IP Newsletter | Winter 2017/18
	PATENT
	Supreme Court Overrules Both Lower Tribunals to Recognize Inventiveness of Enantiomer Selection Invention
	On August 29, 2017, the Korean Supreme Court issued decisions recognizing the inventiveness of two Novartis patents for the compound and the transdermal composition, covering two products used to treat dementia associated with Alzheimer's disease (Exelon® Capsule and Exelon® Patch).1 Particularly, the decision regarding the compound patent was noteworthy because not only was this only the second time the Supreme Court has recognized the inventiveness of a "selection invention" in Korea, but in fact both lower tribunals had specifically rejected the inventiveness of the selection invention compound (an enantiomer of a previously-known racemate).2
	Background
	Novartis isolated a novel enantiomer ((S)-N-ethyl-3-[1-(dimethylamino)ethyl]-N-methyl-phenyl-carbamate, or "rivastigmine") from a racemate disclosed in prior art references, and discovered that it has remarkably superior transdermal penetration and 24-hour duration ("transdermal effect"), as well as superior anti-dementia effects, over the racemate. Novartis obtained two patents relating to these discoveries: (i) a compound patent directed to Exelon®'s active ingredient (rivastigmine); and (ii) a pharmaceutical composition patent for systemic transdermal administration comprising rivastigmine.3
	The Exelon® Patch was the first patch-type transdermal therapy approved worldwide to treat dementia associated with Alzheimer's disease, and has achieved huge commercial success.
	Procedural History
	SK Chemicals imported a significant amount of the rivastigmine active ingredient during the patent term of the compound patent, and subsequently manufactured and exported their own rivastigmine patches. Novartis responded in 2012 by filing a patent infringement action against SK Chemicals based on their compound patent. SK Chemicals then filed invalidation actions at the Intellectual Property Trial and Appeal Board ("IPTAB") against both of Novartis' patents covering the Exelon® Capsule and Exelon® Patch.
	The IPTAB denied the novelty of Novartis' compound patent on the basis that a person skilled in the art could have directly recognized the enantiomer, rivastigmine, from the racemate4 based on common technical knowledge at the time of the filing date of the patent. The IPTAB also denied inventiveness on the basis that the prior art racemate would have had the same transdermal effect as rivastigmine due to having the same chemical structure, and therefore rivastigmine did not have a qualitatively different effect from the racemate. The Patent Court upheld the lack of inventiveness on appeal.5
	However, the Supreme Court reversed the Patent Court and found both Novartis patents inventive, holding that the transdermal effect of rivastigmine indeed was a qualitatively different effect from what would have been expected from the prior art by focusing on what was specifically described in the prior art reference (especially in the working examples).
	Significance
	The Supreme Court's decisions are noteworthy for at least two reasons. First, the compound patent was reviewed as a selection invention (specific enantiomer vs. racemic mixture), and yet the Court still recognized inventiveness. There are very strict patentability requirements for selection inventions in Korea, and in fact there has only been one previous case in Korea in which the Supreme Court recognized the inventiveness of a selection invention.6
	Second, the Supreme Court came to its conclusion despite the fact that both lower tribunals (the IPTAB and Patent Court) agreed that the compound patent was invalid. Since Supreme Court review is discretionary, and in most cases substantive review is denied if both lower tribunals reach the same conclusion, the Supreme Court's decision in this case not only to take up review, but to reverse the lower tribunals' invalidation decisions was unexpected, and a welcome indication of the Supreme Court's interest in accurate review of the issues in this case.
	1 See Novartis AG v. SK Chemicals cases - Supreme Court Decision 2014Hu2696 and 2014Hu2702, August 29, 2017. Novartis was represented by Kim & Chang. 2 An "enantiomer" refers to each of the two mirror image forms of a chiral molecule. A "racemate" or racemic mixture refers to a mixture containing an equal ratio of a pair of enantiomers. 3 The pharmaceutical composition patent for systemic transdermal administration resulted from a divisional application based on the compound patent application. 4 Only two types of enantiomers exist - the (R) and (S) forms. 5 The IPTAB originally found that the pharmaceutical composition patent was inventive, but the Patent Court denied the inventiveness of both patents. 6 Supreme Court Case 2010Hu3424, August 23, 2012.
	Back to Main Page
	If you have any questions regarding this article, please contact:
	Sang-Wook HAN swhan@kimchang.com Alice Young CHOI aychoi@kimchang.com Seung Hyun LEE shlee4@kimchang.com
	For more information, please visit our website: www.ip.kimchang.com