Summary of findings 2.
Mepolizumab intravenous (IV) compared to placebo for asthma
| Mepolizumab (IV) compared to placebo for asthma | ||||||
| Patient or population: people with asthma Setting: community Intervention: mepolizumab (IV) Comparison: placebo | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with placebo | Risk with mepolizumab (IV) | |||||
| Rate of clinically significant exacerbations Follow‐up: range 32 weeks to 52 weeks | The mean rate in the placebo group was 2.51 events per participant per yeara | The mean rate in the intervention groups was 1.18 fewer events per participant per year (1.41 fewer to 0.90 fewer) | Rate ratio 0.53 (0.44 to 0.64) | 751 (3 RCTs) | ⊕⊕⊕⊝ Moderatec | |
| Rate of exacerbations requiring emergency department treatment or admission Follow‐up: range 32 weeks to 52 weeks | The mean rate in the placebo group was 0.32 events per participant per yearb | The mean rate in the intervention groups was 0.15 fewer events per participant per year (0.22 fewer to 0.04 fewer) | Rate ratio 0.52 (0.31 to 0.87) | 690 (2 RCTs) | ⊕⊕⊕⊝ Moderatec | |
| Health‐related quality of life (AQLQ) Scale from: 1 to 7 (higher is better) Follow‐up: range 32 weeks to 52 weeks | The mean change in the placebo group ranged from 0.18 to 0.71 units | MD 0.21 higher (‐0.06 lower to 0.47 higher) | ‐ | 677 (2 RCTs) | ⊕⊕⊕⊝ Moderatec | A change of ≥ 0.5 is considered the minimum clinically significant difference |
| Health‐related quality of life (ACQ) Scale from: 0 to 6 (lower is better) Follow‐up: range 32 weeks to 52 weeks | The mean change in the placebo group ranged from −0.59 to −0.50 units | MD ‐0.11 lower (‐0.32 lower to 0.09 higher) | ‐ | 369 (2 RCTs) | ⊕⊕⊕⊝ Moderatec | A change of ≥ 0.5 is considered the minimum clinically significant difference |
| Pre‐bronchodilator FEV1 (L) Follow‐up: range 32 weeks to 52 weeks | The mean change in the placebo group ranged from 0.060 L (± 0.038 L) to 0.086 L (± 0.031 L) | MD 0.08 L (0.02 L higher to 0.15 L higher) |
‐ | 690 (2 RCTs) | ⊕⊕⊕⊝ Moderatec | |
| Adverse events leading to discontinuation Follow‐up: range 32 weeks to 52 weeks | 26 per 1000 | 19 per 1000 (5 to 77) | RR 0.72 (0.18 to 2.92) | 751 (3 RCTs) | ⊕⊕⊕⊝ Moderatec | |
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). ACQ: Asthma Control Questionnaire; AQLQ: Asthma Quality of Life Questionnaire; CI: confidence interval; FEV1 : forced expiratory volume in 1 second; MD: mean difference; IV: intravenous; RR: risk ratio | ||||||
| GRADE Working Group grades of evidence High quality: we are very confident that the true effect lies close to that of the estimate of the effect Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect | ||||||
aRounded mean of the rate in the placebo group of the three studies: 1.74, 2.40 and 3.4. bRounded mean of the rate in the placebo group of the two studies: 0.20 and 0.43. cThe intravenous route is not currently licenced for mepolizumab; one point deducted for indirectness.