November 21, 2018 by IPAlchemist
I went last night to the IBIL event that discussed last week’s pregabalin decision. There was a stellar lineup in the panel, and an equally august audience in attendance. But there was a major flaw. The panel jumped straight to discussing how the Supreme Court decision compares with the situation in other countries, and whether it was correct, without first establishing what the decision actually says. What now is the standard for plausibility? Has it changed, and if so how?
I am pleased to be in good company in finding it difficult to discern a difference in legal standard for plausibility as set out between the majority decision (Lord Sumption) and the minority dissents (Lord Mance and Lord Hodge) – Lord Hoffmann last night said that he could see little difference in their respective positions. So what is going on?
Lord Hodge clearly states that he disagrees with Lord Sumption, stating at :
Where I differ from Lord Sumption is that, in agreement with Lord Mance, who has analysed the three cases of ALLERGAN, IPSEN and BRISTOL MYERS SQUIBB, I do not interpret those principles as requiring the patentee to demonstrate within its patent a prima facie case of therapeutic efficacy.
Lord Mance similarly disagrees, stating at :
In my view, Lord Sumption’s analysis imposes too high a threshold, and imposes a burden on a patentee which the case law of the Board of Appeal of the European Patent Office does not justify. I prefer the approach advocated by Mr Mitcheson, but rejected by Lord Sumption in para 30 of his judgment.
What is rejected by Lord Sumption in para 30 of his judgment is the argument that
it is necessary for the patentee to disclose reasons for regarding the claimed therapeutic effect as plausible only when the skilled person reading the patent would be sceptical about it in the absence of such disclosure.
Later on at  Lord Sumption states
It must always be necessary for the patentee to demonstrate that he has included in the specification something that makes the claim to therapeutic efficacy plausible.
And at  he summarises:
The fundamental principle which [these judgments from the EPO Boards of Appeal] illustrate is that the patentee cannot claim a monopoly of a new use for an existing compound unless he not only makes but discloses a contribution to the art. None of them casts doubt on the proposition that the disclosure in the patent must demonstrate in the light of the common general knowledge at the priority date that the claimed therapeutic effect is plausible. On the contrary, they affirm it.
Lord Sumption also disagrees with the Court of Appeal – at  he explains:
They [the Court of Appeal judges] considered that the threshold was not only low, but that the test could be satisfied by a “prediction … based on the slimmest of evidence” or one based on material which was “manifestly incomplete”. Consistently with that approach, they considered (paras 40, 130) that the Board’s observations in SALK laid down no general principle. I respectfully disagree. The principle is that the specification must disclose some reason for supposing that the implied assertion of efficacy in the claim is true. Plausibility is not a distinct condition of validity with a life of its own, but a standard against which that must be demonstrated. Its adoption is a mitigation of the principle in favour of patentability. It reflects the practical difficulty of demonstrating therapeutic efficacy to any higher standard at the stage when the patent application must in practice be made. The test is relatively undemanding. But it cannot be deprived of all meaning or reduced, as Floyd LJ’s statement does, to little more than a test of good faith. Indeed, if the threshold were as low as he suggests, it would be unlikely to serve even the limited purpose that he assigns to it of barring speculative or armchair claims.
So what Lord Sumption appears to be expounding, which goes further than the plausibility test as previously understood (at least by me), is that it is not sufficient that it be objectively plausible that the invention works, based on the information in the patent and what was otherwise known at the priority date, but that the patent specification must actively disclose why it is plausible. Thus there appears to be a new disclosure requirement – “the specification must disclose some reason for supposing that the implied assertion of efficacy in the claim is true” (as quoted above from para 36).
There is considerable advocacy in Lord Sumption’s judgment, and reading it alone it is entirely convincing. It is only when trying to work out precisely how it differs from the views of Lord Hodge, Lord Mance, and indeed the Court of Appeal, that it becomes evident that the standard it purports to lay down, and how this standard has evolved from earlier English jurisprudence, is not clearly expressed.
But there is a bigger problem. Having set out a standard, albeit unclearly, Lord Sumption does not then apply it. When reversing the finding of Mr Justice Arnold that the specification satisfied the plausibility requirement for peripheral neuropathic pain, Lord Sumption did so not on the basis of a different applicable legal standard, and “not because there was anything wrong with the judge’s findings, but because those findings do not support his conclusion that the specification makes it plausible to predict that pregabalin will be efficacious for treating neuropathic pain.” 
He goes on at :
The judge’s analysis of the implications for peripheral neuropathic pain of the data presented in the specification was based entirely on the common general knowledge that central sensitisation was “involved” in both inflammatory and peripheral neuropathic pain. The judge concluded from this that it was “possible” that a drug which the specification showed to be effective for the first would also be effective for the second, “although this would not necessarily be the case.” In my opinion this is a logical non-sequitur.
Thus, Lord Sumption seems to be saying that Arnold J’s analysis is not logically sound even on its own terms, and so he is reversing on that basis. Not on the basis that the threshold applied by Arnold J was too low, or that the patent failed to satisfy the new disclosure requirement articulated earlier.
I rather hope that I am wrong, but it seems to me that Lord Sumption has not actually applied in the operative part of his ruling the standard that he appears to have set out earlier. If that is the case, is the earlier standard even ratio decidendi? It is hard to see how this ruling from the Supreme Court can be applied to future cases.
A final comment on infringement. We have three dissenting views of what infringes a second medical use claim. They are all obiter. What we are supposed to do with them seems more a matter of philosophy than the practice of law.