Rituximab for eosinophilic granulomatosis with polyangiitis: a systematic review of observational studies

Therapeutic Advances in Eosinophilic Granulomatosis with Polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is an eosinophilic vasculitis that affects a variety of organ systems. Historically, glucocorticoids and a variety of other immunosuppressants were used to abrogate the inflammation and tissue injury associated with EGPA. The management of EGPA has evolved greatly during the last decade with the development of novel targeted therapeutics that have resulted in significantly improved outcomes for these patients, with many more novel targeted therapies emerging.

New Insights into Pathogenesis and Treatment of ANCA-Associated Vasculitis: Autoantibodies and Beyond

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a group of rare systemic diseases affecting small-caliber vessels. The damage caused by AAV mainly involves the lung and kidneys. AAV includes three different types: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Although the different phenotypic forms of AAV share common features, recent studies have shown that there are significant differences in terms of pathogenetic mechanisms involving both the adaptive and innate immune systems. Advances in our understanding of pathogenesis have enabled the development of immuno-targeted therapies. This review illustrates the characteristics of the various forms of AAV and the new therapies available for this disease that can have lethal consequences if left untreated.

Off-Label Uses of Rituximab in Dermatology

Purpose of Review

Rituximab has transformed the treatment of B-cell malignancies and rheumatoid arthritis in the past 2 decades. More recently, this anti-CD20 monoclonal antibody has seen increasing usage in the field of dermatology. This review highlights the evidence supporting its use in several important dermatologic conditions.

Recent Findings

Key recent findings include the 2018 FDA approval of rituximab for the treatment of moderate-to-severe pemphigus.

Summary

Data from randomized controlled trials have demonstrated the efficacy of rituximab in pemphigus, ANCA-associated vasculitis, and cryoglobulinemic vasculitis. More limited data suggests its use in recalcitrant cases of diseases such as pemphigoid, epidermolysis bullosa acquisita, and dermatomyositis. There is scarce evidence and mixed results for rituximab when studied in cutaneous polyarteritis nodosa and cutaneous lupus erythematosus.

Therapeutic advances in eosinophilic granulomatosis with polyangiitis

PURPOSE OF REVIEW

In recent years, therapeutic advances in eosinophilic granulomatosis with polyangiitis (EGPA) have changed our treatment paradigm. This review will summarize and discuss updates in management of EGPA, with a particular focus on biologic therapies.

RECENT FINDINGS

The anti-interleukin (IL)-5 agent mepolizumab (the first FDA-approved drug specifically for EGPA) is effective in induction and maintenance of remission particularly in patients with predominantly asthma and allergic manifestations, though efficacy in ANCA-positive, vasculitic disease is unclear; additional anti-IL-5 agents are under study. Rituximab is currently recommended for remission induction in severe disease, particularly in ANCA-positive patients with vasculitic manifestations, though the supportive evidence is mostly observational. Evidence supporting use of traditional DMARDs and other biologic agents such as omalizumab remains limited and observational.

SUMMARY

Although management of this heterogeneous disease remains challenging and unanswered questions remain, advances in biologics (particularly anti-IL-5 agents and an evolving interest in rituximab) have expanded our treatment armamentarium in EGPA.

[Eosinophilic granulomatosis with polyangiitis : Update on classification and management]

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare chronic inflammatory systemic disease that occurs in patients with bronchial asthma and is associated with significant blood and tissue eosinophilia. Another characteristic is vasculitis of small and/or medium-sized vessels, which may be absent in prodromal stages of the disease and is therefore no longer an obligatory part of the disease definition. Antineutrophil cytoplasmic antibodies (ANCA) can be detected in approximately one third of patients. The ANCA-positive and ANCA-negative EGPA are genetically distinct diseases with common clinical manifestations, which, however, occur with different frequencies. Cardiac involvement is associated with a poor prognosis. Permanent organ damage often occurs as a result of the underlying disease or treatment, especially with glucocorticoids (GC). The standard treatment of EGPA consists of GC in combination with cyclophosphamide for severe organ involvement or medium potency immunosuppressants for more prognostically favorable manifestations. Biologics are increasingly being used in the treatment of EGPA. The interleukin (IL) 5 antagonist mepolizumab reduces the risk of relapses and decreases the demand for GC in patients with relapsing EGPA without severe organ involvement. In analogy to the approach to other ANCA-associated vasculitides, the use of rituximab in ANCA-positive EGPA patients with severe vasculitis recurrence is a possible option, even though formal evidence for such an approach is currently low and formal approval is lacking.

[Biologics for connective tissue diseases and vasculitides]

Despite therapy with glucocorticoids (GC) and conventional immunosuppressants, patients with connective tissue diseases and vasculitides often develop functionally relevant and prognostically unfavourable internal organ damage. Based on new pathogenetic insights, biologics and small molecules have recently been studied as targeted therapies for collagen vascular diseases and vasculitides. The B lymphocyte stimulator antagonist belimumab has been used for the treatment of systemic lupus erythematosus (SLE) for several years and has recently also been approved as an add-on therapy for lupus nephritis. Anifrolumab, an antibody against the type‑1 interferon receptor, has also been shown to be effective in phase III trials for the treatment of SLE. The interleukin (IL)-6-antagonist tocilizumab showed efficacy in the treatment of interstitial lung disease (ILD) in systemic sclerosis (SSc) and thus has been approved in the USA, although the phase III trial had a negative primary endpoint. In Europe the tyrosine inhibitor nintedanib is approved for progressive ILD in SSc. Tocilizumab is approved for the treatment of giant cell arteritis and reduces both the risk of recurrence and the cumulative GC requirement. The B‑lymphocyte depleting antibody rituximab is approved for induction and maintenance therapy of granulomatosis with polyangiitis and microscopic polyangiitis (MPA) and is currently also being investigated for the treatment of eosinophilic granulomatosis with polyangiitis (EGPA). In patients with EGPA, the IL‑5 antibody mepolizumab leads to improved disease control and reduces GC requirements. A phase III trial of the small molecule antagonist avacopan targeting the complement C5a receptor as a replacement for high-dose GC in induction therapy of GPA and MPA met its primary endpoints. Various other biologics and small molecule antagonists are currently in clinical development for several type of vasculitis and collagen vascular diseases, some of them at advanced stages.

B-Cell-Depleting Therapy Improves Myocarditis in Seronegative Eosinophilic Granulomatosis with Polyangiitis

Cardiac involvement is a major mortality cause in eosinophilic granulomatosis with polyangiitis (EGPA), requiring novel therapeutics to spare the use of cyclophosphamide with known cardiotoxicity. Despite the observed efficacy of B-cell-depleting therapy in myocarditis of seropositive microscopic polyangiitis, it remains to be elucidated in seronegative EGPA. A retrospective study was performed in 21 hospitalized active patients aged 20 to 70 years with five-factor score 1 or 2, eosinophil counts 10,034 ± 6641/μL and vasculitis scores 27 ± 6. Overt myocarditis was identified in 10 cases, at disease onset in 6 and relapse in 4, with endomyocarditis in 4 and myopericarditis in 4. Five seronegative and one seropositive patient received rituximab with an induction regimen 375 mg/m² weekly × 4 for refractory or relapse disease, and the same regimen for annual maintenance therapy. All cases had lower eosinophil counts, improved cardiac dysfunction and clinical remission with a relapse-free follow-up, 48 ± 15 months after the induction treatment. One seronegative endomyocarditis patient had eosinophilia and disease relapse with asthma attack and worsening cardiac insufficiency 24 months after induction, achieving clinical remission under anti-IL-5 therapy. Our findings suggest the suppression of IL-5-mediated eosinophilia as an action mechanism of B-cell-depleting therapy in seronegative EGPA myocarditis.

Rituximab Induction and Maintenance in ANCA-Associated Vasculitis: State of the Art and Future Perspectives

Antineutrophil cytoplasmatic antibody (ANCA)-associated vasculitis (AAV) is a group of rare autoimmune diseases characterized by inflammation of the vascular wall. The pathogenesis of AAV is strongly associated with B cell-derived ANCAs; thus, Rituximab (RTX) has become a promising drug in the induction and maintenance treatment of AAV. The purpose of this review is to describe the efficacy and safety of RTX in the induction of remission and maintenance therapy of AAV. Herein, we summarize the randomized controlled trials that have contributed to the refinement of the use of RTX in AAV in the past decades. RTX has been proven to be effective both in new-onset disease and in relapsing disease. Although the optimal duration of AAV maintenance therapy remains unknown, the ANCAs and the B-cell repopulation may offer support for the administration of further RTX cycles (or not). The safety of RTX is comparable with cyclophosphamide, with the advantage of a low risk of malignancy and no concern for fertility. In conclusion, RTX now plays an important role in the induction and maintenance therapy of AAV. Optimizing RTX-based treatment strategies in AAV is one of the main goals of the current research in AAV.

Clinical features of central nervous system involvement in patients with eosinophilic granulomatosis with polyangiitis: a retrospective cohort study in China

Background

Central nervous system (CNS) involvement is extremely rare in eosinophilic granulomatosis with polyangiitis (EGPA), but is associated with a poor prognosis in the five-factor score. This study aims to elucidate the clinical features and independently associated factors of EGPA with CNS involvement.

Results

CNS involvement was observed in 17.3% (19/110) of EGPA patients from Peking Union Medical College Hospital between 2007 and 2019. We retrospectively reviewed their clinical data and analyzed the independently associated factors. Their mean age was 51.7 ± 11.56 years with no male/female predominance. Ischemic lesions were the most common manifestations, accounting for 63.2% of the 19 cases, followed by posterior reversible encephalopathy syndrome (36.8%), spinal cord involvement (15.8%), medulla oblongata involvement (15.8%), and intracranial hemorrhages (15.8%). Compared to the control group, patients with CNS involvement were of older age (51.7 ± 11.56 vs. 43.7 ± 13.78 years, p = 0.019) and had a higher ratio in the digestive tract involvement (52.6% vs. 28.6%, p = 0.042). Further multivariate analysis revealed that age, disease duration, and fever were the potential independent risk factors for CNS involvement of EGPA. Glucocorticoids combined with cyclophosphamide were the strategic therapy (94.7%). Intrathecal injections of dexamethasone and methotrexate were administered to 21.1% of the patients. Although seven patients relapsed during glucocorticoid reduction, seventeen patients finally achieved clinical remission. One patient died of acute intracerebral hemorrhage within one month, and another died of gastrointestinal perforation. Outcomes and cumulative survival show no significant differences between the two groups.

Conclusions

CNS involvement is uncommon in EGPA with various manifestations, and ischemic lesions are the most frequent. Age, disease duration, and fever are independent factors associated with CNS involvement in EGPA. The therapy of glucocorticoids combined with cyclophosphamide and intrathecal injections yields favorable responses. Acute intracranial hemorrhage and gastrointestinal perforation may be the principal causes of death.