Eli Lilly and Company v Genentech, Inc., High Court, London, UK, 14 February 2020, Neutral Citation Number: [2020] EWHC 261 (Pat)

Summary
This decision relates to a preliminary issue and summary judgment application brought by Lilly against Genentech regarding a Genentech divisional patent directed to anti-IL-17 A/F antibodies. Roger Wyand QC, sitting as a Deputy High Court Judge in the Patents Court, found that a previous decision of the Patents Court that the divisional patent was invalid meant that Genentech was prevented from arguing that certain claims of the current patent in suit were valid, and so found them invalid.

However, the judge did allow Genentech to argue that certain claims in the patent in suit were valid on the basis that they were plausible at the filing date, even though near identical claims in the parent patent were found implausible at the priority date. The validity and infringement of these claims will therefore proceed to trial.

Background
Lilly is seeking revocation of Genentech’s patent EP (UK) 2 784 084 (“EP 084”) to clear the way for its antibody drug Taltz® which is authorised in the EU for the treatment of psoriasis. EP 084 is a divisional of EP 1 641 822 (“EP 822”), that Lilly had successfully revoked at first instance in the Patents Court (Lilly v Genentech [2019] EWHC 387 (Pat)). In particular, Arnold J (as he then was) concluded that the antibody product claims and medical use claims in relation to rheumatoid arthritis were obvious, and the second medical use claims for psoriasis were insufficient for lack of plausibility at the priority date.

Genentech was granted permission to appeal this decision with the appeal set to be heard in January 2021. However, since then, EP 822 had been revoked by the EPO TBA for added matter and so, at the time of the hearing, whether the appeal would be allowed to proceed was uncertain.

Although the claims of EP 084 have been amended so they are free from the added matter objection the TBA had against EP 822, the judge found that there were no material differences between the specifications and claims of EP 822 as it was sought to be amended in the earlier proceedings and EP 084 as was sought to be amended by Genentech in the current proceedings. Lilly claimed that given this similarity, the issues of validity were res judicata in that the court’s findings in respect of EP 822 were equally applicable to EP 084, and so the Court should issue summary judgment finding EP 084 invalid.

Issue Estoppel
As EP 084 is a different property right to EP 822, Lilly relied on the English principle of “issue estoppel” which would prevent Genentech from disputing a fundamental issue that was the same as that which had already been determined in an earlier action between the same parties.

Genentech argued that issue estoppel should not be applied as its application would cause Genentech to suffer an injustice. In particular Genentech relied on the possibility of its appeal of EP 822 never being heard due to the revocation of the patent at the EPO for added matter. In this respect Arnold J. had rejected the same added matter arguments that were successful at the EPO in the UK proceedings.

The judge had sympathy with Genentech’s argument but decided that he could not reach a decision based on what the Court of Appeal might do and therefore rejected it. He went on to find that the similarity between EP 084 and EP 822 meant that, under the doctrine of issue estoppel, Genentech was prevented from disputing invalidity of the majority of the claims of the 084 patent.

However, while Arnold J had found that the psoriasis medical use claims were not plausible at the priority date, it had not been established that there were also implausible at the filing date as currently relied upon by Genentech. Issue estoppel would therefore not prevent Genentech from disputing the validity of such claims.

Henderson v Henderson abuse of process and summary judgment
In response Lilly relied on the English principle of Henderson v Henderson abuse of process which arises when a party seeks to raise in subsequent proceedings an issue that could, and should, have been raised in earlier proceedings.

This was as:

(i) Genentech had attempted to amend its case at trial to rely on the filing date of EP 822 as being the relevant date for assessment of the psoriasis medical use claims but had not done so early enough and so was prevented from doing so for case management reasons;

(ii) Genentech had not submitted any evidence as to why Arnold J’s reasons for finding a lack of plausibility at the priority date should be overturned when considering lack of plausibility at the filing date; and

(iii) finally, Genentech took a dilatory approach towards the prosecution of EP 084 to avoid its inclusion in the EP 822 trial, thus prolonging its life and ability to disrupt Lilly’s marketing of Taltz®.

In respect of points (i) and (iii), Mr Roger Wyand found that whether there would be an abuse of process should be subject to a broad assessment, with a focus on whether Genentech was engaging in behaviour which could be characterised as unjust harassment. The judge was unable to conclude that this had occurred in the circumstances.

In respect of point (ii), the judge found it arguable “that the effect of a finding of lack of plausibility at the priority date will only result in a loss of priority if plausibility can be established at the filing date”. He also found that an assessment of the disclosure of a patent has to be made in light of the common general knowledge, and a change in that knowledge between the priority date and filing date could alter that assessment. He therefore found that Genentech had a real prospect of success in defending the relevant claims as plausible at the filing date, and accordingly refused summary judgment.

The judgment can be found here.

Headnote: Jonathan Ross and Adrian Chew, Bristows LLP