Allergan Inc. v. Sandoz Canada Inc.

Allergan Inc. v. Sandoz Canada Inc.
Court (s) Database
Federal Court Decisions
Date
2020-12-24
Neutral citation
2020 FC 1189
File numbers
T-2023-18
Notes
A correction was made on January 17, 2022.
Decision Content
Date: 20201224
Docket: T-2023-18
Citation: 2020 FC 1189
Ottawa, Ontario, December 24, 2020
PRESENT: THE CHIEF JUSTICE
BETWEEN:
ALLERGAN INC.
Plaintiff
and
SANDOZ CANADA INC.
Defendant
and
KISSEI PHARMACEUTICAL CO., LTD.
Defendant/Patent Owner
AND BETWEEN:
SANDOZ CANADA INC.
Plaintiff by Counterclaim
and
ALLERGAN INC. and KISSEI PHARMACEUTICAL CO., LTD.
Defendants by Counterclaim
JUDGMENT AND REASONS – PUBLIC VERSION
(Identical to the Confidential Judgment and Reasons issued on December 23, 2020)
Table of Contents
I. Introduction 3
II. Background 4
A. The Parties 4
B. Benign Prostatic Hyperplasia, Dysuria and Silodosin 6
III. The ‘002 Patent 7
IV. Issues 9
V. Witnesses 9
A. Allergan’s Witnesses 10
(1) Dr. Linda Felton 10
(2) Ms. Jenna Wilson 11
(3) Dr. MacGregor 11
B. Sandoz’s Witnesses 12
(1) Dr. Reza Fassihi 12
(2) Mr. Michael I. Stewart 13
VI. Analysis 14
A. Claim Construction 14
(1) Legal Principles 14
(2) The Skilled Person 17
(3) Common General Knowledge 20
(4) The Essential Elements of the ‘002 Patent 23
(a) Claim 1 25
(i) The First Prong of the Test: A Purposive Construction of the Wet Granulation Elements 26
(ii) The Second Prong of the Test: Would the Skilled Person Have Appreciated that a Dry Process Could be Substituted Without Affecting the Working of the Claimed Invention? 38
(iii) The Prosecution History of the ‘002 Patent 42
(iv) Summary: The Essential Elements of Claim 1 49
(b) Claims 2 and 3 50
(c) Claim 6 51
B. Is the ‘002 Patent Invalid on the Ground of Obviousness? 53
(1) Introduction 53
(2) The Legal Test 54
(3) Assessment 57
(a) Step One - The Skilled Person and the relevant common general knowledge 57
(b) Step Two - The inventive concept 58
(c) Step Three - The differences between the state-of-the-art and the inventive concept 62
(d) Step Four - Were the differences between the inventive concept and the state of the art obvious? 63
(i) Was it more or less self-evident that what is being tried ought to work? Were there a finite number of identified predictable solutions known to the Skilled Person? 64
(ii) What was the extent, nature and amount of effort required? Were routine trials carried out or is the experimentation prolonged and arduous, such that the trials would not be considered routine? 68
(iii) Was there a motive provided in the prior art to find a solution that the ‘002 Patent addresses? 78
(iv) Allergan’s experiment 80
(v) Summary of “obvious to try” assessment 82
(e) Conclusion regarding the allegation of obviousness 83
C. Infringement 83
D. The Gillette Defense 84
VII. Costs 84
APPENDIX 1 — Relevant Legislation 87
I. Introduction
[1] There are three principal issues in this action. The first is whether the Defendant Sandoz Canada Inc. [Sandoz] will infringe a patent pertaining to the prescription drug RAPAFLO®, for which the Plaintiff Allergan Inc. [Allergan] is the exclusive Canadian licensee. The second is whether representations that were made during the patent application process on behalf of the owner of the patent, the Defendant Kissei Pharmaceutical Co. Ltd. [Kissei], can be introduced as evidence in this proceeding pursuant to section 53.1 of the Patent Act, R.S.C. 1985, c. P-4 [the Act]. The third is whether the patent is invalid on the ground of obviousness.
[2] For the reasons that follow, I have concluded that the generic alternative to RAPAFLO® that Sandoz seeks approval to produce [the Sandoz Product] will not infringe the patent at issue, namely, Canadian Patent No. 2,507,002 [the ‘002 Patent]. This is because some of the essential elements of claims 1 to 3 and 6 of that patent are not infringed by the Sandoz Product. Allergan’s suggestion to the contrary is based on a reading of the patent that, if upheld, would undermine the certainty and predictability of the patent system, and chill competition.
[3] I have also determined that section 53.1 of the Act cannot be invoked in this proceeding. This is because Allergan is not a “patentee”, within the meaning of the Act. Accordingly, the representations made to the Patent Office on behalf of Kissei and the amendments made to the proposed patent during the patent application process are inadmissible extrinsic evidence.
[4] Finally, I have concluded that the ‘002 Patent in question is not invalid on the ground of obviousness. This is because (i) it was not more or less self-evident that the claimed invention ought to work; (ii) the person skilled in the art of the ‘002 Patent would not likely have thought that the claimed invention could be achieved relatively quickly, through routine experimentation; (iii) the experimentation actually undertaken to achieve the claimed invention was prolonged and arduous; and (iv) the person skilled in the art would not have had any motivation to pursue the claimed invention.
II. Background
A. The Parties
[5] Allergan is a pharmaceutical company incorporated under the laws of Canada. Its principal address is located in Markham, Ontario. Allergan is a “first person” within the meaning of subsections 4(1) and 6(1) of the Patented Medicines (Notice of Compliance) Regulations, SOR/93-133 [the Regulations].
[6] Allergan is authorized to manufacture, market, and sell RAPAFLO® capsules in Canada pursuant to a series of Notices of Compliance [NOCs] issued by Health Canada dated January 11, 2011, January 29, 2015, April 5, 2017 and March 12, 2018, respectively. RAPAFLO® capsules contain the active pharmaceutical ingredient [API] silodosin and are available in 4mg and 8mg silodosin strengths. RAPAFLO® is indicated for the treatment of benign prostatic hyperplasia [BPH].
[7] Kissei is a pharmaceutical company based in Japan. It was joined to this action pursuant to subsection 6(2) the Regulations. Kissei takes no position on whether the Sandoz Product will infringe the ‘002 Patent. However, Kissei denies that any of the claims of the ‘002 Patent are invalid, void or of no force or effect. It adopts and relies on Allergan's submissions in this regard and did not appear during the trial of this proceeding.
[8] Sandoz is a pharmaceutical company incorporated under the laws of Canada. Its principal office is located in Boucherville, Quebec. It is a “second person” within the meaning of subsections 5(1) and 6(1) of the Regulations.
[9] To obtain approval from Health Canada to market the Sandoz Product in Canada, Sandoz filed an Abbreviated New Drug Submission [ANDS] for a NOC for 4mg and 8mg silodosin capsules indicated for the treatment of the signs and symptoms of BPH. Given that Sandoz's ANDS relied on Allergan's NOC for RAPAFLO®, Sandoz served Allergan with a Notice of Allegation pursuant to subsection 5(3) of the Regulations on or about October 16, 2018.
[10] Allergan commenced this action pursuant to subsection 6(1) of the Regulations shortly thereafter.
B. Benign Prostatic Hyperplasia, Dysuria and Silodosin
[11] BPH is an anatomical change that occurs to a man’s prostate. BPH is typically understood to refer to benign prostatic hypertrophy, a condition in which the cells of the prostate increase in size. BPH is also sometimes used to connote benign prostatic hyperplasia, a condition in which the number of cells in the prostate increases.
[12] BPH is the most common benign tumor in men. It is often age-related and occurs more frequently in men over the age of 50. The clinical symptoms associated with BPH include storage disturbances (e.g., the need to urinate more frequently or urgently), voiding disturbances (e.g., various difficulties associated with urinating), and pain during urination. If left untreated, BPH can lead to other symptoms and infections.
[13] Silodosin is a prescribed oral medication indicated for treatment of the signs and symptoms of BPH. Silodosin belongs to a class of drugs known as “alpha-1 blockers”. These drugs operate by blocking alpha-1 receptors located in the bladder and prostate that are responsible for the contraction of smooth muscles of the bladder and prostate. By causing the muscles in the bladder and prostate to relax, alpha-1 blockers like silodosin can mitigate BPH symptoms and improve the ability to urinate.
[14] Silodosin is manufactured, marketed and sold in Canada and the United States under the brand name RAPAFLO®. The Drug Identification Numbers assigned by Health Canada to RAPAFLO® are 02361663 (4 mg) and 02361671 (8 mg).
III. The ‘002 Patent
[15] The ‘002 Patent is titled “Solid Drug for Oral Use”. The named inventors are Tsuyoshi Naganuma and Mitsuo Muramatsu [the Inventors].
[16] The ‘002 Patent issued from an application filed on December 11, 2003 claiming priority from Japanese Patent JP2002-364238, filed December 16, 2002 [the Claim Date]. It was published (“laid open”) on July 1, 2004 [the Publication Date] and issued on September 18, 2012.
[17] As a preliminary observation, it is common ground between Allergan and Sandoz that the English translation of the ‘002 Patent is sub-optimal and that this may account for some of the ambiguities in the document. In brief, the translation contains some unclear passages, uses some terms inconsistently and has some grammatical deficiencies. Nevertheless, as Allergan observed during the proceedings, the translation still provides “enough … for us to understand what the patent is talking about”: Public Transcript, at 636.
[18] In a short section entitled “Background Art”, the ‘002 Patent indicates that it was known that silodosin, as an API in a solid dosage form, is useful for treating dysuria without causing strong hypotensive activities or orthostatic hypotension. However, the prior literature identified in that patent did not disclose how to prepare a solid dosage form capsule by conventional formulation methods, or indeed by any other method. The patent notes that preparing such a capsule was extremely difficult to accomplish, due to the potent adhesive properties of silodosin that were disclosed by the patent. Given those properties, the use of a lubricant is required to formulate silodosin in a capsule form. However, the addition of a lubricant “causes the problem of delaying in [sic] dissolution time”.
[19] Broadly speaking, the invention claimed in the ‘002 Patent is a solid oral dosage form capsule for the treatment of dysuria which comprises the API silodosin and specific excipients, manufactured in a manner that achieves a defined rapid dissolution profile. According to the patent disclosure, the invention also “has a high precision for content uniformity, good stabilities, and excellent dissolution properties”. It is further noted that an important objective of the Inventors was to achieve “a high content uniformity among formulation batches”.
[20] The specific excipients identified in the patent are (i) D-mannitol, (ii) partially pregelatinized starch, (iii) a lubricant selected from the group magnesium stearate, calcium stearate and talc, and (iv) sodium lauryl sulfate [SLS]. The rapid distribution profile is described in terms of 85% “in not more than 15 minutes in a dissolution test according to method 2 (paddle method) of the Japanese pharmacopoeia in a condition using water as a test medium and a paddle speed of 50rpm [sic]” [Method 2].
[21] Sandoz has admitted, for the purpose of this action, that the Sandoz Product contains silodosin, D-mannitol, partially pregelatinized starch, magnesium stearate and SLS, and that the capsules dissolve by 85% in no more than 15 minutes according to Method 2.
[22] However, the Sandoz Product does not contain “granules” and does not involve “granulating” or a “wet granulation process” [collectively, the Wet Granulation Elements], which are elements included in the independent claims that are in dispute in this proceeding, namely, claims 1 and 6 of the ‘002 Patent. The Sandoz Product is made by a “dry” formulation method.
[23] The disputed claims are reproduced and discussed in Part VI.A.(4) of these reasons below.
IV. Issues
[24] There are three principal issues in this proceeding. They are as follows:
1) Are the Wet Granulation Elements in claims 1 – 3 and 6 essential?
2) Is the prosecution history of the ‘002 Patent admissible against Allergan, pursuant to section 53.1 of the Act? If so, what is the impact, if any, of amendments to the claims and corresponding representations that were made to the Patent Office by a representative of Kissei?
3) Is the ‘002 Patent invalid on the ground of obviousness?
V. Witnesses
[25] Allergan and Sandoz agreed on the qualifications of the four expert witnesses who testified in this case.
A. Allergan’s Witnesses
(1) Dr. Linda Felton
[26] Dr. Felton is a Professor of Pharmaceutics and Chair of the Department of Pharmaceutical Sciences at the University of New Mexico College of Pharmacy. She is an expert in pharmaceutical formulation, principally of solid oral dosage forms, qualified to opine on formulation methods (including wet granulation, dry granulation, and dry blending), the role of excipients used in formulation, evaluating and assessing dissolution, and the physical and chemical properties of excipients and pharmaceutical compositions.
[27] Dr. Felton testified with respect to the “infringement” and “obviousness” issues in this proceeding. More specifically, she testified with respect to the essential elements of claims 1, 2, 3 and 6 of the ‘002 Patent, and whether that patent is invalid on the ground of obviousness. She also opined on related issues such as the person of skill in the art to whom the ‘002 Patent is addressed [the Skilled Person], the common general knowledge of the Skilled Person, how the ‘002 Patent would have been understood by the Skilled Person, the prior art, certain Kissei internal documentation, and the invention contemplated by the patent. In addition, she commented upon experimental tests that were conducted by Dr. MacGregor.
[28] Dr. Felton’s testimony was generally straightforward and frank. She readily made certain concessions on cross-examination. Although counsel encountered some difficulty obtaining answers from her on other occasions, it appeared that this was because she was endeavouring to be precise or to identify potentially important nuances. Broadly speaking, her testimony was better supported and more helpful with respect to the issue of obviousness than it was with respect to the issue of the essential elements of the ‘002 Patent.
(2) Ms. Jenna Wilson
[29] Ms. Wilson is a registered and practicing lawyer and Canadian and United States Patent agent with over 20 years of experience in patent practice. She has expertise in the drafting, filing and prosecution of patent applications before the Canadian Intellectual Property Office [CIPO] and the United States Patent and Trademark Office [USPTO], and in the analysis and interpretation of communications between the Canadian Patent Office and patent applicant leading to the granting of a patent.
[30] Ms. Wilson testified on behalf of Allergan with respect to the legislative history of section 53.1 of the Act and the prosecution history of the ‘002 Patent. Her testimony in relation to the legislative history of section 53.1 was generally direct, straightforward and helpful. However, given the conclusion that I have reached regarding the interpretation of section 53.1, her evidence concerning the prosecution history of the ‘002 Patent had no bearing on my decision.
(3) Dr. MacGregor
[31] Dr. MacGregor is the President and Dean of Faculty at the Toronto Institute of Pharmaceutical Technology [TIPT], an institute for industrial pharmaceutical education. He has taught a variety of courses at TIPT for about 28 years, and has been performing dissolution testing for approximately 30 years.
[32] Dr. MacGregor was a fact witness who testified with respect to dissolution testing experiments he conducted on behalf of Allergan.
[33] Dr. MacGregor’s testimony was candid, very forthcoming and to the point.
B. Sandoz’s Witnesses
(1) Dr. Reza Fassihi
[34] Dr. Fassihi is a Professor of Biopharmaceutics and Industrial Pharmacy at Temple University. He is an expert in: the design of drug delivery systems; preformulation and formulation methodologies for drug delivery systems; excipients/non-medicinal ingredients used in drug delivery systems; the evaluation of drug delivery systems, including bioavailability and dissolution studies; and regulatory requirements relating to drug delivery systems. With respect to each of these five fields, Dr. Fassihi has particular expertise in relation to solid oral dosage forms.
[35] Dr. Fassihi testified with respect to essentially the same issues that were addressed by Dr. Felton. Broadly speaking, his testimony was less straightforward than Dr. Felton’s testimony, as he had several memory lapses (while being strikingly clear on other issues), he seemed reluctant to answer what appeared to be straightforward questions and his testimony was not entirely consistent on occasion. Moreover, his evidence with respect to the obviousness issue was not as well supported or persuasive as Dr. Felton’s evidence. In addition, his testimony conveyed a sense of advocacy on a significant number of occasions, when he went beyond providing an answer by adding out-of-context commentary to convey his view that something was obvious. With the foregoing in mind, I generally found Dr. Felton’s testimony to merit greater weight, and to be more persuasive, than Dr. Fassihi’s on the issue of obviousness.
[36] Nevertheless, I found Dr. Fassihi’s evidence to be very helpful and straightforward regarding the experiment conducted by Dr. MacGregor. It was also forthcoming and helpful with respect to certain matters that had a bearing on the issue of the essentiality of the Wet Granulation Elements. I generally found his testimony to be more persuasive than Dr. Felton’s on these two matters.
(2) Mr. Michael I. Stewart
[37] Mr. Stewart is a registered Canadian and United States Patent agent with over 40 years of expertise in: 1) the preparation, filing and prosecution of patent applications before the CIPO, the USPTO, and other foreign Patent Offices in areas such as chemistry and pharmacology; and 2) the analysis and interpretation of communications between the Patent Office and the patent applicant leading to the grant of a patent.
[38] Dr. Stewart testified on behalf of Sandoz with respect to the ‘002 Patent prosecution process, his interpretation of the positions taken by the patent examiner and by Kissei (through its agent Kirby Eades Gayle Baker), and whether certain of Dr. Felton’s opinions are consistent with the ‘002 Patent prosecution history. His testimony was candid, straightforward and forthright. However, given the conclusion that I have reached regarding the interpretation of section 53.1 of the Act, his testimony did not have a bearing on my decision.
VI. Analysis
A. Claim Construction
(1) Legal Principles
[39] The claims of a patent must be construed before conducting an assessment of the patent’s validity or infringement: Whirlpool Corp v Camco Inc, 2000 SCC 67 at para 43 [Whirlpool].
[40] In performing this exercise, the language of the claims must be read in an informed and purposive way, from the perspective of a skilled person: Free World Trust v Électro Santé Inc, 2000 SCC 66 at para 44 [Free World].
[41] The Skilled Person is presumed to have a mind willing to understand the claims, but to be unimaginative and uninventive. This “person” is often a hypothetical individual or combination of individuals with different skills. It is on the basis of the Skilled Person’s “common knowledge”, sometimes referred to as “common general knowledge”, that the claims of the patent must be construed: Free World, above, at paras 20, 31(e) and 44; Bell Helicopter Textron Canada Limitée v Eurocopter, société par actions simplifiée, 2013 FCA 219 at paras 64-65 [Bell Helicopter]; Hospira Healthcare Corporation v Kennedy Trust for Rheumatology Research, 2020 FCA 30 at para 79 [Hospira Healthcare (FCA)]; Teva Canada Limited v Janssen Inc, 2018 FC 754 at paras 64-66, aff’d 2019 FCA 273 [Teva-Janssen].
[42] In construing the claims of a patent, the Court may require the assistance of expert evidence, for example, with respect to the technical meaning of the terms and concepts used in the claims, and how they would have been understood by the Skilled Person: Free World, above, at para 51. However, at the end of the day, claims construction is a matter of law for the Court alone: Whirlpool, above, at para 61.
[43] Where the wording of the claims in a patent are clear and unambiguous, it is generally improper to have recourse to other parts of the patent in construing those claims: Mylan Pharmaceuticals ULC v Eli Lilly Canada Inc, 2016 FCA 119 at paras 39 and 43 [Mylan Pharmaceuticals].
[44] However, to ensure a construction that is reasonable and fair to both the patentee and the public, the Court may have regard to the specification as a whole. In brief, this can shed light upon the meaning of terms used in the claims or disclose an ambiguity that is not apparent from a reading of the claims alone: Whirlpool, above, at paras 48, 49(g), 52 and 53; Teva-Janssen, above, at paras 73-76.
[45] Nevertheless, the focus of the assessment must remain on the language of the claims: Free World, above, at paras 39-40 and 66. The public is entitled to rely on that language, so long as is interpreted “fairly and knowledgeably”: Free World, above, at para 51. Once the wording of the claims is so interpreted, language situated elsewhere in the patent cannot be relied upon to enlarge or contract the scope of the claims as written, or to achieve a desired result: Whirlpool, above, at para 52; Free World, above, at para 32. This is because “it is the claims, not the rest of the specification, that define the monopoly”: Whirlpool, above, at para 18. In essence, those claims represent the “fences” and “boundaries” of the patent, which give the “fields” of the monopoly “a comfortable pretence of bright line demarcation”: Free World, above, at para 14. For this reason, it is impermissible to have recourse to indications of what may have been the underling “spirit of the invention”: Free World, above, at para 31(d).
[46] In determining which elements in a claim are essential and which are non-essential, the Court begins with the presumption that all of the elements are essential. The party alleging otherwise therefore bears the onus of establishing non-essentiality: Free World, above, at para 57; Teva-Janssen, above, at para 70.
[47] That onus can be met by demonstrating either (i) that on a purposive construction of the words of the claim it was clearly not intended that a particular element be essential, or (ii) that at the date of publication of the patent, the skilled person would have appreciated that the element in question could be substituted without affecting the working of the invention. Another way of stating the latter part of the test is to ask whether the skilled person would have considered it to be obvious that the invention would “work in the same way” with the substituted variant, in the sense of “performing essentially the same function in substantially the same way to obtain substantially the same result”: Free World, above, at para 55.
[48] I am aware that in Shire Canada Inc v Apotex Inc, 2016 FC 382 at para 137, the Court suggested that the Supreme Court of Canada likely intended the disjunctive test described in (i) and (ii) of the immediately preceding paragraph to be conjunctive. However, given the findings that I have made in Part VI.A.(4) below with respect to the two prongs of the test for essentiality, nothing in this decision turns on the issue of whether that test is disjunctive or conjunctive.
[49] In ascertaining the inventor’s intention, the Court must confine itself to objective manifestations of that intent in the claims of the patent, interpreted through the eyes of the skilled person at the relevant date and without resort to extrinsic evidence (except to the extent now permitted by section 53.1 of the Act): Free World, above, at para 66.
[50] In purposively construing the claims, it is incumbent upon the Court to keep in mind that the scope of patent protection must be reasonably predictable and uncertainty must be kept to a minimum. In turn, this requires “that the subjective or discretionary element of claims interpretation be kept to a minimum, consistent with giving ‘the inventor protection for that which he has actually in good faith invented’…”: Free World, above, at para 43, citing Western Electric Co v Baldwin International Radio of Canada, [1943] SCR 750 at 574. Among other things, this avoids chilling potential investment and competition: Free World, above, at paras 41-42 and 50.
[51] For the purposes of construing the claims of the ‘002 Patent, the relevant date is the Publication Date, i.e., July 1, 2004. For greater certainty, the claims of a patent must be given the same interpretation for all purposes, regardless as to whether there may be different relevant dates for such purposes: Whirlpool, above, at para 49(b).
(2) The Skilled Person
[52] Allergan and Sandoz, together with and their experts (Dr. Felton and Dr. Fassihi, respectively), generally agree regarding the credentials of the Skilled Person in relation to the ‘002 Patent. However, Dr. Fassihi opined that the Skilled Person (to whom he referred as the “skilled formulator”) would have somewhat more experience or relevant education.
[53] For Dr. Felton, nothing turned on this minor disagreement. She maintained that her opinions regarding the issues in dispute would remain unchanged even if the Skilled Person were considered to have the additional experience or education described by Dr. Fassihi.
[54] Dr. Fassihi did not explain why he considered the Skilled Person to have at least two years more experience or additional education, relative to the Skilled Person described by Dr. Felton. By contrast, Dr. Felton supported her description of the Skilled Person as follows:
Each of the excipients and their general function in formulations is taught to undergraduate students in pharmaceutics or pharmacy programs. The excipient compatibility and dissolution tests described in the 002 Patent would be understood by and be of interest to undergraduate students in the same discipline. The function(s) of different excipients and the desire to achieve a defined dissolution rate are each described in textbooks from which I have taught.
[55] Given the foregoing explanation, I accept Dr. Felton’s position regarding the experience and education of the Skilled Person. In brief, that person would hold a Bachelor’s degree in pharmaceutical sciences, chemistry, or another related scientific discipline and would have one to three years of experience applying his or her education in a laboratory. The laboratory experience would relate to the formulation of drugs and could have been gained through graduate studies or at a job in the pharmaceutical industry.
[56] During the trial of this action, Dr. Felton testified that while the Skilled Person would know how to prepare formulations, he or she may not be responsible for selecting the excipients to be used in a drug, except in relation to “simple drug products with easy formulation, you know, a stable chemical, very water soluble …”: Public Transcript, at 62. Sandoz interpreted this as suggesting that the Skilled Person, as defined by Dr. Felton and Allergan, “is incapable of formulating a low-solubility drug without assistance – the very problem that the ‘002 Patent purportedly addresses”. I do not interpret Dr. Felton’s testimony in this manner. In my view, Dr. Felton was simply stating that the Skilled Person would not necessarily be responsible for selecting the excipients ultimately used in a drug, before it is finalized for use. Her confirmation that the Skilled Person knows how to formulate drugs implies that the Skilled Person as she defined him/her would have been “sufficiently versed in art to which the patent relates to enable such person on a technical level to appreciate the nature and description of the invention and to put it into practice”: Donald H. MacOdrum, Fox on the Canadian Law of Patents, 5th ed (Toronto: Thomson Reuters, 2019) (loose-leaf updated 2020-6) at §4.13.
[57] In any event, keeping in mind that “[t]he Court must take a fair and generous view as to what sort of person comprises a person skilled in the art” (Janssen-Ortho v Novopharm, 2006 FC 1234 at para 90, aff’d 2007 FCA 217), I consider that the Skilled Person is someone who is familiar with the excipients identified in the ‘002 Patent, as well as with their functions and the alternative excipients available to perform those functions. For greater certainty, the Skilled Person is also someone who has “the ability to pursue reasonable and logical inquiries”: Apotex Inc v Syntex Pharmaceuticals International Ltd (1999 CarswellNat 4895, 1 CPR (4th) 22 at para 39 (FCTD), quoting John Bochnovic, "Invention/Inventive Step/Obviousness" in G.F. Henderson, ed., Patent Law of Canada (Scarborough, Ontario: Carswell, 1994) at 47-48.
(3) Common General Knowledge
[58] Common general knowledge [CGK] refers to the knowledge generally known by the Skilled Person at the relevant time: Apotex Inc v Sanofi-Synthelabo Canada, 2008 SCC 61 [Sanofi] at para 37. This includes the subset of patents, journal articles and technical information that are generally acknowledged to form part of the CGK in the field to which the patent relates. However, it does not include knowledge of all journal articles or other technical information: Bell Helicopter, above, at paras 64-65; Janssen Inc v Teva Canada Ltd, 2020 FC 593 at para 109. For the purposes of patent construction, the relevant time is the patent publication date, in this case, July 1, 2004.
[59] Allergan and Sandoz, generally agree regarding the CGK of the Skilled Person. In particular, it is common ground between them and their respective experts (Dr. Felton and Dr. Fassihi) that the CGK of the Skilled Person would have included a general understanding of:
solid oral dosage forms and the general requirements of dosage forms. This includes tablets, capsules, powders and granules, as well as the fact that powders and granules are often incorporated into capsules for convenience;
common excipients (inactive ingredients) used in pharmaceutical tablets and capsules, and the reasons why particular excipients may be used, including to aid in manufacturing/processing or product performance, and to improve the drug dissolution rate and/or drug stability – common excipients include diluents/fillers/bulking agents (including lactose and mannitol), binders (including starches and pre-treated starches), lubricants (including magnesium stearate), surfactants (including SLS) and disintegrants (including pre-treated starches);
the fact that some common excipients can fill multiple roles within a formulation;
the fact that excipients and the length of mixing time can affect dissolution times;
the importance of drug dissolution rates, dissolution studies and the methodologies to measure the dissolution profile of a drug;
common handbooks and guidelines regarding pharmaceutical formulations, such as: Alfonso R. Gennaro, ed, Remington: The Science and Practice of Pharmacy, 20th ed (Baltimore: Lippincott Williams & Wilkins, 2000) [Remington]; Arthur H. Kibbe, ed, Handbook of Pharmaceutical Excipients, 3rd ed (Washington: American Pharmaceutical Association Press, 2000); The Pharmacopeia of the United States, 25th ed (Rockville, MD: United States Pharmacopeial Convention, 2011); the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use Guidelines; and the Food and Drug Administration’s Guidelines regarding active ingredients and finished dosage forms;
tests performed to assess drug potency and content uniformity, and be able to interpret the results from such tests; and
various manufacturing methods, including (i) wet granulation – including powder granulation, flued-bed wet granulation and spray-dry granulation; (ii) dry granulation; and (iii) dry blending (which can be used entirely separately, or as simply the first step in both wet and dry granulation).
[60] Allergan and Sandoz, supported by Dr. Felton and Dr. Fassihi, respectively, also appear to agree that the CGK of the Skilled Person would have included:
the knowledge that, in a wet granulation process, a lubricant is typically added near the end of the formulation process, before tableting or the filling of capsules,
an understanding of common pre-formulation steps, including optimization procedures, statistical design, the design or experiments or factorial design and tests/processes to determine how an API would interact with common excipients and behave under formulation conditions, such as dry blending and wet granulation;
an understanding of the potential impact of subjecting an API to compression forces (which are part of the tableting process); and
an understanding that if there were other products on the market from the same family of drugs (similar chemical structure), those products should be researched to determine what excipients were used with those formulations.
[61] However, despite the representation in the Joint List of Issues that their respective “experts generally agree regarding the [CGK] of the Skilled Person”, Allergan and Sandoz disagreed about whether 13 articles addressed in the First Fassihi Report formed part of the relevant CGK or the broader “state of the art”. Four of those articles focus on matters relating to light and discolouration that are no longer relevant in this proceeding. The remaining nine articles deal with issues addressed in the immediately preceding paragraphs above. Dr. Felton opined that those articles do not form part of the relevant CGK, as they relate to different therapeutic classes, different biological targets and different chemical structures. For this reason, she added that they would not likely have been found by the Skilled Person on a reasonably diligent search. I do not consider this disagreement between Dr. Felton and Dr. Fassihi in relation to those articles to have a material bearing on the claim construction issue in this proceeding. However, pursuant to the recent decision in Hospira Health (FCA), above, at para 86, those articles must be considered in the obviousness analysis, regardless of whether they may not have been found by the Skilled Person in the course of a reasonably diligent search. This is because they form part of the body of information “available to the public in Canada or elsewhere”, within the meaning of section 28.3 of the Act. The issue of whether the Skilled Person would have found those articles on a reasonably diligent search and then thought to combine their collective teachings with the other CGK and with the other prior art discussed later in these reasons is something that is relevant to the fourth step in the obviousness analysis: Hospira Health (FCA), above at para 86; Biogen Canada Inc v Taro Pharmaceuticals, 2020 FC 621 at para 153 [Biogen].
[62] Allergan and Sandoz, also disagree on certain other aspects of the CGK of the Skilled Person. The principal disagreements in this regard are based on disagreements between Dr. Felton and Dr. Fassihi that will be addressed in Parts VI.A.(4) and VI.B of these reasons, dealing with the essential elements of the ‘002 Patent and obviousness, respectively.
(4) The Essential Elements of the ‘002 Patent
[63] The ‘002 Patent contains six claims. Only four of them are in dispute. Those are claims 1-3 and 6, which state as follows:
1. A capsule which comprises:
(1) a granule prepared by wet granulation of a mixture of a) as the active ingredient, an indoline compound represented by the formula:
b) D-mannitol and c) partially pregelatinized starch; and (2) d) a lubricant selected from the group consisting of magnesium stearate, calcium stearate and talc, and e) sodium lauryl sulfate, wherein 85% dissolution time of the capsule is not more than 15 minutes in a dissolution test according to method 2 (paddle method) of the Japanese pharmacopoeia in a condition using water as a test medium and a paddle speed of 50rpm.
2. The capsule according to claim 1, wherein the lubricant is magnesium stearate.
3. The capsule according to claim 2, which further comprises 0.1 to 2 parts of sodium lauryl sulfate based on 1 part of magnesium stearate.
…
6. A method for preparing a capsule, comprising the steps of (1) granulating a compound represented by the formula:
b) D-mannitol and c) partially pregelatinized starch by a wet granulation process; and (2) mixing the granule obtained in step (1), d) a lubricant selected from magnesium stearate, calcium stearate and talc, and e) sodium lauryl sulfate.
[64] There is no significant dispute in this proceeding regarding the meaning of the words in the foregoing claims. Instead, Allergan and Sandoz disagree on whether the Wet Granulation Elements are essential. For greater certainty, it is common ground between them that the “compound” described in claims 1 and 6, is silodosin.
[65] For the reasons that follow, I consider that the Wet Granulation Elements are essential in each of Claims 1-3 and 6.
(a) Claim 1
[66] Among other things, claim 1 claims a capsule formulation comprising “a granule prepared by wet granulation of a mixture of” silodosin and certain identified excipients. As mentioned above, there is no dispute in this proceeding with respect to the identified excipients and there is no dispute with respect to the words “wherein 85% dissolution time of the capsule is not more than 15 minutes in a dissolution test according to [Method 2]”. The sole claims construction dispute is with respect to whether the Wet Granulation Elements are essential.
[67] On a plain reading of claim 1, the terms “granule” and “prepared by wet granulation” are unambiguous. There is nothing in the language of claim 1 itself to suggest that these elements, which have the effect of limiting the scope of the claim, were not intended to be essential. Accordingly, those elements are presumed to be essential. This presumption will hold unless it is established either (i) that on a purposive construction of the patent disclosure and claims as a whole, those elements were not intended to be essential (Whirlpool, above at paras 48, at 49(g)), or (ii) that at the Publication Date the Skilled Person would have appreciated that those elements could be substituted without affecting the working of the invention: Free World, above, at para 55. (See discussion at paras 46
- 48
above.) I will now address each of those two prongs of this test separately below.
(i) The First Prong of the Test: A Purposive Construction of the Wet Granulation Elements
[68] Allergan and Dr. Felton maintain that there are a number of indicators in the ‘002 Patent that reveal that the Wet Granulation Elements were not intended to be essential. I disagree.
[69] Allergan and Dr. Felton insist that the Skilled Person would have understood that the claims of the ‘002 Patent focus upon, and are directed to, a specific combination of excipients and silodosin in capsule formulations that achieve a well-defined dissolution profile. That profile is 85% dissolution in not more than 15 minutes in a test according to Method 2. Stated differently, the achievement of 85% silodosin dissolution within 15 minutes, as described above, was the purported essence of the invention. This achievement was important because a drug’s dissolution profile and batch-to-batch uniformity can be critical for both efficacy and safety. In addition, the rapid dissolution profile per