Jazz Pharmaceuticals, Inc and UCB announced today positive preliminary top-line results from the second of two phase III clinical trials of sodium oxybate (JZP-6) for the treatment of fibromyalgia.
Confirming the positive results from the first phase III study, this international, placebo-controlled trial of sodium oxybate to treat fibromyalgia achieved its key endpoints. As in the first randomised, double-blind fibromyalgia study, sodium oxybate significantly decreased pain and fatigue and improved daily function and patient global impression of change. Sodium oxybate has not been evaluated by regulators for the treatment of fibromyalgia and is not approved for this use.
“Fibromyalgia is a chronic illness, characterized by widespread pain, unrefreshing sleep, chronic fatigue, and psychological distress,” said I Jon Russell, MD, PhD, lead investigator in the first phase III study and Associate Professor of Medicine, Division of Clinical Immunology and Rheumatology, and Director, University Clinical Research Center, University of Texas Health Science Center at San Antonio. “Sodium oxybate has shown a positive effect on a number of the symptoms of fibromyalgia, and thus could have a significant impact on patients’ quality of life.”
The second 14-week phase III trial, conducted in the United States and seven European countries, included 573 adult patients with fibromyalgia randomised to one of three treatment arms: sodium oxybate 4.5 g/night, sodium oxybate 6 g/night, or placebo. The primary outcome measure, viewed by both US and EU regulatory authorities as a clinically meaningful endpoint, was the proportion of patients who achieved at least 30 percent reduction in pain from baseline to endpoint based on the Pain Visual Analog Scale (VAS). Data from the Fibromyalgia Impact Questionnaire (FIQ) are considered equally relevant as Pain VAS data in the E.U. FIQ data are considered supportive data by US regulators.
In the top-line results, significantly more patients treated with sodium oxybate achieved 30 percent or greater improvement in their pain compared to patients treated with placebo. Of those patients receiving sodium oxybate treatment, 35% of patients on 4.5 g/night and 35% of patients on 6 g/night reported this level of pain relief on the pain VAS, compared with 20% of patients on placebo. These results were highly statistically significant.
Patients’ physical functioning and ability to perform daily tasks, as measured by the FIQ, were highly statistically significantly different from placebo for the 4.5 g/night dose and for the 6 g/night dose. Sodium oxybate-treated patients also reported highly statistically significant improvement in fatigue, another common symptom of fibromyalgia.
The most common adverse events (greater than or equal to five percent and at least twice the rate of placebo) were nausea, dizziness, vomiting, insomnia, anxiety, somnolence, fatigue, muscle spasms, and peripheral oedema. Sodium oxybate was generally well tolerated, with the majority of adverse events reported being mild to moderate in nature.
“These results from our second phase III trial, confirming the positive results of our first phase III study, are an exciting milestone for Jazz Pharmaceuticals,” said Bruce Cozadd, Chairman and Chief Executive Officer of Jazz Pharmaceuticals. “I’d like to thank the investigators, patients, and Jazz Pharmaceuticals employees who helped us complete this trial.”
“UCB is committed to improving the lives of people living with severe CNS diseases,” said Iris Loew-Friedrich, Chief Medical Officer of UCB. “The positive results of the two phase III trials are encouraging and suggest that subject to regulatory approval, this may offer a new treatment option for people with fibromyalgia.”
Only preliminary top-line efficacy and safety data are available at this time. Further analyses are planned, including analyses of additional secondary endpoints. Jazz Pharmaceuticals anticipates submitting a New Drug Application for sodium oxybate to the U.S. Food and Drug Administration (FDA) by the end of 2009. UCB will consult with the European Medicines Agency (EMEA) to define the path forward. UCB has the exclusive marketing and distribution rights to sodium oxybate for fibromyalgia in Europe and some other countries outside North America and will manage registrations accordingly.