Changes in outcome variables from baseline to endpoint in subjects with fibromyalgia after blinded treatment with 4.5 g or 6 g sodium oxybate, compared with placebo*
| Placebo | Sodium oxybate | ||||
|---|---|---|---|---|---|
| Outcome | (n=188) | 4.5 g (n=195) | p Value vs placebo | 6 g (n=190) | p Value vs placebo |
| Pain and tenderness | |||||
| Pain VAS | |||||
| n (%) of responders | |||||
| ≥30% criteria | 49 (26.8) | 81 (42.0) | 0.002 | 94 (51.4) | <0.001 |
| ≥50% criteria | 28 (15.3) | 54 (28.0) | 0.003 | 69 (37.7) | <0.001 |
| ≥80% criteria | 11 (6.0) | 22 (11.4) | NS | 29 (15.8) | 0.003 |
| Pain VAS (change in score from baseline) | −11.9±2.0 | −19.2±2.0 | 0.010 | −23.4±1.9 | <0.001 |
| Tender point | |||||
| TPC (change in score from baseline), median (range)† | 0 (−16, 5) | 0 (−16, 4) | 0.003 | 0 (−17, 4) | NS |
| TPI (change in score from baseline) | −5.5±1.0 | −9.1±1.0 | 0.007 | −7.8±1.0 | NS |
| MTPS (change in score from baseline) | −14.1±2.6 | −27.9±2.6 | <0.001 | −21.7±2.6 | 0.036 |
| Sleep and fatigue | |||||
| Fatigue VAS (change in score from baseline) | −13.7±1.9 | −23.0±1.9 | <0.001 | −26.2±1.9 | <0.001 |
| JSS (change in score from baseline), median (range)† | −1.0 (−20, 7) | −4.0 (−18, 8) | <0.001 | −5.0 (−20, 5) | <0.001 |
| FOSQ (change in score from baseline) | 1.0±0.3 | 2.1±0.3 | 0.003 | 2.1±0.3 | 0.004 |
| Functionality and HRQOL | |||||
| FIQ (total score) | |||||
| n (%) of total FIQ responders | |||||
| ≥14% criteria | 79 (43.6) | 119 (62.6) | <0.001 | 131 (70.8) | <0.001 |
| ≥30% criteria | 54 (29.8) | 95 (50.0) | <0.001 | 102 (55.1) | <0.001 |
| Total FIQ (change in score from baseline) | −9.9±1.5 | −19.2±1.5 | <0.001 | −20.6±1.5 | <0.001 |
| SF-36 | |||||
| PCS (change in score from baseline) | 3.6±0.7 | 6.4±0.7 | 0.002 | 6.3±0.7 | 0.003 |
| EQ-5D overall health state | |||||
| EQ-5D (change in score from baseline) | 5.1±2.2 | 9.2±2.2 | NS | 10.6±2.2 | NS |
| Global impression of change | |||||
| PGIC responders‡ n (%) | 29 (16.0) | 61 (32.1) | <0.001 | 71 (39.7) | <0.001 |
| CGIC responders§ n (%) | 34 (18.7) | 68 (35.4) | <0.001 | 69 (37.5) | <0.001 |
| Composites | |||||
| Fibromyalgia composite responders¶ n (%) | 21 (13.7) | 42 (26.6) | 0.005 | 53 (34.0) | <0.001 |
| Functional composite responders** n (%) | 15 (9.8) | 34 (21.7) | 0.004 | 40 (26.0) | <0.001 |
↵* Except when indicated otherwise, values are the least squares mean±SEM.
↵† Median values are presented due to skewed distribution of data.
↵‡ Proportion of subjects who responded ‘very much better’ or ‘much better’.
↵§ Proportion of subjects whose disease was rated ‘very much improved’ or ‘much improved’ by the investigator.
↵¶ Includes pain VAS (≥30% reduction), FIQ total score (≥30% reduction) and PGIC responders (‘very much better’ or ‘much better’).
↵** Includes pain VAS (≥30% reduction), PGIC (‘very much better’ or ‘much better’) and SF-36 PCS (≥6 increase) responders.
CGIC, clinical global impression of change; EQ-5D, EuroQol-5 dimensions self-report questionnaire; FIQ, fibromyalgia impact questionnaire; FOSQ, functional outcomes of sleep questionnaire; HRQOL, health-related quality of life; JSS, Jenkins sleep scale; MTPS, manual tender point survey; NS, not statistically significant; PCS, physical component summary; PGIC, patient global impression of change; SEM, standard error of least squares mean; SF-36, Medical Outcomes Study 36-item short-form health survey; TPC, tender-point count; TPI, tender-point index; VAS, visual analogue scale.