Valeant Pharmaceuticals International has signed a licensing agreement for the Canadian rights to Xyrem (sodium oxybate) for the treatment of cataplexy, a debilitating symptom of narcolepsy, from Jazz Pharmaceuticals, Inc. The agreement calls for Valeant to pay Jazz Pharmaceuticals an upfront fee and payments based on sales.
"Xyrem is a strategic fit for our existing marketing and sales organizations in Canada and we are excited about the potential of this agreement and the opportunity to work with Jazz Pharmaceuticals," Valeant's president and chief executive officer, Timothy C Tyson said. "The product expands our neurology business in Canada in a niche market with unmet medical needs."
Xyrem, a liquid formulation of sodium oxybate, is the first and only product approved in Canada to treat cataplexy, which is a sudden loss of muscle tone associated with narcolepsy. Valeant expects to launch and distribute Xyrem in Canada in mid 2007 through its neurology sales force.
Xyrem has demonstrated an acceptable safety profile in narcoleptics with cataplexy when administered in nightly divided doses of 6 to 9 g with a recommended starting dose of 4.5 g/night. The adverse event profile was generally consistent with the known pharmacological actions of sodium oxybate and intercurrent disease states. The most commonly reported adverse drug reactions are dizziness, nausea, and headache, occurring in 17-25 per cent of patients. These are not the only possible effects with Xyrem. Patients administered Xyrem should be monitored for treatment-emergent adverse events.
Cataplexy is a sudden loss of muscle tone that is a debilitating symptom of narcolepsy. Cataplexy may occur more frequently during times of stress or fatigue. The cataplectic attack may involve only a slight feeling of weakness and limp muscles (i.e., sagging facial muscles, a nodding head, buckling knees, loss of arm strength, garbled speech), or it may result in immediate and total body collapse, during which the person may appear unconscious, but is actually awake and alert. These attacks may last from a few seconds up to several minutes. Cataplectic episodes are related to the loss of muscle tone usually associated with the normal dreaming stage of sleep called rapid eye movement (REM); as a protection against acting out one's dreams, the muscles become immobile or paralyzed.
Narcolepsy is a complex, lifelong neurological disease characterized by fragmented night-time sleep, excessive daytime somnolence (EDS), cataplexy, sleep paralysis, and hypnagogic hallucinations. At various times throughout the day, people with narcolepsy experience fleeting urges of sleep. If the urge is overwhelming, individuals will fall asleep for periods lasting from a few seconds to several minutes. In addition to excessive daytime sleepiness, three other major symptoms frequently characterize narcolepsy: cataplexy or the sudden loss of voluntary muscle tone; vivid hallucinations during sleep onset or upon wakening; and brief episodes of total paralysis at the beginning or end of sleep.
The cause of narcolepsy is unknown and likely involves multiple interacting factors that causes neurological dysfunction and sleep disturbances.
Valeant Pharmaceuticals International is a global specialty pharmaceutical company that develops, manufactures and markets products primarily in the areas of neurology, infectious disease and dermatology.