AZ-002 (Staccato alprazolam) for Acute Repetitive Seizures
Epilepsy, a disorder of recurrent seizures, affects approximately 2.5 million Americans, making it the third most common neurological disorder in the United States. Acute repetitive seizures (ARS) refers to seizures that are serial, clustered, or crescendo, and ones that are distinct from the patient's usual seizure pattern. ARS occurs in a subset of patients with epilepsy who regularly experience breakthrough seizures, despite treatment with a regular regimen of anti-epileptic drugs.
Among the implications of ARS are concerns for patient safety. Prolonged or recurrent seizure activity persisting for 30 minutes or more may result in serious injury, health impacts or death, that correlate directly with seizure duration. ARS, if left untreated, has been reported to evolve into a state of persistent seizure, or status epilepticus, which has a 3% mortality rate in children and 26% in adults.
Benzodiazepines are considered to be medications of first choice for the treatment of acute seizures. Clinical advantages of benzodiazepines include relatively rapid onset of action, high efficacy and minimal toxicity. The rapidity by which a medication can be delivered to the systemic circulation and then to the brain plays a significant role in reducing the time needed to treat seizures and reducing the likelihood of damage to the central nervous system. Current standard of care for ARS is the rectal gel formulation of diazepam, which must be administered by a caregiver or healthcare professional. In Alexza's market research, patients surveyed have commented that they find that the rectal gel takes longer to work than they would like and that the route of administration is sub-optimal and cannot be used in public. Intravenous benzodiazepines are rapid acting, but must be administered by a healthcare professional in a medical facility. The ability to treat quickly is clinically imperative to prevent an epileptic event from evolving into status epilepticus or causing other serious complications. Alexza believes a product that can be administered easily in the home setting to effectively treat ARS may result in avoiding a trip to the hospital for treatment or diminishing the need to use the rectal formulation of diazepam. If approved, AZ-002 could reduce the use of IV or rectal benzodiazepines in treating patients who experience ARS.
The potential benefits of AZ-002 may include a faster delivery to the blood stream, when compared to rectal delivery, and greater ease of use. AZ-002 could be administered after a first seizure in a cluster with the aim of preventing further seizures. The caregiver could provide dosing assistance between cluster seizures. Alexza believes that alprazolam's ability to inhibit anxiety, or anxiolytic action, may provide additional therapeutic benefits to ARS patients.
The ongoing Phase 2a clinical trial is designed as an in-clinic, randomized, double-blind, evaluation of patients with epilepsy. The primary aim of this study is to assess the safety and pharmacodynamic electroencephalographic effects of a single dose of AZ-002 at different dose strengths, compared to placebo. An interim analysis from this study showed that AZ-002 had dose-related effects on mean Standardized Photosensitivity Range (the primary endpoint of the study), no serious adverse effects and was well tolerated in the patients studied. There were also dose-related changes in two visual-analogue scales for sedation and for alertness, which are established pharmacodynamic markers of benzodiazepine drug activity. Importantly, in both measures the pharmacodynamic effect was demonstrated at the two-minute time point, which was the first assessment in the study, demonstrating the rapid onset of effect of alprazolam as delivered by the Staccato technology.
Alexza owns full development and commercial rights to AZ-002.