In his pre-dinner speech at the CIPA life Sciences conference last week, Lord Neuberger wistfully commented that, if there was one case that he would like to have come back to the Supreme Court bench for, it was Warner-Lambert vs Actavis. Following the Supreme Court hearing of this case in February, we have spent the summer on tenterhooks waiting for the decision to be handed down.
The decision was handed down this morning, and can be read here. In summary, the Supreme Court dismissed Warner-Lambert’s appeal that the patent was sufficiently disclosed, and upheld Actavis and Mylan’s appeal that the disputed claims were not even partially sufficient. The Supreme Court also unanimously held that, if the claims had been found valid, they would not have infringed. The Supreme Court was also unanimous on construction and found that the post-trial amendment sought by Warner-Lambert was an abuse of process.
The full analysis of the decision will follow shortly. Whilst we digest the decision in full, some context to some of key issues of the case has been provided.
Today’s Supreme Court case is the latest installment in a long-running dispute between Pfizer (parent company of Warner-Lambert) and Actavis et al. concerning the validity of and infringement of Warner-Lambert’s Lyrica® patent. The patent claims pregabalin (marketed as Lyrica®) for the treatment of pain using the Swiss-type style. Dependent claim 2 is limited to the treatment of inflammatory pain. Dependent claim 3 is limited to the treatment of neuropathic pain.
Actavis manufactures Lecaent, a pregabalin generic. Mylan and Actavis brought separate claims for revocation of the patent in 2014, on the ground that the claims were insufficiently disclosed. Warner-Lambert brought an infringement action against Actavis later the same year. In first instance proceedings, the High Court ruled that claim 1 and 3 were insufficient ( EWHC 2548 (Pat)). Even if valid, the claims were deemed not infringed. In 2015, the Court of Appeal upheld these findings, and ruled that a post-trial amendment filed by Warner-Lambert after the High Court decision that limited the claims to valid and infringed subject-matter, was an abuse of process.
The substantive issues for the Supreme Court to consider was the role to be played by plausibility in the statutory test for insufficiency and how infringement by Swiss-style claims should be determined.
Untangling the web: Insufficiency, enablement and plausibility
First some background on insufficiency. The concept of sufficiency (and the related concepts of enablement and plausibility) have predominately been raised in the pharmaceutical and biotech arena. The sufficiency requirement is designed to ensure a patentee satisfies their side of the bargain with the state by providing a full public disclosure of their invention in exchange for the granted patent.
Legal basis for sufficiency in the UK can be found in Section 72(1)(c) of the UK Patents Act 1977 (UKPA). This states that a patent may be revoked on the grounds that “the specification of the patent does not disclose the invention clearly enough and completely enough for it to be performed by a person skilled in the art”. In other words, a patent may be found invalid on the grounds that the invention is insufficiently disclosed. The corresponding provisions in the EPC are Article 83 and Article 100(b) .
A patent may be insufficient because a skilled person would not be able carry out the invention, i.e. the invention is not enabled. Lack of enablement may be due to the lack of the necessary experimental details. The UK Court of Appeal has recently re-confirmed what is considered an enabling disclosure. In Regeneron v Kymab (see here), a patent was found enabled and thus sufficiently disclosed despite the example methods provided in the specification being unworkable at the time of the invention. The Court of Appeal afforded the theoretical skilled person considerable time and expertise in order to find a workable method.
Another form of insufficiency found in UK case law, is where an invention is found not to be enabled across its entire scope. A claim to a drug for the use in treating cancer may not be sufficiently disclosed across its entire scope, for example, if the specification only provided examples for which drug is used to treat lung, but not other types, of cancer. To be sufficiently disclosed, the claim must first be enabled across its entire scope, such that a skilled person would not face undue burden in using the drug to treat any type of cancer. It must also be plausible to a skilled person from the limited data provided, that the drug would work for any type of cancer. This may be because, for example, the drug’s mechanism of action is applicable to any type of cancer.
Recent years have seen a growing number of plausibility objections from the EPO against biotech and pharmaceutical invention. There is a growing feeling in some parts of the patent community that the EPO has raised the bar for plausibility too high (see here), particularly given the lack of direct basis for the concept in the EPC. Since the hearing for Warner-Lambert v Actavis in February there has been growing speculation as to how far the UK Supreme Court would adopt the EPO approach, or seek to limit the requirement for plausibility.
The case in question
In the Court of Appeal (  EWCA Civ 1006), Lord Justice Floyd upheld the High Court decision that claims 1 and 3 of the patent were insufficient. The Court of Appeal held that it was implausible that pregablin would be effective at treating any type of pain (claim 1) or central neuropathic pain (claim 3) based on the data provided in the patent specification (obtained using a mouse model of inflammatory pain). By contrast, the treatment of peripheral neuropathic pain was deemed plausible. This was on the basis that there was a sufficient unifying mechanistic principle connecting inflammatory pain and peripheral neuropathic pain. The unifying principle was that both types of pain have a central sensitisation component. Lord Justice Floyd commented that the data in the specification, whilst not predictive for pregablin’s efficacy for treating peripheral neuropahtic pain, at least rendered its efficacy plausible.
The Supreme Court held by majority (Lord Sumption, Lord Reed and Lord Briggs) that the disclosure in the specification supports the claims so far as they extend to inflammatory pain but not to any kind of neuropathic pain. The Supreme Court thus dismissed Warner-Lambert’s appeal that the the claim to the use of pregablin for the treatment of central neuropathic pain was sufficiently disclosed. The Supreme Court went even further, and upheld Actavis and Mylan’s appeal that the treatment of peripheral neuropathic pain was also insufficiently disclosed. The court reasoned that the mouse models used to provide the data in the specification were only relevant to inflammatory pain. The Supreme Court may have established a higher bar to sufficiency of disclosure for pharmaceutical inventions and firmly placed plausibility as a key aspect of sufficiency. We will consider the consequences of this in future posts once the team has had time to digest the Supreme Court’s reasoning in full.
In the Court of Appeal, Lord Justice Floyd rejected arguments submitted by Warner-Lambert that the term “pain” would be understood by a skilled person as having anything other than its ordinary, broad meaning. The Judge also held that the term “neuropathic pain” in claim 3 would be understood broadly as including both central and peripheral neuropathic pain. A skilled person, the Judge ruled, would not understand the specification as excluding central neuropathic pain from the definition.
Warner-Lambert argued that the construction of the claim by the Court of Appeal ignored expert evidence that should not have been disregarded.
However, the UK Supreme Court unanimously agreed with the lower court that Claim 1 extends to all pain and Claim 3 to all neuropathic pain, whether peripheral or central.
Abuse of Process
In the Court of Appeal Lord Justice Floyd agreed with the High Court that Warner-Lambert’s post-trial amendment, limiting claim 3 to peripheral neuropathic pain, was an abuse of process. Lord Justice Floyd reasoned that Warner-Lambert had failed to provide any good reasons for not raising the amendment at trial. The Supreme Court agreed with the lower courts.
The action for infringement was brought on the basis of claim 1 and 3. Both of these claims were found invalid for insufficiency by the Court of Appeal. Lord Justice Floyd nevertheless considered the issue of infringement in obiter, particularly the proper interpretation of Swiss-form claims. Lord Justice Floyd particularly provided a clear test by which infringement of Swiss-type claims by a generic could be assessed. The court should assess whether the alleged infringer knew or could foresee that at least some of the prescriptions written generically for the claimed drug for the claimed indication would in fact be fulfilled with the generic. The absence of the claimed indication from the label (“skinny label”), the judge suggested, could not “conceivably be sufficient to negative the intention”. Instead, the test will be negative where the manufacturer has “taken all reasonable steps within his power to prevent the consequences occurring”.
The Supreme Court also dismissed by majority Warner-Lambert’s appeal on this point. Particularly, Lord Sumption, together with Lord Reed, Lord Hodge and Lord Briggs, found that if claims 1 and 3 had been valid, they would not have been infringed, but differed in their reasons. Lord Sumption and Lord Reed agreed that the intention of the alleged infringer is irrelevant and that the sole criterion of infringement is whether the product as it emerges from the manufacturing process, including any labelling or accompanying leaflet, is presented as suitable for the uses which enjoy patent protection. Lord Hodge and Lord Briggs preferred the view of Mr Justice Arnold at first instance that the test is whether the alleged infringer subjectively intended to target the patent-protected market.
A version of this article was first published on The IPKat.
This article is for general information only. Its content is not a statement of the law on any subject and does not constitute advice. Please contact Reddie & Grose LLP for advice before taking any action in reliance on it.