Longboard Pharmaceuticals announced positive interim results from its ongoing 52-week open-label extension (OLE) of the PACIFIC Study, evaluating bexicaserin (LP352) in participants aged 12-65 years with Developmental and Epileptic Encephalopathies (DEEs). The data, presented at the 15th European Epilepsy Congress in Rome, Italy, highlight bexicaserin's potential as a transformative medicine for neurological diseases.
The PACIFIC OLE Study is a Phase 2 trial assessing the long-term safety and efficacy of bexicaserin in patients with various DEEs, including Dravet syndrome (n=3), Lennox-Gastaut syndrome (n=20), and other DEEs (n=18). The interim analysis was conducted after approximately nine months of treatment.
Significant Seizure Reduction Observed
The study revealed a median decrease of 57.7% in countable motor seizure frequency over the nine-month treatment period (n=40) compared to baseline. This reduction was consistent across different groups:
- Participants initially randomized to bexicaserin in the PACIFIC Study experienced a 58.2% reduction (n=31).
- Participants who transitioned from placebo to bexicaserin in the OLE showed a 57.3% reduction (n=9).
Favorable Safety and Tolerability Profile
Bexicaserin continued to demonstrate a favorable safety and tolerability profile. Of the PACIFIC Study completers, 100% elected to enroll in the OLE, with 92.7% (38 out of 41) remaining in the ongoing study. Only one participant discontinued due to lethargy, and two discontinued due to withdrawal of consent or relocation. Common treatment-emergent adverse events (AEs) occurring in >5% of participants included upper respiratory tract infections, COVID-19, pneumonia, sinusitis, decreased appetite, pyrexia, and weight decrease.
Path to Phase 3 and Beyond
"We are thrilled that bexicaserin is continuing to demonstrate a sustained, durable response in seizure reduction and a favorable safety and tolerability profile across a broad range of DEE patients," said Dr. Randall Kaye, Longboard’s Chief Medical Officer. "These data provide further support to bexicaserin’s potential to offer a highly differentiated and best-in-class profile."
Longboard expects to provide a full analysis of participants with 12-month data early next year as they complete the OLE Study and transition to their Expanded Access Program. With Breakthrough Therapy designation granted by the FDA, the company remains on track to initiate its global Phase 3 program for bexicaserin later this year. This designation is reserved for drugs that may demonstrate substantial improvement over available therapies for serious conditions.
About the PACIFIC Study
The PACIFIC Study is a Phase 1b/2a double-blind, placebo-controlled clinical trial involving 52 participants aged 12-65 years with DEEs across 34 sites in the United States and Australia. The study assessed the safety, tolerability, efficacy, and pharmacokinetics of bexicaserin. Participants underwent a 5-week screening period, followed by dose titration over 15 days and a 60-day maintenance period at the highest tolerated dose. Eligible participants then had the option to enroll in the 52-week open-label extension study.
