Severe asthma patients, whose disease is driven by eosinophilic inflammation, treated with first-in-class biologic Nucala (mepolizumab) added-on to standard of care, achieved clinically and statistically significant improvements in their health-related quality of life and lung function, when compared to patients treated with placebo and standard of care, according to a press release by GlaxoSmithKline.

These results are from the phase IIIb MUSCA study (NCT02281318, 200862), which successfully met all its primary and secondary endpoints.

Results of the study, presented at the American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting, showed in patients treated with mepolizumab as an add on to standard care:

  • St. Georges Respiratory Questionnaire (SGRQ) score (primary endpoint), a measure of quality of life, improved by 7.7 units from baseline vs. placebo (p=0.001) after 24 weeks – nearly double the defined clinically meaningful difference of ?4.0 units.
  • Lung function (first secondary endpoint), as measured by pre-bronchodilator FEV1, increased by 120mL (p=0.001) more than in placebo patients at week 24 – a clinically relevant and statistically significant improvement.
  • FEV1 and SGRQ scores were also measured during the study, with improvements seen at the first measurement interval, after the first four weeks and sustained throughout the 24-week trial.
  • Asthma control, as measured by the Asthma Control Questionnaire-5 (ACQ-5) (additional secondary endpoint), showed a significant improvement vs. placebo in the mepolizumab treatment group by 0.40 units (p<0.001).

According to GSK, MUSCA is the first mepolizumab clinical trial to specifically look at health-related quality of life as a primary endpoint and assess SGRQ score on multiple occasions throughout the study. In the clinical development program, mepolizumab did not provide consistent improvements in mean change from baseline in FEV1.

Exploratory endpoints were the annual rate of exacerbations (asthma attacks), which was reduced by 58%, and the number of exacerbations requiring emergency room visits or hospitalisation, which was reduced by 68% for people treated with mepolizumab compared with placebo. These results were comparable to those seen in the pivotal phase III MENSA study. Safety was also assessed and the safety profile of mepolizumab in the MUSCA study was consistent with the product label for Nucala.

“The data from the MUSCA study underscore the importance of Nucala as a treatment option for patients with severe asthma with an eosinophilic phenotype. These are patients who have very limited treatment options to control their asthma. For them shortness of breath, wheezing, coughing and the risk of an asthma attack is an ever present occurrence and one that can have a severe impact their life on a daily basis,” said Dr Frank Albers, Medical Affairs Lead for Nucala, GSK. “By demonstrating improvements in a range of important markers of asthma control, including quality of life and lung function, these data reinforce the valuable role Nucala can play in the treatment of some of the most severe asthma patients.”