Marinus Pharmaceuticals is set to start patient enrolment in the Phase III RAISE clinical trial of ganaxolone for the treatment of refractory status epilepticus (RSE).

The announcement comes after the company satisfied the US Food and Drug Administration (FDA)’s protocol-specific questions for the trial.

Marinus develops treatments for rare seizure disorders. In July, the company submitted an updated protocol to the FDA for the trial for IV ganaxolone.

After discussions with the regulator, the first participant is expected to be recruited in October. The company has selected more than 55 out of an anticipated 80 sites for the trial.

The randomised, double-blind, placebo-controlled trial will be conducted in SE patients who have failed benzodiazepines, as well as two or more second-line intravenous anti-epileptic drugs (AEDs).

It plans to enrol about 125 patients who will be given ganaxolone or placebo in addition to standard of care.

The co-primary endpoints of the study are the proportion of patients with SE cessation within 30 minutes after initiation of therapy and those with no progression to IV anesthesia for 36 hours after starting the treatment.

Marinus chief medical officer Joe Hulihan said: “In our recent Phase II trial in RSE, status epilepticus was controlled at a median time of five minutes after starting ganaxolone, with no patients progressing to IV anesthesia for control of seizures within 24 hours, the primary study endpoint.

“There is a pressing need for better treatments for RSE, and we are eager to begin our Phase III clinical trial in this indication.”

In March 2019, Marinus initiated the Phase III trial of ganaxolone to treat children with PCDH19-related epilepsy.