Amrix is a once-daily version of a Johnson & Johnson drug.

Cephalon is buying the North American rights to a muscle relaxant from ECR Pharmaceuticals for $100 million in cash. Cephalon will also pay certain sales-based milestones.

Amrix® was approved in February for short-term use to relieve muscle spasm associated with acute, painful musculoskeletal conditions. Cephalon expects to launch it early in the fourth quarter.

Amrix is a once-a-day, extended-release version of cyclobenzaprine hydrochloride, the active ingredient in Johnson & Johnson’s Flexeril®. “Cyclobenzaprine HCl is the most widely prescribed muscle relaxant in the United States, representing 37 percent of the 45 million prescriptions for muscle relaxants written in 2006, according to IMS,” points out Robert Roche, executive vp, worldwide pharmaceutical operations.

“Amrix has convenient once-daily dosing and a side-effect profile that includes very low rates of sedation, which will provide physicians and patients an attractive alternative to current therapies.”

Cephalon anticipates that the transaction will be modestly dilutive in the fourth quarter due to launch costs and accretion from 2008. Amrix currently has market exclusivity until the first quarter of 2010.

Previous articleClinical Data Pads Genetic Biomarker Portfolio with $11.87M Acquisition
Next articleAverion Expands CRO Services into Brazil