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Pain for Warner-Lambert at the Supreme Court

13 December 2018

The eagerly awaited Supreme Court judgment in the Warner-Lambert V Generics (UK) and Actavis case has recently been issued (see here), a full nine months after the hearing in February 2018. This is the final step in a saga which has been ongoing for years, and which is of huge importance to the pharmaceutical industry. The case concerns a patent with second medical use claims in the so-called “Swiss-form”. This type of claim can be used to protect a new medical use of a known pharmaceutical compound. Finding that a known drug is useful in a new indication can be a bonus for a pharmaceutical company, but getting patent protection for this can be difficult. This case addresses some questions that have arisen about how the sufficiency and infringement provisions apply to second medical use claims. In all aspects Warner-Lambert was not successful.

Summary

The parties to the proceedings were, on one side, Warner-Lambert Company LLC (Warner-Lambert), a company in the Pfizer group. Warner-Lambert was the proprietor of an initial patent for a compound called pregabalin, which was first used in the treatment of epilepsy and marketed as “Lyrica”. Warner-Lambert later filed a further patent application containing second medical use claims relating to the use of pregabalin for treating pain (claim 1), specifically inflammatory pain (claim 2) or neuropathic pain (claim 3).

On the other side, Generics (UK) Ltd (trading as Mylan) and Actavis Group are primarily generics companies, and were seeking revocation of Warner-Lambert’s patent on the grounds of insufficiency and lack of inventive step. Actavis marketed a generic pregabalin product under the brand name “Lecaent”. Lecaent had a so-called “skinny label”, i.e. was marketed for the treatment of some indications only, in this case epilepsy and general anxiety disorder, for which Warner-Lambert’s patent protection had expired. Warner-Lambert nevertheless claimed against Actavis for infringement.

The case initially came to the High Court in 2015 (reported by us here), and subsequently to the Court of Appeal in 2016 which held that claims 1 (to pain in general) and 3 (to neuropathic pain) were insufficient. This was due to the data in the patent being in relation to inflammatory pain only, and not neuropathic pain. A central issue at each stage was the role of “plausibility” in the assessment of insufficiency. The Supreme Court was not in agreement but held by a majority (Lord Sumption, Lord Reed and Lord Briggs) that the disclosure in the specification supports the claims in so far as they extend to inflammatory pain but not to any kind of neuropathic pain, and therefore claims 1 and 3 were insufficient.

The Supreme Court went on to consider the second major area of contention, infringement of second medical use claims. They found that, if claims 1 and 3 had been valid, they would not have been infringed. Again, the court was split, with three (Lord Sumption, Lord Reed and Lord Mance) favouring an “outward presentation test”, in different forms, and two (Lord Hodge and Lord Briggs) favouring a more subjective test.

Insufficiency

In his leading judgement, Lord Sumption reviewed the UK and EPO Case Law behind insufficiency, particularly the development of the “plausibility” test. Plausibility is not a statutory requirement in either the UK or Europe, but originates in the case law of the European Patent Office (EPO) as a response to over-broad claims, mainly in the chemistry and life sciences fields. Classically it applies to the assessment of inventive step, when a particular technical effect is asserted for the claimed invention. Post-filed data supporting the technical effect can be considered, but only if it has been made plausible from the information in the application as filed that the technical effect could be expected.

In the case of medical use claims, the technical effect of being efficacious in the treatment of the named condition is considered to be a technical feature of the claim. As the case law has developed to require the technical effect to be present across the whole scope of the claim, at all stages of the proceedings claim 1 of the patent in question was interpreted as requiring pregabalin to be efficacious in treating all pain. This shifted the assessment of whether the technical effect had been made plausible by the information in the patent application from inventive step to insufficiency.

The Supreme Court judgement makes it clear that the plausibility test is intended to be a relatively low threshold, designed to ensure that a patent cannot be obtained on a wholly speculative basis. It is understood that it would not be reasonable to expect clinical data to be included in an application. However, as nicely summarised by Lord Sumption, it is also clear that a bare assertion that a product is efficacious for the treatment of a given condition does not meet the plausibility test. Experimental data supporting the whole of the claim is ideal but not necessarily required. Also acceptable would be scientific reasoning as to why it would be worth trying the product for a particular condition. That reasoning must cause the skilled person to think there was a “reasonable prospect” that it would work as asserted, based on the direct effect on a metabolic mechanism involved in the disease. An example given in the decision is that the specification may point to some property of the product which would lead the skilled person to expect that it might well produce the claimed therapeutic effect, or to some unifying principle that relates the product or the proposed use to something else which would suggest as much to the skilled person.

In this case, the only data in the patent related to inflammatory pain.  Claim 2 relating to inflammatory pain was held to be sufficiently disclosed. Claim 1 relating to all pain was found by the Courts at each level to be insufficient. Regarding claim 3 relating to neuropathic pain, a distinction was made by Warner-Lambert between peripheral neuropathic pain and central neuropathic pain. They argued that there are links between peripheral neuropathic pain and inflammatory pain which means that the data in the patent did support the claims in so far as they related to peripheral neuropathic pain. The Court of Appeal agreed to the distinction and agreed that peripheral neuropathic pain was supported by the patent (but a late move by Warner Lambert to amend the claim to peripheral neuropathic pain was deemed an abuse of procedure).

However, Lord Sumption noted that the specification said nothing about neuropathic pain of any kind, and said nothing about “central sensitisation”, which was said to provide the link between neuropathic pain and inflammatory pain. Therefore, by a majority the Supreme Court found against Warner-Lambert, overturning the Court of Appeal decision and deeming peripheral neuropathic pain to also be insufficiently disclosed.

The question of plausibility for peripheral neuropathic pain had been acknowledged by the Court of Appeal as “finely balanced”, so although it was overturned by the Supreme Court against Warner-Lambert, it does not seem that the law has substantively changed.  Cases in the future will still be decided on the facts, taking into account the guidance in this decision, as summarised above. This should be of some comfort to pharmaceutical companies.

Infringement

The form of the claim is, of course, of great importance for the issue of infringement. In this case the claims were in Swiss-form, i.e. claim 1 relates to the use of pregabalin for the preparation of a pharmaceutical composition for treating pain. As discussed in relation to insufficiency, this type of claim includes the technical requirement that the preparation of the compound is for treating pain. In view of this the High Court concluded that in order to infringe the manufacturer must make the product with the intention that it be used for that purpose. The difference between the parties concerned the test of intention. Actavis’ case was that the test of the manufacturer’s intention was subjective i.e. the manufacturer must make the product with intent to target the patent-protected market, in this case the treatment of neuropathic pain. The judge in the High Court accepted this argument. Warner-Lambert argued that the manufacturer’s intention was objective, and that a manufacturer must be taken to intend the foreseeable consequences of his actions.

In the High Court, Arnold J took the unprecedented step of granting an order mandating the National Health Service to issue guidance to doctors and pharmacists that the drug pregabalin must only be prescribed for the treatment of neuropathic pain under the brand name Lyrica, and not using the generic name pregabalin. Lord Sumption noted that “it is by no means clear that it will always be appropriate to meet problems arising in relation to second medical use patents by guidance of this kind”. Accordingly, it is probable we will not see this type of remedy in the future.

However the Supreme Court was unable to agree on the correct approach to infringement, particularly on the role of intention. Lord Sumption and Lord Reed were of the opinion that the intention of the alleged infringer is irrelevant, and the sole criterion of infringement is whether the product, as it emerges from the manufacturing process, (i.e. including any labelling or accompanying leaflet) was presented as suitable for the uses which enjoy patent protection. This was summarised as an “outward presentation test”.

Lord Mance agreed to some extent with Lord Sumption and Lord Reed with the outward presentation test, but wanted to leave open the possibility (i) in rare cases the context may make it obvious that the outward presentation is not to be taken at face value, and (ii) there may be certain circumstances in which the generic manufacturer should positively exclude use for the patent-protected purpose. This appears to have been to avoid the situation in which a manufacturer could supply a product which from its outward presentation is non-infringing, but then actively market the product for an infringing use.

Lord Hodge and Lord Briggs preferred the view of Arnold J in the High Court, that the test is whether the alleged infringers subjectively intended to target the patent-protected market.

It is worth noting that the comments on infringement are all obiter, since the relevant claims were held invalid. The comments are also limited to Swiss-form claims, although it is likely that similar considerations would apply to the more modern EPC 2000 form of second medical use claims. Nevertheless, this decision does seem to make it more likely that generic manufacturers will be able to rely on skinny labels to avoid infringement.  However, the Supreme Court was divided and the ruling is by no means decisive. Generic manufacturers will therefore still need to be mindful of infringing sales on the ground.  Although on one level this decision is disappointing for innovator pharmaceutical companies, it is not a carte blanche for their generic competitors. The commercial value of second medical use claims is such that we can expect the issues raised to be further contested.

 

Elizabeth Swan
Life Sciences & Chemistry Group