There has been a long-standing debate over the value of using low-dose prednisone for remission-maintenance among patients with GPA. Recent data demonstrating that even low-dose glucocorticoids may have side effects has renewed interest in this debate.10
This study demonstrates that patients likely do benefit from the use of low-dose prednisone; however, this benefit is not seen in patients who receive rituximab for remission maintenance. We often continue low-dose prednisone in patients with long-standing GPA to prevent symptoms of glucocorticoid withdrawal or adrenal insufficiency; it is, therefore, interesting that patients who remained on low-dose prednisone did not seem to feel better than patients who were tapered off of glucocorticoids entirely.
However, the spectrum of disease manifestations associated with GPA is broad, and a study of this size may not be able to identify specific disease phenotypes (e.g., chronic sinusitis) that may benefit disproportionately from low-dose glucocorticoids.
4. Mepolizumab for EGPA
Abstracts 0827 & 2482: Khoury et al. & Merkel et al.11,12
Mepolizumab is a monoclonal antibody directed against interleukin 5. In 2017, mepolizumab became the first drug approved by the FDA for the treatment of eosinophilic granulomatosis with polyangiitis (EGPA). These two studies examine what we know about the long-term effects of using mepolizumab for EGPA.
MIRRA was a phase 3, double-blind, placebo-controlled trial that randomized 136 patients with EGPA to receive treatment with either subcutaneous mepolizumab (300 mg monthly) or placebo; 100 patients who continued to require at least 5 mg of prednisolone daily to remain in remission were subsequently enrolled in a long-term access program, which allowed them to continue to receive mepolizumab 300 mg monthly until it became commercially available.13
Patients in this study received mepolizumab for a mean of 38.5 months. By months 16–18, 66% of patients were able to decrease their oral glucocorticoid requirement by greater than 50% (i.e., from a median prednisolone dose of 10 mg daily to 5.1 mg daily), and they were able to remain on the lower dose of glucocorticoids as long as they continued to receive treatment with mepolizumab. The most common serious adverse event reported was worsening asthma. However, no new safety concerns were identified.
Interleukin 5 blockade is exceptionally effective for addressing the sinopulmonary manifestations of EGPA. These studies demonstrate that even after prolonged use, mepolizumab continues to be both safe and effective for patients with EGPA.
Benralizumab, a monoclonal antibody directed against the interleukin 5 receptor, was recently approved by the FDA for the treatment of EGPA;14 long-term studies of benralizumab demonstrate it is similarly safe and effective when used for up to five years for the treatment of patients with severe eosinophilic asthma.
