Schering-Plough Canada Inc. v. Pharmascience Inc.

Schering-Plough Canada Inc. v. Pharmascience Inc.
Court (s) Database
Federal Court Decisions
Date
2009-12-22
Neutral citation
2009 FC 1128
File numbers
T-2102-07
Decision Content
Federal Court
Cour fédérale
Date: 20091222
Docket: T-2102-07
Citation: 2009 FC 1128
BETWEEN:
SCHERING-PLOUGH CANADA INC.
and SCHERING CORPORATION
Applicants
and
PHARMASCIENCE INC., SEPRACOR INC.
and THE MINISTER OF HEALTH
Respondents
APPLICATION UNDER Section 55.2 of the Patent Act, Section 6
of the Patented Medicines (Notice of Compliance) Regulations,
SOR/93-133, as am. SOR/98-166, SOR/99-379; SOR/06-242.
PUBLIC REASONS FOR JUDGMENT (Confidential Reasons for Judgment issued on November 4, 2009)
SNIDER J.
1. INTRODUCTION
[1] Schering-Plough Canada Inc. (Schering-Plough), one of the Applicants in this matter, distributes and sells AERIUS, an antihistamine used principally for treating allergy symptoms. The active medicinal ingredient in AERIUS is desloratadine (also known as descarboethoxyloratadine or DCL). Two patents are listed in the Patent Register for AERIUS.
The first is Canadian Patent No. 2,325,014 (the '014 Patent) owned by Schering Corporation, the other Applicant in this matter (Schering Corporation and Schering Plough are collectively referred to as “Schering” or “the Applicants”). The second listing is Canadian Patent No. 2,267,136 (the '136 Patent) owned by Sepracor Inc. (Sepracor) and for which Schering‑Plough holds a licence.
[2] Pharmascience Inc. (Pharmascience) wishes to manufacture and sell a product it describes as “desloratadine tablets, 5 mg of desloratadine per tablet, for the treatment of nasal and non-nasal symptoms of allergic rhinitis”. Pursuant to the relevant Patented Medicines (Notice of Compliance) Regulations, S.O.R./93-133 (NOC Regulations), Pharmascience has applied to the Minister of Health (the Minister) for approval to sell its product into Canada. As required by the NOC Regulations, Pharmascience served a Notice of Allegation (NOA) dated October 17, 2007, addressed to Schering-Plough, wherein Pharmascience alleged that: (a) no claim of the '136 Patent or the '014 Patent would be infringed by the making, construction, using or selling by Pharmascience of its product; and (b) the claims of the '136 and '014 Patents are not valid.
[3] In response to the NOA, as the holder of the notice of compliance for AERIUS, Schering commenced (by way of Notice of Application filed with the Court on December 3, 2007) an application for prohibition pursuant to s. 6(1) of the NOC Regulations. After litigation that ended with the decision of the Federal Court of Appeal in Sepracor Inc. v. Schering-Plough, 2008 FCA 230, [2009] 2 F.C.R. 237, Sepracor, named as a Respondent in this application, was permitted to participate in this application in support of Schering. On the eve of the hearing of this application, Sepracor advised the Court that it would not appear at the hearing and that it would rely on its written submissions.
[4] If the application is allowed in full, the Minister will be prohibited from issuing a Notice of Compliance (NOC) to Pharmascience, thereby preventing Pharmascience from marketing its product until the expiry of the '136 Patent and the '014 Patent.
[5] For the reasons set out in the following, I have concluded that the application will be dismissed in respect of both patents. The determinative findings – stated in summary terms – are that, on a balance of probabilities, the following allegations of Pharmascience are justified:
1. Pharmascience does not infringe Claim 23 of the '136 Patent;
2. Claims 1, 6 and 9 of the '136 Patent were anticipated by certain of the prior art;
3. Claims 1, 6, 9 and 23 of the '136 Patent are obvious;
4. Claim 23 of the '136 Patent is overbroad; and
5. Pharmascience does not infringe Claims 1 and 38 of the '014 Patent.
2. CONTENTS
[6] To assist the reader, I am including an outline of these Reasons, noting the beginning paragraph of each topic.
INTRODUCTION .............................................................................................. [1]
CONTENTS ........................................................................................................ [6]
ISSUES ................................................................................................................ [7]
WITNESSES ..................................................................................................... [10]
BACKGROUND OF AERIUS ......................................................................... [14]
PHARMASCIENCE PRODUCT .................................................................... [18]
THE '136 PATENT ........................................................................................... [24]
Construction of the '136 Patent ................................................................. [25]
General Principles of Construction ................................................ [25]
Person Skilled in the Art ............................................................... [28]
Application of the principles to construction of the '136 Patent
Claims ......................................................................................... [29]
Infringement ............................................................................................. [56]
Validity .................................................................................................... [62]
Anticipation of Claims 1, 6 and 9 by Aberg and Cho ..................... [64]
Obviousness of Claims 1, 6, 9 and 23 of the '136 Patent ............... [97]
Overbreadth of Claim 23 ............................................................ [131]
THE '014 PATENT ......................................................................................... [140]
Construction of the '014 Patent ............................................................... [141]
Application of the principles to the '014 Patent claims................... [141]
Infringement of the '014 Patent ............................................................... [185]
Validity of Claims 1 and 38 of the '014 Patent ......................................... [190]
Lack of Utility, Sound Prediction and Inoperable Species ............ [191]
Obviousness .............................................................................. [196]
Overbroad Claiming ................................................................... [211]
Conclusion on validity allegations ................................................ [216]
OVERALL CONCLUSION ........................................................................... [217]
3. ISSUES
[7] There are two sets of issues to be addressed in this proceeding -- one set for each of the patents.
[8] With respect to the '136 Patent, the issues are as follows:
· What is the proper construction of Claims 1, 6, 9 and 23 of the '136 Patent?
· Has Schering met its burden of satisfying this Court that Pharmascience’s allegation of non-infringement of claims 1 and 9 of the '136 Patent is not justified?
· Has Pharmascience led sufficient evidence to rebut the presumption of validity of Claims 1, 6, 9 and 23 and has Schering, in turn, failed to meet its burden of showing that the allegation of invalidity is not justified?
[9] With respect to the '014 Patent, the issues are as follows:
· What is the proper construction of Claims 1 and 38 of the '014 Patent?
· Has Schering met its burden of satisfying this Court that Pharmascience’s allegation of non-infringement of claims 1 and 38 of the '014 Patent is not justified?
· Has Pharmascience led sufficient evidence to rebut the presumption of validity of Claims 1 and 38 and has Schering, in turn, failed to meet its burden of showing that the allegation of invalidity is not justified?
4. WITNESSES
[10] Each of Schering, Sepracor and Pharmascience provided affidavit evidence from a number of witnesses whose evidence addressed both technical and factual matters. Those witnesses who provided expert or fact evidence of the most significance in this application are described below.
[11] Schering’s expert witnesses include:
1. Dr. Louis Cartilier, Professor with the Faculty of Pharmacy at the University of Montreal. Dr. Cartilier researches and teaches in the area of drug design and manufacturing of pharmaceutical dosage forms and consults to pharmaceutical companies on formulation issues. His first affidavit was directed to the issue of claims construction and infringement. In his Reply Affidavit, he addressed the issue of invalidity raised by Pharmascience.
2. Dr. Gilbert Banker, now retired. Dr. Banker’s lengthy academic career was completed as Dean and John L. Lach Distinguished Professor of Drug Delivery at the University of Iowa College of Pharmacy from 1992-1999. Although his entire career has been in academia, Dr. Banker has acted as a consultant to pharmaceutical companies. He is co-editor with Dr. Christopher Rhodes on Modern Pharmaceutics, 4th ed. (New York: Marcel Dekker, Inc., 2002), a textbook about the formulation of drugs. Dr. Banker’s first affidavit was directed to the issue of claims construction and infringement. In his Reply Affidavit, he addressed the issues of invalidity raised by Pharmascience
3. Dr. Jerry Atwood, Professor and Chairman of the Department of Chemistry at the University of Missouri-Columbia. Dr. Atwood has focused his entire academic, research and teaching career on solid state chemistry. He was asked to opine on the affidavits of Drs. Rhodes and Fiese. In particular, Dr. Atwood was very critical of what he called the “oversimplification”, by Pharmascience’s experts, on the role of the Maillard reaction. Dr. Atwood also responded to the Pharmascience experts’ opinions on patent validity issues. Finally, he provided a short opinion responding to Dr. Rhodes’s reply affidavit on certain limited issues related to formulation and the Food and Drug Administration (FDA) practices.
[12] Pharmascience’s expert witnesses include:
1. Dr. Christopher Rhodes, Professor Emeritus at the University of Rhode Island and co-editor with Dr. Banker on Modern Pharmaceutics. For over 30 years, Dr. Rhodes has been involved with the design and evaluation of drug products. Dr. Rhodes provided opinions on claims construction, the state of the prior art, obviousness, overbreadth, inoperability and utility for both patents in issue.
2. Dr. Eugene Fiese, a pharmaceutics consultant with Fiese Pharmaceutics Consulting. Of particular relevance and assistance, Dr. Fiese has extensive and direct laboratory experience in drug formulation. He provided opinions on the issues of claims construction, the state of the prior art, obviousness and utility for both patents in issue.
[13] Sepracor presented, as a fact witness, Mr. Stephen Wald, one of the named inventors of the '136 Patent.
5. BACKGROUND OF AERIUS
[14] As noted, the key ingredient in AERIUS is DCL. DCL is a molecule with medicinal properties as an antihistamine. As compared to other antihistamines known in the art, DCL is non-drowsy and avoids some other negative side effects. A number of patents relating to DCL have been filed over the years and prior to the patents in issue. This application is not about the invention of DCL. However, two of the earlier patents have particular significance for this application:
· U.S. Patent No. 4,659,716 with a patent date of April 21, 1987 (the Villani Patent) is a product patent that discloses and claims DCL itself and several of its compositions.
· U.S. Patent No. 5,595,997 (the Aberg Patent) with a patent date of January 21, 1997 is a use patent that discloses and claims methods of treating allergies with DCL while avoiding certain side effects of other antihistamines.
[15] Schering and Sepracor claim that, working independently, they invented a form of DCL that was sufficiently stable to bring to market. Each of Schering and Sepracor submits that, prior to the work carried out by the inventors of the '014 and the '136 Patents, it was not known that DCL would degrade when formulated with acidic excipients such as lactose, one of the most common fillers or excipients and a compound that was “taught” by the Aberg Patent.
[16] Thus, Schering asserts that the first “invention” or discovery reflected in the two patents was that DCL degrades and is highly reactive in the presence of acidic excipients, including lactose. Having identified the problem, the inventors of the two patents independently came up with solutions to the problems.
[17] In simple terms, the Schering inventors came up with a DCL composition where the “carrier medium” was free of acidic excipients and contained a “basic salt” ('014 Patent). Sepracor’s invention was a composition where the carrier was lactose free or a composition that was anhydrous (the '136 Patent).
6. PHARMASCIENCE PRODUCT
[18] Pharmascience, in its NOA, alleges that its product will not infringe either the '014 or the '136 Patent. While acknowledging that its composition contains a therapeutically effective amount of DCL with a pharmaceutically acceptable carrier, Pharmascience alleges that:
1. With respect to the '014 Patent, its product “does not contain a DCL-protective amount of a pharmaceutically acceptable basic salt and is not substantially free of acidic excipients, as those terms are used in the '014 Patent”; and
2. With respect to the '136 Patent, its product “is not entirely free or substantially free of reactive excipients and is not substantially free of unbound water, as those terms are used in the '136 Patent”.
[19] For purposes of establishing whether Pharmascience’s allegation of non-infringement is justified, it is necessary to understand the Pharmascience product. Pharmascience declined to give samples of its product to Schering for purposes of this application. As a result of Prothonotary Aronovitch’s Order, dated June 11, 2008, Pharmascience did provide the details of the complete manufacturing process. Schering contracted with the Toronto Institute of Pharmaceutical Technology (TIPT) to perform the formulation described in the produced documentation. Mr. Frank Martinuzzi, Manager – General Operations & Laboratory of TIPT, was engaged to create a “recipe” for formulating tablets that, as closely as scientifically possible, would match those made by Pharmascience, and to carry out the formulation. Subsequently, Mr. George Kretschmann, an engineering technologist at the University of Toronto, subjected the tablets to scanning electron microscopy (SEM) to establish the structure of the particles.
[20] From the experiments of Mr. Martinuzzi and the SEM conducted by Mr. Kretschmann, as interpreted by other experts, I am satisfied that Pharmascience uses a three-step process to manufacture its tablets:
1. [Confidential Step One] In this first process, DCL and [Confidential Compound One] are mixed. After the addition of other excipients, the mixture is formed into [forms] which contain the following:
a. DCL [. . .]
b. [Other compounds including Confidential Compound One and Confidential Compound Two] [. . .]
2. Blending and compression. The above [forms], once dried, are formed into tablets. As part of this step, additional excipients are added, one of which, as acknowledged by Pharmascience, is lactose anhydrous.
3. Coating. At the final stage, the tablets are coated.
[21] Pharmascience does not deny that lactose is added at step two of the procedure. The question of where the lactose is located within the tablet is critical.
[22] Dr. Banker opined that the [forms] of step one survive Pharmascience’s manufacturing process and are found in its tablets (Application Record of the Applicants [A.R.], vol. 3, Tab. 10, p. 487). Dr. Cartilier provided further details in support of his similar conclusion that the [forms] of step one “survive compression and exist intact in tablets made according to the Pharmascience process” (A.R., vol. 2, Tab. 6, p.186). Dr. Cartilier described the Pharmascience tablets as being made up of three compartments: the [forms] comprising DCL and [excipients within the form]; the [space outside the form] comprising the [excipients outside the form] and potentially discrete fragments of some broken [forms]; and, the coating (A.R., vol. 2, Tab. 6, p.188). It follows from this that, on a balance of probabilities, any lactose in the Pharmascience tablets is contained outside the step one [form]. In other words, the DCL is separated from the lactose, except for some inconsequential amounts where the step one [forms] are broken during the tableting process.
[23] I observe that the step one [forms] are designed to be anhydrous and to contain [Confidential Compounds One and Two]. Each of these elements is relevant to the question of whether Pharmascience’s allegation of non-infringement is justified and is considered later in these Reasons.
7. THE '136 PATENT
[24] I turn first to consider the issues with respect to the '136 Patent.
7.1. Construction of the '136 Patent
7.1.1. General Principles of Construction
[25] As taught by the jurisprudence, my first task is to undertake a "purposive construction" of the claims in issue. There is no disagreement and thus no need to set out an exhaustive list of the well-established principles of claims construction (see, principally, 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). In overarching terms:
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, above at para. 45).
[26] The Court must objectively construe the claim through the eyes of the hypothetical skilled person in the art, and decide how this person would have understood the patent at the relevant time (Whirlpool, above, at paras. 45, 53).The Court should construe the claims in light of the description in the specification, assisted, where necessary, by experts as to the meaning of technical terms, if they cannot be understood by the Court from reading the specification (Shire Biochem Inc. v. Canada (Minister of Health), 2008 FC 538, 328 F.T.R. 123 at para. 22; Whirlpool, above, at para. 45).
[27] Finally, it is also important to recognize that purposive construction should be directed at the points at issue between the parties (see Shire Biochem, above, at para. 21).
7.1.2. Person Skilled in the Art
[28] In this case, there is no dispute between the parties as to the notional skilled person. The skilled person for purposes of construction of both patents in issue will hold a BSc in chemistry or a related field with an emphasis on pharmaceutical formulations and solid oral dosage forms along with four years of experience in this field.
7.1.3. Application of the principles to construction of the '136 Patent claims
[29] The first patent in issue is the '136 Patent. The '136 Patent was published on August 13, 1998; this is the date for determining the proper construction of the patent.
[30] The '136 Patent is entitled “Lactose-free, non-hygroscopic and anhydrous pharmaceutical compositions of descarboethoxyloratadine”. As acknowledged in the patent specification, an earlier patent (the Aberg Patent) disclosed that DCL, “while providing effective, non-sedating antihistamic therapy, also avoids many, often severe, adverse side-effects commonly associated with the administration of [other antihistamines]”.
[31] As set out in the specification, beginning at page 3, the inventors first identify a manufacturing “problem”, that being the undesirable degradation of DCL in the presence of lactose or “other similar reactive excipients, such as mono- or di-saccharides”:
Recognizing the desirability of DCL-containing pharmaceutical compositions, we have concluded that under typical manufacturing and storage conditions, DCL is not stable and degrades in the presence of lactose, a compound commonly used as a filler in various pharmaceutical dosage forms, such as tablets, capsules or powders. Over time, the lactose and DCL compound form a brown-colored product, and there is a high degree of DCL degradation. The intensity of the brown color is typically dependent on the amount of DCL present, the conditions of storage, such as humidity and temperature, as well as the length of storage time.
[32] The inventors continue on to describe two aspects of their intervention that are of interest for purposes of the claims in issue before the Court. The first element of their invention is, quite simply, the avoidance of lactose. At page 4 of the specification, the inventors describe their invention as follows:
The present invention relates to stable pharmaceutical compositions of DCL wherein DCL is in intimate admixture with one or more excipient(s), including, but not limited to, blended, granulated or compressed dosage forms, that avoid the incompatibility between DCL and reactive excipients, such as lactose and other mono- or di-saccharides.
[33] In the specification, the inventors describe certain "preferred embodiments” of this first invention, all of which avoid the use of lactose or the describe ways in which the interaction of lactose with DCL may be avoided.
[34] The second aspect of their invention is the problem associated with water in the pharmaceutical compound. The inventors disclose, at page 5, that "our studies have also shown that in the absence of unbound water very little to no degradation occurs in DCL compositions that include lactose”. Recognizing that lactose "is among the best of all direct compression filters in fluidity and is very effective for low dose formulations", the inventors disclose an embodiment of the present invention that encompasses "non-hygroscopic pharmaceutical compositions” comprising DCL and "at least one pharmaceutically acceptable excipient". The inventors contemplate that, where an overall composition is substantially non-hygroscopic or anhydrous, such excipients may include lactose and other reactive excipients such as mono- or di-saccharides.
[35] The specification includes the “Results of Excipient Compatibility Studies" (beginning at page 16 of the specification), following which, various examples or embodiments are described. The inventors specifically comment, at page 19, that the examples "are provided by way of illustration and not by way of limitation".
[36] This brings me to the specific claims in issue. Schering raises Claims 1, 6, 9 and 23 of the '136 Patent.
[37] I pause to consider the position of Sepracor. In its Memorandum of Fact and Law, Sepracor asserted that, in addition to those claims focused on by Schering, Pharmascience’s allegation was not justified insofar as Claims 2, 3 and 31. As noted above, Sepracor withdrew from the oral hearing of the application. This leaves the Court in an odd position. The Applicant before me is Schering who seeks the remedy of prohibition until expiry of the '014 and the '136 Patents. Schering does not take a position with respect to these additional claims raised by Sepracor. Given Schering’s failure to assert that Pharmascience’s allegations are not justified in respect of Claims 2, 3 and 31, I can see no reason why I need or should consider the merits of those allegations.
[38] Accordingly, I will only construe the claims relied on by Schering – Claims 1, 6, 9 and 23. Those claims are as follows:
1. A pharmaceutical composition in blended or granulated form for the treatment of histamine-induced disorders, comprising a therapeutically effective amount of descarboethoxyloratadine, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable inert carrier.
6. The pharmaceutical composition of claim 1 further comprising a therapeutically effective amount of an analgesic.
9. The pharmaceutical composition of claim 1 wherein the composition is present in one of tablet or capsule form.
23. The anhydrous pharmaceutical composition of claim 22 wherein the composition is present in tablet form.
[39] Claim 23 is dependent on Claim 22 which, in turn, is dependent on Claim 16. Claim 16 covers:
16. An anhydrous pharmaceutical composition in granulated or blended form for the treatment of histamine-induced disorders, comprising a therapeutically effective amount of descarboethoxyloratadine, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.
[40] Claims 1, 6 and 9 relate to the alleged invention of the avoidance of lactose. Claim 6 adds an analgesic to the elements of Claim1, and Claim 9 limits Claim 1 to a tablet or a capsule form. By the time of oral arguments, the parties no longer disputed that the term “pharmaceutical composition” meant anything other than the final dosage form. Thus, the only construction issue in dispute for Claims 1, 6 and 9 is whether the term “pharmaceutically inert carrier” encompasses everything in the “pharmaceutical composition” (or final dosage form) or is restricted to only the materials in intimate admixture with the DCL.
[41] It is not disputed that lactose is a reactive excipient rather than an inert carrier.
[42] Pharmascience argues that “carrier” represents the vehicle for delivering or administering the active ingredient DCL to the body. Drs. Rhodes and Fiese opined that “carrier” refers to all of the components of the final dosage form other than DCL. Thus, to Pharmascience, “inert carrier” represents that the final dosage must be free of lactose or any acidic excipient. In support of this construction, Pharmascience argues that the '136 Patent includes, in the definition of “carrier” or “inert carrier”, all manner of excipients, including diluents, lubricants, binders, and coating agents (Patent '136 at p. 10, 14, 15). Since, coating agents are used at the end of the process, it must certainly mean that “carrier” encompasses all excipients of the final dosage form.
[43] In contrast, Schering relies on Drs. Banker and Cartilier in submitting that a “pharmaceutically acceptable inert carrier” refers solely to the excipients in “intimate admixture” with the DCL, and not those outside. Thus, the “inert carrier” must be lactose free, even though the pharmaceutical composition can include some lactose (A.R., vol. 3, Tab 10, p. 463-464; A.R., vol. 2, Tab 6, p. 176-177)., In my view, the construction offered by Schering and its experts is to be preferred.
[44] The first problem with Pharmascience’s interpretation is with its reference to the coating agents. On reading the '136 Patent, one can see that the inventors set out several ways to solve the problem of DCL’s degradation when in contact with lactose. One such solution, “coating DCL”, is found at page 7 of the Patent’s specification. This is where DCL is first granulated with inert excipients, and then the [forms] are coated with inert coating agents. Finally, in the tableting process, these [forms], already protected, can be blended with other excipients, including lactose. As stated at p. 7, lines 25-30:
Once the particles or granulated formulations of DCL are coated with the inert coating agent, the coated DCL may be formulated using standard techniques, including, but not limited to blending, granulation, compression and combinations thereof, with other inert and reactive excipients, such as lactose, to make various dosage forms, for example, tablets, caplets, capsules, torches, and the like.
[Emphasis added.]
[45] This embodiment of the invention shows that “coating agents” do not always have to be used at the end process, and thus, this argument of Pharmascience fails.
[46] Next, I observe that all of the experts appear to accept that the word “comprising” is not limiting. That is, what follows the word “comprising” does not necessarily identify everything that is included in the composition. In the case of Claim 1, when the inventors describe the composition as “comprising” DCL with an inert carrier, the skilled person would know that other things could be included in the composition. (For further discussion of the word “comprising”, see paragraphs [150]-[151] below.)
[47] Furthermore, while “pharmaceutical composition” is used often in the specification to represent the final dosage form to be administered to patients, “carrier” is never used synonymously or interchangeably with “pharmaceutical composition” or with “dosage form”. This differentiation is included in the language of the claims, where the inventors state that the “pharmaceutical composition” comprises DCL together with a “pharmaceutically acceptable inert carrier”.
[48] Drs. Cartilier and Banker state that “inert carrier” is that which is intimately admixed with DCL. They rely on the following paragraph found at page 4, lines 3 to 7 of Patent '136:
The present invention relates to stable pharmaceutical compositions of DCL wherein DCL is in intimate admixture with one or more excipients, including, but not limited to, blended, granulated or compressed dosage forms, that avoid the incompatibility between DCL and reactive excipients, such as lactose and other mono- or di-saccharides.
[49] I prefer the opinions of Drs. Cartilier and Banker that the skilled person would understand that, in order to protect DCL, those excipients that are in admixture with the DCL must not include “reactive excipients”. According to Dr. Cartilier, this passage is “consistent with the purpose of the invention which is to provide a formulation in which DCL will not be decomposed or discoloured” (A.R., vol. 2, Tab. 6, p.177). Dr. Cartilier continued by saying “the ‘136 Patent recognizes that some pharmaceutical product have different ‘compartments’ or sections” (A.R., vol. 2, Tab 6, p.178). He also stated: “The disclosure tells the Skilled Formulator that a formulation (or product) with multiple compartments is contemplated by the ‘136 Patent” (A.R., vol. 2, Tab 6, p.178). Dr. Cartilier pointed to the language of the patent that states (‘136 Patent, p. 7, lines 25-29):
Once the particles or granulated formulations of DCL are coated with the inert coating agent, the coated DCL may be formulated using standard techniques, including, but not limited to, blending, granulation, compression and combinations thereof, with other inert and reactive excipients, such as lactose, to make various dosage forms, for example, tablets, caplets, capsules, troches, and the like.
[50] On the other hand, Dr. Rhodes stated that the reference to “intimate admixture”, by Schering’s experts, would lead the skilled person “to apply an unusual interpretation of the commonly used term ‘carrier’” (Application Record of the Respondent, Pharmascience Inc. [R.R.], vol. 1, Tab 1, p.43). According to Dr. Rhodes, carrier represents the whole dosage form, not an inner [form]. Dr. Rhodes justified this interpretation by stating that inventors included “coating agents” in their list of excipients that may comprise the carrier (R.R., vol. 1, Tab 1, p. 43). I do not agree with this interpretation. As I have stated previously (at paragraphs [45]-[46] of this decision), coating agents do not have to be used at the end process.
[51] The essential element of Claims 1, 6 and 9 is that the DCL must be in intimate admixture only with inert carriers, thus avoiding the intimate mixture of DCL with reactive excipients. The claims are silent on what excipients can be used outside the carrier but still within the “pharmaceutical composition”. I believe that this is a reasonable construction of the words of Claim 1. The construction of Claims 6 and 9 would follow.
[52] The only issue with respect to Claim 23 – and Claim 16 on which Claim 23 depends – is what is meant by the term “anhydrous pharmaceutical composition”. And, as I read the submissions of Schering and Pharmascience, I am not persuaded that there is a material difference in their proposed constructions. Each of Pharmascience and Schering acknowledge that the term “anhydrous” would not be read by the skilled person to mean absolutely no water present in the composition. According to Dr. Cartilier, the person skilled in the art would know that “pharmaceutical compositions are never anhydrous in an absolute sense” and 100 percent water free (A.R., vol. 2, Tab 6, p.180). Dr. Rhodes, for Pharmascience, agreed and stated that the skilled person would read “anhydrous” as referring “to an amount of unbound water that may be greater than zero, but still insufficient to initiate or accelerate the degradation reaction” (R.R., vol. 1, Tab 1, p.11). In cross-examination, Dr. Atwood stated: “It’s very difficult to make a pharmaceutical tablet that doesn’t have some water but some water could be parts per million” (R.R., vol. 5, Tab 10, p.1053, q. 151). Thus, the question is what the patent teaches about the amount of water that could be contained in the composition.
[53] The term “anhydrous” is defined in the '136 Patent, at page 11, lines 24-27, as:
The amount of unbound water present, if any, is insufficient to initiate and/or accelerate the incompatibility between DCL and reactive excipients, such as lactose.
[54] The term “unbound water”, as stated by the inventors, at page 11, lines 22-24, refers to “water that is not present in the form of a stable hydrate of one or more components of the pharmaceutical composition, e.g., α-lactose monohydrate.”
[55] The inventors have not set out any absolute limit of water content that would meet the requirement to be “anhydrous”. Rather they have defined the amount of water content by its function. Stated simply, a composition of DCL appears to satisfy Claims 16 and 23 if it remains stable in the presence of lactose. If the composition with lactose degrades, it is not anhydrous. If it does not degrade, it is anhydrous. Dr. Rhodes accepted this construction, but he raised several concerns: “the person of ordinary skill in the art would not know, from reading the ‘136 Patent, either how much unbound water will be acceptable, nor even how to measure or determine this amount” (R.R., vol. 1, Tab 1, p.11). I agree. While I accept the construction of “anhydrous” as an insufficient amount of unbound water to initiate or accelerate the degradation process, I find that it raises significant questions on: (a) how one measures infringement; and (b) the allegations of invalidity. These questions are discussed below.
7.2. Infringement
[56] Based on these constructions, I turn to the question of whether Pharmascience’s allegation of non-infringement is justified.
[57] As discussed above, the Pharmascience tablets contain [forms] that are free of reactive excipients such as lactose. The lactose in the Pharmascience tablets is situated outside the [form] or “carrier”. I am satisfied that the allegation of non-infringement of Claims 1, 6 and 9 is not justified.
[58] The question with respect to Claim 23 is more difficult to answer. While Claims 1, 6 and 9 require, in effect, that the carrier be free of lactose, Claim 23 (through Claim 16) refers to the entire formulation or tablet as being anhydrous. The final tablets made according to the Pharmascience specifications contain water in the amount of [confidential]% of the total weight. This amount has been confirmed by Dr. Fiese (R.R., vol. 3, Tab 4, p.789), and Dr. Banker (A.R., vol. 3, Tab 10, p. 501). According to Dr. Rhodes, “under typical manufacturing conditions, a tablet will normally contain less than about 2% of total water and will rarely if ever exceed about 3%” (R.R., vol. 1, Tab 1, p.50). Dr. Atwood, in cross examination, acknowledged that while some tablets can be higher than 3% of unbound water, the normal level of water ranges from 1 to 3% in pharmaceutical products that undergo usual manufacturing processes (R.R., vol. 5, Tab 10, p.1053-1054). Nevertheless, the tablets are stable; they do not degrade. Thus, it appears that the tablets contain insufficient water to initiate or accelerate the incompatibility between DCL and reactive excipients, such as lactose. If this is correct, the allegation of non-infringement of Claim 23 is not justified.
[59] In my view, however, this is an overly-simplified approach to the question of infringement.
[60] Claim 16 is a “functional” claim. According to Justice Noël in Burton Parsons Chemicals Inc v. Hewlett-Packard (Canada) Ltd. (1972) 7 C.P.R. (2d) 198 at p. 215: “functional claiming, in the sense of claiming in terms of a desired result, is in principle permissible in this country”. Implicit in Claim 16 is that a stable or non-degrading composition is a function of the avoidance of water. As I see it, this is not a simple question to answer. For example, the '136 Patent teaches at least two ways of avoiding degradation – avoidance of lactose or avoidance of water. The '014 Patent discloses another method – the avoidance of lactose together with the use of a basic salt. How would one know that the stability of any Pharmascience product is as a result of an infringement of Claim 16? Could the stability be due to the use of a different excipient? There is no simple way to establish that a lack of degradation is due to the avoidance of water rather than to some other variable in the formulation. Schering did not, it appears, perform any testing to determine what effect, if any, the amount of water in Pharmascience’s tablets – as opposed to other elements in its composition – had on the stability of the final product. Accordingly, I am not persuaded that Schering has met its burden to show that the Pharmascience product would infringe Claims 16 and 23. I find that Pharmascience’s allegation of non-infringement of these claims is justified.
[61] Even if I am wrong in this conclusion, I am also satisfied that Pharmascience’s allegation that Claim 16 (and hence Claim 23) is invalid due to obviousness or overbreadth is justified. This is discussed below.
7.3. Validity
[62] In its NOA, Pharmascience makes a number of allegations related to the validity of Claims 1, 6, 9 and 23. For purposes of these reasons, I will focus on those allegations that appear to have the most merit; specifically:
1. Claims 1, 6, 9 and 23 were anticipated or rendered obvious as of February 7, 1997 by the prior art or common general knowledge; and
2. Claim 23 is overbroad.
[63] I find Pharmascience’s allegations regarding a failure by the inventors to demonstrate the utility or sound prediction of their invention (either avoidance of lactose or avoidance of water) to not be justified.
7.3.1. Anticipation of Claims 1, 6 and 9 by Aberg and Cho
[64] I turn to the first argument of Pharmascience – that of anticipation. In its NOA, Pharmascience relies on, inter alia, United States Patent No. 5,595,997 (the Aberg Patent) and United States Patent No. 4,990,535 (the Cho Patent), to allege that “[t]he subject matter of claims 1 to 36 of the '136 Patent was . . . disclosed to the public prior to the claim date of the '136 Patent . . .” and that, “[t]herefore, each of the claims 1 to 36 of the '136 Patent are invalid for lacking novelty (i.e. for being anticipated) pursuant to section 28.2 of the Act”.
[65] In its final submissions, Pharmascience narrowed its allegations to argue that Claim 9 of the '136 Patent was anticipated by certain of the teachings of both the Aberg Patent and the Cho Patent.
7.3.1.1. Principles of Anticipation
[66] I begin this section of the Reasons by referring to the general legal principles of anticipation.
[67] The concept of anticipation arises from s. 28.2 of the Patent Act, R.S.C. 1985, c.P-4. In short, this provision requires that the subject matter of a claim must not have been disclosed to the public before the claim date.
[68] Until the decision of the Supreme Court in Apotex v. Sanofi-Synthelabo, 2008 SCC 61, [2008] 3 S.C.R. 265, the test for anticipation followed by the Courts was as described in Beloit Canada Ltd. v. Valmet O