invention is [R-(R*,R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid, hemicalcium salt.
[51]
Dr. Spargo points out
that a person skilled in the art would know that this refers to “that salt’s
superior physical properties over the other salts of atorvastatin” (A.R. Vol. 8
at 2394).
[52]
Even Dr. Adelstein,
Novopharm’s witness conceded this point under cross examination.
Q. This is teaching you that, of all the
aspects of the invention that are disclosed in the ‘546 patent, the most preferred
embodiment is the atorvastatin hemicalcium salt. Right?
A. Yes.
Q. You would agree then that, reading
the ‘546 patent, the person of ordinary skill in the art would know that
atorvastatin calcium is the most preferred embodiment of this invention?
A. Yes.
(A.R. Vol. 16 at 5066.)
[53]
From the various
experts, it seems clear that typically, the preferred properties of a salt are
low hydroscopicity, good dissolution and good compaction. However, the 546
Patent does not tell the world in what way the properties of the hemicalcium
salt are unexpectedly superior over other pharmaceutically acceptable salts. In
other words, the patent does not disclose the special advantage peculiar to the
hemicalcium salt that was hitherto unknown and that is revealed in the 546 Patent.
[54]
I have no reason to
reject Dr. Spargo’s and Dr. Adelstein’s explanation (that a person skilled in
the art knows that ‘preferred embodiment’ refers to that salt’s superior
physical properties over the other salts of atorvastatin). However, this is not
enough for a selection patent; it is an insufficient disclosure as the special
characteristics of hemicalcium are neither identified nor quantified. The mere
assertion that the hemicalcium salt of atorvastatin is the preferred embodiment
of the invention does not meet the requirements of a selection patent. As
Maughan J. specifically stipulated in I. G. Farbenindustrie, supra at 323 [underlining added]:
I must add a word on the subject of the
drafting of the specification of such a patent. It should be obvious, after
what I have said as to the essence of the inventive step, that it is
necessary for the patentee to define in clear terms the nature of the
characteristic which he alleges to be possessed by the selection for which he
claims a monopoly. He has in truth disclosed no invention whatever if he
merely says that the selected group possesses advantages. Apart altogether
from the question of what is called sufficiency, he must disclose an invention;
he fails to do this in the case of a selection for special characteristics, if
he does not adequately define them. The cautions repeatedly expressed in
the House of Lords as regards ambiguity have, I think, special weight in
relation to selection patents. (Natural Colour etc. Ld. v. Bioschemes Ld.,
(1915) 39 R.P.C. 256, at p. 266; and see British Ore etc. Ld. v. Minerals
Separation Ld., (1910) 27 R.P.C. 33, at p. 47.)
[55]
As the foregoing analysis has shown, the 546 Patent does not meet
the requirements of a valid selection patent claim in terms of a salt
selection.
Significance
of Selection Patent
[56]
The entire case
stands or falls on the issue of selection patent and specifically the ten-fold
increase in activity of one of the enantiomers over the racemate. If the 546 Patent
is a valid selection patent, this is a complete answer to the allegations of
anticipation, obviousness and double patenting. None of Novopharm’s witness
have asserted either:
a.
that a ten-fold
activity was anticipated on the basis of the 893 Patent;
b.
that it was obvious
to a person skilled in the art that resolving the racemate of atorvastatin
would result in a ten-fold increase of activity by the enantiomer; quite the contrary
they allege that a two-fold increase was to be expected; or
c.
that the 441 Patent
or the 768 Patent discloses or claims an enantiomer of atorvastatin that displays
a ten-fold increase of activity of the enantiomer over the racemate.
[57]
Pfizer in its first
proposition asserts that the 546 Patent is a selection patent that selects atorvastatin
in its lactone form, its corresponding ring-opened acid form, and the
pharmaceutically acceptable salts thereof from the range of compounds described
in the 893 Patent. According to Pfizer, the 546 Patent discloses an unexpected
advantage hitherto unknown: the ten-fold increase in activity in lieu of the
expected two-fold increase. Thus,
the key issue becomes whether Novopharm can effectively challenge the 546
Patent as a selection patent; i.e., challenge the claim to the ten-fold
increase in activity. In my view, it cannot for the following reasons.
I.
Insufficiency of the NOA
[58]
Novopharm in its NOA
makes allegations of invalidity based on anticipation, obviousness and double
patenting. The NOA makes absolutely no reference to selection patents or
inutility. Nor is there any mention that the data used to support the selection
patent is questionable, unreliable or unsupported.
[59]
Novopharm
takes the position that the NOA is not deficient. It argues that implicit in
the allegations of anticipation, obviousness and double patenting is the allegation
that the 546 Patent is not a selection patent. This selection patent is based
on an alleged ten-fold advantage. That advantage depends on the CSI 118 data
displayed in the disclosure of the patent. Therefore, although neither selection
patent nor defective data are mentioned in the NOA, Novopharm maintains that
they are implicitly ‘in play’ through the
allegation of anticipation, obviousness and double patenting.
[60]
Novopharm further asserts
that it did not know that the issue of selection patents would be raised or
that the support for the data was based on such fragile grounds until it
received the affidavits from Pfizer and cross-examined on them.
[61]
Finally, Novopharm argues that Pfizer was in no
way confused, never complained about lack of specificity of the NOA and never
brought a motion to that effect. Accordingly, Novopharm argues that it can lead evidence by
trying to impugn the data of CSI 118.
[62]
As a result, the main
thrust of Novopharm’s case consists of extensive evidence from experts
regarding assays. They specifically criticize the CSI 118 assay that is the
foundation of the ten-fold claim set out in the chart in the disclosure of the
546 Patent. Novopharm’s contention is that the assay is very questionable, was
never repeated and should not be relied on for a variety of reasons. However,
that will be discussed more fully later on under the sub heading “CSI 118”.
[63]
The jurisprudence on
NOAs is clear and firmly established. Strayer J.A. described the nature of NOAs
in Bayer AG v. Canada (Minister of National Health and Welfare)
(1995), 179 N.R.
122 at para. 13, 60 C.P.R.
(3d) 129 (F.C.A.)
[underlining added] as
follows:
In particular this
Court in Pharmacia Inc. et al. v. Bull (David) Laboratories (Canada) Inc.
(1994), 175 N.R. 334 (F.C.A), at p. 335, stated the following:
“It seems
to us that while a notice of allegation does play an important role in the
ultimate outcome of litigation of this nature, [it] is not a document by which
the judicial review application may be launched under section 6 of the Regulations.
That document was put in as a piece of evidence by the appellants; it
originated with the application filed before the Minister. Because it is not a
document that was filed with the Court but with the Minister, in our view the
notice of allegation is beyond the reach of the Court's jurisdiction in a
judicial review proceeding. That being so, the Court, in our opinion, lacks
jurisdiction to strike out the notice of allegation.”
This clearly means
that the Court has no jurisdiction to make orders concerning the filing of
notices of allegation or requiring them to be perfected in some way. The
principle is that, by the scheme of the Regulations, the notice of
allegation precedes the institution of prohibition proceedings in this Court. It
forms part of the background to that proceeding, perhaps what one might loosely
refer to as part of the "cause of action". A court cannot order that
a cause of action be created, or that it be created at a certain time, or in a
certain way. It can only deal with it after it is created or allegedly created.
Those who fail to file notices of allegation, or adequate notices of
allegation, must assume their own risks when it comes to attacks on the
adequacy of such allegations once prohibition proceedings are commenced before
the Court.
[64]
Rothstein J.A. (as he
then was) added in Procter & Gamble v. Canada (Minister of Health), 2002 FCA 290, [2003] 1
F.C. 402 at para.
22, 216 D.L.R.
(4th) 376 (F.C.A.)
[underlining added]:
22 However,
the notices of allegation and the detailed statement of legal and factual basis
for the allegation must provide all the facts the generic producer intends to
rely upon in subsequent prohibition proceedings. It cannot rely on facts
that exceed those laid out in its detailed statement. See Merck Frosst
Canada Inc. v. Canada (Minister of Health), supra, at para. 9 per Stone
J.A.
[65]
In support of its
assertion that there was no surprise, Novopharm quotes Sharlow J.A. in Pharmascience
v. Sanofi-Aventis Canada Inc, 2006 FCA 229, 352 N.R.
99 at paras. 23-24
[underlining added]:
23 … There are two senses in which a notice of allegation may
be said to be "inadequate" or "insufficient". In these
reasons, I am using those words as they are used in AstraZeneca
AB v. Apotex Inc., 2005 FCA
183 (and a long line of prior cases) to describe a judicial
determination as to whether the person to whom the notice of allegation has
sufficient information to determine whether to seek a prohibition order.
24 The same words are sometimes used in what I call their
"secondary sense", to describe a situation where a non-infringement
allegation is not justified because it fails to address a relevant patent
claim, or because it is not capable of establishing non-infringement (for
example, where it is based on an incorrect construction of a patent claim). A
notice of allegation cannot be found to be inadequate or insufficient in that
secondary sense without addressing the allegation on the merits.
[66]
I don’t think this
case supports Novopharm’s contention. While it is well established that a
generic does not need to anticipate every possible defense a brand name
manufacturer may raise
(Pfizer Canada Inc. v. Novopharm Ltd., 2005 FCA 270, 341 N.R.
330 at para. 16, 42 C.P.R.
(4th) 97) it must however mention
in its NOA the legal and factual basis of its allegation. The contention about
the allegedly flawed data supporting the ten-fold increase in activity claimed
in the 546 Patent is part of what Strayer J.A. described as “part of the cause
of action”. Novopharm must allege in the NOA that this data is flawed or else
the Court cannot deal with it.
[67]
It is no defense to
say ‘we did not know how questionable the data is until we saw Pfizer’s
affidavits and cross-examined them’. Novopharm intends to market the
bioequivalent of atorvastatin. The patent on its face is a selection patent of
the 893 Patent and can only stand if it meets the selection patent criteria
referred to above. Special advantage is obviously a key criterion and depends
on the ten-fold increase in activity. It thus begs belief to suggest Novopharm
did not know that the data evidencing the ten-fold advantage would be an issue.
[68]
When asked during the
hearing about this point; i.e. why Novopharm did not put the issue of selection
patents and the data supporting the selection in the NOA, counsel for Novopharm
gave the following revealing answer:
THE COURT: ... You've heard
Mr. Shaughnessy say absolutely outright to me, I asked: Isn't the ‘546 a
selection patent? He said yes. That was your position. Mr. Shaughnessy; did I
mishear you?
MR. SHAUGHNESSY: That's
right, my lord. I think we've taken a position, both Mr. Wilcox and I, and Ms.
Block have said that on its face the patent is a selection patent.
THE COURT: Right. So
you're basically saying, no, it's not.
MR. STAINSBY: We're not
saying, no, it's not, I'm saying it wasn't apparent on the face of the patent at
the time they served the NOA. [Notice of Application]
THE COURT: And
therefore you could not have put it in your NOA?
MR. STAINSBY: Well, I
suppose we could have. We could also have put in there that it failed for lack
of sound prediction, it failed for insufficient disclosure. We could have put
lots of things in there but we didn't because those were not claims that it was
clear that we were going to have to make. . . .
(Rough Draft, Day 3, Transcript
at 64.)
[69]
Yet
later on in a further exchange Mr. Stainsby states:
There has not been a
hint of prejudice. All there is is a technical argument, which I say is wrong
at law, to the effect that Novopharm because it didn't say in its NOA the ‘546
is an invalid selection patent cannot challenge the evidence that was put
forward by Pfizer.
Now, the main challenge
to that evidence comes only after we see the evidence, because the patent on
its face contains data which purports to show a ten-fold increase in activity
of the R-trans over the racemate. …
(Rough Draft, Day 3
Transcript at 66.)
[70]
This in my view is
not the right way of proceeding. Novopharm cannot first allege anticipation, obviousness
and double patenting and then in response to evidence from Pfizer, attack the
patent on what amounts to be an attack based on a lack of utility or sound
prediction. The 546 Patent on its face is a selection patent. The expert
witnesses from both sides had no difficulty in identifying it as such. If
Novopharm is of the view that the selection is based on flawed data it has to allege
it at the outset.
[71]
I repeat what Strayer
J.A. stated in Bayer AG, supra. [The NOA refers to]:
“what one might
loosely refer to as part of the ‘cause of action’. A court cannot order that a
cause of action be created, or that it be created at a certain time, or in a
certain way. It can only deal with it after it is created or allegedly created.”
[72]
Since the data evidencing the ten-fold advantage was not challenged
in the NOA, it does not form part of the ‘cause of action’. The Court will take
it as established. The Court will not take into consideration any part of the
evidence or submissions that question the veracity, soundness or reliability of
that data.
[73]
For the reasons set out in paragraph 56 above, this position
of the Court disposes of this case. However,
in case the Court of Appeal is of another view, I will briefly review and deal
with Novopharm’s attack on the data underlying the ten-fold advantage.
II.
Unsuccessful attack on CSI 118
[74]
If the court were to
accept Novopharm’s argument regarding sufficiency of the NOA as set out in paragraph
59 above (which it explicitly does not do), an examination of the data
underlying the ten-fold advantage is required. That advantage is based on the CSI
118 assay. Before delving into the CSI 118 assay, a few words on the background
of assays might be in order.
Assays
[75]
As part of the drug
development process at any pharmaceutical company, compounds of interest are
evaluated to determine whether they have any biological effect. Typically,
these compounds are evaluated by means of assays.
[76]
Assays, which are
also referred to as “screens”, are experiments conducted on test compounds to
determine whether they have a particularly desirable characteristic. An assay
will allow one to determine how effective a given compound is in inhibiting
enzyme activity or an enzymatic process (cholesterol biosynthesis) by measuring
its activity in vitro or in vivo. In vitro screens are
carried out in a test tube, culture dish or elsewhere outside a living
organism. In vivo screens are carried out in a living organism.
[77]
This invention
involves enzymes, which are involved in converting compounds into other
compounds. They act as biological catalysts that speed up the rate of a
chemical reaction.
[78]
HMG-Co-A reductase is
an enzyme that catalyzes the conversion of HMG-CoA and NADPH into mevalonic
acid (mevalonate). As such, one assay that can be used to assess activity of a
potential HMG-CoA reductase inhibitor is to put it into a medium containing,
among other things, HMG-Co-A, NADPH and HMG-CoA reductase, and then monitor the
inhibitor’s ability to stop or slow down the conversion of HMG-CoA into
mevalonic acid (as compared to the same reaction conducted without the
inhibitor). This type of assay is also referred to as the COR assay. The
purpose of the COR assay is to measure the effect that a statin has on only one
enzyme, the HMG-CoA reductase.
[79]
Another type of assay
is the Cholesterol Synthesis Inhibition (CSI) screen. It measures the effect of
the test compound on the incorporation of radiolabelled acetate into
nonsaponifiable lipids as a measure of the inhibitory activity of a test
compound with respect to the entire cholesterol biosynthesis pathway. In other
words, it measures the effect that a test compound, a “statin”, has on the
entire cholesterol biosynthesis pathway.
[80]
For in vitro assays
involving enzymes, the ability to inhibit the reaction of interest is typically
expressed as the IC50 value. The IC50 represents the concentration of an
inhibitor that is required for 50% inhibition of the enzyme in the in vitro assay.
The control measures the amount of cholesterol (CSI assay) or mevalonic acid
(COR assay) produced in the absence of a test compound. The lower the IC50 the more potent the compound, since less
of the compound is required to cause 50% inhibition.
[81]
Pfizer used these two
in vitro assays, the COR assay and the CSI assay, to evaluate its
“statins” and to test whether their potential HMG-CoA reductase inhibitors had
activity. Once a test compound had shown sufficient inhibitory activity with
respect to the cholesterol biosynthesis, it was tested using the COR screen.
[82]
Initially, Pfizer
relied on both the COR and the CSI assays to support the 546 Patent. However,
as part of the litigation Pfizer re-examined the COR evidence. It found that:
a.
The data was not
properly graphed;
b.
The IC50 values were calculated by taking the inverse log of the
concentrations in error; and
c.
In the case of COR
111, an error was made in preparing the stock solutions of the racemic calcium
salt.
(See
Dr Newton A.R. Vol. 29 at
9778-79; Dr. Dietschy A.R. Vol. 29 at 9781-82.)
[83]
As a result of these
concrete errors, Pfizer abandoned the COR assays and no longer relies on them
to support the 546 Patent.
[84]
Pfizer however, still
relies on the CSI assay. Novopharm alleges that it should not be relied on as
well.
[85]
Novopharm’s attack on
the CSI 118 assay involves the following allegations:
a.
118 is a single
assay, there is no evidence that it has been replicated, therefore, one should
not rely on it;
b.
The lab notes for CSI
118 are deficient and not scientifically kept;
c.
The lab technicians
were not called notwithstanding that they are available. One of the technicians
is still in Pfizer’s employ, while the other technician lives in Michigan;
d.
No margin of error
was established for the CSI 118 test, yet this is standard for scientific
tests;
e.
CSI 118 cannot be
relied upon as the test compounds did not fully dissolve in the buffer
solutions and the concentrations of the compounds in the solution were not
measured;
[86]
An examination of the
affidavits and the cross-examinations of Pfizer’s experts reveal that the
assays were no models of scientific testing. However, the criticisms by
Novopharm’s experts are limited to the methodology used. They suggest that a different
and more rigid methodology of assay testing should have been used which would
have led to different outcomes.
[87]
Surprisingly, Novopharm,
who wants to sell the bioequivalence of LIPITOR offered no evidence of its own
as to either solubility and/or increased activity. It produced no evidence obtained
using its own efforts that could be compared to the CSI 118 assay. Thus, the only
evidence available to the Court is the data furnished by Pfizer, the affidavits
commenting on the data and the cross-examinations on those affidavits. There is
no counter evidence of any kind.
[88]
The most severe
criticism of Novopharm’s experts concerns the dissolution of the compound in
the buffer solutions.
[89]
Novopharm’s experts
contend:
a.
Dr. Heathcock (A.R.
Vol. 14 at 4297):
113. As noted above, in order to obtain
accurate IC50 values, one needs to know the
concentration of the test solutions. As acknowledged by Dr. Newton in his
affidavit, Pfizer did not determine the concentrations of its test solutions.
This is especially troubling considering that Pfizer’s lab notebooks for CSI
118 (Appendix J to the Newton Affidavit) indicate that some of the test
compounds were insoluble in the solution used to make up the assays (“stock
solution”).
114. More specifically, the lab notebooks
indicate that the stock solutions for atorvastatin calcium, the 3S,5S
enantiomer and atorvastatin racemate calcium were all insoluble and that the
stock solution for atorvastatin racemate sodium solution was only “partly
soluble”. It was not determined what amount of each test compound dissolved in
each stock solution. The stock solution is used to make the assay solutions
(i.e., aliquots of the stock solution are removed, put into a tube and further
diluted to give the assay solution). In order to know the concentration of the
assay solution, one needs to know how much compound was taken from the stock
solution and put into the assay solution. If all of the compounds dissolve in
the stock solution, it is easy to make an accurate determination. However, if
not all of the compound has dissolved, one should measure the concentration of
the assay solution in order to accurately determine its concentration. As
Pfizer does not measure the concentrations of each assay solution, it is not
clear what the concentration is for each assay solution.
116. Accordingly, without accurate
information about the concentration of the solutions used in CSI 118, the IC50 values obtained in CSI 118 should be [sic] not be relied
upon to support a 10-fold increase in activity of atorvastatin over the
racemate.
b.
Dr. Alberts stated
(A.R. Vol. 15 at 4587):
55. In order for a compound to inhibit an
enzyme, it must be in solution. It is not clear from Pfizer’s lab books that
all of the compounds tested by Pfizer had completely dissolved in the assay
solution. If the compound has not all dissolved in the assay solution, this
would impact the concentration of the compound which in turn would effect the
IC50. In other words, if the reported
concentrations are incorrect, the IC50
would also be
incorrect.
56. It is clear from Pfizer’s lab books
that the compounds did not all dissolve in the stock solution. For instance,
CSI 118 describes the solutions as insoluble and requiring sonication. The
stock solution is used to make the assay solutions (a small amount of the stock
solution is removed and diluted to make the assay solutions). Therefore, if the
compound has not all dissolved in the stock solution it would be difficult to
know that one has transferred the correct amount of the compound to make the
assay solutions. The concentration of the assay solutions is critical to
obtaining accurate IC50
values. Based on my
review of Pfizer’s assay results, I question whether they had transferred the
correct amount of compound into each assay solution.
71 (vi). It is also not clear that the
assay solutions had the reported concentrations. I note that the stock solution
for atorvastatin racemate calcium, atorvastatin calcium and the calcium salt of
the S enantiomer are described as insoluble. There is no indication as to
whether all of the compounds were dissolved in the assay solutions. Again, for
such an important assay, I would have expected Pfizer to confirm that the
concentrations of the assay solution were correct …
74. As well, it is my opinion that Dr.
Dietschy should not assume that CSI 118 used uniform suspensions simply because
the laboratory notebook contains no notation as to whether or not there were
undissolved lumps in the stock suspension. I question the correctness and
reliability of the notes given the errors apparent in Pfizer’s assays and
laboratory techniques employed. Further, the notes for CSI 118 do not say a
“uniform suspension” was achieved. While a homogenous suspension may be
acceptable to determine whether a compound has activity, it is my opinion that
it should not be relied on for quantitative analysis (i.e., to discriminate
between 2-fold and 10-fold activity). For a quantitative analysis, a solvent
system should be used which completely dissolves the compound.
c.
Dr. Weinstock (A.R.
Vol. 16 at 5101):
101. … In order to inhibit an enzymatic
reaction, the drug must get to the enzyme, and the only reliable way for that
to occur is for the drug and enzyme to be in common solution and for all the
drug to be dissolved in the solution.
103. … The protocol for drug dissolution
did not specify that the drug was to be ground before use, or how long attempts
to dissolve drug should continue. From this, I conclude that a large variation
in the amount of drug dissolved could have occurred during preparation of drug
“solutions” to be used in the bioassays. …
104. … You would therefore expect the IC50 values to be the same for both the sodium and calcium salts
as they would both be potassium salts in the solution. This was, however, not
observed and, therefore, I question the reliability of the assay results
obtained by Pfizer.
108. Note that atorvastatin racemate
calcium, atorvastatin calcium, and the S-enantiomer calcium are all insoluble
in Step 1, and that atorvastatin racemate sodium is milky and only part soluble
in Step 2. Assuming that all the drug dissolve, if all the activity of the
racemic compound resides in atorvastatin, then the atorvastatin sodium would
have an IC50 of 4.72 nM which is 5 times more potent
than atorvastatin calcium. Since under the conditions of the experiment all the
soluble salts exists as the equilibrium mixture of all the different salts in
the test solution (as explained above), atorvastatin will be equally active
regardless of the salt form in which it was dosed. This suggests that in this
experiment only 1/5 of atorvastatin was dissolved for atorvastatin calcium and
able to inhibit the enzyme. Since this is the data on which the claim that
atorvastatin is ten times more potent than the racemic form is based, this
claim is not correct.
d.
Dr. Ness (A.R. Vol.
17 at 4587):
41. It should be noted that the
solubility of the various atorvastatin preparations (including the atorvastatin
racemate preparations) appears to have been a significant problem with the
Pfizer assays. Many of these test compounds are very lipophilic and non-water
soluble. According to paragraph 58 of the Newton Affidavit, Pfizer appeared to
be satisfied with preparations of dispersed suspensions (i.e. solutions in
which the test compound was not fully dissolved). However, using
non-homogeneous suspensions could result in variations in the concentration of
compound in the assay solutions, leading to wide variations in the results
obtained.
42. There is not sufficient information
provided in Pfizer’s lab notebooks for me to determine whether Pfizer’s
solutions were homogeneous or not. Further, if I was alleging that an
enantiomer had a 10-fold increase in activity over the racemate, I would have
ensured that a solvent was used that completely dissolved the compound. Without
doing so, I would not consider the assay results to be reliable.
[90]
Pfizer’s expert
counter these criticisms as follows:
a.
Dr. Newton (A.R. Vol.
4 at 746):
58. When attempting to solubilize a test
compound, the objective was to obtain a clear solution. If a clear solution was
unattainable, the secondary objective was to prepare as finely a dispersed
suspension of the compound as possible. Such a suspension was acceptable for
use in the assays. A suspension would be unacceptable for use only if it
contained “chunks” of test compound.
61. The concentration of the test
compounds in the stock solution or serial dilutions was not determined prior to
testing in the CSI or COR assays. To do so would have been expensive and
cumbersome and was not a routine step in the drug discovery process at
Warner-Lambert or at other pharmaceutical companies.
b.
Dr. Newton (A.R. Vol.
7 at 1970):
17. We did not determine the
concentration of each salt of every test compound as such a procedure would
have been time consuming and atypical of the drug discovery process at the
time. Today there are automated techniques for taking such measurements, but in
the mid-1980s such techniques were unavailable. In any case, it was not
necessary to know the precise concentration of the test solution to find the IC50 values and to compare those IC50 values in a head-to-head assay run on the same day. The
reason this was not necessary was because we were only interested in the
relative IC50 values and not the absolute IC50 values.
29 (e). Dr. Alberts states at paragraph
71(vi) that he would have expected the Warner-Lambert scientists to confirm
that the concentrations of the assay solutions were correct. As discussed
above, given the nature of the drug discovery program and the importance of
rapid throughput, we did not confirm the concentrations for every assay. That
was not routinely or easily done at the time.
c.
Dr. Dietschy (A.R.
Vol. 17 at 2096-98):
58. In addition to opening the lactone ring
(if necessary) prior to testing, the test compounds also had to be solubilized
into either a solution or a suspension (because they would have been provided
by the chemists in powdered form). Statins are not readily soluble in many
common solvents, and although the techniques for solubilizing them were well
known at that time, I would expect to see variation in the quantity of test
compound actually solubilized depending on the solvents and techniques used.
59. Because statins are relatively
insoluble molecules, solubility problems were very common. This does not mean
that all test results involving statins are invalid, however. On the contrary,
anyone who has worked with statins over the last 30 years has had to deal with
problems of solubility, and it was (and is) routine to sue solubilizing agents
(such as PEG, detergents or albumin) to assist in obtaining a uniform
dispersion of the statins in a particular solvent.
60. In order to test a statin in one of
these assays, one needs to get the compound into some sort of uniform state so
that the amount of compound being introduced into each assay tube is known.
This is essential for looking at comparative data and can be done in a number
of ways.
61. Ideally, the compound can be
completely dissolved to give a clear stock solution. Often, however, this does
not happen spontaneously due to the limited solubility of statins. The
technician preparing the stock solution may therefore try sonication or
vortexing in order to achieve a uniform dispersion in an aqueous phase. These
stock solutions will look slightly opalescent or milky but will show no
manifestation of gross lumps. These stock solutions would be acceptable. The
worse-case scenario would arise when all of the common solubilization
techniques have been tried but gross lumps of material remain. Such a stock
solution would be unacceptable.
62. I understand that the Warner-Lambert
technicians who prepared the stock solutions did not measure the solution
concentrations after solubilizing the candidate drug compounds. In my view, it
is the usual practice not to do this. I do not know of anyone, either in the
industry or in academics laboratories, who would routinely carry out such a
procedure. In any case, it is not necessary that the concentration of the
compounds in the stock solution be measured. If one has a solution or uniform
suspension, each aliquot will very accurately deliver a uniform amount of the
compound in a known volume, either to the in vitro or the in vivo assay
systems. Once an aliquot of the statin is delivered to the assay system, it
undergoes some degree of dilution, allowing the bulk of the statin to be
dissolved.
63. Furthermore, it would be incredibly
expensive and difficult to actually measure the concentration of the test
compounds in each of the hundreds of assays run. Those techniques would have
been very tedious and difficult from a practical standpoint of drug discovery,
and would have slowed down the entire procedure by months.
d.
Dr. Dietschy (A.R.
Vol. 17 at 2242):
21. Dr. Alberts states at paragraphs
55-59 that the test compounds were not sufficiently soluble to permit the data
to be relied upon, and further, that other solvents should have been used. I
disagree. The data show that the test compounds were sufficiently soluble in
the solvents that were used in the Warner-Lambert protocol to cause inhibition
of the enzyme. In this regard, I note Dr. Weinstock’s comment at paragraph 101
of his affidavit where he suggests that for a drug to cause enzyme inhibition, all
the drug must be dissolved in the solution. This is an overstatement.
Obviously, some drug must be dissolved in order for it to reach the enzyme and
inhibit it, but it is not necessary that all the drug be dissolved. Since the
solubility of the calcium salts of the R-(R*,R*) enantiomer, the S-(R*,R*)
enantiomer and the racemic mixture are the same, the inhibitory activity of
these compounds could be validly compared.
[91]
Pfizer’s counsel
characterized Novopharm’s attack on CSI 118 as ‘poking holes’. This is quite an
apt description. Novopharm allegations certainly raise questions about the scientific
rigour of CSI 118. However, these questions do not go so far as to totally
discredit the assay or to establish that it is wrong.
[92]
As the example of
dissolution of the compound in the buffer solution demonstrates, the evidence
of the experts is contradictory. In the absence of any evidence of their own,
Novopharm’s experts can only suggest such things as:
-
“ using
non-homogenous suspensions could result in variations in the
concentrations of the compound in the assay solution leading to wide variations
in the results obtained. (Dr. Ness, A.R. Vol. 17 at 5400.)
-
“The
improper scientific protocol used by Pfizer demonstrates a general degree of
sloppiness in the Pfizer laboratory and therefore leads me to disbelieve
the results provided by Pfizer. I am confident that I would not be alone
in this opinion. (Dr Alberts, A.R. Vol. 15 at 4716.)
-
“After reviewing
Pfizer’s reply evidence, it remains my opinion that Pfizer’s assay results
cannot be relied upon to quantitatively determine the activity of one compound
over another. The most that Pfizer’s assay results can be used for is to
determine whether a compound has activity but not to determine whether one
compound has a two- fold, three-fold or ten-fold increase in activity over
another compound.” (Dr. Heathcock, A.R. Vol. 14 at 4319.)
(Underlining added.)
[93]
If one takes a step back and looks at the
overall situation, the following picture emerges. Pfizer
produced the compound, tested it in the laboratory, produced data, interpreted
the data and made certain findings, i.e., a ten-fold increase in activity of
the R-trans enantiomer. There is no evidence that Novopharm produced the
compound, tested it, collected data, or interpreted it. It merely had its experts
examine the data and the methodology used to obtain it. Novopharm’s experts
criticized Pfizer’s methodology and made certain assumptions, conjectures,
extrapolations and drew conclusions. The nub of these conclusions is that employing
a more rigorous scientific data would have revealed at best a two-fold
advantage.
[94]
Being faced with laboratory tests, data from the tests, the
experts’ interpretation of the data, and the experts’ defence of the
methodology employed on the one hand and on the other hand, no test, no divergent
data, and only criticisms of the methodology employed and conjecture as to the results
that may be obtained under a different methodology, the Court is driven to the
conclusion that, on a balance of probabilities, Pfizer’s data (although not
perfect) together with the interpretation of its experts disproves the allegations
of Novopharm (which are not backed by any laboratory evidence whatsoever).
[95]
Thus, in
the alternative, even if the NOA was found to be sufficient, the 546 Patent is
still a valid selection patent, as the allegations by Novpoharm questioning the
data of the ten-fold advantage can not be sustained.
Conclusion re Anticipation and Obviousness
[96]
As
mentioned above, the 546 Patent is a selection patent claiming a ten-fold
advantage of the atorvastatin calcium (the R-trans enantionmer) over the racemate
of atorvastatin calcium. This is the surprising and unexpected advantage that the
enantiomer has over the other members of its class. For the reasons given above
(either failure to allege anything about the selection patents and unreliable data
in the NOA or the lack of contrary evidence disproving Pfizer’s claim of
ten-fold increase in activity) there is no need to examine in further detail the
allegations of anticipation or obviousness. Novopharm has not presented any
evidence whatsoever that the ten-fold advantage was either:
1. anticipated in the 893
patent; or
2. obvious in light of the state
of the art in July 1989.
Double Patenting
[97]
A few
words about the issue of double patenting are required. Novopharm alleges that
the 546 Patent is void for double patenting. Particularly it argues that with
respect to the 441 Patent:
161. The ‘441 Patent was filed February 7, 1989 and claims priority
to February 1, 1989 (almost 6 months prior to the filing of the ‘546 Patent).
It provides a purportedly novel process for making atorvastatin. The ‘441
Patent teaches a person of ordinary skill in the art:
a.
the preferred enantiomer is the 3R,5R-dihydroxy
acid;
b.
the compounds may be in their lactone form,
their 3R,5R-dihydroxy acid form, or as a base addition salt of
the acid;
c.
the acid form may be made by stopping the
reaction prior to forming the lactone;
d.
alternatively, the acid form may be made by
conventional hydrolysis of the lactone;
e.
the 3R,5R-dihydroxy acid may react
to form salts with pharmaceutically acceptable metal and amine cations;
f.
the formation of pharmaceutically acceptable
salts is done using conventional means; and
g.
the term “pharmaceutically acceptable metal
salt” contemplates salts formed with the calcium, sodium, potassium, magnesium,
aluminium, iron and zinc ions.
164. Because the
processes disclosed in the ‘441 Patent inevitably make atorvastatin, it is
irrelevant that the ‘441 Patent only has process claims. The ‘441 Patent
contains specific claims to a process for making atorvastatin, and not to
making other compounds. The determination of which form of atorvastatin to use
required no inventive ingenuity but merely the application of method.
(R.R. at 54-55.)
[98]
With
respect to the 768 Patent, Novopharm argues:
165. In view of
Pfizer’s position that the ‘768 Patent claims atorvastatin racemate and
atorvastatin and its pharmaceutically acceptable salts, the ‘546 Patent
represents an improper evergreening on the claims of the ‘768 Patent.
166. For the same
reasons that the ‘546 Patent is anticipated by the ‘893 Patent, it represents
an impermissible, co-terminus double patenting over the ‘768 Patent.
167. For the same
reasons that there is nothing inventive in the ‘546 Patent over the ‘893
Patent, the ‘546 Patent is invalid for obviousness-type double patenting over
the ‘768 Patent.
(R.R. at 56.)
[99]
There are
two types of double patenting, same invention double patenting and obviousness
double patenting. (See Whirlpool, supra at paras. 63 -70)
[100]
In same
invention double patenting, the claims must be identical or co-terminus. Since
the 441 Patent is a process patent, it is obviously not the same as the 546 Patent,
which claims a compound. Given that the 546 Patent is a selection from the
group of compounds disclosed in the 768 Patent (the Canadian equivalent of the
US 893 Patent), the 546 Patent is obviously not identical with the claims of
the 768 Patent.
[101]
As far as
obviousness double patenting is concerned, the claims or disclosure must exhibit novelty or ingenuity in order for the second patent to
be valid. (See Sanofi-Synthelabo Canada Inc., supra at
para. 86).
[102]
As the Court
found that the 546 Patent was a selection patent, by definition it is novel and
unexpected. It thus cannot be invalid on the basis of obviousness double
patenting.
Overall Conclusion
[103]
For the
reasons stated above, Novopharm’s allegations have been disproved and the
prohibition order sought will be granted.
ORDER
THIS COURT ORDERS that:
1. The Minister of Health may not issue an NOC to
Novopharm in respect of the proposed tablets for oral administration comprised
of atorvastatin calcium in 10 mg, 20 mg, 40 mg, and 80 mg strengths until after
expiry of Canadian Patent No 2,021,546; and
2. Novopharm shall pay Pfizer its costs of this
application.
“Konrad W. von Finckenstein”
Annex
1
2. The 546 Patent is
Not Valid
The claims of the 546 patent are
not valid for the following reasons:
1.
The claims are anticipated.
2.
The claims are obvious.
3.
The claims are double patented.
2.1 Anticipation
US Patent No. 4,681,893 (the “893
patent”), which issued on July 21, 1987, discloses certain trans-6-[2[(3- or
4-carboxamidosubstitutedpyrrol-1-yl)alkyl]-4-hydroxypyran-2-ones and the
corresponding ring-opened acids. The 893 patent was listed by Pfizer on the US
Orange Book for LIPITOR. The Canadian equivalent to the 893 patent is Canadian
Patent No. 1,268,768 (the “768 patent”) which is listed on the Canadian Patent
Register for LIPITOR. By listing the 768 patent on the Canadian Patent
Register and the 893 patent on the Orange Book, you have taken the position
that both the 768 patent and the 893 patent claim Atorvastatin Calcium as
distinct from mixtures of the RR trans and SS trans enantiomers.
Specifically, at column 2 of the
893 patent, it provides the following structure for the compounds claimed in
the 893 patent:
As required by United States Law,
the 893 patent also discloses methods for making these compounds and their
corresponding ring-opened acid forms in sufficient detail to allow persons
skilled in the art to make them as of the date the 893 patent became publicly
available. To the extent that any steps are not explicitly described, these
steps would have been well known to persons skilled in the art. As such, since
you have taken the position that the 893 patent relates to Atorvastatin Calcium
then it must be your position that a person skilled in the art would have been
able to make Atorvastatin Calcium as well as the racemic mixture of
Atorvastatin Calcium and its SS trans enantiomer as of that date.
Table 1 of the 893 patent
discloses a number of examples which are representative of the compounds within
the scope of the 893 patent. Compound 1 of Table 1 is described as having the
following structure:
As noted above, the 893 patent
discloses and claims the lactone ring forms (the ring-closed lactone form) of
various compounds as well as their corresponding ring-opened acids (the
ring-opened form). The 893 patent also discloses how to prepare both forms of
these compounds.
The 893 patent also discloses
that the ring-opened acids corresponding to the lactone forms of the compounds
of the invention may be used as their pharmaceutically acceptable salts and
more specifically as their metal or amine salt. The 893 patent discloses that
the metal salt can be the sodium, potassium, calcium, magnesium, aluminum,
iron, and zinc salt and that the amine salt may be formed with ammonia or
organic nitrogenous bases strong enough to form salts with carboxylic acids.
The 893 patent also discloses how to make the metal salts. For instance,
Example 2 describes a process for making the sodium salt of
2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrole-1-heptanoic
acid.
The 893 patent also discloses
that the compounds of the 893 patent:
1.
are potent inhibitors of cholesterol biosynthesis by virtue of their
ability to inhibit the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase
(HMG-CoA reductase);
2.
can be used as hypolipidemic or hypocholesterolemic agents in
pharmaceutical compositions comprising a hypolipidemic or hypocholesterolemic
effective amount of the compound in combination with a pharmaceutically
acceptable carrier; and
3.
can be used to inhibit cholesterol biosynthesis in a patient in need of
such treatment by administering an effective amount of a pharmaceutical
composition containing these compounds.
As stated above, since it is your
position that the 893 patent claims and discloses Atorvastatin Calcium, claims
1, 2, 6, 11 and 12 of the 546 patent would be anticipated by the 893 patent.
As well, to the extent that claims 3 to 5 and 7 to 10 are relevant and are
asserted as being infringed, they too are invalid as anticipated by the 893
patent for the same reasons as set out above.
2.2 Obviousness
We also allege that each of
claims 1, 2, 6, 11 and 12 of the 546 patent (and claims 3 to 5 and 7 to 10 if
relevant and asserted as being infringed) are invalid on the basis of
obviousness. Prior to the relevant date of the 546 patent:
1.
Trans-5-(4-fluorophenyl)-2-(1-methylethyl)-N,4-diphenyl-1-[2-(tetrahydro-4-hydroxy-6-oxo-2H-pyran-2-yl)ethyl]-pyrrole-3-carboxamide
(the ring-closed lactone form of trans-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid and the racemate of the RR and SS forms) was known, having been prepared
in example 1 of the 893 patent.
2.
The ring-opened form was also known as it and the process for its
manufacture were described in the 893 patent.
3.
As stated above, based on your position that the 893 patent discloses
RR-trans-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid) (i.e., Atorvastatin), Atorvastatin was known having being disclosed in
the 893 patent.
4.
The use of
trans-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid and, in view of your position as described above, Atorvastatin, in the
form of their pharmaceutically acceptable salts was known having been disclosed
in the 893 patent. Specifically, the sodium, potassium, calcium, magnesium,
aluminum, iron and zinc salt forms had been disclosed in the 893 patent. The
choice of which form to use (i.e., as the ring-closed form or as a calcium salt
or as a sodium salt) is based on routine determinations that were well known to
a person skilled in the art.
5.
The use of trans-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid or its pharmaceutically acceptable salts as a hypocholesterolemic agent
had been disclosed in the 893 patent.
6.
The use of
trans-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid or its pharmaceutically acceptable salts in a pharmaceutical composition
had been disclosed in the 893 patent.
7.
The use of
trans-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid or its pharmaceutically acceptable salts for inhibiting cholesterol
synthesis in a human suffering from hypercholesterolemia had been disclosed in
the 893 patent.
8.
More specifically, in view of your position that the 893 patent
discloses Atorvastatin Calcium, then the use of Atorvastatin Calcium as a
hypocholesterolemic agent, in a pharmaceutical composition and for inhibiting
cholesterol synthesis in a human suffering from hypercholesterolemia, had been
disclosed in the 893 patent.
9.
It is well known to person skilled in the art how to manufacture
trans-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid in the ring-opened form, the ring-closed lactone form and as its
pharmaceutically acceptable salts an, as well, Atorvastatin and its
pharmaceutically acceptable salts in view of your position that the 893 patent
discloses Atorvastatin Calcium.
10.
Lastly, the stereochemistry needed in the dihydroxyheptanoic acid side
chain in order to achieve the biological effect in the class of compounds that
includes Atorvastatin was well known to person skilled in the art.
Specifically, it was known that the β-hydroxy in the lactone ring
(sometimes referred to as the 4 hydroxy group or the 3 hydroxy group) needed to
be in the R configuration. It was also known that the two hydroxyl groups in
the lactone ring needed to be in the trans configuration. For instance, in US
Patent No. 4,474,971, it states:
“The process
of this invention provides that 2H-pyran-2-one derivatives exclusively in the
4R,6S configuration of the naturally occurring compounds (i.e., compactin) with
none of the undesired stereochemical or optical isomers being produced.”
As well, in
the US Patent No. 4,375,475, it states:
“However, it
has been found that the 4R enantiomers of the trans racemates corresponding to
formula I specifically inhibit with high potency the activity of
3-hydroxy-3-methylglutaryl-coenzyme A reductase, which is known to be the
enzyme involved in the rate limiting step in the process of cholesterol
biosynthesis.”
Also, it was well known that the
other HMG-CoA inhibitors in the same class of compounds as Atorvastatin such as
lovastatin, simvastatin, pravastatin and compactin, all of which were known
prior to the filing of the priority application for the 546 patent, all had the
β hydroxyl in the R configuration and the two hydroxy groups were in the
trans configuration relative to one another.
As such, based on the above, a
person skilled in the art would have been led directly and without any
difficulty to the RR trans form of
2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid (Atorvastatin) and its salts including the calcium salt over the SS trans
form and its salts. As such, claims 1, 2, 6, 11 and 12 are obvious in view of
the prior art and the common general knowledge of a person skilled in the art
(as represented by the art set out in Schedule A). Also, to the extent that
they are relevant and alleged to be infringed, claims 3 to 5 and 7 to 10 for
the reasons given above are also obvious in view of the prior art and the
common general knowledge of a person skilled in the art.
2.3 Double Patenting
The claims of the 546 patent are
invalid for double patenting on the basis of Canadian Patent No. 1,330,441 (the
“441 patent”). The 441 patent claims a process for making Atorvastatin in the
ring-closed form, the ring-opened form and as its pharmaceutically acceptable
salts. For instance, claim 14 claims a process for making Atorvastatin in the
ring-closed form. As such, both the claims and the disclosure of the 441
patent disclose Atorvastatin and its pharmaceutically acceptable salts
including the calcium salt. The 546 patent is therefore invalid for
obviousness double patenting.
The claims of the 546 patent are
also invalid for double patenting on the basis of the 768 patent. The 768
patent was filed in Canada on May 7, 1987 and issued on May 8, 1990. In view
of your position as discussed above, the 768 patent discloses and claims
trans-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic
acid and its pharmaceutically acceptable salts including the racemate (a
mixture of the RR and SS trans forms) and each of the enantiomers (i.e., the RR
trans and SS trans enantiomers). As such, since the 768 patent claims
Atorvastatin and its pharmaceutically acceptable salts, the 546 patent is also
invalid for coterminous double patenting.
As well, the claims of the 546
patent are invalid for obvious double patenting based on the 768 patent. A
person skilled in the art would know that the RR trans form is the preferred
form based on the art disclosed in Schedule A. As such, a person skilled in
the art would have been led directly and without difficulty to the claims of
the 546 patent with the results that the claims of the 546 patent claiming
Atorvastatin, its various salt forms and its ring-closed lactone form are not
patentably distinct from the claims of the 768 patent.
Annex 2
For Pfizer
Dr. Dr. Bruce D. Roth: He is the inventor of the patent relating to LIPITOR. He is
currently employed by Pfizer as Vice-President of Chemistry, Pfizer Global Research
and Development. He has been working for Pfizer since 1999 when Pfizer acquired
the Warner-Lambert Company. Previous to his current employment with Pfizer, he
had been working for Warmer-Lambert Company since 1982. He holds a Ph.D. in
organic chemistry from Iowa State University. He is the co-author of 8
review articles and approximately 50 scientific papers. He has also given many
lectures and presentations at various universities and conferences in the United States and Canada. He also has received many awards, one of which was the
Warner-Lambert Chairman’s Distinguished Scientific
Achievement Award, which he shares with Dr. Roger Newton. In 1999, he was named
Inventor of the Year by the New York Intellectual Property Law Association.
Dr. Roger S. Newton: His field of experience is within the area of lipid biochemistry.
He holds a Ph.D. in the area of lipid metabolism from the University of California. During his
post-doctoral fellowship, he worked with compactin. From 1981 to 1998 he was
employed by Parke-Davis, the pharmaceutical research division of the
Warner-Lambert Company, in the Atherosclerosis Pharmacology Department. His
mandate was to establish and lead a drug discovery program aimed at finding a
chemical composition capable of being commercialized as a cholesterol-reducing
drug. Along with Dr. Bruce Roth, he was awarded the Warner-Lambert Chairman’s Distinguished Scientific Achievement Award.
Dr. William R. Roush: He is a chemist with almost 30 years experience in organic
chemistry and medicinal chemistry. He is presently the Executive Director of
Medicinal Chemistry at the Scripps Research Institute. He is also the Associate
Dean of the Kellogg Graduate School at Scripps. He holds a Ph.D. in
Chemistry from Harvard University. From 1978 to 1987 he was an assistant professor of chemistry and
researcher at Massachusetts Institute of Technology. Thereafter, he became a
Distinguished Professor of Chemistry at Indiana University, where he initiated a research program on the design and
synthesis of inhibitors of cysteine proteases. He has given numerous lectures
at universities and pharmaceutical companies. He has also published over 225
scientific papers and related publications dealing with organic synthesis and
medicinal chemistry. He is the Associate Editor of the Journal of the American
Chemical Society.
Dr. Michael P. Doyle: He is a Professor and Chair of the Department of Chemistry and
Biochemistry at the University
of Maryland, College Park. He
has been a professor of chemistry since 1968. He holds a Ph.D. in organic
chemistry from Iowa State University. He was also a Distinguished
Professor of Chemistry at Trinity University for 13 years. Then he joined
the faculty of the University
of Arizona at a Professor of Chemistry. He is also the author or co-author of
10 books, including “Basic Organic Stereochemistry” (published by Jon
Wiley and Sons, New York, NY, 2001). He has published more than 250 scientific papers and has
served on the editorial boards of a number of publications. Throughout his
career, he has received many awards.
Dr. John M. Dietschy: He is a Medical Doctor and a Professor of Internal Medicine at the
University of Texas, Southwestern Medical Center. He holds the H. Ben and “Isabel T.
Decherd Chair in Internal Medicine at the University of Texas. He has been involved in research relating to medicinal
substances that inhibit the biosynthesis of cholesterol for more than 40 years,
including research on statins. During this time, he has worked with
atorvastatin, simvastatin, mevinolin and fluvastatin. He has published 230
scientific papers, most of which deal with the biosynthesis and/or metabolism
of cholesterol. He has received a number of prestigious professional honours
and awards for his work on the control of cholesterol metabolism and regulation
in animals.
Dr. Peter Lionel Spargo: He
obtained his BA with First Class Honours in Natural Science (Chemistry) from Cambridge
University in 1983 and was awarded a Ph.D. in Synthetic Organic Chemistry, also
from Cambridge University in 1986. He joined Pfizer Ltd. in 1988 as a Medicinal
Chemist. Within two years he transferred to Pfizer’s Process (now Chemical)
Research and Development Department, where he progressed from Laboratory Team
Leader to Section Head, then Manager, then Director, and Ultimately Head of
Department. During his time at Pfizer, he identified, developed, and scaled up
manufacturing processes for new drug candidates. He led Pharmaceutical Sciences
teams, which worked on developing optimum formulations of compounds. Salt and
solid form selection has been a key element of almost every project he has been
involved with. In 2003, he joined Scientific Update LLP as a Scientific
Director, where he has been expanding Scientific Update’s consultancy services.
Dr. Peter Howard Jones: He is a Medical Doctor and
Associate Professor of Medicine at Baylor College of Medicine in the section of
Atherosclerosis and Lipid Research. He is the Medical Director of the Methodist
Wellness Services Weight Management Center and Co-Director of the Lipid
Metabolism and Atherosclerosis Clinic. He graduated with a Bachelor of Science
in Chemistry in 1974 from Washington and Lee University. He received an MD from
Baylor College of Medicine and graduated at the top of his class in 1974. His medical
practice focuses on preventive cardiology and obesity treatment. He has
extensive experience with the diagnosis and management of lipid disorders, as
well as pharmacology with cholesterol lowering agents including HMG-CoA
reductase inhibitors. He has particular experience in the treatment of
hyperlipidemia and in the clinical use of statins, including LIPITOR. He has
been a principal investigator or co-investigator in at least 30 clinical trials
involving statins. He has also participated in numerous scientific committees
and has published 80 scientific papers and over 20 abstracts, most of which
deal with clinical trials involving statins.
Dr. Christopher Bokhart: He is the Vice President of
CRA International, an international consulting firm dedicated to advising
clients and counsel in the areas of business evaluations, licensing, and
litigation support services. During his tenure at CRA, he consulted with
clients and counsel on business valuation issues, licensing, technology,
commercialization and transfer, and market assessment. Prior to becoming a Vice
President with CRA, he was an Executive Consultant with Peterson & Co.
Consulting and then he became a Managing Director with InteCap, and he was one
of the founding Principals of IPC Groups, LLC, a predecessor to InteCap.
Sam Gourdji: He graduated from McGill University with
a Bachelor of Science degree. He obtained his Masters in Business
Administration with a specialization in marketing from McGill University in
1982. He is employed by Pfizer Canada Inc. as the Vice-President Strategic
Planning & New Product Development. From 1994 to 2000, he worked at
Parke-Davis, a Division of Warner-Lambert Company, LLC as Director of
Marketing. In that capacity, he oversaw the marketing for LIPITOR/atorvastatin calcium and provided Canadian input to the global
development of LIPITOR. As the Director of Marketing,
he was responsible for reviewing and approving information concerning the
marketing and commercial success of LIPITOR in Canada. During this time, he was also a
member of the Canadian Joint Operating Committee on LIPITOR. In 1994 he accepted a cross-development position in Government
Affairs/External Affairs. His role in this position was to help secure
government formulary listings for Parke-Davis medicines.
For Novopharm
Dr. Clayton H. Heathcock: He is a chemist with over 40 years experience in organic chemistry
and medicinal chemistry. He is currently a Professor in the Graduate School at the University of California at Berkeley and a consultant with a number of pharmaceutical and
biotechnology companies. He is also a Chief Scientist with the Berkeley branch of the California Institute
for Quantitative Biomedical Research. He holds a Ph.D. in Organic Chemistry
from the University of
Colorado. He has synthesized a number of structural analogues of compactin and
evaluated their biological activity. In 1985 he, along with Terry Rosen,
completed their synthesis of compactin and published the results as a
preliminary communication. They also synthesized other stereoisomers of
compactin and the completed results were published in 1987. They were granted a
patent for their discovery of a stereoselective method for the synthesis of
various compounds in this series. He has since received a number of awards for
his work in organic chemistry.
Dr. Alfred Alberts: He is an independent pharmaceutical and scientific consultant and
advisor in the field of drug research and drug design. He has over 45 years of
experience in biochemistry and drug discovery. Between 1975 and 1995, he held
positions of increasing responsibilities at Merck Research Laboratories,
including the position of Distinguished Senior Scientist and the Vice-President
in Biochemistry and Director of Natural Product Discovery. For 15 years, he was
the leader of Merck’s atherosclerosis program which developed the HMG-CoA
reductase inhibitors, which are a class of drugs used to lower blood
cholesterol. He also discovered lovastatin (also known as mevinolin), and is
the named inventor. He has received numerous awards for his research on HMG-CoA
reductase inhibitors and on lovastatin, including the Inventor of the Year
Award, Intellectual Property Owners, Inc.
Dr. Gilbert W. Adelstein: He is a medicinal chemist with more than 21 years of experience in
the design and synthesis of new pharmaceutical active ingredients. He has a
Bachelor of Science in Pharmacy from the University of Illinois as well as a Master of Science and a Ph.D. in Medicinal
Chemistry from the University of Michigan. He began working for G.D. Searle
& Co. from 1968 to 1990 as a laboratory scientist and eventually elevated
to the position of Assistant Director of Regulatory Affairs. His work at G.D.
Searle & Co. included synthesizing new chemical entities in the
gastrointestinal, cardiovascular, and central nervous system disease research
areas and later on he was responsible for developing and implementing research
plans. From 1990 to 1995, he was the Director of Chemistry at Ohmeda, Inc.,
Pharmaceutical Products Division, where he oversaw the research and development
of novel anesthetics and analgesics. From 1995 to 2003, he was the Associate
Director, Regulatory Affairs at Sanofi Pharmaceuticals Inc., the Director of
Regulatory Affairs and Quality Technical Services at Forest Laboratories and a
Project Consultant at Reliant Pharmaceuticals. Since 2003, he has been an
independent consultant to pharmaceutical companies and other organizations on
pharmaceutical development and medicinal chemistry issues.
Dr. Joseph Weinstock: He is an independent consultant having 45 years of industrial
experience in medicinal chemistry and the design and synthesis of drugs. He
received his Bachelor of Science degree from Rutgers University in 1949 and his Ph.D. in Organic Chemistry from the University of Rochester in 1952. From 1954
to 1956, he was an instructor in the Chemistry Department at Northwestern University where he taught general and organic chemistry. From 1956 to 2002,
he was employed at Smith Kline & French, which later became GlaxoSmithKline
(collectively, “SmithKline”). He started as a Senior Medicinal Chemist and
became the Director of Medicinal Chemistry when he retired. While working with
SmithKline, he was responsible for and contributed to a number of major
research projects, including the design and synthesis of three marketed drugs.
Recently, he has been a consultant for Glaxo Medicinal Chemistry Group doing
cancer research. He is the author or co-author of at least 143 publications,
most of which relate to the synthesis and design of new pharmaceutical
compounds. He is also the inventor of at least US 112 patents and numerous
foreign patents.
Dr. Gene C. Ness: He has been a Professor in the Department of Biochemistry and
Molecular Biology, College of Medicine, University of South Florida since 1986. He received his Bachelor of Science in
Chemistry in 1966 from Bemidji State University and his Ph.D. in Biochemistry
in 1971 from the University North Dakota. His current research centers on the
molecular mechanisms by which physiological factors, including insulin, thyroid
hormone and dietary cholesterol, regulate the expression of HMG-CoA reductase.
He was a Senior Research Scientist, Clinical Chemistry Research and
Development, Dade Division American Hospital Supply. He is the author or
co-author of over 90 publications in referred journals, 4 invited reviews, and
over 80 published abstracts, and took part in approximately 60 invited talks
and seminars. He has received at least 8 awards for his research
accomplishments, relating primarily to his work on the regulation of
cholesterol biosynthesis.
Dr. Peter Loewen: He received a post-Baccalaureate Doctor of Pharmacy Degree in 1996
in the area of pharmacotherapeutics from the University
of British Columbia (“UBC”).
He received a Bachelor’s Degree in Pharmacy from UBC in 1993. He has been a
Clinical Pharmacist specializing in pharmacotherapeutic management of adult
internal medicine patients in the Vancouver Coastal Health Authority for the
past nine years and an Associate Professor of Pharmacology at the University of British Columbia. Since 2001,
he has also been the Coordinator of Clinical Pharmacy Services at the UBC Hospital. He
also served as Coordinator of the Vancouver Hospital & Health Sciences
Centre Hospital Pharmacy Residency Program from 2001 to 2005. As part of his
responsibilities, he is a member of the Drug & Therapeutics Committee. This
committee evaluates which drugs are appropriate to have on the hospital’s
formulary. He has also held the position of Clinical Assistant Professor,
Clinical Associate Professor, and Associate Professor at UBC’s Faculty of
Pharmaceutical Sciences since 1996. He has published numerous peer-reviewed
articles and abstracts, and spoken as an invited presenter at many conferences,
including presentations on statins and cholesterol.
Dr. Lea Prevel Katsanis: He is an Associate Professor in the Department of Marketing at the
John Molson School of Business at Concordia University where he teaches Advertising, Marketing Policy, and
Personal Selling at the undergraduate level and Pharmaceutical Marketing and
Sales Management at the graduate level. He obtained his B.A. in Economics from Vassar College in 1976 and participated in
an International Management Program at the London Business School in
1978. He obtained a Masters of Business Administration in 1979 from the Stern School
of Business at New York University. He also holds a doctorate in Business Administration from the
Marketing Department from George Washington University. From 1979 to 1981, he worked for Merck Sharp and Dohme as a Market
Research Analyst and was subsequently promoted to the position of Senior
Product Specialist, Cardiovasculars, and then to the position of Associate
Product Manager, Ophthalmics. He has also worked at The Schering Plough
Corporation between 1981 and 1984 as a Management Associate and then as a
Product Manager. Thereafter, in 1985, he worked at Phone-Poulenc
Pharmaceuticals where he was a Product Manager.