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Posted in patents Dominic Hoar

UK AIPPI rapid response event: Actavis v ICOS (tadalafil) Supreme Court judgment

On 4 April 2019 Hogan Lovells hosted this event, in which Tom Mitcheson QC and Mark Chacksfield QC (who acted against each other) gave their views on the Supreme Court’s decision on inventive step in a case related to the drug tadalafil (Cialis), a PDE5 inhibitor for erectile dysfunction.

Here is a potted history of the case:

Claim 10 of the Lilly/ICOS Patent read: “Use of a unit dose containing 1 to 5mg of a compound having the structure [of tadalafil] for the manufacture of a medicament for administration up to a maximum total dose of 5mg of said compound per day in a method of treating sexual dysfunction in a patient in need thereof”. Such a dose reduced side effects and enables regular daily dosing. That is in contrast to the conventional application of ED drugs (Viagra, sildenafil), which is “on demand”.

Birss J thought the claim inventive, notwithstanding that it was the result of a clinical programme with many routine and obvious steps from a starting point of a 50mg tablet. Some key (to me) factors on the path for the skilled team were that they would:

  • not at the outset know there was a therapeutic plateau at 25 or 10mg
  • not initially know that tadalafil had a longer half-life
  • would have had no reasonable expectation that 5mg would have had a clinically-relevant effect, or one with minimal side effects

Kitchen LJ disagreed. He thought that, on the judge’s findings, the invention lay at the end of a familiar path through pre-clinical and clinical trials. The skilled team “would embark on that process with a reasonable expectation of success and in the course of it they would carry out Phase IIb dose ranging studies with the aim of finding out, among other things, the dose response relationship. It is very likely that in so doing they would test a dose of 5mg tadalafil per day and, if they did so, they would find that it is safe and efficacious. At that point they would have arrived at the claimed invention.”

On appeal to the Supreme Court, Lilly argued that the CA had not applied the test of obviousness correctly under the UK law or the EPO’s approach of finding invention where there was an unexpected technical effect (here, reduced side effects at a dose that worked). Actavis supported the CA’s view: as a matter of policy, routine work cannot be patentable.

Lord Hodge (with whom the other Lords agreed) upheld the CA’s decision.

  • He considered that the CA had been right to carry out its own evaluation of obviousness since Birss had committed an error of principle in failing to appreciate the logical consequences of his finding, that it was likely the skilled team would continue testing. Lord Hodge then carried out his own analysis of the facts, which supported the conclusion of Kitchen LJ. He noted that the claim was not limited to administration once per day and also covered on-demand use.
  • On obviousness, Lord Hodge considered that both the UK and EPO case law were glosses on the statutory test, and neither the Windsurfing nor PSA approaches should be applied mechanistically. He then set out at paragraphs 64 – 77 ten factors that were relevant in the context of the case: key ones being relied upon by Lilly being ‘surprising result’ (#7) and ‘bonus effect’ (#9), the latter not being referred to (sadly) as ‘the Brucie Bonus’.
  • The EPO and other European courts were not a burden:
    • Although the patent had been litigated elsewhere in Europe (Belgium and Portugal, and Denmark, Poland and the Czech Republic) with mixed results, he did not find the judgments helpful. Where the law was the same, courts may nonetheless come to different conclusions. Even where the evidence is the same, a court’s findings of fact based on that evidence may not be the same.
    • The EPO’s PSA is not the only method used by the EPO and is also a gloss. Nor was Lord Hodge convinced that the PSA would necessarily have given a different answer. (With the ‘necessarily’ being rather compacted – and an acknowledgement that there will sometimes be different answers)
  • On selection patents, Lord Hodge was keen not to rule them out. Efficacious drugs discovered by research involving standard pre-clinical and clinical tests should be rewarded with a patent if they meet the statutory tests, even if the enquiries made as to it are otherwise well-established or routine enquiries. Further, inventive step may occur “if the selection is not arbitrary and is justified by a hitherto unknown technical effect”.
  • Yet, Tom noted, the EPO has granted patents in very similar circumstances to these: see G02/98, and T91/98 in which the unexpected and advantageous result was that the compound was effective at such low concentrations.

To me the outcome feels rather tough on the patentee. Consider Kitchen LJ’s “familiar path” through trials. Is a path really “familiar” when it takes unexpected turns (therapeutic plateau, long half-life) and ends in a surprising location (efficacy at 5mg daily with reduced side effects)? One could hardly describe as ‘familiar’ a path through woods if the features it passed were unexpected and the destination a surprise. Unexpected technical effects are often good enough at the EPO but were not good enough here, in this case.

Tom then picked up the following points:

  • Do we have a new ground of appeal: that the judge failed to appreciate the logical consequences of his finding? If so that is likely to make it easier to get an appeal up and running in the future. It is also hard to distinguish the Supreme Court’s reasoning from straightforward interference with a judge’s finding on a multifactorial test, which could have some significant consequences.
  • The English courts appear to be drifting further from the Europe courts and the EPO. In Actavis v Lilly, Lord Neuberger was keen to follow Germany, which was subsequently watered down in Warner Lambert and, now, more so. There are some parallels in current affairs, right there.
  • It hasn’t really changed the law all that much. We now have a list of ’10 factors’ that will be quoted for ever more, but no guidance as to any relative weighting to be applied to them. The Supreme Court has not given us much help in resolving similar issues in the future.
  • The decision was very different in tone to Warner Lambert and Lilly v Actavis. It was more conservative, and less certain in its rightness. There was a hint of Lord Neuberger in it. It will be interesting to see how Kitchen LJ’s voice affects the overall tenor when he joins the Supreme Court.

Mark, I think recently returned from court, chipped in with the following:

  • This is the Supreme Court stressing the statutory test for obviousness, all the rest being gloss and not obligatory. Lord Hodge will no doubt be disappointed when in five years’ time we are all quoting his 10 factors.
  • The most interesting of the factors is the interaction with the surprising and unexpected finding that efficacy could be achieved without big side-effects. Birss J had in mind that efficacy and side-effects would be expected to go hand-in-hand and that the realisation that they did not was capable of producing invention.
  • In paragraph 92 of the decision, Lord Hodge says that Conor v Angiotech “is not authority for the proposition that, in all circumstances, obviousness must be assessed by reference to the precise wording of the claim.” This sentence is likely to cause problems if it is used to dilute the basic proposition in Conor.

In summary, one could define the case (as Tom did) as “MOVE ALONG, NOTHING TO SEE HERE”. We will have to wait to see how it is applied, and whether anything more exciting arrives when the Supreme Court looks into sufficiency for Regeneron.

First published by The IPKat on 17 April 2019.