Eisai's Perampanel Set to Expand Indication in China for Pediatric Epilepsy Treatment

Recently, the status of Eisai’s Class 5.1 import application for perampanel tablets (relevant acceptance numbers: JXHS2000153/154/155/156) at the NMPA has been updated to “Under Review,” and it is expected to be officially approved in the near future. According to the company’s official website, the indication for perampanel to be approved is: monotherapy for pediatric partial-onset seizures in patients aged 4 years and older.

Epilepsy, colloquially known in Chinese as "goat horn wind" or "goat epilepsy wind," is a chronic disease characterized by sudden, abnormal electrical discharges of brain neurons, leading to transient cerebral dysfunction. Based on seizure type, epilepsy is broadly classified into focal seizures (accounting for approximately 60%) and generalized seizures (accounting for approximately 40%). Recent epidemiological data indicate that the overall prevalence of epilepsy in China is 7.0‰, with an annual incidence of 28.8 per 100,000 population. There are approximately 9 million epilepsy patients in China, about 60% of whom are affected by focal seizures. Among these, 40% require adjunctive therapy. However, approximately 30% of epilepsy patients fail to achieve seizure control despite treatment with currently available antiepileptic drugs (AEDs).

Perampanel (Fycompa) is a first-in-class antiepileptic drug (AED) developed in-house by Eisai. It is a highly selective, noncompetitive AMPA-type glutamate receptor antagonist that reduces neuronal hyperexcitability associated with seizures by targeting the activity of postsynaptic AMPA-glutamate receptors. Glutamate is the primary neurotransmitter mediating seizure activity.

In July 2012, Fycompa was first approved in Europe as an adjunctive therapy for the treatment of partial-onset seizures (with or without secondary generalization) and primary generalized tonic-clonic seizures in patients with epilepsy aged 12 years and older. This indication was approved in the United States in October 2012. Subsequently, in July 2017, the FDA approved the drug as a monotherapy for the treatment of partial-onset seizures (with or without secondary generalization) in patients with epilepsy aged 12 years and older. In October 2018, the FDA further approved it as both a monotherapy and an adjunctive therapy for the treatment of partial-onset seizures (with or without secondary generalization) in pediatric patients with epilepsy aged 4 years and older. Fycompa offers convenient dosing, requiring administration only once daily at bedtime. In addition to tablets, approved formulations of Fycompa also include oral suspension and granules.

To date, Fycompa has been approved for marketing in over 70 countries and regions worldwide and has been widely used in the treatment of more than 300,000 patients globally. According to Eisai's financial reports, sales of Fycompa have increased year by year since its market launch, reaching 26.7 billion Japanese yen in fiscal year 2020.

In addition, Eisai is conducting a global Phase III clinical trial (Study 338) to evaluate Fycompa for the treatment of seizures associated with Lennox-Gastaut syndrome. Meanwhile, Eisai is also developing an injectable formulation of Fycompa.

In China, perampanel was approved by the NMPA in September 2019 for the adjunctive treatment of partial-onset seizures (with or without secondary generalization) in patients aged 12 years and older with epilepsy, marketed under the brand name Fycompa. It was subsequently included in the 2020 National Reimbursement Drug List at the end of 2020. According to the company's financial report, sales of perampanel in China increased from JPY 100 million in 2019 to JPY 500 million in 2020. Sales are expected to reach new highs in the future as the indicated patient population expands. Additionally, Eisai's clinical trial application for a perampanel oral suspension has been approved in China.

It is worth noting that perampanel was included in the "Second Catalog of Encouraged Generic Drugs" released in 2021 by the National Health Commission and five other departments, with dosage forms covering tablets and oral suspension. Furthermore, the originator compound patent for perampanel (CN1245386C) expired on June 8, 2021. According to incomplete statistics, companies in China have begun to enter the generic perampanel market. Among them, Kangyuan Huawei Pharmaceutical Co., Ltd. and Nanjing Haina Pharmaceutical Technology Co., Ltd. are currently conducting bioequivalence (BE) trials for perampanel tablets. In addition, Huadong Medicine, Hansoh Pharma, Ruiyang Pharmaceutical, and Heze Pharmaceutical have obtained clinical trial approval for their perampanel tablets.