Ratiopharm Inc. v. Pfizer Limited

Ratiopharm Inc. v. Pfizer Limited
Court (s) Database
Federal Court Decisions
Date
2009-07-08
Neutral citation
2009 FC 711
File numbers
T-1712-07
Decision Content
Federal Court
Cour fédérale
Date: 20090708
Docket: T-1712-07
Citation: 2009 FC 711
BETWEEN:
RATIOPHARM INC.
Plaintiff
and
PFIZER LIMITED
Defendant
REASONS FOR JUDGMENT
(Public version of the Confidential Reasons
for Judgment issued July 8, 2009)
HUGHES J.
[1] This action deals with the validity of Canadian Patent 1,321,393 (the ’393 Patent). The Plaintiff Ratiopharm Inc. seeks a declaration under section 60(1) of the Patent Act, R.S.C. 1985, c.P.4, that the ’393 Patent is invalid and a direction under section 62 of the Patent Act that an entry in the records of the Canada Patent Office be made to that effect. For the Reasons that follow, I find that the ’393 Patent is invalid and that such a declaration will be given. Ratiopharm is entitled to its costs.
INDEX
[2] To assist the reader, the following is a Table of Contents for these Reasons giving paragraph numbers for each heading:
THE PARTIES........................................................................................... [3] to [4]
THE ’393 PATENT.................................................................................. [5] to [10]
AGREED FACTS AND DOCUMENTS ............................................. [11] to [12]
PREVIOUS LITIGATION.................................................................... [13] to [18]
THE WITNESSES.................................................................................. [19] to [26]
ISSUES.................................................................................................... [27] to [28]
PERSON SKILLED IN THE ART....................................................... [29] to [31]
DATE OF INVENTION........................................................................ [32] to [34]
CONSTRUCTION OF THE PATENT – CLAIM 11........................... [35] to [44]
DEVELOPMENT OF A PHARMACEUTICAL IN THE
MID 1980S............................................................................................. [45] to [51]
DEVELOPMENT AND PATENTING OF AMLODIPINE
BESYLATE........................................................................................... [52] to [107]
THE “INVENTION” AS PROMISED BY THE ’393 PATENT..... [108] to [112]
COMPARING WHAT THE ’393 PATENT SAYS AND
WHAT ACTUALLY HAPPENED..................................................... [113] to [152]
CONCLUSIONS AS TO WHAT THE INVENTORS DID
AND WHAT THE PATENT SAYS................................................................. [153]
ADDRESSING THE LEGAL ISSUES............................................. [154] to [204]
A. General ...................................................................................... [154]
B. Obviousness............................................................................... [158]
C. Selection Patent.......................................................................... [174]
D. Utility.......................................................................................... [181]
E. Sufficiency.................................................................................. [187]
F. Section 53.................................................................................. [195]
CONCLUSION................................................................................... [205] to [207]
COSTS................................................................................................ [208] to [209]
THE PARTIES
[3] The Plaintiff Ratiopharm Inc. (sometimes spelled ratiopharm inc.) is a Canadian corporation located in Montréal. It previously was engaged in proceedings in this Court under the provisions of the Patented Medicines (Notice of Compliance) Regulations, SOR/93-133, as amended (NOC Regulations), as a generic pharmaceutical supplier or “second person” as defined in the NOC Regulations, respecting the ’393 Patent. There is no dispute that Ratiopharm is an “interested person” within the meaning of section 60(1) of the Patent Act in seeking the relief requested herein.
[4] The Defendant Pfizer Limited is a United Kingdom corporation located in England. The ’393 Patent on its face states that it was issued and granted to Pfizer Limited. No contest has been made as to the continued ownership of the patent by Pfizer Limited. The Patent Act refers to a patent owner such as Pfizer Limited as the patentee.
THE ’393 PATENT
[5] The patent at issue is Canadian Patent No. 1,321,393. It was issued and granted to Pfizer Limited on August 17, 1993. The application for this patent was filed with the Canadian Patent Office on April 2, 1987 thus the provisions of the “old” Patent Act, applicable to patents maturing from applications filed before October 1, 1989, apply to the ’393 Patent. Thus, unless a challenge to the validity of this patent is successful, it will expire 17 years from the date it was granted, that is on August 17, 2010.
[6] The ’393 Patent claims priority from an application for a patent filed with the United Kingdom Patent Office, Application No. 8608335, on April 4, 1986. A copy of that application has been filed as Exhibit 1 Document 126.
[7] Edward Davison and James I. Wells are named in the patent as inventors. Both of these persons testified at the trial of this action.
[8] The ’393 Patent is entitled “Besylate Salt of Amlodipine” and states in the opening paragraph of the specification at page 1:
“The present invention relates to the improved pharmaceutical salts of amlodipine and pharmaceutical compositions thereof”
[9] The parties have agreed that the validity of the patent as a whole will be determined on the basis of the validity of Claim 11. That claim reads as follows:
“11. The besylate salt of amlodipine.”
[10] I will consider this patent further.
AGREED FACTS AND DOCUMENTS
[11] I have been greatly assisted by counsel for the parties who have come to an agreement on some facts for the purposes of this action and, more particularly, to an agreement as to some 168 documents which may be relevant and have been entered as Exhibit 1 at trial. The individual documents in Exhibit 1 are referred to by Tab numbers. It has been agreed that those documents do not have to be proved in evidence, that they are true copies of the originals sent and received by the parties as indicated on the face on or about the dates as indicated on their face and that the published documents were published on the date indicated on their face. After discussion with Counsel for the parties during argument it was also agreed that the Court should on be required to have regard to those documents in Exhibit 1 that had been specifically referred to by a witness in giving direct evidence or in cross-examination or had been referred to as part of an expert report or in those portions of discovery as put in evidence at trial.
[12] For convenience, I repeat the Agreed Facts which were entered as Exhibit 2:
1. The plaintiff, ratiopharm inc. is a corporation organized and existing under the laws of Canada and having a registered head office at 17800 Rue Lapointe, Mirabel, Quebec, J7J 1P3.
2. The defendant, Pfizer Limited, is a corporation organized and existing under the laws of the United Kingdom and has a principal office or place of business at Ramsgate Road, Sandwich, Kent, CT13 9NJ, England.
3. The defendant is the named owner of Canada Patent 1,321,393 (the “393 Patent”).
4. The 393 Patent is based on an application filed in Canada on April 2, 1987.
5. The 393 Patent claims priority from U.K. patent application 8608335 filed on April 4, 1986.
6. The 393 Patent was issued on August 17, 1993.
7. The 393 Patent expires on August 17, 2010.
PREVIOUS LITIGATION
[13] The ’393 Patent has been the subject of previous litigation in this Court and in the Federal Court of Appeal in the context of the Patented Medicines (Notice of Compliance) Regulations, SOR/93-134,as periodically amended- (NOC) Regulations.
[14] In Pfizer Canada Inc. and Pfizer Limited v. Canada (Minister of Health) and Ratiopharm Inc., February 17, 2006, 2006 FC 220, 46 CPR (4th) 281, Justice von Finckenstein of this Court (as he then was) dismissed an application for prohibition holding that Pfizer had failed to prove that the allegations as to invalidity of the ‘393 Patent were not justified. He held, at paragraph 58 of his reasons that he did not need to deal with the issue of obviousness. The Federal Court of Appeal in a decision delivered on June 9, 2006, 2006 FCA 214, 52 CPR (4th) 241, allowed the appeal and issued a prohibition Order holding that the allegations as to invalidity of the ’393 Patent were not justified. In a related decision based on what the Federal Court of Appeal held to be speculative new matters, Ratiopharm’s application to set aside that Federal Court of Appeal decision was dismissed on December 18, 2007, 2007 FCA 407.
[15] The ’393 Patent came before me in Pfizer Canada Inc., Pfizer Inc. and Pfizer Limited v. Canada (Minister of Health) and Pharmascience Inc. I delivered a decision on April 17, 2008, 2008 FC 500, 326 FTR 88, allowing the application for prohibition. I concluded at paragraph 117:
[117] In conclusion, I have found that Pharmascience is precluded by the earlier “Ratiopharm” litigation from asserting obviousness challenges to the ’393 patent. Given the recent decision of the Federal Court of Appeal, 2008 FCA 108 in Pfizer v. Canada (Minister of Health), the challenge to validity on the basis of sufficiency fails. On the balance of probabilities the challenge to validity bases on lack of utility fails. As a result, Pharmascience’s allegation that the ’393 patent is invalid is not justified. Pfizer is entitled to an Order prohibiting the Minister from issuing a Notice of Compliance to Pharmascience in respect of its application respecting 5 and 10 mg tablets containing amlodipine besylate at issue in these proceedings.
[16] A related patent, United States Patent 4,879,303 (the ’303 Patent), put in evidence as Exhibit 60, has been the subject of litigation in that country. The United States District Court for the Middle District of North Carolina in Pfizer Inc. v. Synthon Holdings BV et al in proceedings identified as 1:05CV39, held the ‘303 Patent to be valid and infringed. The United States Court of Appeals for the Federal Circuit (US CAFC) reversed that decision holding the ’303 Patent to be invalid for obviousness in a decision reported at 480 F.3d 1348, U.S. App. Lexis 6623, 82 U.S.P.Q. 2D (BNA) 1321.
[17] The United States Court decisions are not binding upon this Court and are based on law that may in some respects be different from ours. Nonetheless, the decisions may be instructive.
[18] The decisions of this Court and the Federal Court of Appeal were dealt with in the context of NOC Regulations and do not constitute res judicata in the present action. Again, however, they are instructive.
THE WITNESSES
[19] The Plaintiff Ratiopharm Inc. called 5 witnesses at trial, all as expert witnesses. The Defendant Pfizer Limited called 8 witnesses of which 5 were fact witnesses and 3 were expert witnesses. Each party also entered portions of the transcripts of the discovery of the opposite party. Exhibit 4 is portions of the transcripts and exhibits to the discovery of the Defendant Pfizer Limited. Exhibit 5 is portions of the transcripts of the discovery of the Plaintiff Ratiopharm Inc.
[20] By agreement between counsel, the Defendant Pfizer Limited called some of its factual witnesses first. They were examined in chief and cross-examined. They are, in the order that they were called:
(1) Dr. James I. Wells, one of the two named inventors of the ’393 Patent. He worked with Pfizer Limited in the period from 1981 to 1989. He subsequently has worked with other pharmaceutical organizations and was a university lecturer and author of a text in that area. He testified as to his role in developing what became the subject matter of the ’393 Patent. I believe that he endeavoured to give honest and direct testimony even if he was at times somewhat brusque. He clearly stated in his replies when he did not know or could not remember and when his answers were based on speculation and conjecture. However, where his answers, were directed to obviousness or worth a try or empirical research, they seemed to be rehearsed. It became clear in Cross-Examination that a declaration that he swore in United States Patent Office contained a number of inconsistencies and misstatements. In general, I accept his evidence except where it is contradicted by documents such as, in particular, Exhibit 1, Document 111.
(2) Mr. Edward Davison, the other of the two named inventors of the ’393 Patent. He graduated with a B.Sc. in chemistry and joined Pfizer Limited in 1969 where he continued to work until his retirement in 2000. In the period from the mid 1970’s to 1989, he worked in pharmaceutical research and development. In that context, he worked on what became the subject of the ’393 Patent. He testified as to his role in that regard. I believe that Mr. Davison largely endeavoured to testify honestly, however, his answers were quite often prolix and filled with unnecessary detail which tended to obfuscate his answers. He would often not address the real questions. Therefore I am cautious when dealing with his testimony.
(3) Mr. Alan Pettman, a senior research fellow employed by Pfizer Limited. He was the person representing Pfizer Limited on discovery. Mr. Pettman joined Pfizer limited in 1977 and earned his Bachelor’s degree in chemistry while on the job. He remains with that company to this day. During the period in the early 1980s, he was engaged in the process research and development department and made most of the amlodipine salts which were the subject of the studies made by and on behalf of Wells and Davison. He gave his testimony in an honest and straightforward manner. I accept the evidence that he has given.
(4) Dr. Robin Platt, a PhD chemist in organic chemistry currently employed by an independent pharmaceutical formulation development company. He was employed by Pfizer Limited in the period from 1978 to 1993 where, in a variety of roles having increasing responsibility, he dealt with analytical chemistry including assessments of purity and quality. He testified as to his involvement in assessing amlodipine and amlodipine salts samples particularly as to stability. In general, he testified in a direct and honest manner, however, as Cross-Examination continued, he became somewhat unreasonable and awkward, answering many questions with a “not necessarily” then proceeding to make imperceptible points of difference such as whether a sample had melted as stated in a particular report or only gave an appearance of melting. For this reason, I will treat his evidence cautiously.
[21] At this point, the factual evidence of the Defendant was interrupted due to witness availability. The Plaintiff Ratiopharm Inc. next led the evidence of the following expert witnesses who were examined in chief and cross-examined. By agreement between counsel, the expertise of such witnesses put forward as experts by either side was not challenged but left to be determined, if necessary, in final argument. Further, by agreement between counsel, all expert reports of both parties were deemed to have been read in evidence subject to any corrections noted at the time that the reports were submitted in evidence. The Plaintiff’s experts were called in the following order:
(1) Dr. Ian M. Cunningham of the Orkney Islands, Scotland, an independent consultant to the pharmaceutical industry. He was trained as a medicinal chemist, awarded a Ph.D. and engaged in post-doctoral studies. He held several posts in major pharmaceutical innovator companies in the United Kingdom from 1977 onward, including working for ICI, a major pharmaceutical innovator company in the United Kingdom, in the 1980’s. He provided an initial report, exhibits to that report, and a rebuttal report marked as Exhibit 17, 18 and 19 respectively. I accept his evidence, he was not shaken nor did he retreat from his evidence on Cross-Examination. He spoke in a low voice and, on occasion, was difficult to hear, a problem that was rectified by microphones. He was forthright and honest. I am particularly impressed with his depth of actual experience in the pharmaceutical industry during the relevant period.
(2) Dr. Jerry L. Atwood of Columbia, Missouri. He is a professor and Department Chair of the Department of Chemistry at the University of Missouri – Columbia. He has since 1968 taught, and written many articles, edited journals and been granted patents in the area of solid state chemistry, crystallization and organic chemistry. He has consulted widely in the field of pharmaceutical chemistry. His first report is Exhibit 22 and the documents referred to in that report are Exhibits 23 and 24. His rebuttal report is Exhibit 25. He gave his evidence in a careful, clear and convincing manner. He answered the questions as put carefully and convincingly. I accept his evidence.
(3) Dr. Gilbert S. Banker of Carmel, Indiana. He is Dean Emeritus and Distinguished Professor of Drug Delivery Emeritus at the University of Iowa, College of Pharmacy. He obtained a Ph.D. in Industrial Pharmacy and Pharmaceutical Chemistry. He has since the early 1960’s taught many courses, written many books and articles and received many awards for work in the chemical and physical design for food, drug and cosmetic applications. He is listed in various “Who’s Who” publications. He has consulted to both innovator and generic pharmaceutical companies. He is very knowledgeable and experienced in the area of pharmaceutical preparation and apparatus for that purpose. His report is Exhibit 27 and the documents referred to in that report are Exhibits 28, 29, and 30. He gave his evidence in an honest and forthright manner. I accept his evidence.
(4) Dr. Gordon Amidon of Ann Arbor, Michigan. He is a professor of Pharmacy and Pharmaceutical Sciences at the College of Pharmacy at the University of Michigan. He received his Ph.D. in Pharmaceutical Chemistry from that University. He has taught, written and held leadership positions in pharmaceutical related areas for over 30 years. His report is Exhibit 35 and the documents referred to in that report is Exhibit 36. He gave his evidence in an honest and straightforward manner. I accept his evidence.
(5) Dr. Nicholas F. Cappucino of Lambertville, New Jersey. He is the Chief Scientific Officer of Eagle Pharmaceutical, a specialty pharmaceutical company involved in the preparation of dosage forms and difficult generic products. He received his Ph.D. in Organic Chemistry from the Stevens Institute of Technology, Hoboken, New Jersey. He has over30 years experience in the pharmaceutical industry. His report is Exhibit 40 and the documents referred to in that report are Exhibit 41. Although Dr. Cappucino gave his evidence in a clear and straightforward manner it is evident that he is closely associated with the generic pharmaceutical industry in many ways including representing that industry in various capacities in trade and government relations associations. I treat his evidence cautiously for that reason.
[22] The Defendant Pfizer Limited next called its expert witnesses who were examined and cross-examined in the following order:
1. Dr. Trevor Laird of East Sussex, England. He received a Ph. D. in organic chemistry and engaged in post-doctoral work in that area. He was engaged as a research pharmaceutical chemist at increasing levels of responsibility at Smith-Kline-French in the 1980’s period with which we are concerned. Presently he is engaged as a principal in Scientific Update, an organization that publishes literature and trains scientists and others in the chemical and pharmaceutical industries. His report is Exhibit 44 and the documents referred to in that report are Exhibit 45. He gave his evidence candidly except in the area of the use of benzene hydrochloric acid where when confronted with evidence to the contrary as to what was set out in his report he became overly defensive. Thus I will use his evidence cautiously in that area but only in that area since the balance of his evidence did provide a useful overview.
2. Dr. Gerald S. Brenner of Plymouth Meeting, Pennsylvania. He is a pharmaceutical chemist who has worked in the industry for over 40 years including working with Merck, a major pharmaceutical company, in the 1980’s in formulation development. He received a Ph. D. in organic chemistry from the University of Wisconsin. His report is Exhibit 48 and the documents referred to in that report are Exhibit 49. Dr Brenner has appeared frequently as a witness in this Court and elsewhere including giving testimony in other proceedings respecting the ‘393 Patent. On Cross-Examination he tended to avoid or obfuscate questions that he found difficult. I will treat his evidence very cautiously. When he conceded answers that were unfavourable to Pfizer those concessions must be given weight.
3. Dr. James McGinity of Austin, Texas. He is a tenured professor at the College of Pharmacy, University of Texas, teaching and having taught a number of courses in the pharmaceutical area. He received his Ph. D. in physical pharmacy from the University of Iowa in 1972. He has written and consulted widely in respect of a range of pharmaceutical formulation issues. His report is Exhibit 57 and the four Volumes of documents referred to in that report are collectively marked as Exhibit 58. Like Dr Brenner, Dr. McGinity has testified previously in this Court and in the United States Court system in respect of the ‘393 Patent and the US ‘303 Patent. He was confronted in Cross-Examination with several contradictions between his evidence given in the United States litigation and his evidence given in this case. I found his endevours to distinguish between his evidence in this action and the United States proceedings to be unsatisfactory. I found that initially his answers on Cross-Examination were succinct and to the point however when difficult questions arose he tended to avoid giving a direct answer or to obfuscate. I have difficulty in having any confidence in his evidence. Further his evidence in chief by way of a report (Exhibit 57) is drafted in a way that on several occasions leaves the impression that he is giving factual first hand evidence as to what the inventors or other at Pfizer said, did, or thought, which is not the case. He was not there and did not participate in the development work. By way of example he says at paragraph 37: “However because of their hygroscopicity, these salts were not progressed further” and in paragraph 38: “The inventors were not looking for a salt that met any particular numerical threshold”. There are other examples. His report says at paragraph 14(g) that he looked at “various other documents which I understand from counsel to Pfizer to have been produced in this matter”. At paragraph 45 he says “I am advised by counsel to Pfizer that there are limited data available…” Dr. McGinity said in Cross-Examination that he had not spoken to the inventors. Taking the tenor of his evidence as a whole I view it as containing much that is hearsay, prepared in conjunction with counsel for Pfizer, under the guise of giving expert evidence, while in reality providing a narrative of a Pfizer-biased view as to the development of the besylate product. In so doing Dr. McGinity overstepped the role of an expert and became an advocate. I will treat his evidence with great caution.
[23] The Defendant Pfizer Limited concluded the evidence by calling one more factual witness, who was examined and cross-examined. Counsel for Pfizer had indicated early in the trial that Dr. Davidson, a senior person at Pfizer Limited heavily involved in the relevant development work, would also be called as a witness for Pfizer but he never appeared. Pfizer’s Counsel in argument made reference to portions of Pfizer’s discovery read in at trial by Ratiopharm in which it was stated that Dr. Davidson had no recollection as to certain matters however this does not mean that he need not be called. Dr. Davidson could well have remembered various matters relevant to the issues and been made available for cross-examination. He was not. No reason has ever been given for his failure to testify at trial particularly since in the early days of the trial the Court was led to believe by Pfizer’s Counsel that he would appear. Pfizer concluded its evidence by tendering an affidavit upon which there was no Cross-Examination. The evidence therefore, as presented, was:
1. Dr. James W. Moore of Sandwich, Kent, England. He is a retired Chartered Patent Agent. He worked in the Pfizer Limited patent department from 1975 until his retirement in 2000. During that time he drafted and prosecuted patent applications and mentored the work of others including Jenny Bowery, a trainee who worked briefly with Pfizer in the mid 1980’s and left, apparently finding the chemistry too challenging. He gave evidence as to the preparation and filing of the parent UK patent application respecting the ‘393 patent. He gave his evidence in a clear and forthright manner but somewhat cryptically. I accept his evidence for what it is but must take it in conjunction with the documents that were generated at the time to derive a more complete picture.
2. An Affidavit of David Chametzky (Ex 56). This affidavit from the Manager of Pfizer Inc., parent of Pfizer Limited attests as to the unsuccessful efforts made to locate Jenny Bowery who at one time was a trainee in the Pfizer Limited patent department. Dr. Wells spoke of her in his evidence as did Dr. Moore. Certain documents put in evidence mention her name.
[24] In cases such as this, the Court must accept factual witnesses as they are, weighing their evidence based on the Court’s findings as to credibility and, where the evidence conflicts, weighing the evidence on the balance of probabilities. Here there is no evidence in conflict from a factual point of view although there are many gaps. For instance, Mr. Davison’s personal notebooks, including data as to stickiness and slope calculations, cannot be located. Much of the dialogue between the inventors and Pfizer’s patent personnel has been forgotten or is missing.
[25] As to the experts, there are conflicting opinions. I have expressed already my reservations concerning some of the evidence of some of these experts. I prefer the evidence of Dr. Cunningham where it conflicts with the evidence of others. He has a substantial background in pharmaceutical development including during the relevant period from a practical standpoint as a person working in the United Kingdom with an innovator pharmaceutical company. He gave his evidence in Cross-Examination in a direct and straightforward way. I give least weight to the evidence of Dr. Brenner and Dr. McGinity save where they gave admissions against their evidence as it would otherwise have been. Their evidence was seriously discredited during cross-examination. I accept the evidence of Dr. Laird as giving a good overview of the manner in which pharmaceuticals are developed but give less weight to his opinions as to benzenesulphonic acid. Dr. Banker, Dr. Atwood and Dr. Amidon are all highly qualified academics who have consulted widely in the pharmaceutical area. Their evidence is valuable from an academic point of view but less so from a “person in the trenches” point of view. I accept their evidence particularly in academic matters. I regret that I will give little weight to Dr. Cappucino’s evidence. His close ties with the generic pharmaceutical industry makes me apprehensive in placing substantial reliance on that evidence however well meaning his intent may have been.
[26] I contrast the evidence given in proceedings such as this action where witness can be observed live in the stand as opposed to the simple reading of affidavits and cross-examination transcripts as in NOC Proceedings. Live witness are much more valuable in seeking out the truth of a matter and sound opinions. I still regret however not being able to place all expert witnesses on similar subject matter on the stand at the same time so that Counsel and the Court can determine clearly where consensus exists and what controversies remain and why.
ISSUES
[27] The parties have agreed as to the issues for determination at trial, which agreement was entered as trial Exhibit 3. That agreement states:
1. The parties agree that the following are the issues to be determined at trial:
(a) Is the 393 Patent invalid for lack of novelty over EP 167?
(b) Is the 393 Patent invalid for failure to satisfy the requirements of a valid section patent?
(c) Is the 393 Patent invalid for obviousness in view of EP 167 and the prior art?
(d) Is the 393 Patent invalid for insufficiency of specification?
(e) Is the 393 Patent invalid for lack of utility?
(f) Is the 393 Patent invalid under Section 53(1) of the Patent Act?
2. The parties further agree that the validity of the 393 patent as a whole will be determined on the basis of the validity of claim 11.
[28] In final argument, Counsel for the Plaintiff advised the Court that the issue as to novelty (1(a)) would not be pursued. No issue as to the infringement of the ’393 Patent has been raised in this action.
PERSON SKILLED IN THE ART
[29] The patent, in particular Claim 11, is directed to a particular salt form of a pharmaceutical, amlodopine besylate. I accept the identification of the notional person skilled in the art or person of ordinary skill in the art (some lawyers use the acronym, POSITA) to whom the patent is addressed as set out by Dr. Cunningham at paragraph 158 of his first report, Exhibit 17, below. This description accords essentially with that expressed by Pfizer’s experts Dr. McGinity at paragraph 16 of his report (Ex 57) and Dr. Brenner at paragraph 17(a) of his report (Ex 48):
158. The Patent is addressed to salt selection for use in pharmaceutical formulations. The person skilled in the art would be a pharmaceutical development team comprising chemists (synthetic and analytical) and formulation scientists. Leaders within such a team may have a doctorate and many of the team members would have at least a Bachelor’s degree in chemistry or pharmacy or at least five years of practical experience in synthetic, or analytical chemistry or pharmaceutical formulation.
[30] That “person skilled in the art” plays a role as of different dates. For purposes of construction of the patent, that person plays a role as of the date the patent was granted, here August 17, 1993, since the ’393 Patent is an “old” Act patent (Whirlpool Inc. v. Camco Inc., [2002] 2 S.C.R. 1067 at para. 55).
[31] For the purposes of considering a question of “obviousness,” since this is an “old” Act patent, the relevant date is the “date of invention” (Windsurfing International Inc. v. Bic Sports Inc. (1985), 8 C.P.R. (3d) 241 at 256 (FCA); Johnson & Johnson Inc. v. Boston Scientific Ltd., 2008 FC 552, at para. 330).
DATE OF INVENTION
[32] The “date of invention” for an “old” Act patent such as the ’393 Patent at issue is initially accepted as being the date of filing the application for the patent in the Canadian Patent Office, here April 2, 1987. However, where priority is claimed from an application filed elsewhere, here Great Britain, it is presumed to be the filing date of that application, here April 4, 1986. An even earlier date may be established if the evidence shows that the inventors formulated orally or in writing a description which affords a means of making that which was invented (Apotex Inc. v. Wellcome Foundation Ltd., 2002 SCC 77, [2002] 4 S.C.R. 153 at pages 170-171; Johnson & Johnson Inc. v. Boston Scientific Ltd., supra, at para. 339).
[33] Usually if a date earlier than the priority date is relevant, it should be pleaded. There is no such pleading here. However, I have the evidence of the inventors Wells and Davison before me, as well as that of some of their colleagues. From that evidence, I find that it is reasonable to state that the “date of invention” is 25th November, 1985, the date of the so-called patent memorandum written by Wells for the purpose of instructing the Pfizer patent department to prepare a patent application (Exhibit 1, Document 111). I will refer to the course of the development work later in these Reasons.
[34] Amlodipine besylate had been made and tested previously by Wells and Davison, however, this is the first document that endeavours to pull together their work for the purpose of describing it to others.
CONSTRUCTION OF THE PATENT – CLAIM 11
[35] The jurisprudence directs that a Court, before dealing with issues as to validity of a patent, or infringement, must first construe the claim(s) at issue. Such a construction in the case of an “old” Patent Act patent, such as the one at issue here, is to be made by the Court as of the date it was granted, here August 17, 1993, through the eyes of a person skilled in the art to which the patent pertains. The Court is to look at the claims in the context of the entire patent specification, being neither benevolent nor harsh, to give meaning to the claim, not by applying this or that gloss, but by reading the document as a whole. Experts may assist as to the meaning of technical terms and as to the state of the art at the relevant time but construction is for the Court, not experts. [e.g. Whirlpool Inc. v. Camco Inc., supra. at paras. 43-45 & 57; Johnson & Johnson Inc. v. Boston Scientific Ltd., supra. at paras. 88 to 93; Janssen-Ortho Inc. v. Novopharm Inc. (2007), 59 C.P.R. (4th) 116 (FCA) at para. 4].
[36] In the present case, the parties have agreed that the validity of the ’393 Patent may be determined having regard to one claim only, Claim 11, which reads:
“11. The besylate salt of amlodipine.”
[37] This claim is quite straightforward. Besylate is a shortened form of the word “benzenesulphonate” which has for many years been known as one of the salts approved by the United States Food and Drug Agency (FDA) for pharmaceutical use. It is listed, among several other salts, in a paper acknowledged by all parties to be a definitive piece of prior art in the area, Berge et. al., “Pharmaceutical Salts,” January 1977, Journal of Pharmaceutical Sciences, Vol. 66, No. 1 at pages 1 to 19 (Berge), as being a “potentially useful salt” in dealing with pharmaceuticals.
[38] Amlodipine is acknowledged to have been a previously known pharmaceutical compound. The ’393 Patent describes it at page 1:
The compound amlodipine (3-ethyl 5-methyl 2-(2-aminoethoxymethyl) - 4 - (2-chlorophenyl) -1, 4-dihydro-6-methylpridine-3, 5-dicarboxylate) is a potent and long acting calcium channel blocker have utility as an anti-ischaemic and anti-hypertensive agent.
[39] The ’393 Patent continues, at page 1, to acknowledge that it was already known that several different pharmaceutically acceptable salt forms of amlodipine had been disclosed in a prior European patent application publication no. 89167 ( sometimes referred to in evidence in this case as the ‘167 patent). In particular, amlodipine maleate (which the evidence at trial shows is a short form of methanesulphonate) was a known preferred salt as set out at page 1 of the ‘393 patent:
European patent application publication no. 89167 discloses several different pharmaceutically acceptable salt forms of amlodipine. In particular, the pharmaceutically acceptable acid addition salts are said to be those formed from acids which form non-toxic addition salts containing pharmaceutically acceptable anions such as the hydrochloride, hydrobromide, sulphate, phosphate or acid phosphate, acetate, maleate, fumarate, lactate, tartrate, citrate and gluconate salts. Of these salts, the maleate is disclosed as being particularly preferred.
[40] Claim 11 can be construed as being directed to a particular salt form, besylate, of the known pharmaceutical compound amlodipine. Thus, for purposes of this action, the essential feature of Claim 11, and by agreement between the parties, all claims of the ’393 Patent, is that a particular salt form, besylate, of a known pharmaceutical compound, amlodipine, is the claimed invention.
[41] The ‘393 patent at page 6, the penultimate paragraph, states the rationale for choosing the besylate salt:
“Thus the besylate salt of amlodipine shows a unique combination of good solubility, good stability, non-hygroscopicity and good processability which makes it outstandingly suitable for the preparation of pharmaceutical formulations of amlodipine.”
[42] No particular use of the besylate salt form of amlodipine is stated in Claim 11. The ‘393 patent makes reference to three types of pharmaceutical formulations in which that salt that would be used beginning at the last paragraph on page 1 over to the next two paragraphs on page 2. They are: a tablet formulation, a capsule formulation and, a sterile aqueous solution for parenteral (iv or IV or intra-venous) administration.
[43] The ‘393 Patent does not make reference to any particular form that amlodipine besylate is to take, that is, whether it is solid, liquid or oily or, if solid, whether it is amorphous or crystalline or whether or not it is hydrated and, if so, to what extent is it hydrated. Dr. Brenner opined, with reference to Example 1 of the ‘393 patent, that the besylate salt of amlodipine, at least as prepared by that process, was potentially crystalline ( Cross-Examination, Volume 11, pgs 99-101). Dr. McGinity opined that the besylate could be anhydrous or a hydrate ( Cross-Examination, Volume 12, pages 48-75).
[44] I find that Claim 11 is to be read simply as it is, unrestricted as to any particular use, and unrestricted as to any particular form of the compound.
DEVELOPMENT OF A PHARMACEUTICAL IN THE MID 1980S
[45] The ‘393 Patent arises from work done during the pre-formulation stage in developing a commercial pharmaceutical producty and, in particular, a stage known as salt selection or salt screening.
[46] Dr. Laird discussed the salt screen process in his report, Exhibit 14. I repeat paragraphs 17, 22, 23, 24, 25 and 26:
17. A new drug substance is often produced as a free base, but its properties in that form can make it unsuitable for pharmaceutical formulation or administration to a patient. Free bases can often be oils or low melting solids, or non crystalline amorphous solids, and can be difficult to crystallise (e.g. stelazine, paroxetine and citalopram). As I explain further below, salts tend to be more crystalline than free bases with higher melting points and have other properties which make them easier to manufacture and formulate.
. . .
22. There are many other potential advantages to making a salt. The formation of a salt usually produces a solid form which is more stable and higher melting than the free base. The salt may, depending on the acid used to form the salt, have a higher aqueous solubility than the free base. In addition, it is usually easier to remove impurities from crystalline salts than from their free base counterparts. Thus, the salt formation step often leads to an important upgrade in quality of the drug substance. Salts are therefore often made as a means of purification of the drug substance as well as to provide the optimal formulated product.
F. How Salts Were Synthesized
23. During the 1980s in the pharmaceutical industry, companies tended to conduct salt screening (and other methodologies such as polymorph screening) in a manner that was not entirely systematic rather than through a strict standard operating procedure. The individual scientist would choose which acids to use and the conditions (such as the solvent, temperature, and concentration) under which to try