Patent application disclosures clarified by Supreme Court

That scientific evidence does not need to necessarily prove the claims are true, but should at least show why the product "might well work" as claimed, the court said.

It is not enough for patent applications to make bare assertions of what is plausible from using the product. Companies that fail to meet the standards of disclosure in their patent applications risk having their patents revoked for lack of sufficiency, according to the judgment.

The Supreme Court said that scientific grounds disclosed in patent applications "need not definitively prove the assertion that the product works for the designated purpose". However, it said "there must be something that would cause the skilled person to think that there was a reasonable prospect that the assertion would prove to be true".

According to Lord Sumption, pharmaceutical companies do not need to demonstrate plausibility using "experimental data". Instead, "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", it said.

The Supreme Court said patent applications can rely on "the common general knowledge of the skilled person" to supplement or explain their disclosures, but that "it is not enough that the patentee can prove that the product can reasonably be expected to work in the designated use, if the skilled person would not derive this from the teaching of the patent".

The Supreme Court's guidance was issued in a case where a dispute had arisen over the validity of a patent owned by pharmaceuticals manufacturer Warner-Lambert, and alleged infringement of that patent by two generics, Mylan and Actavis.

Warner-Lambert claimed Mylan and Actavis infringed its European patent which protected the use of the drug pregabalin to treat pain, inflammatory pain and neuropathic pain. Warner-Lambert, via its Lyrica brand, marketed the product for the treatment of peripheral neuropathic pain and epilepsy, the treatment of central neuropathic pain, and for the treatment of generalised anxiety disorder.

Warner-Lambert's patent is a 'Swiss-form' patent, which is a term used to describe a previously patented invention for which a second medical use has been found. The term was coined after the Swiss Intellectual Property Office announced in the 1980s that it would be willing to grant patents covering the use of a drug compound in the manufacturing process for the treatment of a specified condition. Other patent offices, including in the UK, have since endorsed Swiss-form patents. In its ruling, the Supreme Court described 'Swiss-form' patents as "purpose-limited process patents" which can apply to "a manufacturing process for a novel purpose".

The Supreme Court ruled that the disclosure by Warner-Lambert in specifying its Swiss-form patent did not support the claims it made about its ability of the product to treat neuropathic pain, whether peripheral or central. It said the disclosure did support claims in relation to treating inflammatory pain, but the company has not obtained a marketing authorisation for its product to be used for such purpose.

Warner-Lambert therefore failed to overturn earlier rulings by the High Court and Court of Appeal in England and Wales - both those courts had found its Swiss-form patent to be invalid.

The Supreme Court then considered that, had Warner-Lambert's claims in relation to the use of its product for treating neuropathic pain been valid, then it would have held that both Mylan and Actavis had not infringed its patent rights when they had manufactured generic rivals to the Lyrica product.

The Supreme Court attempted to clarify the test for determining infringement of a patent manufactured for a limited use in its ruling. However, there was disagreement between the five judges.

Lord Sumption and Lord Reed said that infringement depends solely on whether the rival product emerges from the manufacturing process, including any labelling or accompanying leaflet, and is presented as suitable for the uses which enjoy patent protection. They said the intentions of the alleged infringer are irrelevant in the consideration of whether they have infringed the patent.

Lord Mance said that while he agrees that the test for infringement generally depends on the objective appearance and characteristics of the product as it is prepared, presented and put on the market, there will be some "rare cases" where "the context may make it obvious that these are not to be taken at face value", and that generic manufacturers could or should go further and "positively exclude use for the patent-protected purpose".

Lord Briggs and Lord Hodge preferred another approach which had been articulated by the High Court judge earlier in the case. That test is "whether the alleged infringer subjectively intended to target the patent-protected market".