King Pharmaceuticals has begun a Phase II clinical trial program for the development of an extended-release formulation of Sonata (zaleplon), a nonbenzodiazepine treatment for insomnia. The trial is designed to select the most effective extended-release formulation of Sonata using Elan's Spheroidal Oral Drug Absorption System as the drug-delivery technology. The goal of the trial is to determine which new formulation is the most efficacious for the purpose of increasing total sleep time and reducing any potential for premature awakenings, while continuing to build on the quick onset profile currently available in the immediate-release formulation of Sonata.