Patents - Accord Healthcare Ltd v Regents of the University of California

Office of the President of the University of California

Author Coolcaesar Licence CC BY-SA 4.0   Source Wikimedia Commons

 

Jane Lambert

Court of Appeal (Lords Justices Arnold, Snowden and Zacaroli) Accord Healthcare Ltd and others v Regents of the University of California and another [2025] EWCA Civ 936 (23 July 2025)

This was an appeal by Accord Healthcare Limited and other generic pharmaceutical manufacturers against Mr Justice Mellor's dismissal of their claims for revocation of European Patent (UK) No. 1 893 196 (“the patent”) and SPC No. SPC/GB13/079 (“the SPC”) on grounds of obviousness, implausibility and insufficiency in Accord Healthcare Ltd and others v Regents of the University of California and another [2024] EWHC 2524 (Pat) (8 Oct 2024). They appealed with the permission of Lord Justice Arnold.  His lordship heard the appeal with Lord Justice Snowden and Lord Justice Zacaroli on 2 July 2025.  The Lord Justices handed down their judgment in Accord Healthcare Ltd and others v Regents of the University of California and another [2025] EWCA Civ 936 on 23 July 2025.  Lord Justice Arnold delivered the lead judgment.   By para [105] of the transcript of his judgment, he dismissed the appeal.  Lord Justice Snowden and Lord Justice Zacaroli delivered short concurring judgments at [106] and [107] respectively.

The Patent

The patent disclosed and claimed enzalutamide as a treatment for prostate cancer, and in particular, hormone-refractory prostate cancer (“HRPC”). The patent and SPC were owned by the Regents of the University of California and exclusively licensed to Astellas Pharma Europe Limited.  Both the Court of Appeal and the trial judge referred to the patentee and its exclusive licensee collectively as "Astellas."  

Mr Justice Mellor had discussed the patent between para [385] and para [405] of his judgment. Para [0001] of the specification stated that the invention related to a diarylhydantoin compound and methods for synthesizing it and using it in the treatment of HRPC. The invention was said to be the compound RD162, the structure of which was given at para [0011]. It was said to have strong antagonistic activity with minimal agonistic activity against increased androgen and to inhibit the growth of HRPC. Para [0017] taught a method of synthesizing RD162'. Claim 1 of the patent claimed a compound with the formula of RD162’ or a pharmaceutically acceptable salt thereof.

The Trial

The claimants challenged the validity of the patent and SPC on the ground that the invention was obvious in the light of each of two items of prior art referred to respectively as “the Poster” and “the Slides”. The Poster was by Samedy Ouk and others, entitled Development of Androgen Receptor Inhibitors for Hormone-refractory Prostate Cancer.   It was presented at the Prostate Cancer Foundation Scientific Retreat at Scottsdale, Arizona, on 29 Sep to 1 Oct 2005 (“the Retreat”). The Slides were from a presentation given by Charles Sawyers at the Retreat.  As well as alleging obviousness, the claimants argued that the patent did not plausibly disclose a technical contribution and that it was insufficient, if not obvious.

Mr Justice Mellor set out the relevant principles of law relating to obviousness between para [177] and para [226] of his judgment, none of which were disputed.   His lordship noted at para [23] that the parties had agreed that the skilled addressee would be a team that would include a skilled cancer biologist and a skilled medicinal chemist. The agreed common general knowledge was discussed between [28] and [143].  The judge referred to the disputed common general knowledge on [144] and [145].  Para [229 (i)] identified the inventive concept of the patent as "a compound with the structure of RD162’ [that] has potential for treating prostate cancer or HRPC." Para [367 (i)] was to similar effect.

On the difference between the inventive concept and the Poster, the judge rejected the claimants' contention that the invention was obvious on the ground that their expert evidence was tainted by hindsight. As to whether the invention was obvious over the Slides, the arguments were more finely balanced. His lordship said that he had changed his mind more than once and that the claimants' argument came very close to succeeding. However, he held at [383] that he had to bear in mind the following points:

"i) First, that if the steps required to get from the prior art to the claim are obvious, it ought to be possible to explain that case clearly and in evidence in chief.
ii) Second, in the litigation process there is an intense focus and much analysis of the route(s) to obviousness and the obstacles in the way.
iii) Third, that it is hardly surprising that, with a skilful cross-examination driven by an intense focus on the target, an argument for obviousness may appear to have force."

He did not say that an obviousness argument cannot be proved through cross-examination of the patentee’s expert witness, but in the circumstances of this case, he could not conclude that he had received sufficient primary evidence to establish the allegation of obviousness over the Slides.

Finally, his lordship was not persuaded by the claimants' plausibility and insufficiency arguments.

Grounds of Appeal

The claimants argued that the judge should have found in their favour on obviousness over the Poster because their expert evidence on the topic had never been challenged, while the defendants' had been expressly rejected.  They contended that the trial judge had been wrong in law to look for a context or scenario for what was technically obvious.  In their submission, finding a motivation to take a particular step was not a necessary condition for a finding of obviousness.  Finally, they pointed to an apparent contradiction in the judge's reasoning in respect of their expert's evidence, alleging hindsight in one context but not in another,

As for obviousness over the Slides, the claimants argued that Mr Justice Mellor had misinterpreted their expert's report. They also contended that the judge had been wrong to look for a scenario or context to arrive at the invention.

The Test on Appeal

Referring to paras [78] to [81] of the Supreme Court's judgment in Actavis Group PTC EHF v ICOS Corp  [2020] 1 All ER 213, [2019] Bus LR 1318, (2019) 167 BMLR 1, [2019] UKSC 15, [2019] RPC 9, Lord Justice Arnold directed himself that as the assessment of obviousness involves a multi-factorial evaluation by the judge, the Court of Appeal is entitled to intervene only if the judge erred in law or principle. Recalling paras [46] to [50] of the Supreme Court's judgment in Lifestyle Equities CV v Amazon UK Services Ltd [2024] 3 All ER 93, [2024] FSR 21, [2024] UKSC 8, [2024] 2 All ER (Comm) 663, [2024] Bus LR 532, [2024] WLR(D) 105 and paras [94] and [95] of its judgment in Iconix Luxembourg Holdings SARL v Dream Pairs Europe Inc  [2025] Bus LR 1391, [2025] UKSC 25, [2025] WLR(D) 337, he reminded himself that the possibility that an appeal court might have reached a different conclusion would not be enough to disturb the judgment of the court below.

The Judgment

Lord Justice Arnold reached his conclusion at para [105] for the following reasons.

Dealing first with the question of obviousness over the Poster, his lordship said that the claimants had misunderstood the trial judge's point on context and scenario. Mr Justice Mellor had thought it significant that the expert had not said that he was approaching the issue on the premise that the skilled team, having read the Poster, would be interested in developing an antagonist for hormone-sensitive prostate cancer and HRPC that was simply an alternative to RD162. Indeed, the expert did not explain the objective of the skilled team at all. As for the alleged contradiction, Lord Justice Arnold could see no inconsistency in Mr Justice Mellor's evaluation of the claimants' expert evidence at all.

Turning to the Slides, the answer to the claimants' contention that the judge had erred in looking for context for what was technically obvious was the same as for the Poster.  The judge had been entitled to take the expert's omission in his report into account and had made no error in doing so,

Lord Justice Zacaroli observed that "a conclusion on obviousness is a highly fact-dependent evaluative decision".  He added that a judge who had been immersed in the detail of the case had a significant advantage over an appeal court. That was particularly so in a specialist area in which the judge was well-versed and had heard the cross-examination of the experts. The trial judge’s findings that the claimants' expert's conclusion was tainted with hindsight and had failed to identify the context for what was technically obvious were themselves fact-dependent aspects of that overall evaluative decision. The claimants’ arguments on appeal did not reach the threshold for establishing that the trial judge's findings involved an error of law or principle.

Comment

Lord Justice Zacaroli's remarks beg the question of why permission to appeal was granted in a case that turned entirely on technical evidence that a highly respected assigned judge with many years of experience at the patent bar was in the best position to evaluate.  Not only that, but the appeal was heard just a few months after a 6-day trial.  My guess is that enzalutamide is an effective treatment for prostate cancer.  Wikipedia states that the drug is on the World Health Organization's list of essential medicines.  Generics manufacturers are likely to have invested heavily in manufacturing processes for when they can lawfully make and sell the drug.  Their production will increase availability and reduce the cost to the benefit of the NHS and other healthcare providers.

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