On August 29, 2017, the Korean Supreme Court upheld the inventive step of a patent covering a method of administration of a particular dosage ("Dosage/Administration Method Patent") for Rivastigmine (Patent Registration No. 121596 (the "Patent-at-Issue")). (Korean Supreme Court Case No. 2014Hu2702, decision issued on August 29, 2017). 

First, the Korean Supreme Court set forth a new standard for determining the inventive step of Dosage/Administration Method Patents. The Korean Supreme Court stated that developers of pharmaceuticals exert significant effort to find the appropriate administration method and dosage in order to meet technical goals, such as improving the medicinal effects or efficient administration of the pharmaceutical. Therefore, the Korean Supreme Court concluded that the validity of a Dosage/Administration Method Patent will be determined by whether such method/dosage achieves a remarkable or qualitatively different effect that cannot be easily conceived by a person having ordinary skill in the art.

Second, based on the particular facts of this case, the Korean Supreme Court held that a person having ordinary skill in the art could not easily conceive the percutaneous absorption rate of the patented invention at issue from the prior art. The reasons for this holding are as follows:

- Prior Art 1-1 merely states that administration methods other than oral administration are possible, without expressly suggesting transdermal administration; and

- Although the compositions in Prior Art 1-1 and Prior Art 1-2 appear to share properties found in other compounds that show high absorption rates when administered transdermally, the fact that those compounds have such properties does not necessarily mean they have high transdermal absorption rates.

As a result, the Court held that the transdermal administration method of Claim 1 of the Patent-at-Issue is indeed a remarkable or qualitatively different effect that cannot easily be conceived by a person having ordinary skill in the art in view of the state of technology or disclosed technology at the time of filing the patent application. Therefore, the Court upheld the inventiveness of Claim 1 of the Patent-at-Issue.

This case is significant because it is the first case in which the Korean Supreme Court designated a specific test for determining inventive step in a case involving patentability of a Dosage/Administration Method Patent.

Previously, in the Korean Supreme Court Case No. 2014Hu768, dated May 21, 2015 (en banc), the Court had held for the first time that administration method and dosage were patentable elements of an invention. In that case, however, the Court did not designate a specific test for determining the inventive step.

Similar to the new test provided by the Supreme Court in Case No. 2014Hu2702 discussed above, in a case in which the inventive step of the administration method of Tadalafil was an issue, the Patent Court accepted Yulchon’s newly devised test for determining inventive step. Accepting Yulchon’s arguments, the Patent Court held

"Optimizing administration methods to achieve a desirable effect — such as optimizing administration methods, such as dosage and administration frequency — in order to maximize the medicinal effect or reduce side effects is within the creativity scope of a person having ordinary skill in the art. Notwithstanding the foregoing, inventive step shall be recognized, barring special circumstances, if (i) the advantageous effect resulting from a particular administration method or dosage is remarkable and exceeds what is commonly conceivable to a person having ordinary skill in the art, or (ii) a person having ordinary skill in the art could not have foreseen the particular administration method or dosage that provides the pharmaceutical effect while minimizing particular negative effects or side effects."

(Korean Patent Court Decision No. 2015Heo2889, dated Feb. 3, 2017 and 5 other cases). The Supreme Court denied review, effectively affirming the Patent Court's decision. (Korean Supreme Court Decision No. 2017Hu547, dated Jun. 29, 2017 and 5 other cases).

As a result, when determining the inventive step of a Dosage/Administration Method Patent, the key issue is the unexpectedness or remarkableness of the effect, not the difficulty of deriving the particular administration method or dosage. This standard is consistent with the Korean Patent Court decision discussed in the preceding paragraph, as well as the Korean Supreme Court decision discussed above, and it appears to represent the view of the courts generally. Therefore, the test the Supreme Court established in Korean Supreme Court Case No. 2014Hu2702 is likely to be an important standard in the foreseeable future for determining the inventive step of Dosage/Administration Method Patents.

However, when applying the above test for determining inventive step under the specific facts of this case, we note the Korean Supreme Court also held that, "[i]n view of the fact that a person having ordinary skill in the art was not able to derive transdermal administration easily from the combination of prior art and common effort, transdermal administration in this case is a qualitatively different effect not foreseeable by a person having ordinary skill." As a result, based on the particular facts of a case, the difficulty of deriving the particular administration method or dosage may still be relevant and may also play a part in the inventive step analysis. In other words, the inventive step analysis for Dosage/Administration Method Patents will primarily follow the new test of unexpectedness or remarkableness of the effect, but the difficulty of deriving a particular administration method or dosage cannot be completely ignored. Accordingly, continued observation of court decisions is necessary for clarification of the importance of the administration method or dosage in the inventive step analysis, as well as other issues.