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 Sleep and Fatigue in Patients with Fibromyalgia: Pooled Analysis from 2 Pivotal Clinical Trials.

Silverman3,  Stuart L., Holman4,  Andrew J., Benson1,  Beverly, Alvarez-Horine1,  Sarah, Wang1,  Y. Grace, Sarzi-Puttini2,  Piercarlo

Jazz Pharmaceuticals, Inc.
L. Sacco University Hospital, Milano, Italy
Osteoporosis Medical Center, Beverly Hills, CA
Pacific Rheumatology Associates, Inc., Renton, WA

Background:

Fibromyalgia (FM) is characterized by chronic widespread pain as well as sleep disturbance and fatigue. Two pivotal clinical trials of sodium oxybate (SXB) demonstrated that SXB significantly reduced pain and fatigue, and improved sleep relative to placebo. This analysis further evaluates the effects of SXB on sleep and fatigue using pooled data from the two trials.

Methods:

Both trials were of similar design (randomized, double-blind, placebo-controlled), length (14 weeks), and dosing regimens (placebo, SXB 4.5 g and 6 g equally divided between a dose at bedtime and another one 2.5 to 4 hours later). Baseline assessments were made after a washout period (up to 30 days) and prior to treatment initiation. Data from each treatment group were pooled (n=371 placebo; n=377 SXB 4.5 g; n=373 SXB 6 g) to evaluate the efficacy of SXB for pain (0–100 visual analogue scale [VAS]), fatigue (0–100 VAS), sleep disturbances (Jenkins Sleep Scale [JSS]; a validated, 4-item, self-report questionnaire for sleep disturbances), and effects of excessive daytime sleepiness on daily functioning (Functional Outcomes of Sleep Questionnaire [FOSQ]; a patient-report questionnaire); last observation carried forward was used for missing data.

Results:

Demographics of the pooled patients are consistent with the FM population (90.4% female, and 91.2% white, median age 48.0 years). Mean baseline pain, fatigue, sleep disturbance, and FOSQ scores were also similar to the individual studies and consistent with significant impairment. The proportions of patients who achieved 30% and 50% reductions in pain were significantly greater with SXB than placebo (p<0.001). Least squares mean changes from baseline in fatigue VAS showed significant reductions with both SXB doses beginning at Week 1 that were maintained over the duration of treatment and were significantly greater than placebo at each weekly assessment (p<0.001). At 14 weeks, changes from baseline in fatigue VAS were -25.3 and -28.0 for SXB 4.5 g and 6 g, respectively, compared with -15.5 for placebo. SXB resulted in reduction in sleep disturbances at Week 14 as indicated by a significant overall treatment effect (p<0.001) and pairwise comparisons with placebo (p<0.001 for both SXB groups) on the JSS total score; least squares mean changes at Week 14 were -5.4 and -6.0 for the SXB 4.5 g and 6 g groups, respectively, compared with -2.9 for placebo. Similarly, treatment effects on functioning related to daytime sleepiness and tiredness at Week 14 were observed for the FOSQ, with least squares mean changes (improvement) from baseline of 2.2 for both SXB groups compared with 1.3 for placebo (both p<=0.001). The most common adverse event was headache, 22.9%, 18.4%, and 15.1% in the pooled SXB 6 g, SXB 4.5 g, and placebo groups, respectively. Adverse events with an incidence >5% in all SXB treated patients and twice the rate in placebo were nausea, dizziness, vomiting, and anxiety.

Conclusions:

This pooled analysis of two pivotal clinical trials supports the efficacy of SXB. SXB significantly reduced pain and fatigue, improved sleep, and lessened the impact of daytime sleepiness on daily functioning.

To cite this abstract, please use the following information:
Silverman, Stuart L., Holman, Andrew J., Benson, Beverly, Alvarez-Horine, Sarah, Wang, Y. Grace, Sarzi-Puttini, Piercarlo; Sodium Oxybate Improves Sleep and Fatigue in Patients with Fibromyalgia: Pooled Analysis from 2 Pivotal Clinical Trials. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :815
DOI: 10.1002/art.28583

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