In this case, Besanko J rose to the occasion and found that Apotex had threatened to infringe two of ICOS’s patents, which he also found valid, concerning the manufacture and dosing of an erectile dysfunction (ED) drug, tadalafil.

In an earlier interlocutory dispute, ICOS got up on its application to amend the specification of the patent that concerned dosing (the 946 Patent) and to enlarge the claim set of the other patent that concerned the particle size of the drug (the 666 Patent). It appears that the amendment assisted ICOS at least in respect of defending a lack of utility and false suggestion attack against the 946 Patent. The addition of the claims to the 666 Patent appears to have been otiose, given all the previously existing claims of that patent were held valid and infringed.

As ever, the devil of this case was in the detail, with the reasons for judgment reaching 777 paragraphs and canvassing the evidence of numerous experts from various fields including clinicians, pharmacologists and formulators. Accordingly, we set out below some points that may be of interest.

Infringement effectively was conceded. Accordingly, the gravamen of the dispute concerned validity, which raised the usual phalanx of grounds including priority date, inventive step, novelty, utility and false suggestion.

In the 946 Patent, ICOS asserted that it had discovered that tadalafil, a known ED drug but not part of the common general knowledge, could be administered in a unit dose which was effective and without all the side effects associated with Viagra (sildenafil). Apotex contended that the 946 Patent simply involved the selection of lower dosages of tadalafil which would have been determined by the notional skilled team, in light of knowledge about Viagra, following a conventional Phase II dose ranging study, informed by the usual in vitro preclinical and Phase I work.

On the question of the correct test for inventive step, ICOS submitted that the reformulated Cripps question was appropriate, namely whether the skilled addressee would be led as a matter of routine to the desired result with a reasonable expectation of achieving that result. ICOS submitted that the steps from the prior art document in issue (Duggan) were not routine and, in any event, Apotex had not proven that the skilled addressee would have the relevant expectation of success. His Honour ultimately accepted that argument.

In answer, Apotex contended that references to the reformulated Cripps question for inventive step “does not exclude the possibility that routine experiments – whose results can test a hypothesis and advance a process of drug development, but cannot be expected with any certainty – come within the statutory question posed by s 7(2)” (emphasis in original). That is, it submitted that the reformulated Cripps question was not the sole or exclusive test for obviousness, and that the test formulated by Aickin J in Wellcome Foundation Ltd v VR Laboratories (Aust) Pty Ltd [1981] HCA 12; (1981) 148 CLR 262 was equally available, namely “whether the hypothetical addressee faced with the same problem would have taken as a matter of routine whatever steps might have led from the prior art to the invention, whether they be the steps of the inventor or not.”

Justice Besanko identified Apotex’s argument as “the proposition that, providing one could characterise a particular trial, test or experiment as routine or conventional, then it satisfied the ‘requirement’ that it be carried out with an expectation of success”: [346]. His Honour did not accept that approach, observing (at [347]) that the “step must be one that the development team is directly led to and would carry out as a matter of course. It is at least implicit that that step would be taken because it may well succeed”, and that it was not sufficient that the development team considered the step or series of steps as “worthwhile to try”: [348]. Justice Besanko concluded (at [349]) that it was a requirement for inventive step that the “step or series of steps be carried out with an expectation of success”, apparently regardless of whether one applies Justice Aickin’s test or the reformulated Cripps question.

After a detailed review of the evidence, Besanko J held that, although he was satisfied that the development team would, as a matter of course, be directly led to try tadalafil with the required expectation of success, he was not satisfied that the team would, as a matter of course, be directly led to the claimed doses with an expectation of success. This was because “the nature of the condition, the nature of measurement tools available and the limits on the information available lead me to conclude that a dose ranging study at the claimed doses would not be undertaken as a matter of course and, even if a decision was made to carry out a study at the claimed doses, it would not be a decision made with the required expectation of success”: [465].

As for the 666 Patent, his Honour likewise concluded that the development team would not be directly led, as a matter of course, to try micronisation with the required expectation of success.

On the question of the law pertaining to whether a broad disclosure is an anticipation, his Honour observed that, even though the alleged anticipation encompassed the device specifically claimed, where it was at least as likely the teaching in the anticipation would be carried out in a way that did not infringe the claims in the patent, there was no anticipation. His Honour there referred to IGT (Australia) Pty Ltd v Aristocrat Technologies Australia Ltd where the Full Court referred to the proposition in General Tire that there is no anticipation where the prior art “would be at least as likely to be carried out in a way which would not” infringe.

As with most novelty cases, the primary issue was one of construction, namely whether the claims were to a “monotherapy” or, because of the use of the word “comprising”, encompassed a “combination therapy” as disclosed in the prior art. His Honour concluded that the claimed therapy was a monotherapy so that there was no anticipation. Among other problems with the novelty case, Besanko J observed that the broad disclosure of unit dosages and a daily dose did not anticipate the specific maximum daily doses of tadalafil claimed.

This post was initially posted by The Hon Peter Heerey AM QC, Tom Cordiner QC and Alan Nash on IPForum.