This week, researchers from the National Institute of Allergy and Infectious Diseases (NAID) reported that the FDA-approved mepolizumab (nucala) significantly improved clinical outcomes when added to standard treatment for eosinophilic granulomatosis with polyangiitis (EGPA).
EGPA, previously known as Churg-Strauss syndrome, is the cause of the number of eosinophil white blood cells dramatically increasing. People affected by the disorder typically experience severe asthma, followed by multi-organ damage as the result of eosinophils accumulating in the walls of blood vessels, leading to restricted blood flow and tissue damage.
, a Phase 3 trial for GlaxoSmithKline’s mepolizumab met its primary endpoint, and showed promising results as a potential treatment for the disease.
EGPA patients are currently treated with steroids, but, as per the Phase 3 clinical trial, the efficacy of adding mepolizumab to treatment could lessen the number of serious side effects. NAID, part of the National Institutes of Health (NIH), and GSK held the trial at 31 research sites in 9 different countries.
In the trial, 136 patients who either had not responded to the usual steroid treatment, or had relapsed, were tested to see the efficacy of adding the drug, with or without immunosuppressant. For 1 year, 68 of the participants were given injections of mepolizumab and half received injections of a placebo every 4 weeks.
At the time of the trial, neither the investigators nor the participants knew who had received which until the end of the trial. EGPA was in remission cumulatively for a minimum of 24 weeks in 28% of participants who were given mepolizumab but only in 3% who received placebo. Additionally, the disease was in remission at weeks 36 and 48 in 32% of participants who received mepolizumab but in only 3% who received placebo.
Nearly half of participants who received mepolizumab did not achieve remission, compared to 81% of those who received placebo. An NIAID-funded study is under way to learn what biological markers distinguish those who benefitted from mepolizumab from those who did not.