Boehringer Ingelheim Animal Health USA Inc. v Intervet International BV

[2020] FCA 1333

In this case, Moshinsky J dismissed Boehringer’s opposition to grant of Intervet’s patent for veterinary anti-parasite medicaments. The invention relates to injectable formulations comprising a macrocyclic lactone and levamisole for controlling parasites in animals and using such formulations to prepare a medicament for controlling parasites in animals.

Boehringer was previously named Merial Inc. A quick search of cases involving Intervet and Merial suggests that each might consider the other somewhat of a pest in at least the New Zealand and Australian patents arena. So far, neither innovator has identified a solution to the repeat exposure to patent litigation. Hopefully, their respective veterinary medicaments are more effective.

Boehringer’s opposition to grant was originally heard and dismissed by a delegate of the Commissioner of Patents. Unsatisfied with that result, Boehringer appealed the decision to the Federal Court. The grounds of opposition to grant were that the claims lacked novelty in light of one prior art patent application (CN’291); lacked an inventive step in light of common general knowledge alone or with CN’291; and lacked utility in that the claims of the Patent Application included embodiments that did not achieve the promise of a physically and chemically stable suspension formulation of a macrocyclic lactone and levamisole.

As a pre-Raising the Bar Amendment Act patent application, Boehringer bore the onus in relation to each of its grounds of opposition, requiring it to establish that it is “clear” (or “practically certain”) that the patent, if granted, would not be valid.

Moshinsky J heard the case partially in person and partially by Microsoft Teams. His Honour observed that, where there was a debate between the parties as to the transcript, his Honour reviewed a recording of the hearing to check the accuracy of the transcript. As an aside, it may be observed that hearings that proceed by way of Microsoft Teams are all recorded by the Court – in which case, arguably, in any appeal from the trial, the appellate court could presumably also have the benefit of such recordings so that any deference to the trial judge’s ability to observe the demeanour of witnesses might have less weight on appeal.

Boehringer called two principal expert witnesses; Intervet called one. It appears that one of Boehringer’s witnesses, Mr Lau, made concessions during his oral evidence which bolstered his credibility as a witness but which were not to Boehringer’s benefit. Moshinsky J indicated a preference for his oral evidence over his written evidence. Reading between the lines, Moshinsky J was impressed with Mr Lau’s frank oral evidence but perhaps less so his written evidence.

Claim 1 of the patent application was to:

An injectable formulation of a macrocyclic lactone and levamisole in a non-aqueous solvent system comprising oil and an organic solvent, wherein the macrocyclic lactone is in solution and the levamisole is a salt in a particulate form, and wherein the levamisole salt is present in the range of between 10-35% w/v.

On the question of novelty, an example of CN’291 disclosed a formulation with macrocyclic lactone in solution and levamisole HCl. However, that example did not describe the levamisole HCl as being in particulate form (or in a suspension). Boehringer therefore relied on experimental evidence of its experts to demonstrate that the levamisole HCl of CN’291 is in particulate form in a suspension. Those experts followed a series of manufacturing (or formulating) steps which resulted in the levamisole HCl in particulate form. However, those steps were not set out in CN’291.

However, during cross-examination, Mr Lau accepted that that the relevant example of CN’291 (example 3) might produce either a solution or a suspension (or particles). That uncertainty was a death knell for novelty. His Honour also observed that Boehringer had failed to “conduct experiments that were designed to prove that any steps used to manufacture a formulation having the composition of Example 3 [of CN’291] would inevitably contain levamisole HCl in particulate form.” As Moshinsky J observed “Boehringer bore the onus of establishing the inevitability of the outcome that it contended for, not merely that this was one possible result, or even a likely result”, plainly with an eye to General Tire & Rubber Company v Firestone Tyre & Rubber Company Ltd (1971) 1A IPR 121 (General Tire) at 138 where it was stated that “[i]f, on the other hand, the prior publication contains a direction which is capable of being carried out in a manner which would infringe the patentee’s claim, but would be at least as likely to be carried out in a way which would not do so, the patentee’s claim will not have been anticipated”.

The other issue with CN’291 was that the example relied on by the experts only disclosed levamisole HCl at 5 per cent w/v whereas the claims of the patent application require 10-25 per cent w/v. While there was an earlier broad disclosure of the use of levamisole at 10-20 per cent, there was no direction to modify the example to embrace that higher range. Boehringer sought to address this by adducing evidence to the effect that 5 per cent was too low a dose to be effective and that a higher dose would be chosen. Intervet’s evidence was to the effect that the dose in CN’291 was too low and that a dose ranging study would be performed to identify a higher percentage falling within the claims. It is difficult to see how either approach could give rise to a lack of novelty case and his Honour found that there was no clear disclosure of this integer.

On the question of lack of inventive step, Moshinsky J set out a series of excerpts from the transcript of the concurrent evidence of witnesses for Boehringer and Intervet in which counsel for Boehringer cross-examined Intervet’s expert as to various matters and asked if the expert for Boehringer agreed – in essence cross-examining its own witness. It may be observed that this style of cross-examination seems a far cry from the original concept of concurrent evidence being an opportunity for the experts to describe the debate between them, rather than have counsel simply cross-examine an expert in the usual way and seek agreement from one’s own witness. However, recent experience suggests that this is now par for the course.

Nevertheless, this approach did not appear to assist Boehringer on this occasion. Moshinsky J observed: “Insofar as Dr Martin’s evidence is concerned [the witness called by Boehringer], there was some hesitation in the acceptance of the propositions put to him by senior counsel for Boehringer [i.e., put to him by the party calling him]. […] In relation to Mr Vickers’s evidence [called by Intervet], while he acceded to certain propositions as to expectation of achieving an acceptable result, this was qualified by the need for testing, and he made clear in his evidence that this was not merely routine testing but testing of a more fundamental nature.”

However, the main issue for Boehringer was that Mr Lau’s approach to formulation of the two key active ingredients was done without knowledge as to the mode of action and desired release profile of levamisole, including considerations that pointed away from using levamisole as a particulate in an oily formulation – this called into question whether his approach to the hypothetical formulation task was representative of that of the notional skilled team. To the extent that Mr Lau’s evidence in reply sought to disagree with the proposition that a potential change to the release profile or absorption rate of levamisole salt was a reason not to formulate the combination injectable with the levamisole salt in suspension, it was contrary to his oral evidence where he accepted that the release profile and absorption rate of levamisole were relevant considerations. For the above reasons (and others) his Honour found that the claimed invention had an inventive step.

As to utility, Boehringer’s primary position was that the promise of the specification was that the claimed formulations would be stable for six months under accelerated conditions. While an example in the specification did show such stability, his Honour did not consider that involved a promise that the formulations the subject of the claims would also have that stability. Nevertheless, while indicating some doubt about the matter, by reference to another statement in the specification, his Honour ultimately accepted that three months’ accelerated stability was promised. Boehringer then sought to rely on data from another patent application to establish that formulations falling within the claims would not meet that three-month accelerated stability. His Honour rejected Boehringer’s argument because of the inherent unreliability of that data.

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