Upsher-Smith Laboratories initiated a phase III clinical trial to evaluate the safety and efficacy of USL261, an investigational intranasal midazolam, for the rescue treatment of seizures in patients on stable anti-epileptic drug (AED) regimens who require control of intermittent bouts of increased seizure activity, frequently referred to as seizure clusters. USL261 has been granted Orphan Drug designation for this use by the FDA.

The phase III randomized, double-blind, placebo-controlled study, ARTEMIS1 ["Acute Rescue Therapy in Epilepsy with Midazolam Intranasal Spray"], will compare intranasal midazolam, a benzodiazepine, with an intranasal placebo in males and females ages 14 to 65 years with a diagnosis of seizure clusters and who have a competent caregiver.  The seizure clusters must have a pattern that is different from the individual's other non-cluster seizure activity and must be recognizable by a caregiver. USL261 may allow a caregiver to deliver an appropriate dose of the medication intranasally to an individual who is experiencing an intermittent bout of increased seizure activity. It is intended that this administration will not require an active inhalation by the patient.

The trial will enroll eligible patients with partial or generalized seizures who are on stable AED regimens. USL261 is the subject of a global phase III clinical trial (ARTEMIS1), being conducted under a Special Protocol Assessment (SPA) agreement with the FDA.

Seizure clusters are characterized by multiple seizures which occur over a relatively brief period of time, generally within 24 hours for adults and 12 hours for children, with a pattern distinguishable from the usual seizure pattern.