UK Supreme Court Confirms Warner-Lambert Patent Claims Insufficient

...and leaves readers wondering whether the internet is yet available in the Supreme Court's library (!)

The UK Supreme Court has handed down its long-awaited judgment in Warner-Lambert v Generics & Anr [2018] UKSC 56. It took the form of separate judgments from four Law Lords, who agreed that key claims of Warner-Lambert's patent were invalid and could not be amended, but disagreed about almost everything else.

Deciphering what exactly the Supreme Court has ruled is not straightforward. What we can say is that the concept of plausibility is now not a "low, threshold test" (as the Court of Appeal had indicated); but the Law Lords were split on what the test should be. Consequently the law in this area has become unsettled. Further, the interpretation of Swiss form claim language and the operation of the infringement provisions in respect of such claims has been unsettled by the Supreme Court's obiter reasoning on these issues, some of which appears to conflict with previous judgments of the court without express departure.

What is clear is that the Supreme Court's latest patent judgment gives commentators much to discuss, and it is to be expected that the issues of sufficiency and infringement of Swiss form claims will need to be revisited by the court in another case.

Introduction

Swiss form claims are a construct introduced by the European Patent Office (EPO) as a way of enabling patent protection to be awarded for inventions residing in a new therapeutic use of a known medicine - which can require considerable research investment - while navigating past the legislative provisions preventing both the re-patenting of a substance per se and the patenting of a process of treating a patient. Such a claim takes the general form "use of X in the manufacture of a medicament for the treatment of Y".

The legislation has since been altered to enable second medical use inventions to be claimed in "X for the treatment of Y" (known as 'purpose-limited product' or 'EPC 2000') format. Claims in Swiss form subsequently ceased being granted. However, we can expect the courts to be called upon to resolve disputes concerning existing Swiss form claims until the 2030s. The enforcement of such claims in practice has at times proved to be problematic, as demonstrated by the Warner-Lambert case.

The Warner-Lambert case also raised issues going to the heart of patent law more generally, including the interpretation of claim language and the requirement of sufficiency, and on which the Supreme Court was also called upon to rule. Unusually, the case was heard at a time when the Supreme Court had no intellectual property specialist amongst its members.

Following a four day trial in February 2018, the judgment of the Supreme Court was handed down on 14 November 2018. It took the form of four separate judgments, written by Lords Sumption (with whom Lord Reed agreed), Briggs, Hodge and Mance. The extent of their agreement was limited, and the consequence of the Supreme Court's judgment for the direction of several aspects of patent law is likely to remain unsettled until further, clearer, Supreme Court guidance is handed down.

In this article, we take a look at what this means for you, covering the following:

Amendment Validity Interpretation of "neuropathic pain" in claim 3 Insufficiency Infringement The length of the Swiss form process and contributory infringement under s.60(2) Patents Act What makes an alleged infringer's medicine for the treatment of the claimed indication and s.60(1)(c) infringement What does all of this mean for you? Amendment

The question of amendment arose after the first instance judge (Arnold J) had handed down his judgment but for the purposes of this article it is convenient to discuss this first.

Following the judge's finding that key claim 3 was invalid for insufficiency, Warner-Lambert applied for conditional amendment of that claim (in the event its appeals on validity were unsuccessful), to add words to the end of claim 3 with a view to limiting its scope down to the subject matter found by the judge to be plausible.

The Patents Court, Court of Appeal and Supreme Court were unanimous in refusing to allow Warner-Lambert to seek this re-writing amendment. In short, irrespective of Articles 105a-105c of the EPC 2000, which enables the claims of a European Patent to be centrally limited in all the designated Contracting States by a single application to the European Patent Office, Warner-Lambert's application to the English court was governed by national law and procedure. Applying the test articulated by the House of Lords in Johnson v Gore Wood & Co [2000] UKHL 65, the application was an abuse of process because it could and should have been made prior to trial. The judge had not erred in striking it out.

Validity

Interpretation of "neuropathic pain" in claim 3

Underpinning the question of whether Warner-Lambert's patent was invalid for insufficiency was a question regarding the interpretation of the language of claim 3. This claim was in Swiss form, to pregabalin for the treatment of "neuropathic pain". Should this be interpreted as covering both the peripheral and central types of neuropathic pain or as limited to "peripheral" neuropathic pain?

The Patents Court and the Court of Appeal agreed with the defendants that the claim covered both types of neuropathic pain, and this was confirmed by the Supreme Court. One of the Law Lords, Lord Mance, said that he would have been tempted by Warner-Lambert's case that in the context of the specification, claim 3 should be limited to peripheral neuropathic pain, but he noted "force" in points made by Lord Briggs (in paragraphs 104(4)&(5)) regarding the skilled person's understanding of the term, and in these circumstances did not press his reservation on construction.

The discussion of the legal principles regarding construction was confined to Lord Briggs' judgment. He referred to the Patents Act (section 14(5)(a)&(b) and section 125(1)&(3)), the Protocol on the interpretation of article 69 of the European Patent Convention (EPC) and article 84 EPC. He then considered jurisprudence regarding whether a claim capable of two constructions should be given the construction which would uphold the validity of the patent. Originating in contract law, the principle was considered in patent contexts in Parkinson v Simon (1895) 12 RPC 403 (House of Lords), Kirin-Amgen Inc v Roche Diagnostics GMBH [2002] RPC 1 (Neuberger J) and Smithkline Beecham plc's Patent [2003] EWCA Civ 872. Lord Briggs also noted dicta from the United States, Canada and Australia.

Lord Briggs concluded that particularly in the case of second medical use patents, there is a need for legal certainty in fixing the dividing line between the original use and the new one. An issue as to the construction of a Swiss form claim should therefore be addressed, as far as possible, by deciding what it really does mean, rather than by too easily accepting that there is ambiguity, and resolving it "by inventing a meaning which saves the claim from invalidity". Further, he did not consider claim 3 to be ambiguous in any case, so the condition to applying an interpretive presumption was not present.

Notable for its absence from the Supreme Court's judgment is any discussion of the modern jurisprudence on the general principles governing the interpretation of patent claims. Catnic v Hill & Smith [1982] RPC 182 (House of Lords) is noted as greatly diminishing the importance of dicta regarding validating construction in modern times. The judgments of the House of Lords in Kirin-Amgen v Hoechst Marion Roussel [2005] RPC 9, the Supreme Court in Actavis v Eli Lilly [2017] UKSC 48 and the Court of Appeal in Virgin v Premium [2009] EWCA Civ 1062, are not...