An amendment to the Korean Patent Act ("KPA") was promulgated on January 21, 2025. The key changes include: (i) limitations on the extension period and the number of patents eligible for patent term extension ("PTE"), (ii) the addition of exportation as an act of working patented inventions, and (iii) the introduction of penalties for violations of secrecy orders for inventions necessary for national defense. The revised law will go into effect on July 22, 2025.

▶Restrictions on the Extension Period and the Number of Patents Eligible for PTE of Pharmaceutical Patents 

According to Article 89 of the KPA, the term of a patent for a pharmaceutical invention requiring approval to practice the patented invention may be extended for the amount of time the invention could not be worked due to pending efficacy and safety tests necessary to obtain the approval, for up to a maximum of five years.

In general, unlike other jurisdictions, such as the U.S. and Europe, Korea's PTE system had no limits on the extended patent term running from the date of drug approval, and further had no restrictions on the number of patents that were eligible for PTE based on a single drug approval. As a result, certain drugs in Korea had patent terms that extended beyond the terms in other countries, thereby delaying the launch of generic drugs.

To address this, the revision to the KPA limits the patent term extendable via PTE within a period of up to 14 years from the date of drug approval, and the number of patents that may be extended based on a single drug approval to only one. In addition, the revised KPA stipulates that, if patent term adjustment ("PTA") has been granted to a patent whose registration was delayed due to prolonged examination thereof, the PTE based on a drug approval begins from the date extended via PTA, clearly differentiating both extension systems.

Violation of any of the aforementioned provisions may result in the rejection of a PTE application and invalidation of a PTE registration. If an extension is granted for a period exceeding 14 years from the date of drug approval, the extension will be nullified only with respect to the duration exceeding 14 years. 

The revised provisions are applicable to a PTE application filed based on a drug approved on or after the effective date of the amended law, i.e., July 22, 2025.

▶Addition of Exportation as an Act of Working Patented Inventions

Article 2(iii) of the current KPA defines the act of working a product invention to encompass making, using, assigning, leasing, importing, or offering to assign or lease (including displaying for the purpose of assigning or leasing) the product. 

While the act of importation was included in the scope of working a patented invention, exportation was not; making it difficult to seek compensation for damages or claim infringement under the KPA. Consequently, when patentinfringing products were exported, customs could only prevent or impose fines based on other laws, such as the Customs Act or the Acts on the Investigation of Unfair  International Trade Practices and Remedy against Injury to the Industry.

Under the revised KPA, exportation is added to the scope of working an invention, broadening the avenue of protection for patentees.

▶Introduction of Penal Provisions for Violations of Secrecy Orders for Inventions Necessary for National Defense

Under Article 41 of the current KPA, if an invention is deemed necessary for national defense, the government may order not to file a patent application on the invention in a foreign country or to keep such invention secret. However, there were no specific penal provisions for violations of these secrecy orders that may serve as a deterrent for non-compliance.

The amended KPA now introduces penal provisions to prevent leakage of technology covered in a secret patent relating to national defense. Anyone who violates secrecy orders will be subject to imprisonment for a term of up to 5 years or a fine of up to 50 million won. In addition, a legal entity or its representative who bears the responsibility of supervision and fiduciary duty may be fined up to 100 million won.

▶Impact of the Amendments

The revisions to the KPA strengthen the protection of patents crucial to national defense and the economy, while allowing early market entry for generic drugs. Notably, due to the limitation that only one patent per drug approval is eligible for PTE, it will be essential to carefully evaluate and select which patent to apply for PTE among multiple patents covering the approved drug. Some factors to consider would be the type of the patent (e.g., compound, use, or preparation patent), original expiry date and length of extension period computed for each patent, and strength and/or ease of design-around of the patents, among others.