ANTI-IL5 THERAPY IN EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS (EGPA): A LONGITUDINAL FOLLOW-UP STUDY ≥ 24MONTHS
Authors: Allyson Egan et al.
Treatment of relapsing and refractory eosinophilic granulomatosis with polyangiitis (EGPA) using adjuvant Mepolizumab (anti-IL-5) leads to longer times in remission, reduced steroid exposure and reduced relapse rates. In this retrospective descriptive study, 20 EGPA patients received 100mg s/c Mepolizumab every 4 weeks for a minimum of 24 months (maximum duration 43 months). Anti-IL-5 therapy was switched between agents for poor response or intolerance. Disease activity was assessed at 6, 12, 18 and 24 months.
There was a 50% reduction in steroid use by month 12, the reduction continued over 24 months. All patients remained on therapy, 50% on Mepolizumab and 50% switched to an alternative anti-IL-5 agent (9 to benralizumab, 1 to reslizumab). 8 are on anti-IL-5 monotherapy, 6 weaned off conventional immunosuppressants, 6 continued or commenced conventional immunotherapy therapy. ANCA serology normalized in all four positive patients by 12 months.
The study shows an excellent tolerability of anti-IL-5 monoclonal antibody therapy. However, as only 4 patients were ANCA positive, it remains unclear to what extent an anti-IL-5 strategy controls vasculitis. Notably, in 6/20 patients, conventional immunotherapy had to be initiated. Collectively, the data suggest that anti-IL-5 is very potent to control eosinophilia but may not suffice to control early pathogenic events in a sizable number of patients.