Lundbeck Reports Seizure Reductions in Rare Childhood-Onset Epilepsies

Lundbeck has announced new long-term Phase 2 follow-up data showing that patients with Developmental and Epileptic Encephalopathies (DEEs) who experienced early seizure reduction on bexicaserin maintained those improvements for up to two years. The results were presented at the 2025 American Epilepsy Society Annual Meeting in Atlanta.

Bexicaserin is an investigational, centrally acting 5-HT2C receptor superagonist being developed for seizures associated with a broad range of DEEs, a group of rare and severe childhood-onset epilepsies marked by drug-resistant seizures, developmental impairment, and lifelong care needs.

In the new data, patients who had completed the Phase 1b/2a PACIFIC trial, then participated in a 12-month open-label extension, continued treatment through expanded access for a total of up to two years. During this period, patients experienced a median reduction in countable motor seizures of 60.2 percent at roughly 18 months and 53.7 percent at around 24 months, with consistent results across diverse DEE subtypes. No new safety concerns were identified.

Highlighting the impact on families, Johan Luthman, EVP and Head of Research and Development at Lundbeck, said: “The constant management of DEEs place a heavy emotional and financial burden on families, underscoring the urgent need for better seizure control. We are increasingly hopeful that bexicaserin can address this need. The data so far show durable seizure reductions, an encouraging safety profile and minimal risk of drug-drug interactions, reinforcing bexicaserin's potential as a first-in-class therapy across a broad range of DEEs.”

DEEs represent some of the most challenging epilepsies to treat, with many patients resistant to available anti-seizure medications and few options spanning the full spectrum of DEE subtypes. The two-year findings suggest that patients who achieve an initial meaningful reduction may sustain that benefit long term, an important consideration in conditions where effective therapies are limited.

The full results of the PACIFIC trial were recently published in Epilepsia, marking a milestone for DEE research and supporting the continued development of bexicaserin, which is currently being evaluated in a global Phase 3 program.

Lundbeck presented seven additional scientific updates at AES 2025, emphasizing the company’s expanding commitment to rare childhood epilepsies and its broader neuroscience research portfolio.

Bexicaserin remains investigational and is not yet approved by any regulatory authority.