Generic Equfina entry intensifies…high-dosage·unlisted patent challenge

Bukwang Pharmaceutical‧Myung In Pharmaceutical‧Samil Pharmaceutical have submitted generic marketing authorizations…companies are expected to secure a prioritized marketing authorization

Differentiation strategies with a high-dosage formulation competing against the original…Samil Pharmaceutical preemptively eliminated the unlisted patent risk

Product photo of 'Equfina'

Review of generic approval applications for Eisai Korea’s Parkinson’s disease therapeutic, Equfina (safinamide) has officially commenced. Given that administrative issues do not arise during the Ministry of Food and Drug Safety (MFDS)'s marketing authorization review process, the filing companies are expected to secure a Prioritized Marketing Authorization.

As the commercialization timeline draws closer, industry interest is focusing on the distinctive differentiation strategies deployed by Bukwang Pharmaceutical, Myung In Pharmaceutical, and Samil Pharmaceutical, the three domestic players competing in the Equfina generic market. The companies have played completely different strategic cards, including introducing a high-dose formulation that is absent from the innovator product portfolio and preemptively overcoming unlisted patents.

Four products submitted to notified drug registry…'100mg high-dose' variable emerges  

According to the MFDS list of notified drug applications released on the 10th, four products containing safinamide mesylate have been submitted for marketing authorization. The three domestic companies finalized their regulatory filings within just two days after the innovator's Post-Marketing Surveillance (PMS) block expired on the 23rd of last month.

Notably, a 100mg high-dose formulation has emerged as a major variable. The original product, Equfina, is currently commercialized exclusively as a single 50mg dosage strength. While three of the four filings on the notified drug list match the reference product's 50mg strength, the remaining application seeks authorization for a 100mg formulation.  

Analysis suggests that one of the three manufacturers filed for an expanded dosage strength to differentiate itself from the original drug by offering enhanced dosing convenience and improved patient compliance.  

Bukwang, Myung In, and Samil previously secured victories in negative scope-of-right confirmation trials targeting an Equfina formulation patent (Patent No. 10-1491541) slated to expire in 2028. Having already satisfied two key regulatory prerequisites for First Generic Exclusivity, namely the "first-to-file trial claim" and "trial victory", the companies will secure a 9-month market exclusivity period once the current review of their "first-to-file marketing authorization applications" is finalized.

Samil successfully overcomes unlisted patent…preemptively disarms patent risk

Independent of the generic exclusivity timeline, one specific manufacturer has explored a distinct competitive pathway by preemptively mitigating its legal risk and patent exposure.  

Among the three generic competitors, Samil Pharmaceutical acted independently to file separate patent challenges against Equfina’s unlisted patents, securing an affirmative trial decision in April. Through this move, Samil became the first player to dismantle potential post-launch patent litigation risks.

Equfina is known to have two underlying patents that are not registered in the MFDS Drug Patent List. While unlisted patents do not impede marketing authorization or the acquisition of First Generic Exclusivity, launching a generic product without invalidating or evading them exposes the generic sponsor to future patent infringement lawsuits or substantial damages claims from the innovator company.

These three companies include CNS portfolios…target post-launch portfolip synergies

Because all three companies undergoing regulatory review have commercial expertise within the Central Nervous System (CNS) therapeutic area, the market battle is expected to center on driving portfolio synergies with their existing neurodegenerative disease pipelines post-launch.

This strategic interplay stems from Equfina's clinical positioning as an adjunctive therapy to 'levodopa'-containing therapy for Parkinson's disease patients experiencing end-of-dose motor fluctuations.

In its existing portfolio, Myung In Pharmaceutical has a comprehensive portfolio of levodopa-based Parkinson’s therapies, including 'Myungdopar' (levodopa·benserazide), 'Perkin (levodopa·carbidopa)', and 'Trilevo (levodopa·carbidopa·entacapone)'. At the same time, Samil Pharmaceutical markets 'Onedopa (levodopa·benserazide)'. Conversely, Bukwang Pharmaceutical lacks a direct levodopa formulation. Still, it has aggressively invested in its CNS portfolio following the domestic commercial launch of its novel atypical antipsychotic 'Latuda (lurasidone)' for schizophrenia and bipolar disorder last year.

Meanwhile, Equfina is a third-generation MAO-B (monoamine oxidase type B) inhibitor with a dual mechanism of action targeting both dopaminergic and non-dopaminergic signaling pathways. Since its launch as a reimbursed drug by Eisai Korea in February 2021, the product's domestic import volume has grown more than fourfold over three years, rising from $770,000 (approximately KRW 1.2 billion) in 2021 to $3.28 million (approximately KRW 5 billion) in 2024.