Pfizer Canada Inc. v. Canada (Minister of Health)

Pfizer Canada Inc. v. Canada (Minister of Health)
Court (s) Database
Federal Court Decisions
Date
2005-12-20
Neutral citation
2005 FC 1725
File numbers
T-1142-04
Notes
Digest
Decision Content
Date: 20051220
Docket: T-1142-04
Citation: 2005 FC 1725
BETWEEN:
PFIZER CANADA INC. and PHARMACIA ITALIA S.p.A.
Applicants
and
THE MINISTER OF HEALTH
and MAYNE PHARMA (CANADA) INC.
Respondents
REASONS FOR ORDER
HUGHES J.
[1] This is an application made under the provisions of the Patented Medicines (Notice of Compliance) Regulations SOR/93-133 as amended (the NOC Regulations). The Applicants Pfizer Canada Inc. and Pharmacia Italia S.p.A. (Pfizer) seek to the prohibit the Minister of Health (Minister) from issuing a Notice of Compliance under the Food and Drug Regulations to Mayne Pharma (Canada) Inc. (Mayne) in respect of its proposed injectable ready-to-use Epirubicin Hydrochloride solution in a strength of 2mg/ml (Mayne Product) until the expiry of Canadian Patent 1,291,037 ('037 Patent). Pfizer also seeks a declaration that Mayne did not serve a proper notice of allegation as required by the NOC Regulations, costs and other relief.
[2] The '037 patent was issued and granted by the Canadian Patent Office on October 22, 1991 from an application filed in Canada on June 27, 1986. As such the '037 Patent falls to be considered under the "old" provisions of the Patent Act, R.C.S. 1989, c.P.4 as they pertain to patents granted in respect of applications filed in Canada before October 1, 1989. This patent is concerned with injectable solutions used to treat tumours. It contains 116 claims which can be divided into three categories 1) product claims directed to ready-to-use solutions; 2) process claims directed to the making of such solutions; and 3) use claims directed to the use of such solutions. Of the product claims, claims 1 (and dependent claims 2-11), 12 (and dependent claims 13-22), 60 (and dependent claims 61-68), 69 (and dependent claims 70-88) and 98 (and dependent claims 99-105 and 115) are at issue. Of the use claims, claims 47 and 59 are at issue. By reason of the nature of the NOC Regulations, no process claims are at issue.
[3] The Applicants Pfizer are "first parties" as defined by the NOC Regulations. There is no dispute that the '037 patent has been properly listed in accordance with those Regulations.
[4] The Respondent Mayne is a "second party" as defined in the NOC Regulations. Mayne has, in its letter of allegation, stated that it is seeking a Notice of Compliance under the Food and Drug Regulations from the Minister for Epirubicin Hydrochloride Injection Ph. Eur. having a strength per dosage unit of 2 mg/ml (Mayne Product). Mayne alleges that no claim of the '037 patent will be infringed by the Mayne Product, the process for its manufacture and its route of administration for use. The letter of allegation states as follows:
3. The Mayne Product that is subject of the abbreviated new drug submission which has been filed and is pending with the Minister of Health, is formulated as a ready to use injectable solution in a single dose, sealed vial (10 mg/5ml, 50 mg/ml, 200 mg/ml). The Mayne Product comprises the following ingredients: the active pharmaceutical ingredient (API) Epirubicin Hydrochloride [which has been reconstituted from lyophilized Epirubicin Hydrochloride (Ph. Eur.) manufactured and supplied to Mayne by a third party]; Water for Injection (Ph. Eur.); Sodium Chloride (Ph. Eur.); and Hydrochloric Acid (Ph. Eur.) [for pH adjustment within the range 2.5 to 4.0, if necessary]. Nitrogen (Ph. Eur) is present to deoxygenate the Water for Injection and to provide an inert headspace within the vial.
4. The Mayne Product will be manufactured by Mayne's Australian parent (Mayne Pharma Pry.) using the following process:
(a) 65% of the required volume of Water for Injection (Ph. Eur) is added to a mixing vessel and purged with Nitrogen (Ph. Eur) fro 15 minutes. [Solution A]
(b) A slurry of Epirubicin Hydrochloride is prepared by reconstituting lyophilized Epirubicin Hydrochloride (Ph. Eur) with Water for Injection (Ph. Eur) to form a slurry. The slurry is added to the Solution A described above while stirring. The solution is mixed for 30 minutes.
(c) 10% of the required volume of Water for Injection (Ph. Eur) is added to a second mixing vessel and purged with Nitrogen (Ph. Eur) for 15 minutes. Sodium chloride (Ph. Eur) is added to the Water for Injection (Ph. Eur) while stirring. The solution is mixed for 10 minutes [Solution B] Potency of the solution may be checked and the addition of Water forInjection may be adjusted, as necessary.
(d) Solution B is added to Solution A and stirred for 10 minutes. The pH of the resultant bulk solution is checked and adjusted, if necessary, to a target range of 2.8 to 3.0 with Hydrochloric Acid, (Ph. Eur).
(e) Thereafter, the volume of the bulk solution is progressively adjusted to 100% of the volume necessary for an epirubicin hydrochloride drug concentration of 2 mg/ml with addition of Water for Injection (Ph. Eur). The pH of the solution is checked and, if necessary, the pH of the solution is adjusted to the target range of 2.8 to 3.0 with Hydrochloric Acid (Ph. Eur).
(f) The solution is then passed through a sterilizing filter, and aseptically dispensed into sterile, glass vials under a nitrogen atmosphere. The vials are then stoppered and sealed.
5. The route of administration for the Mayne Product is intravenous.
[5] Pfizer does not dispute the accuracy of these representations.
[6] The only issue in these proceedings is that of infringement, validity of the '037 patent is not challenged. The issue of infringement turns on a question of construction of the claims and in particular, to what does the phrase "not reconstituted from a lyophilizate" refer in construing the claims. In this regard it is sufficient, for illustration, to refer to claim 1, a broad product claim, and claim 47 a broad use claim.
1. An injectable, ready-to-use, sterile, pyrogen-free, anthracycline glycoside solution which consists essentially of a physiologically acceptable salt of an anthracycline glycoside dissolved in a physiologically acceptable aqueous solvent therefore at an anthracycline glycoside concentration of from 0.1 to 50 mg/ml, which has not been reconstituted from a lyophilizate and the pH of which has been adjusted to from 2.5 to 5.0 solely with a physiologically acceptable acid.
***
47. Use of an injectable, ready-to-use, sterile pyrogen-free solution as defined in claim 1 to inhibit the growth of a tumour selected from sarcomas, carcinomas, lymphomas, neuroblastoms, melanoma, mycloma, leukemias and wilms tumour.
[7] The other claims at issue differ in detail, which detail is not material to the issue before this Court. I accept those differences as enumerated in the Beijnen affidavit filed herein at paragraphs 29 to 33 and 35.
29. Claim 12 claims the same solution as in claim 1, except that the pH of the solution is adjusted with a physiologically acceptable acid selected from a group that includes hydrochloric acid.
***
30. Claim 60 claims a solution which is the same as the solution in claim 1, except that it is storage stable and has a narrower pH range.
***
31. Claim 69 claims a solution which is the same as the solution in claim 12, except that it is storage stable and has a narrower pH range.
***
32. Claim 98 claims a solution which is the same as the solution in claim 69, except that the pH of the solution has been adjusted from 2.5 to 3.5 solely with a glycine buffer.
33. There are also various dependent solution claims, which include the following:
(a) an anthracycline glycoside salt solution in a sealed container (claims 2, 13, 61, 70 and 99);
(b) a solution of an epirubicin salt (claims 3, 14, 62, 71 and 100);
(c) a solution of an epirubicin salt in a sealed container (claims 63, 72 and 101);
(d) a solution of epirubicin hydrochloride (claims 4, 15, 64 and 73);
(e) an anthracycline glycoside salt solution having a pH of from 2.62 to 3.14 (claims 5 and 16), or from 2.6 to 3.5 (claims 65 and 74) or of about 3 (claims 6, 17 and 102); and
(f) a solution in which the concentrations of the anthracycline glycoside is from 1 mg/ml to 20 mg/ml (claims 9, 20, 68, 77 and 105).
***
35. Claims 47 and 59 of the '037 Patent are the use claims. They cover the use of the solutions described in solution claims 1 and 12. The use claims read as follows:
Use of an injectable, ready-to-use, sterile, pyrogen-free solution as defined in claim (1 or 12, in claims 47 and 59 respectively) to inhibit the growth of a tumour selected from sarcomas, carcinomas, lymphomas, neuroblastoma, melanoma, myeloma, leukaemias and Wilms tumour.
[8] The process claims are not at issue in these proceedings. The NOC Regulations do not extend to processes. However claim 36, the broadest of the process claims, should be noted. It reads:
36. A process for producing an injectable, ready-to-use, sterile, pyrogen-free, anthracycline glycoside solution which consists essentially of a physiologically acceptable salt of an anthracycline glycoside dissolved in a physiologically acceptable aqueous solvent therefore, which has not been reconstituted from a lyophilizate and which has a pH of from 2.5 to 5.0, which process comprises dissolving the said physiologically acceptable salt, which salt is not in the form of a lyophilizate, in the said solvent at an anthracycline glycoside concentration of from 0.1 to 50 mg/ml; adding solely a physiologically acceptable acid to adjust the pH to from 2.5 to 5.0 as desired and passing the resulting solution through a sterilising filter.
[9] The other process claims are directed to narrowing parameters similar to the solution claims.
[10] The issue in this proceeding is one of construction of the claims. The answer as to infringement will be apparent once the claims are construed. Construction is a matter for the Court alone, to be done before consideration is given to issues of infringement or validity, it is not to be "results oriented", one and the same interpretation applies to validity and infringement issues (Whirlpool Corp. v. Camco Inc, [2000] 2 S.C.R. 1067 at paras. 43 and 49(a) and (b)). Onus does not come into play at the construction stage of a patent proceeding.
[11] For the purposes of the construction issue in this proceeding the claims can be divested of their more technical terms and presented more simply. One of the more technical terms is that of lyophilization which, in everyday terms can be expressed as freeze drying. A benefit of such freeze drying is that it enhances the shelf life of the product. A detriment is that it must be reconstituted, by mixing with a suitable solvent, before use.
Solution Claims:
An injectable, ready-to-use solution which consists essentially of a salt of the active ingredient dissolved in an acceptable solvent at a given range of concentration, which has not been reconstituted from a lyophilizate and the pH of which has been adjusted to a certain range solely with an acceptable acid
Use claims:
Use of an injectable, ready-to-use solution to inhibit the growth of certain tumours.
Process Claims(not at issue in this NOC proceeding):
A process for producing an injectable, ready-to-use solution as described in the solution claims, comprising dissolving the salt, which salt is not in the form of a lyophilizate in the solvent to a certain concentration; adding solely an acceptable acid to adjust the pH to a certain range and filtering.
[12] Pfizer argues that the words "not reconstituted from a lyophilizate" in the solution claims and, by implication in the use claims, refer to the final product as it is presented to the medical professional for administration to a patent. Mayne on the other hand argues that those words refer to the salt of the active ingredient anthracycline glycoside. Given Pfizer's construction the Mayne Product and its use, would infringe the claim at issue; given Mayne's construction, they would not.
[13] The Court is aware that these issues have already been litigated by the parties or entities related to them, in the United Kingdom and Australia. Those decisions can be located at:
UK - Mayne Pharma Pty Ltd. v. Pharma Italia SpA, [2004] EWHC 2458 (Ch.) a decision dated 1 November 2004, by Wyand Q.C. a Deputy Judge which was reversed by the Court of Appeal in [2005] EWCA Civ 317, on February 1, 2005, judgment for that Court given by Jacob L.J. Leave to appeal in the House of Lords was refused.
Australia - Pharmacia Italia SpA v. Mayne Pharma Pty Ltd, [2005] F.C.A. 1078 and [2005] F.C.A. 1675. Decisions of the Federal Court of Australia. No appeal has been taken from these decisions, and, I am informed, none is now possible.
[14] These decisions are not binding upon this Court.
[15] This case rests simply on the question of claim construction. For that purpose I propose to examine, briefly, the history of claim construction in Canada and the United Kingdom. Then I will address the principals to be applied in construing a claim as instructed by the Supreme Court of Canada in Whirlpool (Whirlpool Corp. v. Camco Inc. [2000] 2 S.C.R. 1067) and Free World (Free World Trust v. Electro Santé Inc. [2000] 2 S.C.R. 1024). Then I propose to construe the claims at issue.
The History of Claim Construction
[16] In the earliest of days in patent history, a patent did not contain claims as we know them. A patent may have ended with a phrase such as "A device substantially as described herein". A good summary was given by Blanco White in "Patents for Inventions", 4th ed, London, Stevens & Sons 1979 at paragraph 1-305:
Origin and growth of claims
In such circumstances there was not room for the modern system of patent claims. The patentee quite often did, during the nineteenth century, end his specification with an indication of the features of his invention he considered new and important ("and what I claim is the levers x and y, co-operating with the wheel b and rod c," or something like that)-much as the proprietor of a design today makes a statement of the features of novelty claimed for his design. It was not until the 1883 Act that the inclusion of claims was compulsory, and it was not until the transfer of the key jurisdiction in patent actions from the jury of a court of common law to the Court of Chancery and the Chancery Division had resulted in the growth of rules for determining how to construe a principle of operation out of the description of a machine that we find claims in the modern sense growing up. For the essence of modern claim is that the patentee no longer leaves it to the jury to determine the scope of his invention, but tries to set this out for himself in his claims. By now it is a commonplace that this is precisely what claims are for, but it was not a commonplace seventy years ago; it was not even clear law that claims had that effect, until the famous decisions in Nobel v. Anderson in 1894 made it so. Nor until the second decade of the present century was it clear that a patentee who wished to cover the principle of operation of his machine, and not only the details of its construction, must say so in his claims and not just leave it to the jury. Thus it is hardly necessary to go back more than fifty years in the Reports of Patent Cases to find the distinction between the invention claimed and the preferred embodiment of it described in detail in the specification, which is so fundamental to present-day ideas, either not drawn at all or drawn only in vague and ambiguous terms. Since a judicial decision does not lose its authority by becoming obsolete-rather it gains in sanctity-the law is still bedevilled by authoritative judgments delivered before the days of claims.
[17] The bedevilling of the law by the ghosts of these earlier, pre-claim, cases is evident in the cri de coeur of Lord Loreburn in Natural Colour Kinematograph Co. Ltd. v. Bioschemes Ltd, (1915) 32 R.P.C. 256 (H.L.) at page 266 where he speaks of counsel shaping and re-shaping a claim with references to the specification and other evidence:
I wish to add that, quite apart from these grounds, I think this Patent is bad from ambiguity in the Specification. There seems to be some danger of the well known rule of law against ambiguity being in practice invaded. Some of those who draft Specifications and Claims are apt to treat this industry as a trial of skill, in which the object is to make the Claim very wide upon one interpretation of it, in order to prevent as many people as possible from competing with the patentee's business and then to rely upon carefully prepared sentences in the Specification which, it is hoped, will be just enough to limit the Claim within safe dimensions if it is attacked in Court. This leads to litigation as to the construction of Specifications, which could generally be avoided if at the outset a sincere attempt were made to state exactly what was meant in plain language. The fear of a costly law suit is apt to deter any but wealthy competitors from contesting a Patent. This is all wrong. It is an abuse which a Court can prevent, whether a charge of ambiguity is or is not raised on the Pleadings, because it affects the public by practically enlarging the monopoly, and does so by a kind of pressure which is very objectionable. It is the duty of patentee to state clearly and distinctly, either in direct words or by clear and distinct reference, the nature and limits of what he claims. If he uses language which, when fairly read, is avoidably obscure or ambiguous, the Patent is invalid, whether the defect be due to design, or to carelessness or to want of skill. Where the invention is difficult to explain, due allowance will, of course, be made for any resulting difficulty in the language. But nothing can excuse the use of ambiguous language when simple language can easily be employed, and the only safe way is for the patentee to do his best to be clear and intelligible. It is necessary to emphasize this warning. To my mind, this is a very plain case of offence against the rule to which I have referred. I cannot see what purpose there could have been using the roundabout language here employed, which has provoked so much argumentative subtlety and taken up so much time, unless the object was to hold in reserve a variety of constructions for use if the Patent should be called in question, and in the meantime to frighten off those who might be disposed to challenge the Patent.
[18] The same sentiment was expressed by the United States Supreme Court in the 'nose of wax" case, White v. Dunbar, 119 US 47 (1886) per Bradley J. at pp 51-52 as cited by the Supreme Court of Canada in the Whirlpool case, supra, at paragraph 51:
Some persons seem to suppose that a claim in a patent is like a nose of wax which may be turned and twisted in any direction, by merely referring to the specification, so as to make it include something more than, or something different from, what its words express... . The claim is a statutory requirement, prescribed for the very purpose of making the patentee define precisely what his invention is; and it is unjust to the public, as well as an evasion of the law, to construe it in a manner different from the plain import of its terms.
a) In Canada
[19] As matters developed in Canada, the Court would not, typically, first attempt to construe a claim, rather, it would go first to either validity or infringement and apply what was described as a "literal" reading of the claim. If the claim survived validity on a "literal" reading, then infringement would be considered "literally" and if there was no such infringement, then a second look at the claims on the basis of the "substance" was taken, as infringement was considered either literally or in substance. A good example of this practice in Kramer v. Lawn Furniture Inc. (1974), 13 C.P.R. (2nd) 231 a decision of Addy J. of the Federal Court. At pages 235 and 236 he found the patent to be valid without any discussion as to how the claim was to be construed. He then turned to infringement at page 237 and gave a classic statement as to claim interpretation:
The claims should be interpreted by reading them and applying common vocabulary of the art to the wording of the claim. They should be interpreted as if read by a person who is possessed of all the technical knowledge required to fully understand the terms used and the principles involved. The specifications and drawings should be read as a whole to provide background to assist in the interpretation of the claim or to supply the vocabulary necessary for the interpretation of the claim but should not be used to vary or enlarge the claims, except in so far as the vocabulary, as supplied by the specifications, reasonably and fairly provides for such a variation or enlargement. As has been often stated, the patentee may act as his own lexicographer.
[20] Having given that statement, he said at page 238:
In the light of these general principles, the text of the claims of the plaintiffs' two patents must be examined to see, first, if there has been a literal infringement of the patents as expressed in the claims and, if not, then whether there has nevertheless been a true infringement of the substance of the inventions.
[21] He then examined infringement on a "literal" interpretation of the claims and, finding none, embarked on a consideration of the "substance" of the claim. At page 239 he said:
Although there is no literal infringement, the Court must also determine whether the variations are minor ones and whether the alleged infringer has in fact taken the substance of the invention, refer Omark Industries (1960) Ltd. v. Gouger Saw Chain Co. et al., supra; whether the object under attack is but a colourable imitation of the invention, refer Fox's Canadian Law and Practice Relating to Letters Patent for Inventions, 4th ed. (1972), at pp. 364-9 and whether the defendant has in effect taken what has been described in the cases as the pith and marrow of the patent or invention.,
[22] The "two step" approach respecting infringement was conflated to one by the Federal Court of Appeal in the Mobil Oil case (Mobil Oil Corp. v. Hercules Canada Inc (1995), 63 C.P.R. (3rd) 473) where Marceau J. for the Court said at page 488:
The established law in Canada, as stated long ago by Thorson P. in McPhar Engineering Co. v. Sharpe Instruments Ltd. (1960), 35 C.P.R. 105, [1956-60] Ex. C.R. 447, 21 Fox Pat. C. 1 (Ex. Ct.), is "that if a person takes the substance of an invention he is guilty of infringement and it does not matter whether be omits a feature that is not essential to it or substitutes an equivalent for it". That being the case, I do not appreciate the utility of the traditional twofold test and even its relevance. No doubt a textual infringement will simplify the problem as it will put an immediate end to the inquiry. But it seems to me that the exercise may be useless in cases like this one where the distinction between textual and substantial infringement may be difficult to draw.
[23] As an "outlier" to the main stream of thought, there are a few cases, notable of which is Schweyer Electric and Mfg Co. v. New York Central Railroad Co. [1935] S.C.R. 665 where the Supreme Court took claims directed to electrically operated railroad signal devices without reference to whether or not alternating current was to be used and, by reading the specification found that the claims "inevitably" meant alternating current. Per Duff C.J. for the Court at 669:
In construing these claims they must be read with reference to the earlier part of the specification and, so reading them, it seems to me the conclusion is inevitable -- I am convinced this is not putting it too strongly -- that, as regards the devices in the apparatus on the vehicle which respond to the "caution" and "danger" signals, these claims do not contemplate a system which could be effectively worked without the use of alternating current circuits. In that view, since the respondents employ direct current circuits alone, no infringement is established.
b) In the United Kingdom
[24] Claim construction has come to its current state in the United Kingdom in two cases. The first, Catnic (Catnic Components Limited v. Hill and South Limited [1982] R.P.C. 183 with the House of Lords decision starting at 239) was reviewed by the Supreme Court of Canada in Whirlpool supra. The second is more recent and after Whirlpool. It is Kirin-Amgen Inc. v. Hoechst Marion Roussel Ltd. a 2004 decision of the House of Lords reported, in Canada, at 331 N.R.1.
[25] Catnic was a breakthrough in that it did away with the two part approach - textual then pith and marrow - and replaced it with one criteria "purposive construction." It should be noted, however, that this was done in the context of an infringement analysis only and, rather than being directed to the claim alone, the House of Lords speaks of an "invention" and a "patent specification". Lord Diplock at pages 242 and 243 says:
My Lords, in their closely reasoned written cases in this House and in the oral argument, both parties to this appeal have tended to treat "textual infringement" and infringement of the "pith and marrow" of an invention as if they were separate causes of action, the existence of the former to be determined as a matter of construction only and of the latter upon some broader principle of colourable evasion. There is, in my view, no such dichotomy; there is but a single cause of action and to treat it otherwise, particularly in cases like that which is the subject of the instant appeal, is liable to lead to confusion.
***
My Lords, a patent specification is a unilateral statement by the patentee, in words of his own choosing, addressed to those likely to have a practical interest in the subject matter of his invention (i.e. "skilled in the art"), by which he informs them what he claims to be the essential features of the new product or process for which the letters patent grant him a monopoly. It is those novel features only that he claims to be essential that constitute the so-called "pith and marrow" of the claim. A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous, verbal analysis in which lawyers are too often tempted by their training to indulge. The question in each case is: whether persons with practical knowledge and experience of the kind of work in which the invention was intended to be used, would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention so that any variant would fall outside the monopoly claimed, even though it could have no material effect upon the way the invention worked.
[26] By the time the Kirin- Amgen decision was made by the House of Lords, the United Kingdomhad adhered to the European protocol respecting patents and article 69 of the protocol became important. It reads:
Article 69
Extent of protection
(1) The extent of the protection conferred by a European patent to a European patent application shall be determined by the terms of the claims. Nevertheless, the description and drawings shall be used to interpret the claims.
(2) For the period up to grant of the European patent, the extent of the protection conferred by the European patent application shall be determined by the latest filed claims contained in the publication under Article 93. However, the European patent as granted or as amended in opposition proceedings shall determine retroactively the protection conferred by the European patent application, insofar as such protection is not thereby extended.
[27] This article, it should be noted, does not differ materially from what has become standard Canadian practice namely, reading the claims in the context of the whole of the specification, a point which the Supreme Court of Canada makes at paragraph 50 of the Whirlpool decision.
[28] In Kirin- Amgen, Lord Hoffman, with whom the other Lords agreed, gave a tour de force as to patent construction which bears repeating here. In brief, he said as to construction that is objective, it is concerned with what a reasonable person, here the reasonable person skilled in the art to which the patent pertains, would have understood the author (inventor) to mean. The question is not what the inventor might have intended but rather what the addressee understands. Lord Hoffman said at paragraphs 32 to 35:
32. Construction, whether of a patent or any other document, is of course not directly concerned with what the author meant to say. There is no window into the mind of the patentee or the author of any other document. Construction is objective in the sense that it is concerned with what a reasonable person to whom the utterance was addressed would have understood the author to be using the words to mean. Notice, however, that it is not, as is sometimes said, "the meaning of the words the author used", but rather what the notional addressee would have understood the author to mean by using those words. The meaning of words is a matter of convention, governed by rules, which can be found in dictionaries and grammars. What the author would have been understood to mean by using those words is not simply a matter of rules. It is highly sensitive to the context of and background to the particular utterance. It depends not only upon the words the author has chosen but also upon the identity of the audience he is taken to have been addressing and the knowledge and assumptions which one attributes to that audience.
***
33. In the case of a patent specification, the notional addressee is the person skilled in the art. He (or, I say once and for all, she) comes to a reading of the specification with common general knowledge of the art. And he reads the specification on the assumption that its purpose is to both to describe and to demarcate an invention - a practical idea which the patentee has had for a new product or process - and not to be a textbook in mathematics or chemistry or a shopping list of chemicals or hardware. It is this insight which lies at the heart of "purposive construction". If Lord Diplock did not invent the expression, he certainly gave it wide currency in the law. But there is, I think, a tendency to regard it as a vague description of some kind of divination which mysteriously penetrates beneath the language of the specification. Lord Diplock was in my opinion being much more specific and his intention was to point out that a person may be taken to mean something different when he uses words for one purpose from what he would be taken to mean if he was using them for another. The example in the Catnic case was the difference between what a person would reasonably be taken to mean by using the word "vertical" in a mathematical theorem and by using it in a claimed definition of a lintel for use in the building trade. The only point on which I would question the otherwise admirable summary of the law on infringement in the judgment of Jacob LJ in Rockwater Ltd v Technip France SA (unreported) [2004] EWCA Civ 381, at paragraph 41, is when he says in sub-paragraph (e) that to be "fair to the patentee" one must use "the widest purpose consistent with his teaching". This, as it seems to me, is to confuse the purpose of the utterance with what it would be understood to mean. The purpose of a patent specification, as I have said, is no more nor less than to communicate the idea of an invention. An appreciation of that purpose is part of the material which one uses to ascertain the meaning. But purpose and meaning are different. If, when speaking of the widest purpose, Jacob LJ meant the widest meaning, I would respectfully disagree. There is no presumption about the width of the claims. A patent may, for one reason or another, claim less than it teaches or enables.
34. "Purposive construction" does not mean that one is extending or going beyond the definition of the technical matter for which the patentee seeks protection in the claims. The question is always what the person skilled in the art would have understood the patentee to be using the language of the claim to mean. And for this purpose, the language he has chosen is usually of critical importance. The conventions of word meaning and syntax enable us to express our meanings with great accuracy and subtlety and the skilled man will ordinarily assume that the patentee has chosen his language accordingly. As a number of judges have pointed out, the specification is a unilateral document in words of the patentee's own choosing. Furthermore, the words will usually have been chosen upon skilled advice. The specification is not a document inter rusticos for which broad allowances must be made. On the other hand, it must be recognised that the patentee is trying to describe something which, at any rate in his opinion, is new; which has not existed before and of which there may be no generally accepted definition. There will be occasions upon which it will be obvious to the skilled man that the patentee must in some respect have departed from conventional use of language or included in his description of the invention some element which he did not mean to be essential. But one would not expect that to happen very often.
35. One of the reasons why it will be unusual for the notional skilled man to conclude, after construing the claim purposively in the context of the specification and drawings, that the patentee must nevertheless have meant something different from what he appears to have meant, is that there are necessarily gaps in our knowledge of the background which led him to express himself in that particular way. The courts of the United Kingdom, the Netherlands and Germanycertainly discourage, if they do not actually prohibit, use of the patent office file in aid of construction. There are good reasons: the meaning of the patent should not change according to whether or not the person skilled in the art has access to the file and in any case life is too short for the limited assistance which it can provide. It is however frequently impossible to know without access, not merely to the file but to the private thoughts of the patentee and his advisors as well, what the reason was for some apparently inexplicable limitation in the extent of the monopoly claimed. One possible explanation is that it does not represent what the patentee really meant to say. But another is that he did mean it, for reasons of his own; such as wanting to avoid arguments with the examiners over enablement or prior art and have his patent granted as soon as possible. This feature of the practical life of a patent agent reduces the scope for a conclusion that the patentee could not have meant what the words appear to be saying. It has been suggested that in the absence of any explanation for a restriction in the extent of protection claimed, it should be presumed that there was some good reason between the patentee and the patent office. I do not think that it is sensible to have presumptions about what people must be taken to have meant but a conclusion that they have departed from conventional usage obviously needs some rational basis.
The Principles of Whirlpool and Free World
[29] The Supreme Court of Canada in Whirlpool and Free World supra, gave landmark decisions respecting Canadian patent law. While preceding Kirin- Amgen by almost four years, these decisions are remarkably in agreement. In its decisions the Supreme Court endorsed the "purposive construction" approach and did away with the "two tiered" approach (Free World paras 45-50, Whirlpool paras 42-50). The Court expressly rejected a "grammatical" or "meticulous verbal analysis" approach (Whirlpool paragraphs 48 and 53).
[30] These two cases, together with Kirin-Amgen provide instruction as to the construction of a claim in a "purposive" manner.
Statutory Basis in Canada
[31] Section 34(2) of the Patent Act R.S.C. 1985, c.P.4 requires that a patent specification and with a claim or claims which "distinctly and in explicit terms" set out the scope of the monopoly claimed. As the Supreme Court in Whirlpool said at paragraph 42:
42 The content of a patent specification is regulated by s. 34 of the Patent Act. The first part is a "disclosure" in which the patentee must describe the [page1089] invention "with sufficiently complete and accurate details as will enable a workman, skilled in the art to which the invention relates, to construct or use that invention when the period of the monopoly has expired": Consolboard Inc. v. MacMillan Bloedel (Sask.) Ltd., [1981] 1 S.C.R. 504, at p. 517. The disclosure is the quid provided by the inventor in exchange for the quo of a 17-year (now 20-year) monopoly on the exploitation of the invention. The monopoly is enforceable by an array of statutory and equitable remedies and it is therefore important for the public to know what is prohibited and where they may safely go while the patent is still in existence. The public notice function is performed by the claims that conclude the specification and must state "distinctly and in explicit terms the things or combinations that the applicant regards as new and in which he claims an exclusive property or privilege" (s. 34(2))". An inventor is not obliged to claim a monopoly on everything new, ingenious and useful disclosed in the specification. The usual rule is that what is not claimed is considered disclaimed.
The Questions to be Addressed in Construing a Claim
[32] When construing the claims, therefore, the following questions may be addressed:
1. Who construes the claims?
2. When are the claims construed?
3. As of what date is the claim to be construed?
4. What are the criteria for construction?
5. What resources may be used for purposes of construction?
6. Through whose eyes is construction to be made?
7. What is to be made of the resulting construction?
1) Who Construes the Claim
[33] The Court construes the claim (Whirlpool at paragraphs 43 and 45).
[34] It is not the function of an expert witness to construe the claim. As the Supreme Court said at paragraph 57 of Whirlpool:
"The role of the expert was not to interpret the patent claims but to put the trial judge in the position of being able to do so in a knowledgeable way."
2) When are the Claims Construed
[35] The claims are construed by the Court at the outset of its decision before considering issues of validity or infringement. It is not to be a "results oriented" exercise, rather, it is to be carried out without an eye either to the alleged infringement or the prior art. (Whirlpool paragraphs 43 and 49(a)).
3) As of What Date are the Claims to be Construed
[36] The claims are to be construed as of the date of the patent was issued and granted in the case of an "old" Act patent, that is, one that was applied for in Canada before October 1, 1989. In respect of a "new" Act patent, that is, one for which an application was filed in Canada after October 1, 1989, the date upon which the claim is to be construed is the publication date. (Whirlpool paragraph 42, Free World paragraph 44).
4) What are the Criteria for Construction
[37] In this regard consideration must be given to the words of the Supreme Court in Whirlpool at paragraph 45:
"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."
[38] In Free World in paragraph 51 the Supreme Court says:
"The words chosen by the inventor will be read in the sense the inventor is presumed to have intended."
[39] These words do not mean that the Court