As of May 5 2021, a four-year re-examination period for post-marketing surveillance (PMS) can be granted for pediatric drugs by the Ministry of Food and Drug Safety (MFDS) upon regulatory approval involving ‘foreign’ clinical trials. Previously, only pediatric drugs approved based on ‘domestic’ clinical trials were subject to the re-examination.
In South Korea, the re-examination period (PMS period) acts as de facto data exclusivity period for new drugs and certain prescription drugs. With patent protection, this de facto data exclusivity plays an important role in protecting originator companies.
Protection by de facto data exclusivity
As evidenced by the ‘de facto’, in South Korea, there is no data exclusivity per se; however, the re-examination system provides substantially similar protection to the data exclusivity in other jurisdictions.
Under this system, the re-examination period running from the time of marketing approval may vary depending on the criteria below (see table), and follow-on companies (i.e. generic companies) seeking marketing approval for the same drug must submit their own safety and efficacy data equivalent to or exceeding the scope of the original approval holder’s data, except in the following cases:
When permission to use the data has been obtained from the original approval holder; or
When an application is filed on the condition that the drug product will be approved after expiration of the re-examination period.
In other words, generic companies are not allowed to rely on the original approval holder’s data in order to obtain regulatory approval for their generic product during the PMS period. Since it is difficult for generic companies to fulfill such data submission requirements, re-examination acts much like data exclusivity.
After the re-examination period expires, submission of safety and efficacy data is exempted for marketing approval of the same product.
Thus, the burden on the follow-on companies is significantly reduced, and marketing approval can be granted upon the submission of the bio-equivalence data. The re-examination system applies to both chemical drugs and biologic drugs.
Eligible drugs, re-examination period, and exemption
The following table summarises eligible drugs and the re-examination period.
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Criteria
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Period
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| 1-i.
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New drugs – Drugs with a new chemical entity
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6 years
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1-ii.
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New combination – Prescription drugs different from already-authorised drugs in terms of active ingredient(s) or combination ratio
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| 1-iii.
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New administration route – Prescription drugs different from already-authorised drugs in terms of administration route, while containing the same active ingredient(s)
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2-i.
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New indication – Prescription drugs identical to already-authorised drugs in terms of active ingredient(s) and administration route(s), but having clearly different indication(s) added
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4 years
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| 2-ii.
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Other drugs determined under the consideration of the MFDS
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3-i.
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Orphan drugs for use in a disease for which adequate treatment and medicines have not been developed
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10 years
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3-ii.
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Orphan drugs of 3-i where a pediatric indication is added
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11 years
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Although the above drugs are eligible for re-examination, the MFDS may exempt the re-examination of the drugs for those satisfying any one of the following at its discretion:
Pesticides, etc. which are not directly applied to a human body;
Orphan drugs;
Drugs for which re-examination is considered unnecessary by the MFDS due to lack of novelty;
Drugs, the safety and efficacy of which are considered as sufficiently ensured by the MFDS; and
Drugs for which the number of patients to be surveyed is too small to meet the re-examination requirements.
As a consequence, of course, if the re-examination is exempted, de facto data exclusivity is not provided.
What strategies are available
From the perspective of brand companies, a six-year de facto data exclusivity period, which is relatively long compared to other jurisdictions, can be granted for so-called ‘incrementally modified drugs’.
Incrementally modified drugs are those having some improvements to existing drugs, such as new combination and new administration routes. The practical utility of the system becomes clear when the improvement of the drug is not so remarkable as to allow patent protection. The patent may not protect the drug, but data exclusivity may, at least for six years.
As for new drugs, like many other countries, patent term extension (PTE) may also be available if there is a first marketing approval for the new substance, up to five years, for the period that the patented inventions could not have been practiced.
As for generic companies, those who wish to enjoy first generic exclusivity need to tune the timing of filing an invalidation trial. Under the Korean drug patent-linkage system, nine-month first generic exclusivity may be granted to the successful generic challenger(s) meeting the ‘first-trial prerequisite’. To earn the position as a first-trial challenger, it is better to initiate the invalidation proceedings as early as possible. However, because the patent must be validly listed when the generic company applies for the marketing approval, those seeking the first exclusivity need to ensure that the patent is not invalidated too early before they apply for the marketing authorisation.
Min Son, PhD
Managing partner, Hanol IP & Law
