Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Sodium Oxybate Improves Pain, Function, and PGIC in Patients with Fibromyalgia: A Pooled Analysis of 2 Pivotal Clinical Trials.

Russell5,  I. Jon, Bennett3,  Robert M., Alegre1,  Cayetano, Winfield4,  John B., Lai2,  Chinglin, Wang2,  Y. Grace, Benson2,  Beverly

Hospital de la Vall d'Hebron, Alella, Spain
Jazz Pharmaceuticals, Inc.
Oregon Health and Science University, Portland, OR
University of North Carolina, Chapel Hill, NC
University of Texas Health Science Center, San Antonio, TX

Background:

In addition to chronic pain, fibromyalgia (FM) patients exhibit fatigue, sleep disturbances, and functional impairment. Sodium oxybate (SXB) demonstrated efficacy and tolerability for the treatment of FM in two pivotal phase 3 clinical trials. The current analysis further evaluates the effects of SXB on pain, function, and global status using pooled data from the two trials.

Methods:

The trials were of similar design (randomized, double-blind, placebo-controlled), length (14 weeks), and dosing regimens (placebo, SXB 4.5 g and 6 g dosing equally divided between bedtime and 2.5 to 4 hours later). The primary outcome variable for both studies was the proportion of patients who achieved a 30% reduction in pain on a 0–100 mm visual analog scale (PVAS). Other measured variables included quantitative changes in PVAS, changes in daily function assessed as the proportion of subjects with >=30% reduction in Fibromyalgia Impact Questionnaire (FIQ) score, changes in patient-reported health status (Patient Global Impression of Change [PGIC]), and two composite endpoints: a "Pain Composite" with two measures (PGIC of "very much better" or "much better"+>=30% reduction in PVAS) and an "FM Composite" with three measures (PGIC of "very much better" or "much better"+>=30% reduction in PVAS +>=30% reduction in FIQ). Last observation carried forward was used for missing data.

Results:

A total of 1121 subjects were randomized (placebo n=371; SXB 4.5 g n=377; SXB 6 g n=373). The demographic characteristics of the patients in the pooled trials were comparable (overall, 90.4% female; 91.2% white; median age 48.0 years). The proportion of patients with >=30% pain reduction was significantly greater with SXB; 47.8% and 54.8% for 4.5 g and 6 g, respectively, relative to placebo (30.9%; p<0.001). Pain reduction >=50% was reported by 36.0% of SXB 4.5 g patients and 40.4% of SXB 6 g patients compared with 18.9% on placebo (both p<0.001). Least squares mean changes from baseline showed greater PVAS reductions with both SXB doses relative to placebo, beginning at Week 1 and maintained through Week 14 (p<0.001). Greater proportions of patients treated with SXB 4.5 g (52.6%) and 6 g (55.6%) achieved >=30% reduction in FIQ total score relative to placebo (34.3%; p<0.001). Improvements in pain and function were paralleled by greater proportions of SXB patients reporting PGIC scores of "much better" or "very much better" (p<0.001 for both doses). The proportion of patients at Week 14 meeting the Pain Composite criteria and those achieving the FM Composite criteria were significantly greater with both SXB doses compared with placebo (p<0.001). The most common adverse events with an incidence greater than 5% in either SXB treatment group and twice the placebo rate were nausea, dizziness, vomiting, anxiety, and fatigue.

Conclusions:

This pooled analysis supports the results of the individual trials in demonstrating that SXB provides statistically and clinically significant improvements in FM pain, function, and global health status relative to placebo.

To cite this abstract, please use the following information:
Russell, I. Jon, Bennett, Robert M., Alegre, Cayetano, Winfield, John B., Lai, Chinglin, Wang, Y. Grace, et al; Sodium Oxybate Improves Pain, Function, and PGIC in Patients with Fibromyalgia: A Pooled Analysis of 2 Pivotal Clinical Trials. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :814
DOI: 10.1002/art.28582

Abstract Supplement

Meeting Menu

2010 ACR/ARHP