Pfizer Canada Inc. v. Novopharm Ltd.

Pfizer Canada Inc. v. Novopharm Ltd.
Court (s) Database
Federal Court Decisions
Date
2005-10-03
Neutral citation
2005 FC 1299
File numbers
T-2448-03
Notes
Digest
Decision Content
Date: 20051003
Docket: T-2448-03
Citation: 2005 FC 1299
Ottawa, Ontario, October 3, 2005
PRESENT: The Honourable Mr. Justice Blanchard
BETWEEN:
PFIZER CANADA INC. and
PFIZER INC.
Applicants
and
NOVOPHARM LIMITED and
THE MINISTER OF HEALTH
Respondents
REASONS FOR ORDER AND ORDER
(Confidential Reasons for Order and Order issued on September 21, 2005)
1. Introduction
1 Pfizer Canada Inc. and Pfizer Inc. seek an order to prohibit the Minister of Health from issuing a notice of compliance to Novopharm Limited (Novopharm) in respect of its tablets for oral administration comprising azithromycin monohydrate in a strength equivalent to 250 mg azithromycin until after the expiry of Canadian Patent 2,148,071 (the '071 Patent). Azithromycinis manufactured and sold by the Applicants under the brand name ZITHROMAX. Novopharm alleges that claim 23 of the '071 Patent is invalid for anticipation, obviousness, overbroad claiming and indefiniteness. Novopharm further asserts that its version of the drug will not infringe claims 1, 2, 9, 10, 17, 18 and 24 to 28 (the tablet claims) of the '071 Patent on the basis that it does not make its tablets by wet granulation. The issue to be determined in this application is whether Novopharm's allegations of invalidity and non-infringement of the patent are justified.
2. Background
2 The Applicants, Pfizer Canada Inc. and Pfizer Inc. (collectively Pfizer), are brand-name drug manufacturers. The Respondent Novopharm Ltd. (Novopharm) is a generic drug manufacturer. The Respondent Minister of Health (Minister) is charged with the administration of the Patented Medicines (Notice of Compliance) Regulations, SOR/93-133 (the Regulations).
3 Azithromycin dihydrate (azithromycin) is an antibiotic used in the treatment of various infections. It was first patented in the United States in 1984 as U.S. patent no. 4,474,768.
4 The shortcoming associated with azithromycin was its " adverse food effect" when taken in capsule form. When dosed orally, a drug may be affected by the presence of food in the gastrointestinal tract. A key feature of any drug administered orally is its bioavailability. Bioavailability is the percentage of the drug's active ingredient that enters the body's system for therapeutic effect. If the bioavailability of a drug is affected beyond a certain point by the presence of food in the gastrointestinal tract, a drug is said to exhibit an adverse food effect.
5 To counter this adverse food effect, azithromycin was prescribed with instructions to be taken in a fasted state, i.e. more than one hour before eating or more than two hours after a meal. This requirement had the potential to reduce patient compliance and clinical effectiveness of azithromycin.
6 Pfizer claims to have found a way of addressing the adverse food effect so that azithromycin could be administered effectively to patients that have eaten. It applied for patent protection of this breakthrough. On April 27, 1995, the Applicants filed an application in Canada claiming priority from the U.S. patent application filed on April 29, 1994. The '071 Patent was issued on October 17, 2000. On August 13, 2003, the '071 Patent was listed with the Minister on the patent register.
7 On November 4, 2003, Novopharm sent a notice of allegation and detailed statement to Pfizer stating that it intended to "make, construct, use and/or sell an azithromycin monohydrate 250 mg strength tablet for oral administration".
8 Pfizer filed the present application asking this Court to prohibit the Minister from issuing a notice of compliance which would permit Novopharm to produce its tablets, which activity, according to Pfizer, would infringe its patent.
3. The Legislative Framework
9 Subsection 55.2(4) of the Patent Act, R.S.C. 1985, c. P-4, provides for the making of the Regulations.
10 In the present case, Pfizer is the first person and Novopharm is the second person as defined in section 2 of the Regulations.
11 Pursuant to the Regulations, the second person must, in the notice of allegation, allege either that the first person is not the patentee, that the patent has expired, that the patent is invalid, or that the patent would not be infringed by the second person if the notice of compliance issued. The notice of allegation is sent to the Minister and served on the first person.
12 Subsection 6(1) of the Regulations provides that, after a notice of allegation is sent, the first person may apply, within 45 days, to a court for an order prohibiting the Minister from issuing a notice of compliance until after the expiration of the patent, on the grounds that the allegations are unjustified. Pursuant to subsection 6(2) of the Regulations, the Court shall issue the prohibition order if it is satisfied that "none" of the allegations is justified.
13 Subsection 6(6) of the Regulations, which deals with "product-by-process" claims, sets out a presumption that the proposed medicine, absent proof of the contrary, is made in accordance with the patented process.
14 Once a first person has applied for a prohibition order under section 6, paragraph 7(1)(e) of the Regulations is triggered, and provides that the Minister shall not issue a notice of compliance until the expiration of 24 months after the section 6 application.
15 In this application, Pfizer is asking this Court to prohibit the Minister from issuing a notice of compliance to Novopharm. Pfizer filed and served its objection to the notice of allegation on December 23, 2003. The 24-month period for what is essentially a presumptive injunction will therefore expire on December 23, 2005.
4. The Nature of Section 6 Proceedings
16 Section 6 proceedings are not actions for determining the validity or infringement of a patent: Fournier Pharma Inc. v. Canada (Minister of Health), 2004 FC 1718. They are proceedings in judicial review, to be held expeditiously, which aim at determining whether the Minister is free to issue the requested notice of compliance. The scope of these proceedings is confined to administrative purposes: Apotex Inc. v. Canada (Minister of National Health and Welfare), [1997] F.C.J. No. 1251 (F.C.A.) (QL); (1997), 76 C.P.R. (3d) 1 (F.C.A.).
17 The determination must turn on whether there are allegations, by the second person, sufficiently substantiated to support a conclusion for administrative purposes, i.e. the issuance of a notice of compliance, that the first person's patent would not be infringed if the second person's product is put on the market: Pharmacia Inc. v. Canada (Minister of National Health and Welfare), [1995] 1 F.C. 588 (F.C.A.); (1994), 58 C.P.R. (3d) 209 (F.C.A.).
18 The Regulations require the Court to determine summarily, on the basis of the evidence adduced, whether the allegations are justified. Section 6 proceedings are not adjudicative and cannot be treated as res judicata: AB Hassle v. Genpharm Inc., 2003 FC 1443. The first person, or patentee, is in no way deprived of all the recourses normally available to enable it to enforce its rights. If a full trial of validity or infringement issues is required, this can be obtained in the usual way by commencing an action: Pfizer Canada Inc. v. Apotex Inc. [2001] F.C.J. No. 17 (F.C.A.) (QL); (2001), 11 C.P.R. (4th) 245 (F.C.A.).
19 The legal burden in section 6 proceedings is well established in the jurisprudence. The allegations of non-infringement and invalidity are presumed to be true and the applicant must prove on a balance of probabilities that the allegations made in the NOA were unjustified. Left unchallenged, the allegations would allow the Minister to issue a notice of compliance: Merck Frosst Canada Inc. v. Canada (Minister of National Health and Welfare), [1998] 2 S.C.R. 193; (1998), 80 C.P.R. (3d) 368 (S.C.C.); SmithKline Beecham Pharma Inc. v. Apotex Inc., [2001] 4 F.C. 518; (2001), 14 C.P.R. (4th) 76 (F.C.T.D.) aff'd [2003] 1 F.C. 118 (F.C.A.); (2002), 21 C.P.R. (4th) 129 (F.C.A.); Novopharm Limited v. Pfizer Canada Inc. et al., 2005 FCA 270.
5. The Evidence
20 Both parties have submitted affidavits from experts and corporate officials.
21 Pfizer relies on the evidence of four witnesses:
(1) Madeleine Pesant, who swore her affidavit on February 19, 2004, is employed by the Applicant Pfizer Canada Inc. as Associate Director, Regulatory Intelligence and Information, Drug Regulatory Affairs and Safety - Canada. Ms. Pesant attested to the procedural history of the file, to the general history of Pfizer's production of azithromycin, and to the commercial success of Zithromax. Exhibits were also attached to her affidavit, notably the notice of allegation and the '071 Patent.
(2) Dr. Vincent Andriole, who swore his affidavit on February 12, 2004, is professor of medicine at Yale University School of Medicine and attending physician at the Yale-New Haven Hospital. He was certified by the American Board of Internal Medicine in 1964 and certified in the sub-specialty of infectious diseases in 1976. He obtained a Bachelor of Science degree from the College of the Holy Cross, in Worcester, Massachussets, in 1953 and a medical degree from the Yale University School of Medicine in 1957. In addition to his academic teaching, research and service activities, Dr. Andriole is a member of numerous professional societies, national committees, scientific advisory committees and editorial boards of specialized publications. He has conducted extensive research in the field of infectious diseases and has published approximately 100 research and review papers, chapters and texts on a variety of topics such as infectious diseases and drugs for their treatment, and more specifically on azithromycin itself. He attests to his experience with azithromycin, azithromycin's characteristics and use in treatment for infectious diseases and Pfizer's clinical investigation and improvement of azithromycin. Dr Andriole also attests to his review of the '071 Patent and the notice of allegation. He was asked by the Applicant to give his opinion on three issues: (1) whether the subject matter of claim 23 of the '071 Patent is anticipated by the literature references cited by Novopharm in its notice of allegation; (2) whether a person skilled in the art would be led directly and without difficulty to the subject matter of claim 23, based on the state of the art set out in Novopharm's notice of allegation; and (3) whether there is any merit to Novopharm's complaint that claim 23 is indefinite and broader than any invention disclosed in the '071 Patent. Dr. Andriole is offered as a witness expert.
(3) Dr. Robert Rapp, who swore his affidavit on February 19, 2004, is a professor of pharmacy in the College of Pharmacy and professor of surgery in the College of Medicine at the University of Kentucky. He also serves as manager of clinical services at the Department of Pharmacy Services at the University Hospital. Professor Rapp earned a Bachelor of science in pharmacy from the University of Kentucky in 1963. In 1970, he received a doctorate in pharmacy at the University of Kentucky College of Pharmacy. In addition to his academic teaching and research activities, he is a member of various societies, served on the editorial boards of specialized publications, acts as a consultant to the pharmaceutical industry. He has published in excess of 200 papers in professional and scientific literature, particularly in the field of pharmacology. He attests to his experience with azithromycin and his study of food-drug interactions. He reviewed the '071 Patent and the notice of allegation and was asked by Pfizer to give his opinion on two issues: (1) whether a person skilled in the art would be led directly and without difficulty to the subject matter of claim 23, based on the state of the art in April 1994; and (2) whether the subject matter of claim 23 is anticipated by the literature references cited by Novopharm in the notice of allegation. Professor Rapp also comments on infectious diseases and the use of azithromycin to treat infections, as well as the general state of knowledge among clinicians and researchers. He is offered as an expert witness.
(4) Rose Lombardi, a law clerk for Pfizer's counsel, swore a confidential affidavit on February 23, 2004. She attests that counsel for Novopharm delivered two binders of information containing portions of Novopharm's abbreviated new drug submission (ANDS) for Novo-Azithromycin. She attaches pages 18 to 47 of that portion of the submission entitled Quality Overall Summary-Chemical Entities to her affidavit.
22 Madeleine Pesant, Dr. Andriole, Dr. Rapp and Rose Lombardi were cross-examined on their affidavits.
23 Annexed to Dr. Rapp's affidavit are copies of the literature references or prior art relied on by Novopharm in its notice of allegation, which are filed as exhibits "D" through "R" of Dr. Rapp's affidavit. Pfizer also annexed its own evidence to Dr. Rapp's affidavit as exhibits "S" through "FF".
24 This additional evidence annexed to Dr. Rapp's affidavit pertains to the properties of azithromycin, studies of the pharmacokinetics of azithromycin, studies of its disposition in humans, the effects of food on drug absorption, studies of clarithromycin and food effect, the clinical toleration of azithromycin, the drug interaction profiles for approved macrolide and azalide antimicrobials, the pharmacokinetics and pharmacodynamics of intravenous and oral azithromycin. The evidence also contains an article by Foulds et al, entitled The absence of an effect of food on the bioavailability of azithromycin administered as tablets, sachet or suspension, which Pfizer contends is the "pivotal study (...) upon which the '071 patent is based, that informed the medical community that azithromycin tablets, unlike capsules, could be taken by a patient in the fed state."
25 Novopharm relied on the evidence of four witnesses:
(1) Dr. Jeffrey Rudolph, a pharmaceutical consultant, swore his affidavit on May 21, 2004. He holds a Bachelor of science degree from the University of Illinois and a Master of science and Ph.D. in industrial pharmaceutical science from Purdue University. He is registered as a pharmacist in Illinois and Florida. He has published articles and chapters and has been involved in national and international pharmaceutical organizations. He attests that he has reviewed the '071 Patent, the notice of allegation and the affidavits of Dr. Andriole, Professor Rapp, Ms. Pesant and Ms. Lombardi. He was asked by Novopharm to give his opinion on the following issues: (1) what is the invention of the '071 Patent; (2) what would claim 23 of the '071 Patent mean to a person skilled in the art; (3) would the subject matter of claim 23 have been obvious to a person skilled in the art in view of the prior art and the common general knowledge. He was also asked to provide his opinion of the affidavits of Dr. Andriole and Professor Rapp. He is offered as an expert witness.
(2) Dr. Isadore Kanfer, who is Dean and Head of the Faculty of Pharmacy of Rhodes University in Grahamstown, South Africa, swore his affidavit on May 22, 2004. He holds a Bachelor of science in Pharmacy and an Honours Bachelor of science from Rhodes University which he respectively obtained in 1967 and 1968. He obtained his Ph.D. in pharmacy in 1975. In addition to his academic teaching and research, he is a member of numerous national and international professional bodies, he has published extensively in the field of biopharmaceutics. He attests that he reviewed the '071 Patent, the notice of allegation, the affidavits of Ms. Lombardi, Ms. Pesant, Dr. Andriole and Professor Rapp. He was asked by Novopharm to give his opinion on the same issues submitted to Dr. Rudolph. He is offered as an expert witness.
(3) Gregory Bell, Ph.D. is a Group Vice President and Director of the Pharmaceuticals and Intellectual Property practices at Charles River Associates, an economics and management consulting firm. He swore his confidential affidavit on May 20, 2004. He holds a master of business administration and a doctorate in business economics from Harvard University. He is also a chartered accountant in Canada. In his capacity as director of the pharmaceuticals practice, he has worked on product pricing, contracting strategy for managed care organizations and hospitals, influences on physician prescribing behaviour, product launch strategy, and the impact of competing launches within a therapeutic category. He was asked by Novopharm to provide an opinion regarding the extent to which the commercial success of Zithromax in Canada was causally related to the introduction of Zithromax 250 mg tablets. He has been asked, in this regard, to respond to the affidavit of Madeleine Pesant. He reviewed the notice of allegation, the '071 Patent and product monographs.
(4) Timothy Butler, who swore an affidavit on May 18, 2004, is an information specialist at the law firm of Kenyon & Kenyon, in New York, who attests and provides a copy of U.S. Patent application no. 08/235069.
26 Dr. Rudolph and Dr. Kanfer were cross-examined on their affidavits.
6. Person Skilled in the Art
27 Novopharm argues that its experts are better qualified to address matters relating to the '071 Patent. Novopharm contends that since the '071 Patent relates to how azithromycin should be formulated to overcome adverse food effects, the evidence of its experts should be preferred since they both have extensive knowledge and experience in the formulation of pharmaceutical dosage forms. It is Novopharm's contention that Pfizer's experts are not formulators and therefore do not have expertise relevant to the invention of the '071 Patent.
28 Novopharm argues that the person skilled in the art of the '071 Patent is a person with knowledge and experience in physical pharmacy, the science of formulating pharmaceutical dosage forms. Dr. Rudolph, expert witness for Novopharm, attests that the person skilled in the art, in the present case, is the individual with a background in industrial pharmaceutical science / product development, which involves the design, development and quality assessment of pharmaceutical dosage forms, the physical, chemical and biological aspects of active pharmaceutical ingredients and pharmaceutical excipients, and the physics, micrometrics, unit operations and a variety of engineering disciplines. Novopharm's other expert witness, Dr. Kanfer, suggests that the subject matter of the '071 Patent is directed to a person with a background in pharmaceutical science and formulation or pharmaceutical dosage forms as well as exposure to the concepts of basic physical pharmacy.
29 Pfizer argues that a person skilled in the art for the purpose of the '071 Patent is a person of ordinary skill familiar with the clinical application of azithromycin and not pharmaceutical formulation or physical pharmacy. According to Dr. Rapp, for Pfizer, a person of ordinary skill in the art is a person with a Pharm. D. or a Ph.D. in pharmacology or chemistry or the equivalent, or with a Masters or Bachelors degree in the pharmaceutical arts with several years of experience in the pharmaceutical industry.
30 I do not accept Novopharm's contention that only a pharmaceutical formulator can assist the Court in construing the '071 Patent. While a pharmaceutical formulator may be versed in the common knowledge of the worker skilled in the art to which the patent relates, in my view, so too, would a person with a degree in the pharmaceutical arts with several years of experience in the pharmaceutical industry. In the context of the '071 Patent it may also be helpful and of assistance to the Court to have expertise in respect to the study of food-drug interactions, the effects of food on drug absorption and drug interaction profiles for approved azalide anti-microbials. Pfizer's experts are qualified to address such issues. Consequently, I find that the evidence of the four expert witnesses is admissible for the purposes of this proceeding. Weight to be afforded the expert evidence will depend on opinions proffered by the experts on the issues raised.
7. The Prior Art
31 I have carefully reviewed the prior art tendered in evidence by the parties including the prior art annexed to the notice of allegation.
8. The Patent in Suit
32 The '071 Patent was issued on October 17, 2000, on the basis of the application filed on April 27, 1995. The application claimed priority from U.S. Patent Application no. 08/235,069 filed April 29, 1994. The '071 Patent contains 33 claims. Since the application for the patent was filed in Canada after October 1, 1989, and before October 1, 1996, the Patent Act applicable to applications filed in that time period is applicable here.
33 The '071 Patent pertains to various forms of azithromycin: tablets, unit dose packets, suspension, powder, oral suspension. The '071 Patent does not, however, pertain to capsules which are explicitly excluded from the patent. The specification provides as follows at page 4 of the summary of the Invention: "Capsules as a dosage form do not form a part of the invention."
34 The '071 Patent discloses, inter alia, the invention of a tablet composed of azithromycin, a disintegrant and optional excipients such as binders, flavours, fillers, diluents, lubricants, glidants or colours which do not exhibit an adverse food effect when administered to a fed patient.
9. The Notice of Allegation
35 Novopharm sent Pfizer its notice of allegation dated November 4, 2003. It informed Pfizer that it intended to make, construct, use and/or sell an azithromycin monohydrate 250 mg strength tablet for oral administration. The notice of allegation contains the following two allegations:
(1) The first allegation made pursuant to subparagraph 5(1)(b)(iii) of the Regulations states that a claim in the '071 Patent, more specifically claim 23, is invalid on the grounds of anticipation, obviousness, over breadth and indefiniteness. Novopharm frames the allegations as follows:
Claim 23 of the '071 Patent is not valid. Claim 23 is relevant to the Novopharm Tablet and is invalid for the following reasons :
a) the claim is anticipated;
b) the claim is obvious;
c) the claim is broader than the invention made and disclosed; and
d) the claim is indefinite under subsection 27(4).
(2) The second allegation, made pursuant to subparagraph 5(1)(b)(iv) of the Regulations, states that the tablet claims will not be infringed. Novopharm frames this allegation as follows:
Claims 1, 2, 9, 10, 17, 18, 24-28 of the '071 Patent will not be infringed by the making, constructing, using or selling by Novopharm of the Novopharm Tablet.
36 The Court notes that the adequacy of these allegations is not contested by Pfizer. Consequently, the adequacy of the notice of allegation is not an issue for the Court to consider in the present proceeding.
10. The Issues
37 The fundamental question that must be answered is whether the Court should grant an order prohibiting the Minister from issuing Novopharm a notice of compliance until after the expiration of Pfizer's '071 Patent.
38 For this determination to be made, the following issues arise and must be answered:
1) Whether the allegations of non-infringement raised in Novopharm's notice of allegation are justified?
2) Whether the allegations of invalidity raised in Novopharm's notice of allegation are justified?
11. The Analysis
A. Claims Construction
(1) Principles of Patent Claims Construction
39 The first step before reaching a determination with respect to Novopharm's allegations of non-infringement and invalidity is to construe the relevant claims of the '071 Patent in order to identify "what the inventor considered to be the 'essential' elements of his invention": Whirlpool Corp. v. Camco Inc., [2000] 2 S.C.R. 1067.
40 Subsection 27(3) of the Patent Act provides what must be found in the specification of an invention.
27. Specification
(3) The specification of an invention must
(a) correctly and fully describe the invention and its operation or use as contemplated by the inventor;
(b) set out clearly the various steps in a process, or the method of constructing, making, compounding or using a machine, manufacture or composition of matter, in such full, clear, concise and exact terms as to enable any person skilled in the art or science to which it pertains, or with which it is most closely connected, to make, construct, compound or use it;
(c) in the case of a machine, explain the principle of the machine and the best mode in which the inventor has contemplated the application of that principle; and
(d) in the case of a process, explain the necessary sequence, if any, of the various steps, so as to distinguish the invention from other inventions.
27. Mémoire descriptif
(3) Le mémoire descriptif doit :
a) décrire d'une façon exacte et complète l'invention et son application ou exploitation, telles que les a conçues son inventeur;
b) exposer clairement les diverses phases d'un procédé, ou le mode de construction, de confection, de composition ou d'utilisation d'une machine, d'un objet manufacturé ou d'un composé de matières, dans des termes complets, clairs, concis et exacts qui permettent à toute personne versée dans l'art ou la science dont relève l'invention, ou dans l'art ou la science qui s'en rapproche le plus, de confectionner, construire, composer ou utiliser l'invention;
c) s'il s'agit d'une machine, en expliquer clairement le principe et la meilleure manière dont son inventeur en a conçu l'application;
d) s'il s'agit d'un procédé, expliquer la suite nécessaire, le cas échéant, des diverses phases du procédé, de façon à distinguer l'invention en cause d'autres inventions.
41 Subsection 27(4) of the Patent Act explains the role of the claims, which are found at the end of the specification.
27. Claims
(4) The specification must 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.
27. Revendications
(4) Le mémoire descriptif se termine par une ou plusieurs revendications définissant distinctement et en des termes explicites l'objet de l'invention dont le demandeur revendique la propriété ou le privilège exclusif.
42 The patent specification is made up of the disclosure and the claims. The patent disclosure may include the title of the invention, a full description of the invention to enable a person reasonably skilled in the art to put the invention into practice, drawings, and at the end, the claims which are a distinct and explicit statement of the invention claimed. The disclosure must also set forth a detailed description of the preferred embodiments of an invention. The disclosure must describe the characteristics of the invention defined in the claims. The claim or claims must define distinctly and in explicit terms the subject matter of the invention for which an exclusive property or privilege is claimed. In essence, the disclosure describes the invention and the claims define its scope.
43 Patent construction aims at defining the purpose of the invention; it is a "purposive construction": Free World Trust v. Electro Santé Inc., [2000] 2 S.C.R. 1024. The objective of the purposive construction of the claims is to reach an interpretation of the patent claims that is "reasonable and fair to both patentee and public", as set out by Dickson J. in Consolboard Inc. v. MacMillan Bloedel (Saskatchewan) Ltd., [1981] 1 S.C.R. 504:
We must look to the whole of the disclosure and the claims to ascertain the nature of the invention and methods of its performance, (Noranda Mines Limited v. Minerals Separation North American Corporation, [1950] S.C.R. 36), being neither benevolent nor harsh, but rather seeking a construction which is reasonable and fair to both patentee and public. There is no occasion for being too astute or technical in the matter of objections to either title or specification for, as Duff C.J.C. said, given the judgment of the Court in Western Electric Company, Incorporated, and Northern Electric Company v. Baldwin International Radio of Canada, [1934] S.C.R. 570, at p. 574, "where the language of the specification, upon a reasonable view of it, can be so read as to afford the inventor protection for that which he has actually in good faith invented, the court, as a rule, will endeavour to give effect to that construction."
44 The Supreme Court of Canada in Whirlpool, supra, and Free World Trust, supra, established that, in adopting a purposive approach to interpret a claim, the Court should stay within the four corners of the specification and limit itself to the words of the claim interpreted in the context of the specification as a whole, avoiding the use of extrinsic evidence of intent: GlaxoSmithKline Inc. v. Apotex Inc. (2003), 234 F.T.R. 251; (2003), 27 C.P.R. (4th) 114. Expert evidence is admissible, but only to assist the Court so it is able to interpret the patent claims in a knowledgeable way: Whirlpool, supra.
45 The claims are the starting point of patent construction and are directed to the person skilled in the art and are to be purposively construed based on the whole specification at the date of the publication of the application of the patent. Purposive construction of the claims requires that they be interpreted in light of the whole of the disclosure, including the specifications: Schmeiser v. Monsanto Canada Inc., [2004] 1 S.C.R. 902, at paragraph 18. Recourse to the rest of the specification is not necessary where the words to be construed in the claim are plain and unambiguous. It will also be improper where it is used to vary the scope of the claim: Canamould Extrusions Ltd. v. Driangle Inc., 2004 FCA 63; [2004] F.C.J. No. 266 (QL).
46 The underlying objective of claims' construction, is to determine the purpose of the invention in order to give the inventor protection for what he actually invented: Western Electric Co. v. Baldwin International Radio of Canada, [1934] S.C.R. 570 at page 574. In accomplishing this task, the Court must distinguish the essential and the non-essential elements of the invention. For an element to be considered non-essential, it must be shown either that it was clearly not intended to be essential or that, at the date of publication of the patent, the skilled addressee would have appreciated that a particular element could be substituted or omitted without affecting the working of the invention: Free World Trust, supra, at paragraph 55. Perhaps the simplest expression of the way to determine what constitutes a non-essential element was established by Justice Denault in Martinray Industries Ltd. v. Fabricants National Dagendor Manufacturing Ltd. [1991] 49 F.T.R. 81; (1991), 41 C.P.R. (3d) 1, when he wrote:
In short, each component of a claim will be regarded as essential unless it is clear to one skilled in the art that the inventor knew that the failure to comply with this specific component would have no effect on the way the invention worked.
47 Claims construction is a task lying in the exclusive domain of the judge: Fournier Pharma, supra. Claims will receive one and the same interpretation for all purposes, i.e. invalidity and infringement allegations: Whirlpool, supra.
48 In Free World Trust, supra, at paragraph 31, Justice Binnie, for the Supreme Court of Canada, provided a list of principles that guide the purposive approach to the construction of a claim:
1) The Patent Act promotes adherence to the language of the claims.
2) Adherence to the language of the claims in turn promotes both fairness and predictability.
3) The claims must be construed in an informed and purposive way.
4) The language of the claims thus construed defines the monopoly. There is no recourse to such vague notions as the "spirit of the invention" to expand it further.
5) The claims language will, on a purposive construction, show that some elements of the claimed invention are essential while others are non-essential. This allocation will be made in the following manner :
a) on the basis of the common knowledge of the worker skilled in the art to which the patent relates;
b) what constitutes an "essential" element is to be interpreted in light of the knowledge of the art at the date of the publication of the patent specification;
c) regard is to be had to whether it was obvious at the time the patent was published that substitution of a different variant would make a difference to the way in which the invention works;
d) according to the intent of the inventor expressed or inferred from the claims of the patent;
e) without, however, resort to extrinsic evidence of the inventor's intention.
(2) Claims at Issue
49 There are 33 claims in the '071 Patent. The claims at issue in the present case are claim 23 and the "tablet claims".
50 Claim 23 reads as follows:
Use of a therapeutically effective amount of azithromycin for the preparation of a pharmaceutical dosage form which does not exhibit an adverse food effect for administration, in the treatment of antimicrobial infection, to a patient that has eaten
51 The tablet claims read as follows:
1. An oral dosage form of azithromycin in the form of a tablet made by wet granulation and administrable to a mammal that has eaten, which comprises azithromycin and a disintegrant and which exhibits substantially no adverse food effect, the dosage form effecting at least about 90% dissolution of azithromycin within about 90 minutes when an amount of the dosage form equivalent to 200 mg of azithromycin is tested as set forth in USP test < 711 > in a USP-2 dissolution apparatus under conditions at least as stringent as the following : 900 ml sodium phosphate buffer, pH 6.0, 37oC, with paddles turning at 100 rpm, provided that the dosage form contains less than a taste-masking amount of an alkaline earth metal oxide or hydroxide.
2. A dosage form as defined in claim 1, wherein the mammal is a human.
9. An oral dosage form of azithromycin in the form of a tablet made by wet granulation and administrable to a mammal that has eaten, which comprises azithromycin and a disintegrant and which exhibits substantially no adverse food effect, the dosage form exhibiting a value of (AUC fed) / (AUC fst) of at least 0.80 with a lower 90% confidence limit of at least 0.75, provided that the dosage form contains less than a taste-masking amount of an alkaline earth metal oxide or hydroxide.
10. A dosage form as defined in claim 9, wherein the mammal is a human.
17. A therapeutic package, comprising a container, an oral dosage form of azithromycin which is defined in any one of claims 1 to 16 contained therein, and, associated with the package, written matter non-limited as to whether the dosage form can be taken with or without food.
18. A therapeutic package as defined in claim 17, wherein the dosage form is in the form of a tablet.
24. A tablet of azithromycin for administration to a human patient that has or has not eaten food, which comprises:
azithromycin in an amount of from 25 mg to 3 g,
a disintegrant in an amount of from 1 to 25% by weight based on the total tablet, and
at least one pharmaceutically acceptable excipient,
provided that the tablet contains no or less than a taste-masking amount of an alkaline earth metal or hydroxide,
wherein the tablet exhibits substantially no adverse food effect and exhibits a value of (AUC fed) / (AUC fst) of 0.80 to 1.25 with a lower 90% confidence limit of 0.75 to 1.40 and is made by wet granulation.
25. A tablet defined in claim 24, which contains at least one member selected from the group consisting of sodium croscarmellose, sodium starch glycolate, microcrystalline cellulose and cross-linked polyvinylpyrrolidone in an amount of 3 to 15% by weight based on the total weight of the tablet as the disintegrant.
26. A tablet as defined in claim 25, which contains sodium croscarmellose and pregelatinized starch as the disintegrants.
27. A tablet as defined in any one of claims 22 to 26, which is coated with a film of hydroxypropylmethylcellulose, hydroxypropylcellulose or acrylate-methacrylate copolymer.
28. A therapeutic package for commercial sale, comprising a container, the table as defined in any one of claims 24 to 27, contained therein, and, associated with the package, a written message that the tablet can be taken with or without food.
(3) Parties' Proposed Construction
52 The parties' submissions in respect of the essential elements of the invention are made only in respect of claim 23 of the '071 Patent. The Applicants argue that claim 23 "reflects the use aspect of the invention embodied in the '071 Patent". They maintain that claim 23 provides a new use, namely the use of orally administered azithromycin that does not exhibit an adverse food effect to treat a microbial infection in a patient that has eaten. Pfizer's expert, Dr. Rapp, at paragraph 46 of his affidavit attests "... that claim 23 relates to pharmaceutical formulation that does not exhibit a food effect, or, more particularly, the use of a dosage form of azithromycin to treat a microbial infection in a patient that has eaten". At paragraph 37 of his affidavit, Dr. Andriole, also Pfizer's expert, reads claim 23 "... as claiming the use of a preparation of azithromycin that is not affected by food in the treatment of a microbial infection to a patient that has eaten." The Applicant therefore contends that the essential elements of claim 23 are the following: (1) the oral administration of a dosage form of azithromycin; (2) to treat a microbial infection; (3) where the oral dosage form does not exhibit a food effect in a patient who has eaten.
53 The Respondent states that the invention encompassed in the '071 Patent, and of which claim 23 represents but one aspect, is to administer a rapidly disintegrating dosage form of azithromycin in order to overcome the adverse food effect observed with capsules. Both of the Respondent's experts attest that the terms "adverse food effect" and "a patient that has eaten" are defined in the patent. Both experts agree that "pharmaceutical dosage form" should be read to encompass all dosage forms, not only oral dosage forms. The Respondent therefore contends that the essential elements of claim 23 are the following: (1) use of a therapeutically effective amount of azithromycin; (2) to make a pharmaceutical dosage form that does not exhibit an adverse food effect; (3) for administration to a patient that has eaten; and (4) to treat a microbial infection.
(4) Court's Construction
54 As a preliminary matter, it is noted that claim 23 erroneously refers to an "antimicrobial" infection. Both parties accept that the intended reference in claim 23 is to a "microbial" infection. It is agreed that the error is of no consequence to the within application.
55 With respect to the purpose of the invention disclosed in the '071 Patent, the background of the invention and detailed summary explain, as Pfizer suggests, that the adverse food effect encountered with azithromycin capsules posed a problem in the treatment of patients due to the fact that it had to be taken in the fasted state. Accordingly, the '071 Patent states that it would be useful if azithromycin could be administered to patients that have eaten. The solution to this problem is taught by the '071 Patent.
56 After reviewing the claims and the whole of the disclosure, and after considering the expert evidence in order to assist the Court to interpret the patent in a knowledgeable way, I find that the essential elements of the invention disclosed by the claims at issue of the '071 Patent include at least the following:
(1) an oral pharmaceutical dosage form;
(2) containing a therapeutically effective amount of azithromycin;
(3) which w