Second medical use

A second medical use is the new use, in a method of treatment, of a substance or composition that is already known and already used in medicine. It is patentable, although methods of treatment of the human body are excluded from patentability, thanks to a construction specific to European patent law. The second medical use is one of the main instruments for extending the value of a medicinal product and one of the most contested grounds of pharmaceutical litigation.

The patentability of the second medical use

First, the European Patent Convention accepts, in Article 54, that the novelty of a known substance may derive from its use in a method of treatment, provided that use is not comprised in the state of the art. Next, the claim takes the form of a purpose-limited product claim: substance X for use in the treatment of disease Y. Before the revision of the Convention, the same protection was obtained through a Swiss-type claim. Finally, the new use may consist of a new disease, but also a new patient group, a new dosage regimen or a new mode of administration, provided it is new and inventive and its effect is made plausible by the application. French law contains an equivalent provision. The Guidelines for Examination can be consulted on the website of theEuropean Patent Office.

Infringement of a second medical use patent

The difficulty lies in the fact that the substance is free for its old uses. A generic manufacturer may therefore market it for the indication that has fallen into the public domain by excluding the patented indication from its leaflet, a practice known as the skinny label. Infringement then requires showing that the generic is intended for the patented indication or will necessarily be used for it, which leads the courts to examine the leaflet, the packaging, prescribing and substitution practices and the information given to healthcare professionals. The French, British and German courts and the Unified Patent Court have issued nuanced decisions on these questions.

Key points

In practice, the second medical use combines validity questions, in particular plausibility and inventive step, and novel infringement questions linked to the organisation of the medicines market. It joins the debate onevergreening. The firm acts in these disputes for originator companies and for generic manufacturers, as presented on the page pharmaceutical patents and regulation.