EGPA in 2025 Save

Eosinophilic Granulomatosis with Polyangiitis (EGPA), the artist formerly known as Churg-Strauss syndrome, remains somewhat of a rogue agent among the vasculitides. 

Formerly classified as an ANCA-associated vasculitis, it is both most commonly ANCA negative and clinically different to the other two ANCA-associated vasculitis conditions, GPA and MPA. The management of EGPA has frequently fallen into the trap of being copied from its more common and well-known cousins. In the past this was relatively acceptable, we did not have much available agents, and the GPA/MPA treatments actually worked reasonably well. In more recent years however, we are now seeing a discordance and following GPA/MPA management will potentially lead to both over-treatment and suboptimal treatment for EGPA.

In this context, the Sunday morning session at RNL 2025 on “EGPA management in 2025 and beyond” by Dr. Michael Wechsler was both timely and clinically relevant. 

Dr. Wechsler began by reminding us what is and isn’t EGPA – eosinophilia and pulmonary symptoms does not make the diagnosis and only a fraction of these patients have EGPA. I have frequently seen this tendency to over-suspect and over-diagnose EGPA based on some half-remembered information from medical school or boards. Dr Wechsler reminded us of the flip side of this however, there are still many patients being treated for severe asthma and not-responding because they have undiagnosed EGPA. He also reminded us of one of my favorite EGPA teaching points – the triphasic nature of EGPA. A first phase of allergic rhinitis/sinusitis progressing to asthma. A second phase of eosinophilia in blood and/or organs. And a final vasculitic phase. This is sequential (although occasionally can be very rapidly so) and if you don’t have this pattern, you really should question the diagnosis.

Moving on to management Dr. Wechsler emphasised how effective glucocorticoids are in EGPA, not surprising given how much they flatten eosinophils. He highlighted however that similar to many of our diseases, there are major issues with steroid monotherapy – relapse, side effects, and need for long term therapy to maintain remission. Beyond steroids we really have a dearth of evidence, very few trials, very little EGPA specific evidence (borrowing from GPA/MPA and asthma). This leads to a bit of a Wild West scenario where everyone is kind of doing their own thing.

Dr. Wechsler then went through the very limited evidence we have for traditional immunosuppressants in EGPA. 

Azathioprine which is relatively frequently used has reasonable evidence that it does not work. Rituximab seems to have an effect but may be disappointing in terms of glucocorticoid free remission. Dr. Wechsler was a big advocate for the use of anti-IL-5 agents such as mepolizumab in EGPA. I’m really not so sure about this to be honest. It makes me genuinely uncomfortable to consider treating a severe vasculitis with these agents. The data is there that it has an effect, and it is the highest quality data available. For me though the concern mirrors my concern with nintedanib in ILD. We have this “best” evidence because money was put into trials of these agents for financial reasons. The reason we don’t have comparative data for many other agents is that there was no incentive there in terms of potential profit. So the best evidence we have for treatment in EGPA is for mepolizumab, but that does not necessarily mean that mepolizumab is the best treatment for EGPA just that it is the best studied.