A randomized phase 2b efficacy study in patients with seizure episodes with a predictable pattern using Staccato® alprazolam for rapid seizure termination

Abstract

Objective: Alprazolam administered via the Staccato® breath-actuated device is delivered into the deep lung for rapid systemic exposure and is a potential therapy for rapid epileptic seizure termination (REST). We conducted an inpatient study (ENGAGE-E-001 [NCT03478982]) in patients with stereotypic seizure episodes with prolonged or repetitive seizures to determine whether Staccato alprazolam rapidly terminates seizures in a small observed population after administration under direct supervision.

Methods: Adult patients with established diagnosis of focal and/or generalized epilepsy with a documented history of seizure episodes with a predictable pattern were enrolled. They were randomized 1:1:1 to double-blind treatment of a single seizure event with one dose of Staccato alprazolam 1.0 mg or 2.0 mg, or Staccato placebo in an inpatient unit. The primary end point of the study was the proportion of responders in each treatment group achieving seizure activity cessation within 2 min after administration of study drug and no recurrence of seizure activity within 2 h.

Results: A total of 273 patients were screened, and 116 randomized patients received treatment with the study drug in the double-blind part. The proportion of treated patients who were responders was 65.8% for each of Staccato alprazolam 1.0 mg (n = 38; p = .0392) and 2.0 mg (n = 38; p = .0392), compared with 42.5% for Staccato placebo (n = 40). Staccato alprazolam was well tolerated when administered as a single dose of 1.0 or 2.0 mg: cough and somnolence were the most common adverse events (AEs) (both 14.5%), followed by dysgeusia (13.2%). AEs were mostly mild or moderate in intensity; there were no treatment-related serious AEs.

Significance: Both 1.0 mg and 2.0 mg doses of Staccato alprazolam demonstrated efficacy in rapidly terminating seizures in an inpatient setting and were well tolerated. The next step is a Phase 3 confirmatory study to demonstrate efficacy and safety of Staccato alprazolam for rapid cessation of seizures in an outpatient setting.

Keywords: acute treatment; alprazolam; clinical trial; deep lung delivery; epilepsy; rapid onset; seizure.