Longboard Pharma Reports Positive Interim Results from Phase 1b/2a PACIFIC Study on Bexicaserin in DEE Participants

Longboard Pharmaceuticals, Inc. (Nasdaq: LBPH), a clinical-stage biopharmaceutical company, has announced encouraging interim results from its ongoing 52-week open-label extension (OLE) of the PACIFIC Study. This study evaluates bexicaserin (LP352) in participants aged 12-65 with Developmental and Epileptic Encephalopathies (DEEs).

Dr. Randall Kaye, Chief Medical Officer of Longboard, expressed enthusiasm over bexicaserin’s continued effectiveness in reducing seizures and maintaining a favorable safety and tolerability profile across a wide array of DEE patients. Dr. Kaye emphasized the commitment to advancing bexicaserin swiftly, with a comprehensive analysis of 12-month data expected early next year as participants complete the OLE Study and transition to the Expanded Access Program. He also confirmed that the global Phase 3 program for bexicaserin is on track to commence later this year, bolstered by the Breakthrough Therapy designation granted by the FDA.

The PACIFIC OLE Study is a Phase 2, open-label, long-term safety study involving participants who completed the PACIFIC Study, including those with Dravet syndrome, Lennox-Gastaut syndrome, and other DEEs. The study objectives are to evaluate the safety and tolerability of multiple doses of bexicaserin, and to analyze its impact on seizure frequency. The interim analysis was conducted after participants reached approximately nine months in the OLE Study.

The median reduction in countable motor seizure frequency for participants over the nine-month treatment period was 57.7% from their baseline in the PACIFIC Study. Specifically, participants initially treated with bexicaserin in the PACIFIC Study experienced a 58.2% reduction, while those who transitioned from placebo to bexicaserin saw a 57.3% reduction.

Safety and tolerability results remained favorable, with 100% of PACIFIC Study completers enrolling in the OLE, and 92.7% remaining in the study. During the nine-month period, one participant discontinued due to lethargy, and two others discontinued due to consent withdrawal or relocation. The most common treatment-emergent adverse events (AEs) included upper respiratory tract infections, COVID-19, pneumonia, sinusitis, decreased appetite, fever, and weight loss, affecting more than 5% of participants.

The PACIFIC Study is a Phase 1b/2a double-blind, placebo-controlled clinical trial designed to assess the safety, tolerability, efficacy, and pharmacokinetics of bexicaserin in 52 participants aged 12-65 with DEEs, conducted across 34 sites in the United States and Australia. Following a 5-week screening period, participants began a dose titration over 15 days and continued on the highest tolerated dose for a maintenance period of 60 days. After the maintenance period, participants were titrated down and could enroll in the 52-week OLE study.

Longboard Pharmaceuticals, Inc. focuses on developing innovative, transformative medicines for neurological diseases, leveraging over two decades of GPCR research. Its product candidates target specific G protein-coupled receptors with high selectivity. The company plans to advance bexicaserin, a 5-HT2C receptor superagonist, into a global Phase 3 program for treating seizures associated with DEEs, following positive results from the PACIFIC Study. Additionally, Longboard is developing LP659, a modulator for S1P receptor subtypes 1 and 5, aiming to treat rare neuroinflammatory conditions, and has recently completed a Phase 1 single-ascending dose clinical trial for LP659 in healthy volunteers.

Bexicaserin and LP659 remain investigational compounds not yet approved for marketing by any regulatory authority.