Prospective study of the effect of rituximab on kidney function in membranous nephropathy.

Background: Patients with membranous nephropathy (MN) and poor kidney function or active disease despite previous immunosuppression are underrepresented in clinical trials. It is unknown how effective rituximab is in this population. Methods: This prospective, multi-centre, single-arm, real-world study of patients with active MN [urine protein-creatinine ratio (uPCR) >350 mg/mmol and serum albumin <30 g/L, or a fall in estimated glomerular filtration rate (eGFR) of at least 20% or more over at least 3 months] evaluated rituximab in those with contraindications to calcineurin inhibitors and cytotoxic therapy. The primary outcome was change in rate of eGFR decline before and after rituximab. Complete or partial remission were defined as uPCR <30 mg/mmol or uPCR <350 mg/mmol with a ≥50% fall from baseline, respectively. Results: A total of 180 patients [median age 59 years, interquartile range (IQR) 48-68] received rituximab and were followed up for a median duration of 17 months. Seventy-seven percent had prior immunosuppression. Median eGFR and uPCR at baseline were 49.2 mL/min/1.73 m2 (IQR 34.4-80.6) and 766 mg/mmol (IQR 487-1057), respectively. The annual rate of decline of eGFR fell from 13.9 to 1.7 mL/min/1.73 m2/year following rituximab (Z score = 2.48, P < .0066). At 18 months 12% and 42% of patients were in complete or partial remission, respectively. Rituximab was well tolerated; patient survival was 95.6% at 2 years and in patients in whom eGFR was available, kidney survival was 93% at 2 years. Conclusion: Rituximab significantly reduced the rate of eGFR decline in active MN including those who had received prior immunosuppression or with poor baseline kidney function.

A randomised, two-arm (1:1 ratio), double blind, placebo controlled phase III trial to assess the efficacy, safety, cost and cost-effectiveness of Rituximab in treating de novo or relapsing NS in patients with MCD/FSGS (TURING).

BACKGROUND: Minimal Change Disease (MCD) and Focal Segmental Glomerulosclerosis (FSGS) are a spectrum of disease causing the nephrotic syndrome (NS), characterised by proteinuria with debilitating oedema, as well as a high risk of venous thromboembolic disease and infection. Untreated, 50-60% patients with FSGS progress to end stage kidney disease after 5 years. These diseases respond to immunosuppression with high dose glucocorticoids, but 75% will relapse as the glucocorticoids are withdrawn, leading to significant morbidity associated with prolonged use. In children, the B cell depleting monoclonal antibody rituximab reduces relapse risk, but this drug has not been tested in randomised controlled trial in adults. METHODS: 130-150 adults with new or relapsing MCD/FSGS, from UK Renal Units, are being randomised to receive either rituximab (two 1 g infusions two weeks apart) or placebo. Partipicipants are recruited when they present with nephrosis, and all are treated with glucocorticoids as per KDIGO guidelines. Once in remission, prednisolone is withdrawn according to a pre-specified regimen. If in remission at 6 months, participants receive a further dose of trial drug. If they relapse, they are unblinded, and if they have received placebo, they are offered open label rituximab with protocolised prednisolone as in the main phase of the trial. The primary end point is time from remission to relapse. A number of secondary endpoints will be assessed including the effect of rituximab on: (1) NHS and societal resource use and hence cost: (2) safety: (3) other measures of efficacy, such as achievement of partial and complete remission of NS and the preservation of renal function: (4) health status of participant. TRIAL REGISTRATION: TURING received ethical approval on 14 Jun 2019 - REC reference: 19/LO/0738. It is registered on EudraCT, with ID number: 2018-004611-50, with a start date of 2019-06-14.

Advances in primary glomerulonephritis.

Primary glomerulonephritis comprises several renal-limited diseases that can cause haematoproteinuria, chronic kidney disease, nephrosis and end stage kidney disease. The most common of these are IgA nephropathy (IgAN), primary membranous nephropathy (PMN), Focal Segmental Glomerulosclerosis (FSGS) and Minimal Change Disease (MCD). Although rare, these diseases cause a significant burden to health care systems, given the high cost of treating End Stage Kidney Disease (ESKD) with dialysis or transplantation. Until recently, the pathogenesis of primary gloerulonephritis has remained obscure. However, recent advances in understanding of how these diseases evolve has led to the introduction of novel therapeutic agents. Trials are underway or have recently completed that have huge implications for the standard of care for the primary glomerulonephritidies, and should dramatically reduce the number of patients who progress onto end stage kidney disease. This article reviews the international Kidney Disease Improving Global Outcomes (KDIGO) guidelines for the treatment of IgAN, PMN, FSGS and MCD, as well as recent research on pathogenesis and treatment.

Management of adult patients with podocytopathies: an update from the ERA Immunonephrology Working Group.

The histopathological lesions, minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) are entities without immune complex deposits which can cause podocyte injury, thus are frequently grouped under the umbrella of podocytopathies. Whether MCD and FSGS may represent a spectrum of the same disease remains a matter of conjecture. Both frequently require repeated high-dose glucocorticoid therapy with alternative immunosuppressive treatments reserved for relapsing or resistant cases and response rates are variable. There is an unmet need to identify patients who should receive immunosuppressive therapies as opposed to those who would benefit from supportive strategies. Therapeutic trials focusing on MCD are scarce, and the evidence used for the 2021 Kidney Disease: Improving Global Outcomes (KDIGO) guideline for the management of glomerular diseases largely stems from observational and pediatric trials. In FSGS, the differentiation between primary forms and those with underlying genetic variants or secondary forms further complicates trial design. This article provides a perspective of the Immunonephrology Working Group (IWG) of the European Renal Association (ERA) and discusses the KDIGO 2021 Clinical Practice Guideline for the Management of Glomerular Diseases focusing on the management of MCD and primary forms of FSGS in the context of recently published evidence, with a special emphasis on the role of rituximab, cyclophosphamide, supportive treatment options and ongoing clinical trials in the field.

Avacopan for ANCA-associated vasculitis with hypoxic pulmonary haemorrhage.

BACKGROUND AND HYPOTHESIS: Pulmonary haemorrhage with hypoxia caused by ANCA-associated vasculitis (AAV) has a high early mortality. Avacopan, an oral C5a receptor antagonist, is an approved treatment for AAV, but patients with pulmonary haemorrhage requiring invasive pulmonary ventilation support were excluded from the ADVOCATE trial. METHODS: A retrospective, observational, multicentre case series of AAV patients with hypoxic pulmonary haemorrhage, requiring oxygen support or mechanical ventilation, who received avacopan. RESULTS: Eight patients (62.5% female), median age 64 years (range 17-80), seven with kidney involvement, median glomerular filtration rate (GFR) 11 (range 5-99) ml/min per 1.73m2, were followed for a median of 6 months from presentation. Seven were newly diagnosed (87.5%), five were MPO-ANCA and three PR3-ANCA positive. All had hypoxia, four requiring mechanical ventilation (three invasive and one non-invasive). Intensive care unit (ICU) stay for the four patients lasted a median of 9 days (range 6-60). Four received rituximab and cyclophosphamide combination, three rituximab and one cyclophosphamide. Four underwent plasma exchange and one received two months of daily extracorporeal membrane oxygenation (ECMO) therapy. Following the initiation of avacopan after a median of 10 days (range 2-40), pulmonary haemorrhage resolved in all patients, even two who had one month of refractory pulmonary haemorrhage prior to avacopan. Additionally, after one month, the median prednisolone dose was 5 mg/day (range 0-50), with three patients successfully discontinuing steroid use. Two patients suffered serious infections, two discontinued avacopan, one permanently due to a rash and one temporarily after three months due to neutropenia. All patients survived and no re-hospitalization occurred. CONCLUSION: We report the use of avacopan as a component of the treatment for pulmonary haemorrhage with hypoxia in AAV. Despite the life-threatening presentations all patients recovered, but attribution of the positive outcomes to avacopan is limited by the concomitant therapies and retrospective observational design.

Randomized Trial on the Effect of an Oral Spleen Tyrosine Kinase Inhibitor in the Treatment of IgA Nephropathy.

Introduction: We reported increased spleen tyrosine kinase (SYK) expression in kidney biopsies of patients with IgA nephropathy (IgAN) and that inhibition of SYK reduces inflammatory cytokines production from IgA stimulated mesangial cells. Methods: This study was a double-blind, randomized, placebo-controlled phase 2 trial of fostamatinib (an oral SYK inhibitor) in 76 patients with IgAN. Patients were randomized to receive placebo, fostamatinib at 100 mg or 150 mg twice daily for 24 weeks on top of maximum tolerated dose of renin-angiotensin system inhibitors. The primary end point was reduction of proteinuria. Secondary end points included change from baseline in estimated glomerular filtration rate (eGFR) and kidney histology. Results: Although we could not detect significant reduction in proteinuria with fostamatinib overall, in a predetermined subgroup analysis, there was a trend for dose-dependent reduction in median proteinuria (from baseline to 24 weeks by 14%, 27%, and 36% in the placebo, fostamatinib 100 mg, and 150 mg groups, respectively) in patients with baseline urinary protein-to-creatinine ratios (UPCR) more than 1000 mg/g. Kidney function (eGFR) remained stable in all groups. Fostamatinib was well-tolerated. Side effects included diarrhea, hypertension, and increased liver enzymes. Thirty-nine patients underwent repeat biopsy showing reductions in SYK staining associated with therapy at low dose (-1.5 vs. 1.7 SYK+ cells/glomerulus in the placebo group, P < 0.05). Conclusions: There was a trend toward reduction in proteinuria with fostamatinib in a predefined analysis of high risk patients with IgAN despite maximal care, as defined by baseline UPCR greater than 1000 mg/g. Further study may be warranted.

Rituximab in Membranous Nephropathy.

Membranous nephropathy (MN) is the most common cause of primary nephrotic syndrome among adults. The identification of phospholipase A2 receptor (PLA2R) as target antigen in most patients changed the management of MN dramatically, and provided a rationale for B-cell depleting agents such as rituximab. The efficacy of rituximab in inducing remission has been investigated in several studies, including 3 randomized controlled trials, in which complete and partial remission of proteinuria was achieved in approximately two-thirds of treated patients. Due to its favorable safety profile, rituximab is now considered a first-line treatment option for MN, especially in patients at moderate and high risk of deterioration in kidney function. However, questions remain about how to best use rituximab, including the optimal dosing regimen, a potential need for maintenance therapy, and assessment of long-term safety and efficacy outcomes. In this review, we provide an overview of the current literature and discuss both strengths and limitations of "the new standard."

Rituximab in adult minimal change disease and focal segmental glomerulosclerosis - What is known and what is still unknown?

Primary forms of minimal change disease and focal segmental glomerulosclerosis are rare podocytopathies and clinically characterized by nephrotic syndrome. Glucocorticoids are the cornerstone of the initial immunosuppressive treatment in these two entities. Especially among adults with minimal change disease or focal segmental glomerulosclerosis, relapses, steroid dependence or resistance are common and necessitate re-initiation of steroids and other immunosuppressants. Effective steroid-sparing therapies and introduction of less toxic immunosuppressive agents are urgently needed to reduce undesirable side effects, in particular for patients whose disease course is complex. Rituximab, a B cell depleting monoclonal antibody, is increasingly used off-label in these circumstances, despite a low level of evidence for adult patients. Hence, critical questions concerning drug-safety, long-term efficacy and the optimal regimen for rituximab-treatment remain unanswered. Evidence in the form of large, multicenter studies and randomized controlled trials are urgently needed to overcome these limitations.

Effect of belimumab on proteinuria and anti-phospholipase A2 receptor autoantibody in primary membranous nephropathy.

BACKGROUND: Immunosuppressant drugs reduce proteinuria and anti-phospholipase A2 receptor autoantibodies (PLA2R-Ab) in primary membranous nephropathy (PMN) with varying success and associated toxicities. This study aimed to evaluate the effect of belimumab on proteinuria and PLA2R-Ab in participants with PMN. METHODS: In this prospective, open-label, experimental medicine study, 14 participants with PMN and persistent nephrotic-range proteinuria received up to 2 years belimumab monotherapy (10 mg/kg, every 4 weeks). Changes in proteinuria (urinary protein:creatinine ratio), PLA2R-Ab, albumin, cholesterol, B-cell subsets and pharmacokinetics were analysed during treatment and up to 6 months after treatment. RESULTS: Eleven participants completed to the primary endpoint (Week 28) and nine participants completed the study. In the intention-to-treat population population, baseline proteinuria of 724 mg/mmol [95% confidence interval (CI) 579-906] decreased to 498 mg/mmol (95% CI 383-649) and 130 mg/mmol (95% CI 54-312) at Weeks 28 and 104, respectively, with changes statistically significant from Week 36 (n = 11, P = 0.047). PLA2R-Ab decreased from 174 RU/mL (95% CI 79-384) at baseline to 46 RU/mL (95% CI 16-132) and 4 RU/mL (95% CI 2-6) at Weeks 28 and 104, respectively, becoming statistically significant by Week 12 (n = 13, P = 0.02). Nine participants achieved partial (n = 8) or complete (n = 1) remission. Participants with abnormal albumin and/or cholesterol at baseline gained normal/near normal levels by the last follow-up. Adverse events were consistent with those expected in this population. CONCLUSIONS: Belimumab treatment in participants with PMN can reduce PLA2R-Ab and subsequently proteinuria, important preludes to remission induction.

Visual loss in giant cell arteritis 3 weeks after steroid initiation.

Giant cell arteritis (GCA) is the most common vasculitis in adults and blindness is a common complication if left untreated. Oral glucocorticoids are the mainstay of treatment and if started promptly, loss of vision can usually be prevented. We present the case of a 77-year-old man who developed irreversible bilateral blindness after a confirmed diagnosis of GCA and oral steroid treatment. The roles of diagnostic delay, steroid dosing, significance of visual symptoms at diagnosis and after commencing oral glucocorticoids, and interpretation of ophthalmological signs are reviewed.

Long-term follow-up of patients who received repeat-dose rituximab as maintenance therapy for ANCA-associated vasculitis.

OBJECTIVE: ANCA-associated vasculitis (AAV) is characterized by a chronic relapsing course. Rituximab (RTX) is an effective maintenance treatment; however, the long-term outcomes after its discontinuation are unclear. The aim of this study was to explore the long-term outcomes of AAV patients treated with repeat-dose RTX maintenance therapy. METHODS: AAV patients receiving a RTX treatment protocol consisting of an induction and maintenance phase were included. For initial remission induction, RTX was dosed at 1 g every 2 weeks or 375 mg/m(2) weekly for 4 consecutive weeks and for remission maintenance at 1 g every 6 months for 24 months. At the first RTX administration, ongoing immunosuppressives were withdrawn. RESULTS: Sixty-nine patients were identified, 67 of whom were failing other therapies. Nine relapsed during the RTX treatment protocol; however, all 69 were in remission at the end of the maintenance phase on a median prednisolone dose of 2.5 mg/day and 9% were receiving additional immunosuppression. During subsequent observation, 28 patients relapsed a median of 34.4 months after the last RTX infusion. Risk factors for relapse were PR3-associated disease (P = 0.039), B cell return within 12 months of the last RTX infusion (P = 0.0038) and switch from ANCA negativity to positivity (P = 0.0046). Two patients died and two developed severe hypogammaglobulinaemia. CONCLUSION: This study supports the efficacy and safety of a fixed-interval RTX maintenance regimen in relapsing/refractory AAV. Relapses after discontinuation of maintenance therapy did occur, but at a lower rate than after a single RTX induction course. PR3-associated disease, the switch from ANCA negative to positive and the return of B cells within 12 months of the last RTX administration were risk factors for further relapse.