Generics (UK) Ltd (t/a Mylan) v Warner-Lambert Company LLC

A post-trial application to rewrite patent claims may constitute an abuse of process where the amendment could and should have been sought before trial and would require a second validity trial. The question is a broad, merits-based assessment of procedural abuse, considering finality, fairness, expense, delay and the public interest. The existence of European procedures for central limitation does not displace the English court’s control over applications under section 75 of the Patents Act 1977. A central limitation may be unobjectionable before the EPO, while reliance on the resulting claims in English proceedings may still be abusive.

Following an earlier judgment, Warner-Lambert Company LLC applied conditionally to amend claim 3 of its patent by adding words limiting the claim to neuropathic pain caused by injury or infection of peripheral sensory nerves. Mylan and Actavis opposed the application, arguing that it was abusive because the proposed validating amendment could have been made before trial and would require a further trial on clarity, added matter and insufficiency.

The earlier judgment had held claim 3 insufficient because it covered both peripheral and central neuropathic pain. The issue was whether the proposed amendment could fairly be considered without a second trial and, if not, whether the circumstances nevertheless justified allowing it to proceed.

1. Application struck out. The proposed amendment was an abuse of process and was struck out.
2. The governing question was whether, in all the circumstances, the application misused the court’s process or subjected the opposing parties to unjust harassment. The principles in Johnson v Gore Wood & Co were consistent with the patent-specific guidance in Nikken Kosakusho Works v Pioneer Trading Co, Vector Corp v Glatt Air Techniques Ltd and Nokia GmbH v IPCom GmbH.
3. The proposed amendment would require a second trial on validity. Evidence would fairly be required on the meaning and clarity of the proposed limitation, including the boundary between peripheral and central neuropathic pain, and on insufficiency. The added-matter issue could probably be decided on the existing evidence, but this did not avoid the need for a second trial overall.
4. The amendment could and should have been sought before trial. Warner-Lambert had ample opportunity to make a conditional application, particularly after the common-general-knowledge statement, expert evidence, reply evidence and skeleton arguments made the peripheral/central distinction clear. Its failure to do so was not caused by procedural ambush or unfairness by Mylan or Actavis.
5. Article 138(3) EPC 2000 and the central-limitation provisions in Articles 105a–105c did not alter the abuse-of-process principles. A central limitation application to the EPO was procedurally distinct from an application under section 75 of the Patents Act 1977. Although reliance on centrally limited claims might not itself be abusive, that question would depend on all the circumstances.
6. The risk of delay and the public interest in the prompt removal of unjustified monopolies were additional, though minor, factors. The application was therefore an abuse because it would expose Mylan and Actavis to successive litigation which could have been avoided by advancing the amendment before trial.

The judgment was a first-instance decision on Warner-Lambert’s post-trial application to amend claim 3. It followed the earlier judgment reported at [2015] EWHC 2548 (Pat).