TABLE II.
Summary of efficacy outcomes
| Primary end point | Placebo (N = 54) | Mepolizumab 300 mg SC (N = 54) | Odds ratio (95% CI) | P value (CMH/logistic regression) |
|---|---|---|---|---|
| Proportion of patients who experienced ≥1 HES flare during the 32-wk study period | ||||
| Patients who experienced ≥1 HES flare during the 32-wk study period or who withdrew from the study, n (%) | 30 (56) | 15 (28) | 0.28 (0.12–0.64) | .002/.003 |
| Patients who experienced ≥1 HES flare during the 32-wk study period, n (%) | 28 (52) | 14 (26) | — | — |
| Patients who withdrew from the study, n (%) | 2 (4) | 1 (2) | — | — |
| Secondary end point | Placebo (N = 54) | Mepolizumab 300 mg SC (N = 54) | Hazard ratio (95% CI) | P value |
| Time to first flare | ||||
| Probability of flare by week 32, % (95% CI) | 52.7 (40.1–66.5) | 26.3 (16.5–40.3) | 0.34 (0.18–0.67) | .002 |
| Secondary end point | Placebo (N = 54) | Mepolizumab 300 mg SC (N = 54) | Odds ratio (95% CI) | P value (CMH/logistic regression) |
| Proportion of patients who experienced ≥1 HES flare during weeks 20–32 | ||||
| Patients who experienced ≥1 HES flare during weeks 20–32 or who withdrew from the study, n (%) | 19 (35) | 9 (17) | 0.33 (0.13–0.85) | .02/.02 |
| Patients who experienced ≥1 HES flare during weeks 20–32, n (%) | 17 (31) | 7 (13) | — | — |
| Patients who withdrew from the study, n (%) | 2 (4) | 2 (4) | — | — |
| Secondary end point | Placebo (N = 54) | Mepolizumab 300 mg SC (N = 54) | Rate ratio (95% CI) | P value |
| Annualized rate of HES flares | ||||
| Adjusted mean rate of HES flares per year | 1.46 | 0.50 | 0.34 (0.19–0.63) | <.001 |
| Secondary end point | Placebo (N = 54) | Mepolizumab 300 mg SC (N = 54) | P value | |
| Change from baseline at week 32 in fatigue severity * | ||||
| Median change from baseline | 0.32 | −0.66 | — | .04 |
CMH, Cochran-Mantel-Haenszel test; SC, subcutaneous.
*
Based on BFI item 3 recorded daily; for each patient, the mean score over the 7 d before baseline and week 32 was analyzed (range 0–10; higher score indicates worse fatigue severity; minimal clinically important difference for patients in HES not determined); patients (7 placebo, 4 mepolizumab) with missing data were included in this analysis with the largest (ie, worst) value observed for any patient.