Friday, March 20, 2015

Product Claim Not Limited to Process Contemplated by Patentee

AstraZeneca Canada Inc v Apotex Inc / omeprazole 2015 FC 322 Barnes J
            1,292,693 / omeprazole formulation / LOSEC

In this Omeprazole formulation decision, which turned primarily on the facts, Barnes J held AstraZeneca’s ‘693 patent to valid and infringed. While the decision does not break new legal ground, it does illustrate some points of interest with respect to claim drafting, claim construction and litigation strategy. Also, in the bigger picture, some are inclined to characterize any pharmaceutical patent other than that for the API per se, and in particular formulation and dosage form patents, as “evergreening” patents which should not be allowed. In this case it was established that formulation of omeprazole presented a difficult problem which had to be solved to produce a medically useful drug and consequently, after a detailed review of the facts - the decision was 177 pages long - the invention was held to be non-obvious [273]. This contrasts with other recent cases, discussed here and here, in which dosage and formulation patents were held to be obvious. The lesson is a simple one, but perhaps worth repeating: sometimes formulation patents are good and sometimes they are bad, and either way, they are carefully scrutinized by the courts.

Claim Construction
Omeprazole was a known compound which was known to be a powerful inhibitor of gastric acid secretion and therefore useful for treating ulcers [5]. Omeprazole turned out to be a particularly difficult API to formulate [244]. It had to be enteric coated to prevent contact with acidic gastric juice, but a conventional enteric coating would react with omeprazole and cause degradation, particularly in storage [6]. The formulation used for Phase II trials was not stable enough for Phase III trials or commercialization [263]. The claimed invention solved this problem with an inert subcoating between the omeprazole core and the enteric coating. (Several claims were asserted but Claim 1 is representative.)

The main twist in this case was that the disclosure contemplated that the subcoating would be applied “by conventional coating procedures in a suitable coating pan or in a fluidized bed apparatus using water and/or conventional organic solvents for the coating solution” (p6). In Apotex’ product, in contrast, the putative subcoating was the end product of an in situ chemical reaction that occurs when the enteric coat is applied by Apotex to the pellet cores [303], and “AstraZeneca undoubtedly did not contemplate the in situ method of creating a subcoat when it applied for patent protection” [179].

In light of this, Apotex argued that Claim 1 does not cover a subcoat which forms in situ [168]. For several reasons, Barnes J rejected this as essentially an attempt to read limitations from the disclosure into the claims.

First, the claim was well drafted. The subcoating was set out in the claim as “(b) an inert subcoating . . . disposed on said core region.” Barnes J noted that “In this case the words “disposed on” do not carry a clear and particular meaning. If Claim 1 had used a limited verb such as “applied”, “coated” or “sprayed”, Apotex’s argument would likely have prevailed” [189]. Many of the difficult and leading claim construction cases arise when a drafter has chosen narrow language reflecting the inventor’s particular embodiment. In the ‘693 patent, the far-sighted decision to use a descriptive term without a fixed meaning may well have saved the case. It certainly made the patentee’s argument much easier.

Second, Rothstein J in the FCA 2003 FCA 409 had construed this very patent and rejected these very arguments in a prior NOC proceeding [173]. While the evidence was different, Barnes J noted that the construction issues turned on grammatical arguments rather than specialized technical knowledge [170], so “the unanimous views of the Federal Court of Appeal carry some persuasive weight” [175].

Third, the fact that held that AstraZeneca did not contemplate the in situ process did not mean that such a process is excluded from the scope of the claim:

[179] Although AstraZeneca undoubtedly did not contemplate the in situ method of creating a subcoat when it applied for patent protection, that is not a point which detracts from its claim to a novel product.

[182] The fact that neither the notional person of skill nor the actual inventors would have had an in situ subcoat in mind or, indeed, any other means by which a subcoat could be formed does not help to define the scope of Claim 1. There may well be a number of methods available to produce the essential elements of a novel formulation that have not been identified or contemplated by the inventors. All that is required is the disclosure of one viable method of manufacture.

[185] I reject the notion that AstraZeneca had an obligation to teach its competitors how to avoid an infringement. A patentee has no obligation to inform the world of all the processes which may give rise to an infringing product. AstraZeneca described its formulation and explained how to make it. It was up to others to avoid an infringement.

Given this conclusion on construction, the main question on infringement was whether the Apotex product in fact incorporated an inert subcoat. This turned entirely on the very technical evidence, which was examined in detail. The main point of general interest is that as a matter of litigation strategy, Apotex choose to attack the methodology of AstraZeneca’s expert rather than conducting its own experiments. Barnes J held that when a party makes that choice, it will not get the benefit of the doubt (my emphasis):

[348] It was open to Apotex to conduct its own equivalent testing and it chose not to do so. It should not be the beneficiary of any uncertainty that could easily have been dispelled.

[298] The Apotex expert witnesses were, therefore, well informed and quite capable of replicating Dr. Davies’ work or of modifying that work to attempt to improve upon it. In large measure, they failed to do so and, instead, focused their criticisms on methodological matters. It is easy to take pot-shots from the sidelines; it is riskier to challenge experimental data head-on.

[361] The fact that a party may not agree with a chosen experimental design is not an excuse for failing to replicate the work to test the reliability of the reported data. The same applies to criticisms about the testing techniques employed by an opposing expert witness. An argument that other tests or controls could have been used loses much of its strength where a party chooses not to employ those same suggested methods in its own responding analysis to see if the results differ.

Of course this is not to say that Apotex would have done better with a different strategy. It does seem that AstraZeneca’s main expert, Dr Davies, was a particularly experienced and meticulous scientist [301] and was consequently a compelling witness whose evidence was not susceptible to this kind of attack.

On a somewhat related note, Apotex’ experts were unduly combative, in several instances leveling “unwarranted criticism” at Dr. Davies which would not have been accepted by any “fair-minded observer” [295]. Similarly, one of Apotex’ experts refused to concede facts that were not realistically in dispute and this detracted from his credibility [305] (and see similarly [357]). In the end, Barnes J much preferred the evidence of Dr Davies in this fact intensive dispute [360]. On one point in particular in which the experts’ positions were diametrically opposed, Barnes J largely accepted Dr Davies’ view [312]. While Barnes J’s conclusions both on this point and generally were based on his detailed assessment of the evidence rather than a blanket assessment of the experts’ credibility, the attitude of Apotex’ experts could not have helped.

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