Title: Efficacy of mepolizumab add-on therapy on health-related quality of life and markers of asthma control in severe eosinophilic asthma (MUSCA): randomised, double-blind, placebo-controlled, parallel-group, multicentre, phase 3b trial

Chupp, GL et al.


What You Need to Know:

According to results of a phase 3b study (MUSCA), mepolizumab, a monoclonal antibody that blocks interleukin-5, is safe and significantly improves health-related quality of life (HRQOL) compared to placebo in patients with severe eosinophilic asthma.

Trial Design:

  • Double-blind, placebo-controlled, parallel-group phase 3b study evaluated the effect of mepolizumab on HRQOL in patients with severe eosinophilic asthma
  • Inclusion criteria: ≥12 years old, experienced ≥2 exacerbations in the 12 months prior to screening despite utilizing high-dose inhaled corticosteroids and controller medicines
  • Patients were randomized (1:1) to receive 100mg mepolizumab administered subcutaneously or placebo every 4 weeks for a total of 24 weeks, in addition to standard of care
  • Primary endpoint: change in the score of the St George’s Respiratory Questionnaire (SGRQ) from baseline to week 24; analyzed in the modified intention-to-treat population (modified ITT)
  • Safety assessments included all patients who received ≥1 dose of study medication

Key Outcomes:

  • Modified ITT population: included 274 mepolizumab patients and 277 placebo patients
  • Change in the SGRQ score: least squares mean (SE) change from baseline of -15.6 (1.0) for mepolizumab patients compared to -7.9 (1.0) for placebo patients (treatment difference: -7.7; 95% CI: -10.5, -4.9; P<0.0001)
  • Zero deaths were reported
  • 70% of mepolizumab patients experienced ≥1 on-treatment adverse event vs 74% of placebo patients
  • Most common on-treatment adverse events: headache (occurred in 16% of mepolizumab patients and 21% of placebo patients) and nasopharyngitis (occurred in 11% of mepolizumab patients and 17% of placebo patients)
  • On-treatment serious adverse events: experienced by 5% of mepolizumab patients vs 8% of placebo patients
  • Most common on-treatment serious adverse event in both groups was asthma, which was experienced by 1% of mepolizumab patients vs 3% of placebo patients