Clinical Data

Staccato Alprazolam is a promising seizure rescue treatment for individuals with epilepsy. The phase 2a proof of concept clinical trial demonstrated an 80% success rate in terminating seizure activity in two minutes in patients with photosensitive epilepsy. Engage Therapeutics is continuing to examine Staccato Alprazolam’s clinical feasibility, safety, and efficacy in the current phase 2b clinical trial, StATES.

Why Staccato Alprazolam

Staccato Alprazolam is a new investigational epilepsy rescue therapy that combines the FDA-approved Staccato inhaler device with Alprazolam, a well-known benzodiazepine with potent anti-epileptic properties. There are currently no approved products indicated to rapidly terminate epilepsy seizure activity once it has begun. We are developing Staccato Alprazolam for FDA approval in this indication.

The Staccato Inhaler Device

The Staccato system, exclusively licensed from Alexza Pharmaceuticals, Inc., is an easy-to-use, non-invasive inhaler device that can deliver medicine as quickly as an IV. The patient simply must hold the device up to his or her mouth and take a single breath, which activates Staccato’s heating element to vaporize the drug. This allows the patient to inhale Alprazolam particles that are small enough to enter the body through the narrower, more vascularized tissue of the deep lung—leading to quick and complete absorption of the drug into the bloodstream.


Alprazolam is a benzodiazepine that has shown great promise as a treatment for epileptic seizures. Commonly known as Xanax®*, Alprazolam enhances the neurotransmitter GABA to produce a calming effect on the body. Alprazolam has been used for decades to treat a variety of neurological conditions and has years of safety data to support its continued commercial availability.

* XANAX is a registered trademark of Pharmacia & Upjohn Company, LLC.

Phase 2a Proof of Concept Trial

80% success rate in stopping seizures

In a double blind, placebo-controlled crossover proof of concept trial, Staccato Alprazolam aborted seizure activity in less than two minutes in 80% of patients.

The trial evaluated the use of Staccato Alprazolam in five patients with photosensitive epilepsy, in whom seizures can be triggered through visual stimuli. Patients were tested on a baseline day, and then in randomized order across several weeks received either an inhaled placebo or various quantities of inhaled alprazolam through the Staccato device.

The study found that all doses of alprazolam decreased seizure activity (known in patients with photosensitive epilepsy as average standardized photosensitivity range, or SPR), with maximal or near-maximal effect occurring two minutes after dosing. The study investigators found that inhaled alprazolam strongly suppressed seizures within two minutes, and that the duration of effect and sedation were related to dosing quantities.

Phase 2b Clinical Trial

The next step in Staccato Alprazolam’s pathway to potential FDA approval is a clinical trial that tests the use of Staccato Alprazolam on naturally-occurring seizures. Engage Therapeutics is recruiting paid participants from across the United States for phase 2b study known as StATES (Staccato Alprazolam Terminates Epilepsy Seizures). This clinical trial aims to assess the clinical feasibility, safety and efficacy of Staccato Alprazolam in treating a seizure episode. Initial trial results (read the full press release or watch this short video) showed great promise for this treatment and were shared during a poster presentation at the 2019 American Association of Neurologists conference.