Background
The dispute concerned the drug pregabalin, marketed by Warner-Lambert under the trade mark “Lyrica” for the treatment of epilepsy, generalized anxiety disorder (GAD) and pain. According to evidence put forward during the trial, prescription of pregabalin for pain accounted for 50% of sales. Patents directed to the compound per se expired in 2013 but Warner-Lambert owns a European patent (No. EP 0 934 061) directed to its use in treating pain which expires in 2017. Marketing of generic pregabalin for pain treatment would constitute an infringement of Warner-Lambert’s patent.
Actavis (and other generic companies) have applied for a marketing authorization for their own products which are limited to the treatment of GAD and epilepsy only.
Although generics suppliers can launch drugs under a “skinny label” (modified product leaflets that list only the authorised indications) to avoid infringement, in practice it is difficult to ensure that a generic drug is not dispensed for the patented treatment since most prescriptions refer only to the INN of the drug (i.e. pregabalin) rather than by brand name, and also do not mention the ailment it is intended to treat. The trial focused on the lengths Actavis should be expected to go to in order to ensure its generic pregabalin for not prescribed for pain.
Judgement
The relief sought by Warner-Lambert was an interim injunction to force Actavis to take steps to prevent its generic pregabalin from being dispensed to treat pain. Specifically, Warner-Lambert requested that Actavis be required to:
- Make it part of a contractual agreement with pharmacies that the pharmacies would make reasonable endeavors not to supply the generic drug for pain treatment;
- Inform Warner-Lambert’s solicitors before supplying the generic drug to intermediaries;
Write to pharmacies and Clinical Commissioning Groups informing them that the use of pregabalin for pain is protected by Warner-Lambert’s patent; - Ensure that the packaging of the generic drug has a removable label stating that the product is not authorized for the treatment of pain; and
- Notify the NICE Medicines and Prescribing Centre of the Department of Health that the generic drug should not be prescribed or dispensed for the treatment of pain.
There was a dispute over Warner-Lambert’s request regarding the label on the packaging, since it was not clear whether such a label would comply with EC Directives. Arnold J. also observed that neither the label nor the contractual terms would help a pharmacist to know whether a prescription for pregabalin had been written for pain, and thus these measures may not be effective anyway.
In deciding whether or not to grant the interim injunction, Arnold J. considered that there were two principal questions to be tried. The first was whether it was seriously arguable that Actavis would be considered to infringe the second medical use claim (set out below) unless it took positive steps to prevent off-label use. Furthermore, if it was determined that there was a serious question to be tried, what steps, if any, should Actavis be forced to take pending a full trial on infringement.
Turning to the patent in question, claim 1 reads as follows:
Use of (S)-3-(aminomethyl)-5-methylhexanoic acid or a pharmaceutically acceptable salt thereof for the preparation of a pharmaceutical acceptable salt thereof for the preparation of a pharmaceutical composition for treating pain.
Arnold J. confirmed that Swiss-type claims should be interpreted as process claims aimed at catching the manufacturers who carry out the process of preparing the drug, rather than at doctors or pharmacists. Arnold J. also held that the word “for” (as in “for treating pain”) imports a requirement of subjective intention on the part of the manufacturer that the drug will be used for treating the condition specified in the patent. In other words, Actavis’ intention to supply the generic version of the drug with the knowledge that pharmacists may dispense it for treating pain, unless positive steps are taken to prevent this, is not sufficient to infringe. Since Warner-Lambert could not show a “subjective intention” on the part of Actavis to manufacture the generic drug for treating pain, the interim injunction was refused.
Comment
Arnold J.’s conclusion that second medical use claims are only infringed if the manufacturer shows “subjective intent” could be seen as being detrimental to patent proprietors, making it more difficult for them to enforce these claims. Certainly, this was the position taken by Warner-Lambert. Furthermore, the Dutch court has taken an opposing view to Arnold J. in a recent decision concerning zoledronic acid, although the facts of the cases materially differed.
Update
A judgment handed down on 6 February by Arnold J. considered this matter further. Actavis applied to strike out Warner-Lambert’s claim for infringement. In addition, Warner-Lambert applied for permission to amend their Particulars of infringement to plead “subjective intent” as foreseen by the earlier interim judgement.
In the latest judgment, Arnold J. ruled that Warner-Lambert’s amended Particulars did not disclose reasonable grounds for alleging intent on Actavis’ part. In coming to this conclusion, Arnold J. agreed with Actavis that even if pharmacists ignore the skinny label, this is not proof of “subjective intent” but rather a foreseeable consequence of Actavis marketing under the skinny label. However, Arnold J. did not dismiss Warner-Lambert’s claim and allowed the case to proceed to a full trial, giving Warner-Lambert some hope of an opportunity to overturn the judgment on appeal.
The decisions can be found here: