Overviewing Phase 1/2 PACIFIC Trial of Bexicaserin in Developmental Epileptic Encephalopathies: Ingrid Scheffer, AO, PhD, FRACP, FAHMS, FAA

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"For the first time, we have a regulatory trial that includes the full spectrum of developmental and epileptic encephalopathies, not just Dravet or Lennox-Gastaut. The signals we’re seeing across these groups are very exciting, and the sustained benefit over 12 months gives real hope for broader treatment options."

Treating patients with developmental epileptic encephalopathies (DEEs) remains highly challenging due to their complex presentation, early onset, and frequent drug resistance. Many patients experience seizures that are refractory to multiple antiseizure medications, and treatment often requires polytherapy with limited efficacy and substantial side effects. One promising therapy in development is bexicaserin (Lundbeck), an oral centrally acting 5-hydroxytryptamine 2C (5-HT2C) receptor superagonist with no engagement of the 5-HT2B and 5-HT2A receptor subtypes.

At the recently concluded 36th International Epilepsy Congress, held August 30 to September 3, 2025, in Lisbon, Portugal, Lundbeck presented new data from the open-label extension of its phase 1b/2a PACIFIC trial (NCT05626634) testing bexicaserin in various DEEs. In addition, the company also presented encouraging preclinical data in the audiogenic seizure model of sudden death in epilepsy, where bexicaserin showed significant reductions in seizures and respiratory arrest. Furthermore, the company outlined 2 ongoing trials, DEEp SEA and DEEp OCEAN, which will test bexicaserin in patients with Dravet syndrome and Lennox-Gastaut syndrome, respectively.

During the meeting, NeurologyLive^® sat down with epilepsy titan Ingrid Scheffer, AO, PhD, FRACP, FAHMS, FAA, laureate professor at the University of Melbourne, to discuss the phase 1b/2a findings. Scheffer, who also serves as a pediatric and adult epileptologist, commented on the study's outline, the reasons behind enrolling patients across the full spectrum of DEEs, and some of the most pertinent early-stage data. Her remarks underscored how these findings set the stage for a larger phase 3 trial and potentially broaden treatment options for a wide range of patients with DEEs.