With regard to an invention relating to a new use of a known product ("use invention"; e.g., a claim directed to a compound or composition for a certain use), the Seoul Central District Court provided specific criteria for determining infringement of a use invention in its decision in a preliminary injunctive action (Seoul Central District Court Case No. 2020 Kahap 20372 decided on Aug. 18, 2020; final and conclusive). 

▶Relevant Fact

The petitioner had four (4) patents, and the claims of the patents were directed toward compositions defined with certain uses, as follows.

Meanwhile, the respondent manufactured and sold soap, lotions, shampoos, and conditioners (hereinafter, "respondent's products") containing Ceriporia lacerata or genetically equivalent species thereof. In addition, the respondent advertised the functionality and efficacy of its products in various ways through product packaging, exhibitions, and online shopping malls. 

▶Arguments of the Parties and Issues 

The petitioner filed a preliminary injunctive action, while arguing that (i) the respondent's products contained Ceriporia lacerata defined in Patents 1 to 4, or genetically equivalent species thereof, and (ii) the respondent's products included at least one (1) use presented in the claims of Patents 1 to 4. (In this regard, the petitioner also brought a main action seeking damages and permanent injunction against the respondent, currently pending before the Seoul Central District Court.) 

The respondent countered that: (i) the claims of Patents 1 to 4 were related to use inventions characterized by particular uses of a natural substance already existing in nature; and (ii) since the respondent's products were manufactured without intent to take advantage of the uses prescribed in the claims, the respondent's products did not fall within the scope of the use inventions claimed in Patents 1 to 4. 

Consequently, the critical issue of the subject case was whether any of the intended or advertised use or function of the respondent's products corresponded to the specific uses recited in the claims of Patents 1 to 4. 

▶Seoul Central District Court's Decision 

The Seoul Central District Court, in its ruling on the subject case, enunciated the criteria for determining infringement of a patent claiming a use invention, as follows:

A use invention is defined as an invention having a technical feature of a newly discovered use for a particular known substance. Thus, to establish patent infringement of a use invention, it is required to demonstrate that the accused product in question not only comprises the particular substance as a component but also includes the specific use presented by the use invention as its primary or incidental use. In determining whether the uses of the accused product include the specific use presented by the use invention, the following factors should be considered: detailed description of the specification of the patent at issue; general function and usage of the product line to which the accused product belongs; functionality or efficacy of the accused product displayed on the product itself or its packaging, packaging containers, etc.; advertising or promotional content for the accused product; and objective recognition of consumers or suppliers on functionality or efficacy of the accused product (emphasis added). 

Based on the above criteria, the Seoul Central District Court determined that the respondent's products included at least one (1) of the specific uses prescribed in the use inventions defined in Patents 2 to 4, for the following reasons: 

• The specifications of the petitioner's patents also describe soap, shampoos, and/or conditioners as examples of the formulation of the claimed compositions. 

• The respondent advertised in, e.g., the packaging of the respondent's products, that the respondent's products provided superior efficacy such as wrinkle improvement, skin whitening, and prevention of freckles, atopy and hair loss.

• The respondent held an exhibition to promote their products, where they stated the respondent's products achieved the effects of moisturizing, whitening, wrinkle improvement, and immunity enhancement.

• The respondent introduced the respondent's products as a "functional shampoo that helps nourish scalp and hair" online on an e-commerce website, and indicated the products could alleviate hair loss symptoms.

• In response to the main action filed by the petitioner, the respondent deleted efficacies such as preventing hair loss and promoting hair growth from the advertisements and promotional materials of the respondent's products. Such deletion, however, does not change the objective and actual use of the respondent's products. 

• In view of the above, it is reasonable to determine that the respondent's products are directed to at least one of the uses prescribed in Patents 2 to 4.

On the basis of the above determination, the Seoul Central District Court concluded that the production and sale of the respondent's products infringed Patents 2 to 4 of the petitioner.

▶Significance of the Decision 

The Court reaffirmed that, to establish patent infringement of a claim relating to a compound or composition for a specific use, the following requirements should be met: (i) the accused product comprises the compound or composition, and (ii) the accused product includes the use recited in the claim as its primary or incidental use. The decision further elucidated that the use of the accused product should be determined by reviewing the objective recognition of consumers or suppliers of the functionality or efficacy of the accused product, providing a clearer guideline for practitioners handling such matters.