Two decisions of the English High Court issued in the Lyrica Litigation

04 December 2015

On 10 September 2015 the English High Court gave its decision in the Warner-Lambert v Actavis litigation, after receiving the case back from the decision of the Court of Appeal which we reported here on 1 June.

The drug at issue, pregabalin, is an off-patent pharmaceutical. Warner-Lambert holds a second-use patent to its use to treat pain. The claims are in Swiss form, that is: they relate to a manufacturing process that is limited by the end use against pain.

Warner-Lambert markets pregabalin in the UK under the Lyrica brand for the treatment of epilepsy, generalised anxiety disorder (GAD) and neuropathic pain. The patent to pregabalin expired in May 2013 and data exclusivity expired in July 2014. 

The judge accepted that about 70% of the UK sales of pregabalin in 2014 and 2015 up to the trial were for pain, including but not limited to neuropathic pain (Decision, paragraph 415).

Pills in bottle

Actavis launched its pregabalin product in the UK on 16 February 2015 under “skinny labelling” (that is: with no statement of pain as the disease to be treated), and therefore relied for its sales on the practice of doctors to prescribe “pregabalin” rather than “Lyrica”, when prescribing for any disease. There is no requirement in the UK for doctors to state the patient’s disease on the prescription for the pharmacist.

The judge held that all the claims involved an inventive step, but that claims 1 (pain), 3 (neuropathic pain), 4 (cancer pain), 6 (phantom limb pain), 13 (idiopathic pain) and 14 (fibromyalgia pain) were invalid for insufficient disclosure of the claimed invention. Claims directed to peripheral neuropathic pain and sub-types of peripheral neuropathic pain would, however, be valid. In particular, claims 10 (trigeminal neuralgia pain), 11 (post-herpetic neuralgia pain) and 12 (causalgia pain) were valid, because those related to sub-types of peripheral neuropathic pain. It is important to note that none of the claims of the original patent specified peripheral neuropathic pain as such. 

On the question of possible infringement, the judge considered that normally a generic manufacturer or supplier supplying under “skinny labelling” does not infringe a Swiss claim stating a particular use of an off-patent drug. Generally speaking, at no point in the supply chain does the generic supplier or a subsequent supplier (e.g. a pharmacist acting on a doctor’s prescription) supply the drug knowing that it will be used for treating the second patented use. The judge concluded that any possible infringement, even if the claims to treatment of pain had been valid, was de minimis and therefore held that the patent had not been infringed by Actavis.   

The result was that the court did not issue any order of the type that had been reviewed in the previous Court of Appeal proceedings (which had related to an earlier strike-out application by Actavis), and held Pfizer, the holder of the marketing authorisation for pregabalin, liable for making groundless threats of patent infringement proceedings.

This decision applies the earlier decision of the UK Court of Appeal.  In that decision, the Court of Appeal held that a manufacturer or supplier infringes a Swiss claim for the new use when he knows or should have known or could reasonably foresee that some of his drug would be intentionally used for the second patented use.  

The decision (paragraphs 620 to 648) explores the reasoning of the Court of Appeal in detail. It focuses on a number of issues: Do the sales figures of pregabalin for pain establish “reasonable foreseeability” by Actavis in this case? And if they do, how is the specific liability of Actavis for patent infringement to be assessed?  Which sales by Actavis should be considered infringing and which not? Even if it might be assumed that a proportion of Actavis’s sales would have gone to treat pain when it was the sole generic pregabalin product on the market (the period from 16 February to 15 July 2015), would such an assumption hold when Actavis was itself under competition from other generic pregabalin products? In any event, how should Actavis’s reasonable foreseeability of counter-action by Warner-Lambert to maintain sales of Lyrica – thus reducing Actavis’s expectation of sales for pain - be factored into the analysis?

Weighing up all these factors, the judge concluded that it was not foreseable to Actavis at any time that more than ade minimisproportion of its product would be intentionally administered for the treatment of pain. He therefore concluded that there was no infringement of the second use patent.

Nevertheless, the judge did call for a new system to be put in place, whereby patents to further medical uses of off-patent drugs would be respected. The judge stated in paragraph 722 of the Decision:

“I have reflected repeatedly and at length on the issues raised by this litigation. At the end of that period of reflection, I remain more convinced than ever that the best solution to the problem of protecting the monopoly conferred by a second medical use patent while allowing lawful generic competition for non-patented indications of the substance in question is to separate the patented market for the substance from the non-patented market by ensuring that prescribers write prescriptions for the patented indication by reference to the patentee’s brand name and write prescriptions for non-patented indications by reference to the generic name of the substance (the INN).”

Following the judgment, Warner-Lambert appealed against the decision, and also applied to the High Court to conditionally amend its claims to the treatment of peripheral neuropathic pain and its sub-types if its appeal fails. This late attempt to introduce for the first time a claiming position specific to the treatment of “peripheral neuropathic pain” - prompted by the judge’s favourable view of the validity of that invention - has given rise to a side issue in the case, namely whether the late amendment constitutes an abuse of process.                                                                                     

The defendants Actavis and Mylan opposed the attempted late introduction of a claiming position specific to the treatment of “peripheral neuropathic pain”, and argued that, by delaying the amendment until after the judgment, Warner-Lambert has abused the legal process, in that a further trial of the amendment application and its possible consequences will be necessary. The judgment on the “abuse of process” challenge to the attempted amendment was delivered on 25 November 2015 by the same judge, Mr Justice Arnold. He held that the late amendment applicationwasan abuse of process and should be struck out.

The 25 November judgment reinforces that patentees run a risk of being unable to amend to a potentially valid position that was not already specifically in the claims, if – knowing or reasonably foreseeing that that position might be worth claiming - they wait until after the judgment on infringement and validity has been delivered. The practice of the English courts to consider conditional amendments at trial mirrors the practice of the European Patent Office to consider “auxiliary” (conditional) claim requests in opposition proceedings. The need for patentees to be up-front with their requests – highlighted by the 25 November judgment – corresponds to the current strictness of the EPO Boards of Appeal in using Article 12(4) of the EPO Rules of Procedure of the Boards of Appeal to refuse to admit such amendments for the first time on appeal, where they could reasonably have been presented earlier and thus considered for the first-instance opposition decision.

The pressure on patentees to propose early amendments that introduce new claiming positions for the first time, before knowing the opinion of the court or tribunal on the original claims, can be uncomfortable, as such amendments can be seen as an implicit acknowledgement that the validity challenge may have merit. The new position(s) selected by the patentee then reveal the area(s) which the patentee hopes would still be valid if the original claims would fail, and inevitably allow the defendants to formulate a more targeted validity challenge in that area or those areas than they would otherwise have done.  

Given the importance of the amendment and the legal issues it raises for patentees seeking to enforce their patents, it is reasonable to assume that Warner-Lambert will seek leave to appeal the 25 November judgment so that it can, if possible, be heard by the Court of Appeal in conjunction with the appeal against the 10 September judgment in the infringement proceedings.

The appeal decision is expected towards the end of 2016.

Warner-Lambert Company, LLC –v- Actavis Group Ptc EHF & Others [2015] EWHC 2548 (Pat)

Generics (UK) Limited trading as Mylan –v- Warner-Lambert Company, LLC [2015] EWHC 3370 (Pat)

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