7.2. Second (or further) medical use

In T 264/17 the board found that the claimed lubricant for replacing synovial fluid was a substance or composition within the meaning of Art. 54(4) and (5) EPC. The therapeutic effect of the claimed perfluorinated polyethers lay in their acting as a replacement for synovial fluid in diseased joints. In the board's view, this effect was achieved as a result of the claimed lubricant's material properties. As set out in the description, the lubricating action of the perfluorinated polyethers was down to their omniphobic properties, i.e. the fact that they repel both hydrophobic and hydrophilic liquids, automatically mass together and, as a result, continuously form a new lubricant film. These material properties were attributable to the chemical structure of the polyethers. Their physiological effect was thus obtained on account of the way in which they interacted (or did not interact) with biological tissue. Moreover, the therapeutic effect was undoubtedly caused by a chemical composition, specifically by the perfluorinated polyethers defined in the claim. The board held that it was secondary whether or not these were to be deemed "active agents" in the traditional sense.

In T 694/16 the claim was directed to a food composition for prodromal dementia patients. The board held that for the therapeutic method to be carried out and the effect to be achieved, the skilled person must, in the first place, be able to identify patients that are in need of treatment and will benefit from the administration of the claimed composition. "Prodromal (dementia) patients" are subjects who, although not yet suffering from dementia, are bound to develop it. The patent defined "prodromal patients" as persons that display at least one, preferably at least two, of a specific list of criteria, which included in particular the presence of specific markers. Claim 1, however, did not mention those criteria; rather, it referred to unspecified "characteristics of a prodromal patient". The difficulty in identifying further characteristics was highlighted by the fact that the patent acknowledged that other manifestations, such as mild cognitive impairment, which could be observed before the onset of Alzheimer's disease, were not sufficient to consider a person to be a "prodromal patient". The board thus held that the patient group was insufficiently disclosed. It held that if a claim is directed to a known compound or composition for use in a therapeutic method of treatment or prevention of a disease, and the claim specifies that the subject to be treated displays a clearly defined and detectable marker, which is not displayed by all subjects affected by or likely to develop that disease, then the purposive selection of the patients displaying the marker for the specified treatment is a functional feature characterising the claim.