Source: DGNews  |  Posted 2 years ago

By Jennifer Reising

SAN ANTONIO, Tex -- February 9, 2010 -- Sodium oxybate significantly improves
pain, produces clinically meaningful improvements in function, and is well
tolerated in patients with fibromyalgia, researchers said here at the 26th
annual meeting of the American Academy of Pain Medicine (AAPM).

“Sodium oxybate is currently being evaluated by the FDA for the treatment of
fibromyalgia,” said Robert M. Bennett, MD, Oregon Health & Science University,
Portland, Oregon, on February 4. “I think it’s a very promising drug and
patients who do well on it, really do well on it.”

This international, randomised, double-blind, phase 3 trial evaluated the
efficacy and safety of sodium oxybate oral solution compared with placebo in
573 patients with fibromyalgia who had a pain score of >=50 mm on the Visual
Analogue Scale (VAS).

Patients were randomised in a 1:1:1 ratio to receive sodium oxybate 4.5 g or 6
g or to placebo for 14 weeks. Treatments were administered in 2 equally divided
doses at bedtime and 2.5 to 4 hours later.

The primary outcome measure was the percentage of patients reporting >=30%
reduction in pain VAS from baseline to week 14. Secondary measures were
improvements on the Fibromyalgia Impact Questionnaire (FIQ) and Patient Global
Impression of Change (PGIC) at week 14.

More patients treated with sodium oxybate reported a clinically relevant pain
reduction of >=30% in VAS versus placebo: 51.4% in the 6-g group and 42% in the
4.5-g group, compared with 26.8% in the placebo group (P <= .002). In
addition, the proportion of patients with a >=50% reduction in pain was
significantly higher in both sodium oxybate groups compared with placebo
(P <= .003).

A significantly greater percentage of patients treated with sodium oxybate
reported >=30% reduction in total FIQ score and a clinically meaningful
improvement in global status, with PGIC scores of “much better” or “very much
better,” compared with placebo (P < .001, for all).

Sodium oxybate was generally well tolerated, with adverse events (AEs) mild or
moderate in severity. The most common AEs with sodium oxybate (>=5% and twice
placebo) were nausea, dizziness, vomiting, anxiety, somnolence, fatigue, muscle
spasms, insomnia, and oedema.

Funding for this study was provided by Jazz Pharmaceuticals, Inc.

Presentation title: Effects of Sodium Oxybate on Pain, Function, and PGIC
in Fibromyalgia: Results From an International, 14-Week, Randomized,
Double-Blind, Placebo-Controlled, Phase 3 Trial. Abstract 186