Exhibit 99.1 Longboard Pharmaceuticals Reports Full Year 2023 Financial Results and Provides Corporate Updates • Bexicaserin (LP352) Phase 1b/2a PACIFIC Study positive topline data in participants with Developmental and Epileptic Encephalopathies (DEEs) was reported in January • Announcing an update to the primary efficacy endpoint data previously reported in January, which show further improvement in seizure reductions and no change in the reported safety results – bexicaserin achieved a median seizure red ...