Xyrem Phase III trial

Jazz Pharmaceuticals announced last week that they had completed enrolment in the first of two Phase III pivotal clinical trials of JZP-6 (sodium oxybate) for the treatment of fibromyalgia.

Sodium oxybate is also known by the brand name Xyrem. It has been approved by the American Food and Drug Administration (FDA) for the treatment of excessive daytime sleepiness and cataplexy (the sudden loss of muscle tone) in narcolepsy patients. In a Phase II clinical trial completed in 2005, Fibromyalgia Syndrome (Fibro) patients taking sodium oxybate had a statistically significant improvement in pain compared to placebo. These results need to be confirmed in the ongoing Phase III clinical trials.

Clinical trials involving new drugs are commonly classified into four phases, with each trial being treated as a seperate trial and the trial process usually taking many years. If a drug passes through phases I, II and III, showing efficiacy and safety, then it will usually be approved by the national regulatory authority for use in the general population. Phase IV are 'post-approval' studies, allowing the drug to be studied in a much wider population, often looking for specific safety issues, such as regarding long-term use or the safety of the drug in pregnancy.

Samuel Saks MD, Chief Executive Officer of Jazz Pharmaceuticals, said that:

"Completion of enrollment in this trial is a key milestone in the JZP-6 program. We expect to report top line results from this trial in the fourth quarter of 2008"

The JZP-6 Phase III clinical trial program includes two randomized, double blind, placebo-controlled studies. The first study, which has completed enrollment, involves 550 fibromyalgia patients at 65 locations in the U.S. The second study is currently enrolling patients at sites in the U.S. and Europe. Both studies primarily aim for a decrease in the participant's pain, as based on the pain visual analog scale. The JZP-6 clinical program also includes an open-label continuation trial to provide long-term safety data. Enrollment in this trial is underway, and is open to patients who complete one of the two Phase III trials.