Rituximab Fails to Show Benefit Over Azathioprine in Vasculitis Relapse

March 6, 2026 Ananya Mittal - World Editor

For individuals managing eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as Churg-Strauss syndrome, maintaining remission can be a long-term challenge. Recent findings suggest that, unlike the situation with ANCA-associated vasculitis, two commonly used drugs – rituximab and azathioprine – appear to offer similar effectiveness in preventing relapse after initial remission is achieved. This nuance is important, as it suggests treatment decisions may necessitate to be more individualized, factoring in patient preferences and potential side effects rather than prioritizing one drug over the other based on efficacy alone.

EGPA and the Remission Landscape

EGPA is a rare autoimmune disease characterized by inflammation of small and medium-sized blood vessels. It often affects the lungs, skin, nerves, and other organs. The disease typically progresses through phases: an initial prodromal phase with asthma and allergic rhinitis, followed by an eosinophilic phase with increased eosinophil levels, and finally a vasculitic phase where organ damage occurs. Achieving remission – a period with minimal or no disease activity – is a primary goal of treatment. However, relapse rates can be significant, necessitating ongoing maintenance therapy.

Traditionally, azathioprine, an immunosuppressant, has been a mainstay of maintenance therapy. More recently, rituximab, a monoclonal antibody that depletes B cells, has emerged as a potential alternative. The initial excitement around rituximab stemmed from its success in ANCA-associated vasculitis, another type of autoimmune vasculitis. However, the experience with EGPA has proven to be different.

New Findings: A Similar Outcome for Two Approaches

Xavier Puéchal, MD, PhD, recently reported that there was no discernible advantage of rituximab over azathioprine in sustaining remission in EGPA patients. This finding challenges the assumption that rituximab would automatically be the preferred option, particularly given its different administration route (intravenous infusions versus daily oral medication) and potential for different side effects.

The observation stems from a careful analysis of clinical data, suggesting that the choice between these two drugs should be guided by a more nuanced discussion between clinicians and patients. Factors such as convenience, cost, and individual risk profiles may become more central to the decision-making process.

Understanding the Study Context: ANCA-Associated Vasculitis vs. EGPA

It’s crucial to understand why the results differ from those seen in ANCA-associated vasculitis. In 2014, the RITAZAREM trial demonstrated that rituximab was superior to azathioprine in maintaining remission in ANCA-associated vasculitis. This study, published in the New England Journal of Medicine, showed a significant reduction in relapse rates with rituximab. Further research, including a 2023 publication in PubMed, confirmed these findings.

The key difference lies in the underlying disease mechanisms. ANCA-associated vasculitis is driven by the presence of anti-neutrophil cytoplasmic antibodies (ANCAs), which directly attack small blood vessels. Rituximab’s ability to deplete B cells, which produce these antibodies, directly addresses the root cause of the disease. EGPA, however, is more complex and involves a broader range of immune cells and inflammatory pathways. Whereas B cells play a role, their contribution may not be as central as in ANCA-associated vasculitis, potentially explaining why rituximab doesn’t offer a clear advantage.

What This Means for Patients with EGPA

For patients currently on rituximab for EGPA maintenance, this new information doesn’t necessarily signify they need to switch medications. Treatment decisions should always be made in consultation with a qualified rheumatologist or vasculitis specialist. However, it does suggest that patients starting maintenance therapy may not automatically need to be directed towards rituximab.

The choice between rituximab and azathioprine should be individualized, considering factors such as:

  • Convenience: Azathioprine is an oral medication taken daily, while rituximab requires intravenous infusions every few months.
  • Potential Side Effects: Both drugs have potential side effects, which can vary from person to person.
  • Patient Preference: Some patients may prefer one route of administration over the other.
  • Comorbidities: Other health conditions may influence the choice of medication.

The Ongoing Research and Future Directions

Research into EGPA continues, with ongoing efforts to better understand the disease mechanisms and identify more effective treatments. NephJC provides ongoing coverage of research in this area. Future studies may explore the potential of combining different therapies or targeting specific inflammatory pathways to improve remission rates and prevent relapses.

Currently, the focus is on refining existing treatment strategies and identifying biomarkers that can predict which patients are most likely to respond to specific therapies. This personalized approach to treatment holds the promise of improving outcomes for individuals living with EGPA.

What comes next: Clinicians will likely integrate these findings into their treatment algorithms, emphasizing shared decision-making with patients. Further research is needed to identify potential subgroups of EGPA patients who might benefit more from rituximab, but for now, azathioprine remains a viable and effective maintenance therapy option.