Korean companies also adopt aggressive patent defense strategies

Chong Kun Dang files patent-scope confirmation trials against 4 Telminuvo generic competitors

Following Hyundai Pharm's petitions earlier this year...strategy expands beyond Novartis, Eisai and other multinationals

An aggressive patent defense strategy once used primarily by multinational pharmaceutical companies is gaining traction among Korean drugmakers. Rather than waiting for generic competitors to challenge their patents, originator companies are increasingly initiating proceedings themselves.

Traditionally, pharmaceutical patent disputes have begun with generic companies filing invalidation petitions or passive trials to confirm the scope of patent rights, which the originator responded to. Recently, however, Korean originator companies have also begun leveraging aggressive administrative trials as a means of patent defense.

Chong Kun Dang files positive scope confirmation trials against GL Pharm Tech and other generic competitors...Hyundai Pharm filed similar petitions earlier this year

According to industry sources on the 10th, Chong Kun Dang recently filed positive trials to confirm the scope of patent rights against four companies, including GL Pharm Tech, that have obtained approval for generic versions of its hypertension combination treatment Telminuvo.

A positive trial to confirm the scope of patent rights is a proceeding initiated by a patent holder to determine whether a competitor's product falls within the scope of its patent. It is the counterpart to a passive confirmation trial, typically initiated by a generic manufacturer seeking to establish that its product falls outside the patent's scope.

Chong Kun Dang has asked the Intellectual Property Trial and Appeal Board (IPTAB) to determine whether the approved generics fall within the scope of Telminuvo's formulation patent. The petitions are understood to have been filed to clarify ambiguities in GL Pharm Tech's claim that its generic version does not infringe the patent.

Telminuvo is a fixed-dose combination of telmisartan and S-amlodipine for hypertension. Since its approval in 2013, it has remained one of Chong Kun Dang's flagship products, generating annual prescription sales of approximately KRW 50 billion to KRW 60 billion. The company has recently strengthened the pipeline by adding a lower-dose combination to its lineup.

Earlier this year, Hyundai Pharm also initiated positive confirmation trials to defend patents covering its dementia combination treatment DM Duo. It filed petitions against SS Pharm in January and Boryung Biopharma in March, although it withdrew both in April.

Until now, such petitions by Korean originator companies have been sporadic. One of the few notable precedents dates back about a decade, when Daewoong Pharmaceutical took similar action.

In October 2016, Daewoong filed a positive confirmation trial against Gastiin CR, a sustained-release mosapride tablet developed by Korea United Pharm, seeking confirmation that the product fell within the scope of its formulation patent. The petition was dismissed the following year, and the two companies subsequently settled the related patent dispute.

Multinationals including Novartis, Regeneron, and Eisai have led aggressive patent defense strategies.

Positive patent-scope confirmation trials have been relatively uncommon in Korea. Even those that have been filed have largely been initiated by multinational pharmaceutical companies seeking to counter the market entry of Korean competitors.

In January 2022, Novartis filed positive confirmation trials against four companies—Kyongbo Pharmaceutical, Korea United Pharm, Ahn-gook Pharmaceutical and Ahngook New Pharm—that had launched generic versions of its diabetes treatment Galvus. Novartis sought a determination of whether those products fell within the scope of its compound patent.

In March 2023, US-based Regeneron filed a positive confirmation trial involving a compound patent against Samsung Bioepis, which was developing a biosimilar of the age-related macular degeneration treatment Eylea. That June, Novartis filed two positive confirmation trials concerning formulation patents against Celltrion, which was developing a biosimilar of its asthma and urticaria treatment Xolair.

In October 2024, Eisai filed a positive confirmation trial involving a method-of-use patent against Boryung, which had developed a generic version of the company’s cancer treatment Lenvima. The petition was withdrawn in May last year.

Industry observers expect the use of positive confirmation trials to spread further among Korean pharmaceutical companies.

Having grown largely through generics, Korean drugmakers have historically had relatively few occasions to challenge competing products as patent holders. But the landscape is changing as more domestic companies introduce independently developed new drugs, incrementally modified drugs and fixed-dose combinations. With a growing number of flagship products protected by proprietary patents, companies are increasingly turning to positive confirmation trials to protect those assets.

Concerns over declining profitability following drug pricing reform may also be contributing to the trend. As price cuts for generics and previously listed drugs make it harder to sustain earnings, pharmaceutical companies have greater incentive to assert their patent rights to protect the markets for their independently developed products.

Filing a positive confirmation trial does not automatically prevent a competing product from being sold. Nevertheless, the procedure is considered a proactive defensive tool because it allows patent holders to challenge whether a competitor's product falls within the scope of their rights and secure a basis for potential future enforcement.