Rituximab versus azathioprine for maintenance in ANCA-associated vasculitis. A prospective study in 117 patients

Long term azathioprine maintenance therapy in ANCA-associated vasculitis: combined results of long-term follow-up data

Objective

We studied whether in ANCA-associated vasculitis patients, duration of AZA maintenance influenced relapse rate during long-term follow-up.

Methods

Three hundred and eighty newly diagnosed ANCA-associated vasculitis patients from six European multicentre studies treated with AZA maintenance were included; 58% were male, median age at diagnosis 59.4 years (interquartile range: 48.3-68.2 years); granulomatosis with polyangiitis, n = 236; microscopic polyangiitis, n = 132; or renal limited vasculitis, n = 12. Patients were grouped according to the duration of AZA maintenance after remission induction: ⩽18 months, ⩽24 months, ⩽36 months, ⩽48 months or > 48 months. Primary outcome was relapse-free survival at 60 months.

Results

During follow-up, 84 first relapses occurred during AZA-maintenance therapy (1 relapse per 117 patient months) and 71 after withdrawal of AZA (1 relapse/113 months). During the first 12 months after withdrawal, 20 relapses occurred (1 relapse/119 months) and 29 relapses >12 months after withdrawal (1 relapse/186 months). Relapse-free survival at 60 months was 65.3% for patients receiving AZA maintenance >18 months after diagnosis vs 55% for those who discontinued maintenance ⩽18 months (P = 0.11). Relapse-free survival was associated with induction therapy (i.v. vs oral) and ANCA specificity (PR3-ANCA vs MPO-ANCA/negative).

Conclusion

Post hoc analysis of combined trial data suggest that stopping AZA maintenance therapy does not lead to a significant increase in relapse rate and AZA maintenance for more than 18 months after diagnosis does not significantly influence relapse-free survival. ANCA specificity has more effect on relapse-free survival than duration of maintenance therapy and should be used to tailor therapy individually.

Classification, diagnosis and treatment of ANCA-associated vasculitis

Diagnosis of anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis is usually not difficult in patient with systemic disease, including lung and kidneys involvement, and laboratory signs of inflammation. The presence of ANCA and the results of histological investigation confirm diagnosis of ANCA-associated vasculitis. Cyclophosphamide/azathioprine in combination with high dose steroids are used to induce and maintain remission of systemic vasculitis. The clinical trials also showed efficacy of rituximab that induces depletion of B-cells. Our understanding and management of ANCA-associated vasculitis improved significantly over the last decades but there is still a lot of debate over its classification, diagnostic criteria, assessment of activity and optimum treatment.

Treatment of severe and/or refractory ANCA-associated vasculitis

Most patients presenting with systemic necrotizing vasculitides improve when they are adequately treated. The presence of life-threatening manifestations or visceral involvement modifying organ function characterizes severe vasculitis, confirmed by disease-severity scores. Sequelae cannot always be predicted and prevented but organ involvement present at disease onset requires rapid therapeutic intervention. Some patients present a persistent active disease, which does not respond to treatments and deserve other drugs or combination of drugs. The therapeutic options for severe and/or relapsing and refractory diseases are described.

Is B-cell depletion first choice in antineutrophil cytoplasmic antibody-associated vasculitis?

PURPOSE OF REVIEW

To discuss in detail the efficacy and safety of rituximab (RTX) for induction and maintenance of remission in patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) who are either treatment naive, relapsing or refractory to standard of care.

RECENT FINDINGS

In treatment naive AAV patients, RTX without maintenance treatment is as effective as cyclophosphamide (CYC) followed by azathioprine (AZA) for maintenance for up to 18 months. RTX is superior to CYC for induction of remission in patients with relapsing AAV. Nevertheless, long-term follow-up shows relapsing disease in up to 50% of patients with proteinase 3-ANCA, irrespective of the induction regimen. RTX is useful in patients with refractory AAV, but percentages of patients achieving complete remission differ between series. RTX seems more effective than AZA for maintaining remission, but detailed results from prospective studies are being awaited. Adverse events do not differ between RTX and classical induction regimens, but infections related to hypogammaglobulinemia and neutropenia could be items of concern with repeated administration of RTX.

SUMMARY

RTX is an alternative for CYC for induction of remission in generalized AAV and could be first choice for relapsing patients and patients refractory to CYC. RTX is promising for maintenance of remission, but long-term safety should be awaited.

Key advances in the clinical approach to ANCA-associated vasculitis

The updated nomenclature for vasculitis defines this varied group of disorders by aetiology, specific features of pathogenesis and clinical symptoms; diagnostic and classification criteria for clinical practice are in development. Here, I review some important advances in the management of vasculitis within the category of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), which encompasses microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA) and eosinophilic granulomatosis with polyangiitis (EGPA). The clinical approach to the management of the patient with AAV should include testing for ANCA specificity; proteinase 3 (PR3)-specific ANCAs are most often associated with GPA, whereas myeloperoxidase (MPO)-ANCAs are usually associated with MPA. Also important to the management of AAV is an assessment of the disease stage and severity, to enable tailored treatment based on an algorithm derived from controlled-trial data. Remaining questions pertain to the dosage and duration of corticosteroid treatment, the selection of patients for, and duration of, maintenance treatment after induction of remission, and the identification of safer and more effective therapies than are currently in use. Outcome measures should assess not only disease activity, but also damage and quality of life. Infections, cardiovascular events and malignancies also contribute to outcome, and their prevention should therefore be part of the clinical approach to managing patients with AAV.

Are anti-proteinase-3 ANCA a useful marker of granulomatosis with polyangiitis (Wegener's) relapses? Results of a retrospective study on 126 patients

OBJECTIVES

Predicting granulomatosis with polyangiitis (Wegener's) (GPA) relapses based on ANCA titers remains a source of debate. Our objective was to evaluate the relevance of monitoring PR3-ANCA titers for GPA management.

METHODS

This retrospective study included 126 patients fulfilling the 1990 ACR criteria for GPA and PR3-ANCA-positive at the time of diagnosis. Disease activity was assessed with BVAS/WG and Disease Extent Index. For each patient, a median of 12 serum samples was analyzed, i.e., one every 5.5months.

RESULTS

Induction therapy obtained remission in 88% of the patients. ANCA became negative by IF for 70/115 (60.9%) patients and by ELISA for 90/115 (78.3%). After median follow-up of 70months, 85/126 (67.5%) patients had 154 clinical relapses associated with cANCA and PR3-ANCA-positivity for 122 (79.2%) and 102 (66.2%) of them, respectively. Relapse-free survival was significantly longer for patients who remained PR3-ANCA-negative (HR 0.60 [95% CI 0.39-0.92], P=0.02). Individual ANCA-profile analysis revealed that, for 60% of GPA patients, clinical outcomes and ANCA-titer changes were closely associated, i.e., ANCA were always positive during relapses and negative during remission. The 35 patients with fluctuating ANCA-positivity during remission were in partial remission or had developed grumbling GPA.

CONCLUSION

Although ANCA were positive during most systemic relapses or residual disease, no strict clinical-immunological correspondence was observed for 25% of the patients. Thus, GPA management cannot be based on ANCA levels alone.

Rituximab: Recommendations of the French Vasculitis Study Group (FVSG) for induction and maintenance treatments of adult, antineutrophil cytoplasm antibody-associated necrotizing vasculitides

Increasing rituximab prescription for ANCA-associated necrotizing vasculitides justifies the publication of recommendations for clinicians. Rituximab is approved in the United States to induce and maintain remission. In Europe, rituximab was recently approved for remission induction. However, governmental agencies' approvals cannot replace clinical practice guidelines. Herein, the French Vasculitis Study Group Recommendations Committee, comprised of physicians with extensive experience in the treatment of vasculitides, presents its consensus guidelines based on literature analysis, the results of prospective therapeutic trials and personal experience.