Bexicaserin benefits seen for Dravet syndrome, other epilepsy types
Nine months of treatment cut frequency of motor seizures by more than half
Nine months of treatment with bexicaserin (LP352), an investigational oral small molecule from Longboard Pharmaceuticals, more than halved the frequency of motor seizures in adults and adolescents with Dravet syndrome or other forms of developmental and epileptic encephalopathies (DEE).
That’s according to new interim data from the 12-month open-label extension study (NCT05626634) to PACIFIC (NCT05364021), a Phase 1b/2a clinical study that tested the safety, tolerability and efficacy of bexicaserin against a placebo in patients with DEEs.
Six-month interim data showed bexicaserin resulted in sustained benefits, with fewer motor seizures compared with the period before starting treatment. Bexicaserin was also generally well tolerated.
“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,” Randall Kaye, MD, Longboard’s chief medical officer, said in a company press release.
With a recently granted breakthrough therapy designation, meant to speed the development and regulatory review of medications for serious or life-threatening diseases, “we remain on track to initiate our global Phase 3 program for bexicaserin later this year,” Kaye said.
Bexicaserin for motor seizures
Like other DEEs, Dravet syndrome causes frequent motor seizures, or sudden bursts of excessive electrical activity in the brain that affect the muscles. They usually begin early in infancy and are often difficult to control with available treatments.
“Given the tremendous unmet need in patients living with DEEs, we are committed to rapidly advancing the development of bexicaserin. We expect to provide a full analysis of participants with 12-month data early next year,” Kaye said.
Bexicaserin is designed to act like serotonin, a chemical that helps nerve cells communicate. When it activates 5-HT2C, a receptor that primarily binds serotonin in the brain and spinal cord, it should reduce excessive electrical activity in the brain, according to the company.
The open-label extension enrolled 41 patients who’d completed PACIFIC. Three patients had Dravet syndrome, 20 had Lennox-Gastaut syndrome, and 18 had other forms of DEE. After the extension, patients can enter an expanded access program where they may continue to receive bexicaserin.
After nine months in the open-label extension, patients had a median decrease of 57.7% in countable motor seizures compared with the start of treatment, or baseline. This reduction was similar for those who’d been on bexicaserin from the beginning of the PACIFIC study and for those who switched from a placebo.
Bexicaserin was generally well tolerated. Thirty-eight patients (92.7%) remained through the first nine months of the open-label extension and only one dropped out due to lethargy, or lack of energy. Common side effects included respiratory infections and weight loss.
“These data provide further support to bexicaserin’s potential to offer a highly differentiated and best-in-class profile,” Kaye said.
About the Author
