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Drug patent expiry in 2021: Opportunities and challenges in the Korean market

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Min Son of Hanol IP & Law looks ahead at the key deadlines in the South Korean drug patent market for 2021

With each new year, pharmaceutical companies are faced with the loss of exclusivity that accompanies the expiration of their patents, and by the same token, drug manufacturers are also afforded new opportunities and challenges due to the entry of generic competition. In South Korea, as many as 62 patents for 158 pharmaceutical products are supposed to expire this year, with more than half of these expected to potentially be launched as generics in the absence of any additional patents in the patent listing.

The Ministry of Food and Drug Safety (MFDS)’s Green List (somewhat analogous to the US FDA’s Orange Book) shows that a total of 62 drug-related patents covering 158 products are scheduled to expire in 2021, with 14 of these (covering 35 products) having already been removed due to patent invalidation, expired marketing authorisation, etc.

Outside of the removed products noted above, 56 products with no additional patents on the Green List may face generic entry immediately after the listed patents (totalling 28) expire this year.

January – March

In January 2021, patents set to expire include Amgen’s Xgeva and Prolia; AstraZeneca’s Faslodex; Pfizer’s Eraxis; LG Chem’s Factive; Bayer’s Angeliq; and Chong Kun Dang’s Bredinin.

Of these, only Xgeva and Prolia remain covered by other patents; Prolia in particular achieved sales of KRW 47.3 billion in 2019 and KRW 54.9 billion by the third quarter of 2020. With its patent expired on January 5, only one patent will remain until its expiration in March 2025; if this can be avoided, the product may face competition from generics.

The last patent for BMS’s Baraclude was finally invalidated in 2016 before its expected expiry this January, and Korean companies such as Dong-A ST, Daewoong Pharmaceutical, and HK inno.N have already successfully avoided the BMS patent and launched competing generics.

The patents of Pfizer’s Sutene; Janssen’s Edurant and Complera; and GSK’s Juluca will expire in February, while in March, those that protect Takeda’s Dexilant DR; Roche’s Mircera; Hanmi’s Amlodipine, Amozaltan, Amozaltan Q, and Amozaltan Plus; and MSD’s Cozaar XQ are set to expire.

Among these, 12 of the 30 patents held for the Amozaltan family will expire in March of this year; the remaining 18 include patents that expire in 2024, 2033, 2035, and 2036. Thus far, about 30 Korean pharmaceutical companies have successfully avoided these patents for Amozaltan and have already released and sold generics.

April – July

In April, the patents of AstraZeneca’s Faslodex, Astellas’ Advagraf SR capsule, and Novartis’ Rydapt soft capsule will expire, although Rydapt will remain protected by a patent expiring in 2024. Thereafter, the patents of GSK’s Requip PD, Takeda’s Omnaris nasal spray, GSK’s Seretide, and SK Chemicals’ Joins tablet are scheduled to expire in May, with Joins covered under a follow-up patent until 2030.

In June, the patents for Bayer’s Ciprouro, Daewoong Pharmaceutical’s Aclasta, Dong-A ST’s Elaspol, and Novartis’ Tykerb will expire, followed by those for Allergan’s Alphagan-P eye drops, Boehringer Ingelheim’s Pradaxa, Gilead’s Vemlidy, Novartis’ Signifor LAR, and Daewoong Pharmaceutical’s Instanyl nasal spray in July.

Although the non-vitamin K antagonist oral anticoagulant (NOAC) Pradaxa will still be protected under a secondary patent which expires in March 2023, eight Korean companies have already prevailed in patent challenges to avoid entry barrier due to this secondary patent and have obtained nine-month first generic exclusivity for their generic products, i.e. from July 18 2021 to April 17 2022. Therefore, it is expected that these generics will go on the market after patent expiry on July 17 2021.

August – December

August will see the expiration of patents for GSK’s Relvar Ellipta, Arnuity Ellipta, and Trelegy Ellipta and Avamys nasal spray; Novartis’ Revolade; Janssen’s Stelara intravenous injection; Genzyme’s Caprelsa; and Kyowa Kirin’s Crysvita; most of these, however, will still enjoy coverage under subsequent patents. Moreover, the term of the patent for Crysvita seems likely to be extended further, with a pending patent term extension application based on the marketing authorisation obtained in September 2020.

Thereafter, patents for LEO Pharma’s Xamiol gel; HK inno.N’s Akynzeo; and Boehringer Ingelheim’s Spiriva capsule are set to expire in September, while patents for Bayer’s Xarelto; Novartis’ Signifor injection; Boehringer Ingelheim’s Spiriva Respimat; and Daewoong Pharmaceutical’s Duaklir Genuair and Eklira Genuair will expire in October.

In the case of Xarelto, another NOAC drug, the 2.5 mg formulation is protected by patents that expire in 2022 and 2024, but companies such as SK Chemicals, Hanmi, GC Pharma, Hanlim Pharm, and Yungjin Pharm have successfully avoided these patents and are expected to launch their own products after patent expiry on October 3 2021. In addition to Eliquis generics, which entered the NOAC market in 2019, the appearance of generic versions of Pradaxa and Xarelto this year is expected to accelerate the penetration of generics into the NOAC market.

In November, expiring patents include those for GSK’s Selzentry, Astellas’ Mycamine, Novartis’ Ilaris, AstraZeneca’s Brilinta, Takeda’s Pantoloc, and Roche’s Mircera prefilled syringe. No drug-related patents, though, are scheduled to expire in December 2021.


With expiration of the patents covering the leading drug products, pharmaceutical companies may encounter an inevitable decline in the revenues due to low-price competition from generics. Therefore, in order to minimise the impact of patent expiration, it is advisable that these companies develop strategies to sustain revenue and maintain market dominance, such as by releasing their own generic versions of drugs, i.e. authorised generic drugs, before their patents expire.

It is also critical that patent holders seek to extend the term of protection for their products as much as possible. Although the duration of a patent in Korea is 20 years from the date of filing the patent application (or the PCT filing date), this may be extended by patent term extension (PTE) or adjustment (PTA) schemes. In the case of patents related to novel drugs, the term may be extended (via PTE) by up to five years to compensate for the loss of term arising from obtaining regulatory authorisation for marketing the new drug.

Further, term adjustment (via PTA) is available for patents in all technical fields to compensate for any unreasonable delays during prosecution. It should be noted, however, that such term extensions are not applied automatically, but must be sought via a separate application process by the relevant statutory deadlines.

Min Son

Partner, Hanol IP & Law


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