APAA e-Newsletter (Issue No. 24, August 2021)

Korean Supreme Court Changes Inventiveness Standard for Selection Inventions

Hong-Joo Ahn, C&S Patent and Law Office (Korea)

  1. Selection Invention and Patentability Thereof

A selection invention is an invention involving selection of a species from a genus disclosed in a prior art reference. Generally, when a selection of matter is not directly disclosed in the prior art reference, a selection invention has novelty. As for inventiveness, the Korean Supreme Court principally considered whether a selection invention can achieve an advantageous effect in comparison with a prior art reference.  Recently, the Korean Supreme Court changed the standard for determining inventiveness of a selection invention by requiring that the inventiveness determination of a selection invention be the same as other types of inventions.

  1.  Case Background

The present case relates to Korean Patent No. 0908176 titled “Lactam-Containing Compounds and Derivatives Thereof as Factor Xa Inhibitors.” The chemical compounds recited in claim 1 cover the active ingredient named Apixaban, commonly used to prevent blood clotting and which is commercially available as Eliquis from Bristol-Myers Squibb Korea. A prior art reference (WO00/39131) also discloses Apixaban through a general chemical formula.  However, theoretically, the present invention corresponds to selecting one from among approximately 66 billion potential combinations, as described in the following.

The Korean Intellectual Property Trial and Appeal Board and the Patent Court did not acknowledge the inventiveness of the present invention, based on strict inventiveness requirements suggested by the precedent Supreme Court rulings.  In the case of 2001Hu2740, the Supreme Court ruled that a selection invention is patentable on the condition that first, a prior art reference has not yet disclosed subordinate concepts comprising a selective invention in concrete terms (Novelty); second, subordinate concepts must possess effects different in quality from the preceding invention, or if not, at least, there must exist conspicuous differences in effect as measured quantitatively therebetween (Inventiveness).  The stance of the Supreme Court has been to consider that the difficulty in constitution of a selection invention can be acknowledged only through qualitatively different effects or significantly different quantitative effects thereof.

  1. Supreme Court Rulings in 2019Hu10609 (April 8, 2021)

The Supreme Court recently held that even if a genus is disclosed in a prior art reference, a selection invention should be considered inventive when the difficulty in constitution is acknowledged.  The Supreme Court further ruled that when determining the difficulty of constitution of a selection invention, the number of compounds that can theoretically be included within the scope of the chemical formulas and substituent in the prior invention, whether or not an ordinary skilled artisan could easily select a particular compound or a particular substituent from among the compounds listed in the prior invention, structural similarity of the selection invention to compounds specifically described in the prior invention, or the like, should be considered as a whole.

Based on the foregoing, the Supreme Court overturned the original decision and found that the present invention does not lack inventiveness, considering that the present invention selects one of hundreds of millions of combinations which are potentially available in the prior art reference, that the present invention has increased the concentration of active drugs in the receptor and has improved the effect of co-administration where it is administered simultaneously with other drugs, and that the prior art reference fails to disclose embodiments similar to the present invention.

  1. Implications of Decision

The Supreme Court maintained the stance of the precedent ruling in which a selection invention is inventive when a selection invention achieves advantageous effects in comparison with a prior art reference.  The decision of the present case can be understood when considering that the requirement of inventiveness should be no different in selection invention cases, as compared to other categories of patentable inventions. In this sense, the present case was not decided by an en banc court, which suggests that the Supreme Court is of view that this case did not overrule its prior decisions but merely clarified the form of its prior decisions. In spite of the Supreme Court’s view, it is expected to significantly change the precedent practices in determining inventiveness of selection inventions. However, even in the present case, qualitatively different effects or significantly different quantitative effects, along with appropriate examples in support thereof, are still important to gauge the patentability of a selection invention, as those effects can be a principal factor regarding the difficulty in constitution.