Early Use of Rituximab in Calcineurin Inhibitor-Refractory and Steroid-Resistant Nephrotic Syndrome

Efficacy of rituximab and risk factors for poor prognosis in patients with childhood-onset steroid-resistant nephrotic syndrome: a multicenter study

BACKGROUND

The efficacy of rituximab in steroid-resistant nephrotic syndrome (SRNS) is controversial. We previously reported that rituximab in combination with methylprednisolone pulse therapy (MPT) and immunosuppressants was associated with favorable outcomes. We determined risk factors for poor response following rituximab treatment, which remains unknown.

METHODS

This retrospective study included 45 patients with childhood-onset SRNS treated with rituximab across four pediatric kidney facilities. Treatment effects were categorized as complete remission (CR), partial remission (PR), and no remission (NR) at one year after rituximab treatment. The primary outcome was the rate of CR, PR, and NR. Risk factors for non-CR were calculated with multivariate logistic regression. Adverse events and the relationship between disease status at one year and long-term prognosis were also evaluated.

RESULTS

The rates of CR, PR, and NR at one year were 69%, 24%, and 7%, respectively. The median time from rituximab administration to CR was 90 days. The median follow-up period after rituximab administration was 7.4 years. In multivariate analysis, significant risk factors for poor response were the pathologic finding of focal segmental glomerular sclerosis and a long interval between SRNS diagnosis and rituximab administration. The rates of CR were 90.3% and 21.4% in patients receiving rituximab within and after 6 months following SRNS diagnosis, respectively (p < 0.001). Five patients developed chronic kidney disease stage G5, including 2 of the 11 patients with PR and all 3 patients with NR, whereas none of the 31 patients with CR developed chronic kidney disease stage G5.

CONCLUSION

Early administration of rituximab in combination with MPT and immunosuppressants might achieve favorable outcomes in patients with SRNS.

Rituximab/Mycophenolate Combination Therapy in Children with Calcineurin Inhibitor-Resistant FSGS

Introduction

There is a paucity of data and therapeutic options nationally and internationally on calcineurin inhibitor (CNI)-resistant forms of focal segmental glomerulosclerosis (FSGS) in children. CNI (tacrolimus or cyclosporine) are proven monotherapy in children with FSGS with a steroid-dependent (SD) or steroid-resistant (SR) course. We analyzed a novel therapeutic option in CNI-resistant FSGS by using the dual therapy of rituximab and mycophenolate to maintain remission.

Methods

This is a retrospective analysis of clinical, therapeutic profile, and treatment outcomes (sustained remission versus no remission) in subjects with CNI-resistant FSGS who received dual rituximab therapy along with mycophenolate as maintenance therapy for a minimum of 1 year.

Results

The median age of presentation of 13 recruited children was 7.8 years (range: 2.4-17.6 years); nine (69.2%) were males. Ten (76.9%) of them had an SD course and three (23.1%) had an SR course. Four (30.7%) had evidence of acute/chronic CNI toxicity, and the remaining nine (69.3%) showed no response to CNI therapy despite adequate trough levels. Post dual therapy, 11 (84.6%) had sustained remission for at 1 year and two (15.4%) children did not show remission. None reported adverse reactions or infections, and all had preserved renal functions.

Conclusion

Dual combination therapy with rituximab and mycophenolate among children with CNI-resistant FSGS can emerge as a promising and efficacious treatment strategy to ensure sustained remission in this subset of patients.

A Systematic Review and Meta-analysis of Rituximab-Associated Infections Among Children and Adolescents With Glomerular Disease: Focus on the Risk of Infections

OBJECTIVE

This systematic review and meta-analysis aimed to explore rituximab (RTX) associated infectious complications in children with glomerular disease.

METHODS

We performed an electronic search of PubMed, International Scientific Information (ISI), Scopus, and EMBASE between January 2010 and July 2021. Infection rates and total drug-related adverse events were the outcomes. Statistical heterogeneity was evaluated by using the I2 statistic. When there was statistical evidence of heterogeneity (I2 > 50%, p > 0.1), a random-effect model was adopted. Data analysis was performed with Stata17.0 software.

RESULTS

A total of 7 studies with 668 patients (136 with lupus nephritis [LN] and 532 with nephrotic syndrome were included in the meta-analysis. The pooled risk ratio showed that the administration of RTX was significantly associated with lower risk of infectious complications in patients with LN and nephrotic syndrome (0.72 [95% CI 0.58, 0.85]) when compared with population data of patients without glomerular disease (p = 0.2). There was no significant difference between the LN and nephrotic syndrome groups in terms of total serious adverse events or the occurrence of infections. There was significant heterogeneity among the reported studies (Q = 42.39, p < 0.001, I2 = 81%).

CONCLUSION

Administration of RTX in children with glomerular disease is associated with a lower rate of infections when compared with population data of patients without LN or nephrotic syndrome. Additional high-quality randomized controlled trials with long-term follow-up are needed to identify the long-term potential complications. Trial registration PROPERO ID: CRD42021274869 (https://www.crd.york.ac/prospero/display_record.php?).

Use of Rituximab in Childhood Idiopathic Nephrotic Syndrome

Rituximab is an established therapy in children with idiopathic nephrotic syndrome to sustain short- to medium-term disease remission and avoid steroid toxicities. Recent trials focus on its use as a first-line agent among those with milder disease severity. Rituximab is used in multidrug refractory nephrotic syndrome and post-transplant disease recurrence, although the evidence is much less substantial. Available data suggest that the treatment response to rituximab depends on various patient factors, dosing regimen, and the concomitant use of maintenance immunosuppression. After repeated treatments, patients are found to have an improving response overall with a longer relapse-free period. The drug effect, however, is not permanent, and 80% of patients eventually relapse and many will require an additional course of rituximab. This underpins the importance of understanding the long-term safety profile on repeated treatments. Although rituximab appears to be generally safe, there are concerns about long-term hypogammaglobulinemia, especially in young children. Reliable immunophenotyping and biomarkers are yet to be discovered to predict treatment success, risk of both rare and severe side effects, e.g. , persistent hypogammaglobulinemia, and guiding of redosing strategy. In this review, we highlight recent advances in the use of rituximab for childhood nephrotic syndrome and how the therapeutic landscape is evolving.

Rituximab, Mycophenolic Acid, and Calcineurin Inhibitors Achieve Long-Term Remission in Pediatric Focal Segmental Glomerulosclerosis with Steroid-Resistant and Frequently Relapsing Nephrotic Syndrome: A Report of Two Cases

Studies investigating the effect of rituximab in children with nephrotic syndrome (NS) due to focal segmental glomerulosclerosis (FSGS) have reported conflicting results, with some concluding that patients may require additional immunosuppressive therapy to achieve and/or maintain long-term remission. We report successful treatment of pediatric FSGS with rituximab infusions, followed by maintenance immunosuppression with mycophenolic acid (MPA) and a calcineurin inhibitor (CNI) in 1 patient with refractory steroid-resistant NS (SRNS), and one with frequently relapsing NS (FRNS). Case 1 is a patient with refractory SRNS due to FSGS. MPA and tacrolimus induced complete remission within 6 months following rituximab treatment. Remission was maintained for over 2 years, and the patient's kidney function and body height also returned to normal ranges within this time. Case 2 is a patient with FRNS due to FSGS, who was treated with rituximab followed by MPA and cyclosporine, which successfully prevented relapses for 18 months, that is, at the end point of the observation. Our case report demonstrates that rituximab and a combination of CNIs and MPA can be effective in achieving complete remission in pediatric refractory SRNS and sustaining remission in pediatric FSGS with FRNS and SRNS for several years. This treatment regimen has the advantage of eliminating the need for long-term high-dose steroid treatments, allowing 1 patient to achieve normal growth and recover from other adverse steroid effects.