Efficacy of mycophenolate mofetil as a remission induction therapy in antineutrophil cytoplasmic antibody: associated vasculitis-a meta-analysis

Systematic literature review informing the 2022 update of the EULAR recommendations for the management of ANCA-associated vasculitis (AAV): part 1-treatment of granulomatosis with polyangiitis and microscopic polyangiitis

OBJECTIVE

To summarise and update evidence to inform the 2022 update of the EULAR recommendations for the management of antineutrophil cytoplasm antibody-associated vasculitis (AAV).

METHODS

A systematic literature review (SLR) was performed to identify current evidence regarding treatment of AAV. PubMed, EMBASE and the Cochrane library were searched from 1 February 2015 to 25 February 2022. The evidence presented here is focused on the treatment of granulomatosis with polyangiitis and microscopic polyangiitis.

RESULTS

3517 articles were screened and 175 assessed by full-text review. Ninety articles were included in the final evidence synthesis. Cyclophosphamide and rituximab (RTX) show similar efficacy for remission induction (level of evidence (LoE) 1a) but RTX is more effective in relapsing disease (LoE 1b). Glucocorticoid (GC) protocols with faster tapering result in similar remission rates but lower rates of serious infections (LoE 1b). Avacopan can be used to rapidly taper and replace GC (LoE 1b). Data on plasma exchange are inconsistent depending on the analysed trial populations but meta-analyses based on randomised controlled trials demonstrate a reduction of the risk of end-stage kidney disease at 1 year but not during long-term follow-up (LoE 1a). Use of RTX for maintenance of remission is associated with lower relapse rates compared with azathioprine (AZA, LoE 1b). Prolonged maintenance treatment results in lower relapse rates for both, AZA (LoE 1b) and RTX (LoE 1b).

CONCLUSION

This SLR provides current evidence to inform the 2022 update of the EULAR recommendations for the management of AAV.

Perspectives on Mycophenolate Mofetil in the Management of Autoimmunity

Before becoming a cornerstone in the treatment of numerous immune-mediated diseases, mycophenolate mofetil (MMF) was first introduced as an immunosuppressive agent in transplant immunology and later received the attention of rheumatologists and clinicians involved in the management of autoimmune diseases. MMF is now a widespread immunosuppressive drug for the treatment of several conditions, including lupus nephritis, interstitial lung disease associated with systemic sclerosis, and anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis while being efficacious also as rescue therapy in various orphan diseases, including dermatomyositis and IgA-associated nephropathy. Similarly, case reports or series support a possible use of MMF in other rare autoimmune diseases. Beyond modulating lymphocyte activation, MMF acts on other immune and non-immune cells and these effects may explain the therapeutic profile of this medication. The effects of MMF are broadly characterized by the impact on the immune system and the antiproliferative and antifibrotic changes induced. In this latter case, mechanistic data on fibroblasts may in the future allow to reevaluate the use of MMF in selected patients with inflammatory arthritis or systemic sclerosis. Attention must be paid towards the possible occurrence of adverse events, such as gastrointestinal complaints and teratogenicity, while the risk of infections and cancer related to MMF needs to be further investigated.

Induction and maintenance of remission with mycophenolate mofetil in ANCA-associated vasculitis: A systematic review and meta-analysis

BACKGROUND

Uncertainties exist about the use of mycophenolate mofetil (MMF) in anti-neutrophil cytoplasmatic antibody (ANCA)-associated vasculitis (AAV), particularly for remission maintenance.

METHODS

Systematic review and meta-analysis of phase II and III trials assessing the use of MMF in AAV (granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA)). A comprehensive search of several databases (Medline, EMBASE, Cochrane, Web of Science, Scopus) from inception to May 5th, 2020 has been conducted. Trial data were extracted to estimate odds ratios (ORs) and estimates (ES) for MMF efficacy (remission-induction and maintenance). Severe adverse effects (SAEs) were collected.

RESULTS

From 565 articles captured, 10 met the predefined criteria, five phase II and five III trials, 4 assessed remission-induction, 3 remission-maintenance, 3 both. The pooled OR for remission-induction at 6 months was 1.06 (95% CI: [0.74, 1.52]), with no significant difference by subgroup meta-analysis of trials stratified by different study-level features (i.e. kidney disease, MPA, myeloperoxidase-ANCA-positivity, newly diagnosed disease) (p > 0.05).The overall ES for remission-maintenance at the end of follow-up ranged between 51%-91% (I2 = 74.8%). Subgroup meta-analysis identified kidney involvement as a possible source of heterogeneity, yielding a significantly higher rate of sustained remission in trials enrolling only patients with kidney involvement (92% [76%-100%]) versus those enrolling patients with and without kidney involvement (56% [45%-66%]). Results were similar in multiple sensitivity analyses.During follow-up, the frequency of SAEs in MMF-based treatment arms was 31.8%.

CONCLUSIONS

In AAV, MMF use significantly associated with higher sustained remission rates in trials enrolling only patients with kidney involvement. These findings might influence clinical practice.

A real-world assessment of mycophenolate mofetil for remission induction in eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a form of ANCA-associated vasculitis (AAV). Clinical trials demonstrating the efficacy of mycophenolate mofetil (MMF) for remission induction in AAV excluded patients with EGPA. Despite this, MMF is commonly used in these patients. The objective of this study was to evaluate, for the first time, the effectiveness and tolerance of MMF in EGPA remission induction. A retrospective, two-center, real-world study was conducted in patients with EGPA who received MMF in addition to prednisolone for newly diagnosed or relapsing disease between 2009 and 2019. Baseline, 3-, 6- and 12-month outcome data were extracted from electronic health records. The primary outcome was disease remission, defined as a Birmingham Vasculitis Activity Score of 0 at 6 months. Secondary outcomes included disease relapse, median prednisolone dose at 12 months and drug tolerance. In total, 15 patients (73% male, median age 57) with EGPA (11 newly diagnosed/4 relapsing) were identified. At 6 months, 67% had achieved disease remission. At 12 months, this was maintained (66.7%) and 4 patients had relapsed. All but one patient remained on MMF at study completion and all patients tolerated MMF. Our real-world data suggest that MMF is an effective and well-tolerated agent for achieving disease remission in EGPA. A future randomized controlled trial of MMF in this neglected orphan disease is now warranted.

The Role of Mycophenolate Mofetil for the Induction of Remission in ANCA-Associated Vasculitis: A Meta-Analysis

Objectives: The successful introduction of mycophenolate mofetil (MMF) as a treatment for renal allograft reduced the incidence of acute rejection. The inspiring effects obtained by the MMF have led to an evaluation of its therapeutic potency on ANCA-associated vasculitis (AAV). However, there is little evidence of the MMF's efficacy on the AAV. The meta-analysis is carried out to evaluate the efficacy of MMF as a remission induction therapy in AAV.

Methods: Up to June 30th, 2020, PubMed, Cochrane Library, and Embase have been searched comprehensively. According to heterogeneity, the pooled remission rates are synthesized by either fixed-effect or random-effect models.

Results: The eight included studies comprising 230 patients who were treated with MMF as induction therapy are included in our analysis. The pooled overall remission rate is 74% (95% CI: 0.68–0.80). The remission rate, the infection rate and the rate of leukopenia of four randomized controlled trials aimed at comparing the effects of MMF with cyclophosphamide (CYC) during induction therapy for AAV have no statistical significance (P > 0.05).

Conclusion: MMF may be an alternative to CYC for remission induction therapy in AAV with MPO-ANCA, mild to moderate renal involvement and non-life-threatening state. Whether to observe the effect of MMF in AAV or to compare the difference between MMF and CYC in the future studies, risk stratification and subgrouping of AAV patients should be first carried out to correctly identify the AAV subgroup suitable for MMF.

Slo-Mo anti-neutrophil cytoplasmic antibody-associated renal vasculitis

Nephrologists are familiar with severe cases of anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) presenting as rapidly progressive glomerulonephritis. However, less is known about AAV with slowly progressive renal involvement. While its existence is acknowledged in textbooks, much remains unknown regarding its relative frequency versus more aggressive cases as well as about the optimal therapeutic approach and response to therapy. Moreover, this uncommon presentation may be underdiagnosed, given the scarce familiarity of physicians. In this issue of Clinical Kidney Journal, Trivioli et al. report the largest series to date and first systematic assessment of patients with AAV and slowly progressive renal involvement, defined as a reduction in estimated glomerular filtration rate (eGFR) of 25-50% in the 6 months prior to diagnosis after excluding secondary causes. Key findings are that slowly progressive AAV may be less common than previously thought, although it still represents the second most common presentation of renal AAV, it usually has a microscopic polyangiitis, anti-myeloperoxidase, mainly renal phenotype in elderly individuals, diagnosis may be late (over one-third of patients had end-stage kidney disease at diagnosis), clearly identifying an unmet need for physician awareness about this presentation, but those not needing renal replacement therapy at diagnosis still responded to immunosuppression.