How to Focus on Small Molecules in Written Description and Enablement


Korean practice is quite strict, with respect to requirements for claiming small molecules, which are usually prepared by organic synthesis.  The basic rules are (i) the whole claim, that is, all the compounds within the scope of the claim, should be sufficiently supported by the detailed description of the specification (Article 42(4)(ii) of the Korean Patent Act; Support requirements for claims), and (ii) the detailed description should sufficiently disclose the claimed compounds so that those skilled in the art can easily carry out the invention (Article 42(3)(II) of the KPA; Written description and enablement requirements for specification).

The above-mentioned two requirements are stated separately, but in essence, govern the same thing: the extent to which the original specification should disclose specific compounds among the claimed compounds defined by a general chemical formula.  If the specification sufficiently discloses exemplified compounds, the claims will be considered as being supported by the specification.  How to meet the written description and enablement requirements in Korea is discussed below.

Compound inventions

If an application includes a claim directed to a group of compounds, the originally filed specification should include (i) identification data, (ii) a method of preparing the compounds, and (iii) working examples identifying specific compounds.

  • Identification data

Physicochemical data such as elemental analysis value, NMR data, melting point, and boiling point should be provided in the specification to show the claimed compounds were actually prepared and existed at the time the application was filed.  Where a group of compounds represented by a general formula are claimed, such data can be provided for some representative compounds.  However, if the original specification lacks identification data, adding such data to the specification as a part of the specification, is not allowed, and even if the applicant submits the data as reference data during the examination, the late submitted data does not cure the deficiency in the specification.  Thus, generally, a rejection based on lack of identification data is not easy to overcome.

  • Preparation methods

The specification should provide a method for preparing the claimed compounds.  Where a group of compounds represented by a general formula are claimed, the method may be described using a general reaction scheme.

  • Working examples

Where a group of compounds represented by a general formula are claimed, whether or not the specification meets the description and enablement requirements is determined by the level of disclosure of specific compounds in the working examples, based on the structural feature(s) of the claimed compounds that is improved over those of the known compounds.  In principle, the specification should provide working examples for representative compounds having the improved structural feature.  For example, if a claimed compound has the feature of having an aryl substituent instead of an alkyl substituent in a known compound, the specification should provide working examples showing preparation of a compound(s) having a benzyl or naphthyl group, and the Korean Examiner may allow a claim comprising a compound having a C6-C10 or C6-C20 aryl group.  That is, a claim can cover specific compounds which are practiced according to the working examples and other compounds which fall within an appropriate and reasonable scope of the specific compounds.  If two functional groups have different chemical properties, they are not considered as being equivalent and within an appropriate and reasonable scope.  Thus, if a compound having a chloro or bromo group is identified in the working examples, it is possible to claim a halo group.  However, if a compound having a nitro or alkyl group is identified in the working examples, it is not generally possible to claim a halo group.  In the latter case, a description of the compound having a nitro or alkyl group will not support a claim to a compound having a halo group, and a claim to a compound having a halo group will not meet the written description and enablement requirements.  Therefore, if a claimed compound can have various types of substituents at a particular position, it is advisable to provide at least one example compound for each type of substituent at that position to secure a broad scope of protection.

Medical use inventions

Where a novel compound is claimed, a general statement about the utility or usefulness of the compound usually meets the description requirements as far as usefulness is concerned.  However, if a novel substance has a medical use and such medical use is claimed, the specification should include pharmacological data to substantiate the claim with respect to the medical efficacy of the substance.  Such pharmacological data should be present in the originally filed specification, and cannot be added or supplementarily added to the specification during prosecution for the purpose of satisfying the description requirement for the specification.

Pharmacological data should be data obtained, in principle, from clinical tests.  However, data obtained from animal tests or in vitro tests such as IC50 and ED50 can be allowed.  In cases where a pharmaceutical composition comprises a group of compounds, it is sufficient to present pharmacological data for representative compounds of the claimed compounds, and it is not necessary to submit pharmacological data for each and every claimed compound.

Additional discussion on biological materials

Isolated genes, DNA fragments, vectors, peptides, and cells are all patentable in Korea.

When a gene is claimed, its base sequence or the amino acid sequence of the protein encoded by the base sequence, the origin of the gene, a method for obtaining the gene, means for identifying the gene, and the utility and effect of the gene should be specified in the specification.  Likewise, when a peptide is claimed, a gene encoding the peptide or the nucleic acid or amino acid sequence of the peptide, the origin of the peptide, preparation methods, physical, chemical or biological properties of the peptide, and utility and effect of the peptide should be described in the specification.

Regarding the utility and effect of a gene or a protein encoded by the gene, the Korean Patent Court holds that mere discovery of a certain gene or peptide is hardly recognized as an invention and lacks industrial applicability; to be considered as industrially applicable and to enable a person skilled in the art to use the claimed invention, a specific, substantial and credible utility should be stated in the specification (Patent Court Case No. 2007Heo5116 rendered on Sep. 26, 2008).  Specific experimental results to identify such utility should also be provided in the speciation.

Each type of invention has its own written description and enablement requirements in Korea, and some of them are very difficult to satisfy during the examination if the necessary information is not present in the originally filed specification.  Trying to overcome such a rejection by presenting arguments based on general knowledge known in the art at the time of filing, could create the risk of the claimed invention being considered to lack an inventive step, and place the applicant in a dilemma.  Because of potential pitfalls like these, we highly advise our foreign associates and international applicants to obtain sufficient knowledge and understanding of Korean patent practice to avoid losing the opportunity to secure a patent to valuable technology in Korea.



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