Status Epilepticus Drug Ganaxolone Shows Benefit in Refractory Seizures

Lawrence Hirsch, MD, PhD

Marinus Pharmaceuticals presented positive results from its phase 2 trial of ganaxolone at the Neurocritical Care Society‘s 17^th Annual Meeting.¹ The top-line findings showed that no patients progressed to intravenous (IV) anesthetics within 24 hours of treatment initiation. The positive results support a potential pivotal phase 3 study of ganaxolone.

The open label, dose-finding study evaluated 3 different doses, a low dose of 500 mg/day, a medium dose of 650 mg/day, and a target dose of 713 mg/day of ganaxolone as adjunctive therapy to existing second-line IV antiepileptic drugs (AEDs). The primary endpoint was the prevention of progression to third line IV anesthetics within 24 hours of treatment initiation. Secondary endpoints included safety, tolerability, and other efficacy analyses.

Treatment with ganaxolone not only prevented progression to third-line IV anesthetics, but also reduced median time to status cessation to 5 minutes. Notably, 16 of 17 patients were status-free 24 hours from infusion initiation; during the follow-up period, 3 patients in the 500 mg group escalated to additional IV AEDs or IV anesthetics due to status relapse during that time.

“Maintaining control of status epilepticus without progressing to addition IV anesthetics or antiepileptic drugs (AEDs) is a remarkable clinical response to IV ganxolone treatment,” said Lawrence Hirsh, MD, professor of neurology; chief, division of epilepsy and EEG; and co-director of the Yale Comprehensive Epilepsy Center and Critical Care EEG Monitoring Program at Yale School of Medicine, in a statement.²

Throughout the trial, 10 serious adverse events were recorded, 8 of which were considered not related to treatment. The most common treatment-related adverse events were somnolence, mild hypotension, and sedation.

Ganaxolone is a synthetic neurosteroid that acts as a positive allosteric modulator of synaptic and extrasynaptic GABAA receptors. It exhibits anti-seizure, anti-depressant and anti-anxiety effects and is noted to be generally safe and well-tolerated in studies.

“These data give us confidence in our IV dose selection as we make preparations for advancing into phase 3 with our first hospital-based ganaxolone indication. I would like to thank the study investigators, patients, and their families for participating in this important study,” Scott Braunstein, chief executive officer of Marinus, said in a statement.²

REFERENCES:

1. Vaitkevicius H, Husain AM, Swisher CB, et al. Phase 2 open-label study of intravenous ganaxolone for the treatment of refractory status epilepticus. Presented at: Neurocritical Care Society 17^th Annual Meeting. October 15-18, 2019; Vancouver, British Columbia. Oral Abstract 2.

2. Marinus Pharmaceuticals Announces Positive Top-Line Results With Ganaxolone in Phase 2 Refractory Status Epilepticus Trial: Radnor, PA: Marinus Pharmaceuticals. September 26, 2019. globenewswire.com/news-release/2019/09/26/1921176/0/en/Marinus-Pharmaceuticals-Announces-Positive-Top-Line-Results-With-Ganaxolone-in-Phase-2-Refractory-Status-Epilepticus-Trial.html. Accessed October 21, 2019.