Supreme Court confirms licensee’s standing
to challenge patent validity

On February 21, 2019, the Supreme Court of Korea issued an en banc decision overruling its prior precedents on the issue of whether a licensee who is continuing to make royalty payments under an existing license agreement nevertheless has standing to challenge the validity of the licensed patent. In short, the Korean Supreme Court held that absent special circumstance, a patent licensee is an “interested party” eligible for challenging the validity of a licensed patent, despite the lack of any threat or potential threat posed by the patent holder against the licensee’s right to use the patented invention. (Supreme Court En Banc Decision No. 2017Hu2819).

To address this unsettled issue, the Supreme Court used this case as the vehicle to clarify the meaning of interested party by holding that any person who has a direct and actual interest in invalidating a patent (due to the risk of loss or damage that may be caused by the rights vested in the patented invention) is an interested party and this includes any person who manufactures or sells or will manufacture or sell using the licensed patent. The Supreme Court further held that pursuant to this legal principle, any person who uses a patent under a grant of license should be considered an interested party, despite the fact that there is no actual or potential threat posed by the patent holder regarding the licensee’s use of the licensed patent.

The Lee & Ko IP Practice Group is one of the largest and most prominent IP practices in Korea and is recognized by clients and adversaries alike as one of the strongest practices of its kind. From representing clients in Korea’s largest patent infringement cases and invalidity trials to helping clients evaluate patent invalidity, the Lee & Ko IP Practice Group has deep experience in a wide range of industries and remains the top choice in Korea and around the world.