In two phase III studies in patients with eosinophilic asthma, mepolizumab cut the number of exacerbations and decreased daily oral corticosteroid use, GlaxoSmithKline (GSK) announced today.
If approved, mepolizumab, an IL-5 antagonist monoclonal antibody, would be the first non-inhaled treatment for severe asthma, Dave Allen, Head of GSK’s Respiratory Therapy Area Unit, R&D, said in a press release. “We now have two studies showing a reduction in exacerbations in a specific group of patients with a severe form of asthma who continue to exacerbate despite treatment with high doses of their current maintenance therapies.”
In the first study, 576 patients were randomized to receive either 75 mg of mepolizumab in IV form, 100 mg as a subcutaneous injection, or a placebo every four weeks for 32 weeks. They continued to take their regular asthma maintenance therapy.
After 32 weeks, those in the IV group experienced a 47% reduction in exacerbations of asthma symptoms compared with those in the placebo group (P<0.001); those who received the drug subcutaneously had a 53% reduction (P<0.001).
Adverse events were reported by 83% in the IV group, 78% in the injection group, and 84% in the placebo group. Serious events occurred at a higher rate in the placebo group at 14% compared with 7% in the IV group, and 8% in the injection group.
In the second phase III study, 135 patients were given either a 100 mg subcutaneous injection of mepolizumab or a placebo every four weeks for 24 weeks to investigate whether mepolizumab would help reduce the need for oral corticosteroid use. By the time the participants reached 20-24 weeks of treatment, participants in the mepolizumab group had greater reductions in their maintenance corticosteroids than did those in the placebo group (P=0.008).
Adverse event frequency was similar in both groups. Common adverse events included headache, fatigue, head cold and chest cold symptoms, sinusitis and asthma.
Study results will be presented at a scientific meeting in the future and GSK hopes to file for approval by the end of 2014.