IP & IT Bytes: Patents: second medical use claims

04 March 2015

Summary

In interim injunction proceedings, the High Court has held that the manufacturer of a product that is the subject of a second medical use claim must have a subjective intent that the product be used for the patented second medical use in order to infringe the claim.

Background

The grant of patents for second medical uses of known compounds must overcome two problems: that the compounds are not new; and that methods of treatment of the human (or animal) body by therapy are not patentable.

Since the amendment of the European Patent Convention (EPC) in 2000, Article 54(5) of the EPC has enabled the grant of claims in the form “product X for treating indication Y” (a purpose-limited product claim). Before the EPC, these patents had to use claims in the “Swiss” form, that is, “use of substance X for the preparation of a medicament (or pharmaceutical composition) for treating indication Y” (a purpose-limited process claim).

Section 60(1)(c) of the Patents Act 1977 (section 60(1)(c)) makes it an infringement to keep, dispose of, or offer to dispose of, any product obtained directly by means of the claimed process.

Facts

W marketed a prescription-only drug for three different indications under a single registered trade mark. Patent protection for the drug had expired but W also owned a current second medical use patent for pain relief, which was one of the three indications. A applied for a marketing authorisation for a generic version of the drug limited to the other two indications.

W was concerned that, despite this, the generic drug would be dispensed for the patented second medical use, because most prescriptions are written generically. Since very few prescriptions state the indication for which the drug has been prescribed, the dispensing pharmacist will generally not know this. W also argued that, because the generic drug is usually cheaper than the patentee’s product, pharmacists have a strong commercial incentive to dispense the generic version of the drug unless positive steps are taken to prevent this.

W sued for patent infringement and sought an interim injunction requiring A to take specific actions to prevent its generic version of the drug being dispensed for patients who had been prescribed the drug for the patented indication.

Decision

The court refused to grant the interim injunction. There was no serious issue to be tried as A would not infringe the patent by marketing the drug for the permitted indications. As the relevant claim was to a process of manufacture, infringement would require a subjective intention by A, as the manufacturer, that the drug would be used for treating the patented indication.

While A might foresee that the product might be prescribed for the patented use, it did not have the requisite intention.

Swiss form claims were process claims, so W’s primary claim for infringement of the patent was under section 60(1)(c). W contended that the generic drug was a product obtained directly by means of the process of the patent claims, and that it was sufficient that A intended to sell the drug, and knew that pharmacists were likely to dispense it for treating pain, unless positive steps were taken to prevent this. There was no dispute that A intended to sell the drug, as it was lawfully entitled to, and it was arguably foreseeable that, unless steps were taken to prevent it, pharmacists would be likely to dispense the drug for treating pain, and that A knew that that was the case. A contended that this knowledge was not sufficient and that what was required was a subjective intention on its part that the drug should be used for treating pain.

The court noted that cases from other EU jurisdictions supported the proposition that subjective intent was required and it held that the word “for” in Swiss form claims imported a requirement of subjective intention on the part of the manufacturer that the medicament or pharmaceutical composition would be used for treating the specified condition.

In case this was wrong, and there was a serious issue to be tried, the court applied American Cyanamid principles and concluded that it would not have granted the interim injunction in any event (American Cyanamid Co v Ethicon Ltd [1975] UKHL 1). The court noted that the relief that W sought against A was intended not to affect A’s own conduct so much as the conduct of third parties who were not before the court. It followed that the principles had to be applied with particular care.

Granting the relief sought by W would create a greater risk of injustice than refusing it. W’s unquantifiable loss in the period up to judgment was not likely to be substantial. However, A was likely to suffer substantial unquantifiable loss if the order sought by W were wrongly granted. If A were required to put a notice on its packaging, this would delay its entry into the market and it would be very difficult to quantify its loss, paricularly if other players entered the market during that period. Also, the evidence showed that the requirement to put a notice on the packaging and the imposition of contractual terms requested by W were both likely to deter pharmacists from stocking the generic drug.

Comment

The decision is important as it defines the requirement of the manufacturer’s knowledge and intention under section 60(1)(c) where there are claims in Swiss form. Claims in EPC form have a different scope of protection to claims in Swiss form so nothing said here about Swiss form claims necessarily applies to EPC claims.

Although W was not successful on the facts, the court noted that there were potential scenarios where Swiss form claims might still be enforced. For example, if a manufacturer put the patented indication on its summary of product characteristics or product information leaflet, that would be strong evidence of a subjective intent to carry out the process for that purpose.

Likewise, it might also be infringement if a manufacturer or third party promoted the prescribing or dispensing of the product for the patented use in another way.

The court has subsequently refused A’s application to strike out W’s infringement claim. The requirement for subjective intention and its precise meaning is likely to be appealed: the court noted that this is a developing area of the law.  However, on the facts, an injunction in the form requested seems unlikely to be granted. Adding wording to packaging that the generic drug should not be prescribed for pain has potential regulatory problems as well as discouraging pharmacists from stocking it. Contractual restrictions on buyers would not necessarily overcome the problem that the dispensing pharmacist often does not know, and would have no reasonable way of finding out, what indications the prescription is intended to treat.

Case: Warner-Lambert LLC v Actavis Group PTC EHF and others [2015] EWHC 72 (Pat).

First published in the March 2015 issue of PLC Magazine and reproduced with the kind permission of the publishers. Subscription enquiries 020 7202 1200.

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