Rituximab for Steroid-Dependent or Frequently Relapsing Idiopathic Nephrotic Syndrome in Adults: A Retrospective, Multicenter Study in Spain

Emerging role of Rituximab in adult minimal change disease: a narrative review of clinical evidence, biomarkers and future perspectives

Minimal change disease (MCD) represents a significant cause of nephrotic syndrome in adults, traditionally managed with corticosteroids despite substantial relapse rates. This review critically evaluates the emerging role of rituximab (RTX) in adult MCD management, synthesizing current evidence across multiple clinical scenarios. Recent studies demonstrate RTX's multifaceted efficacy, particularly in new-onset cases and steroid-dependent/frequently relapsing patients, with the discovery of anti-nephrin antibodies providing unprecedented insights into MCD pathogenesis. RTX's therapeutic mechanisms involve anti-nephrin antibody depletion, T-cell subset modulation, and direct podocyte protection, showing encouraging complete remission rates and substantially reduced relapse rates. While RTX offers a more favorable safety profile compared to long-term corticosteroid therapy, current evidence remains predominantly based on retrospective studies with limited sample sizes. Critical research priorities include large-scale prospective trials, standardization of treatment protocols, and further investigation of anti-nephrin antibodies as therapeutic targets. This review provides evidence-based insights for clinical decision-making while highlighting crucial areas for future investigation in RTX-based MCD management.

Long-term efficacy of Rituximab in steroid dependent and frequent relapsing adult nephrotic syndrome

BACKGROUND

Corticosteroids are highly efficient for treatment of minimal change disease (MCD), however a substantial number of patients become steroid dependent (SD) or frequent relapsing (FR). Response rate is lower in primary Focal Segmental Glomerulosclerosis (FSGS). Since prolonged exposure to corticosteroids should be avoided, an effective alternative is required. Rituximab is a promising agent. We aimed to evaluate the efficacy of Rituximab in adults with SD/FR nephrotic syndrome (NS).

METHODS

A retrospective cohort study, evaluating patients with SD/FR NS treated with Rituximab in a tertiary hospital. Rituximab was given at induction, with additional doses subjected to the treating nephrologist decision. Primary outcome was number of relapses and time to first relapse. Safety was assessed.

RESULTS

Twenty-one adults were included. Among them, 14 (66.7%) were diagnosed with MCD, 5 (23.8%) with FSGS, in 2 cases kidney biopsies were not performed. Median age was 54.6 years. Median follow up was 39.6 months. Number of relapses decreased significantly after Rituximab compared to before treatment (median relapses 0 compared to 3, respectively, W = 3.70, p <.001). Time to first relapse was significantly shorter before Rituximab compared to after (median 11 vs. 536 days, respectively, W = 3.05, p =.002). Hazzard Ratio for relapse was higher in patients who received one Rituximab course compared to those who received an additional maintenance (HR = 4.31, 95% CI: 1.13-16.39, p =.032). Treatment was well-tolerated, serious adverse events included cholecystitis and severe COVID-19.

CONCLUSIONS

Rituximab emerges as an efficient safe steroid sparing in patients with SD/FR NS, with longer remission achieved when an additional maintenance dose is given after the first course.

Rituximab-associated adverse events in nephrotic syndrome: A systematic review and meta-analysis

Objective

Rituximab (RTX) has been recommended to treat nephrotic syndrome (NS), but its safety has not been quantitatively analyzed.

Methods

PubMed, Embase, and the Cochrane Register of Controlled Trials databases were searched from inception to December 31, 2023, for randomized control trials (RCTs) and retrospective studies reporting the adverse events (AEs) related to RTX for treating NS. Data were expressed as odds ratios (OR) and risk difference (RD) with 95 % confidence interval (CI). Heterogeneity was identified using the Cochrane Q test and quantified by the I 2 statistic.

Results

Ten RCTs and five retrospective studies with 1231 patients were enrolled. RTX significantly reduced the risk of total AEs (OR = 0.32, 95 % CI [0.13, 0.78]) compared to the non-RTX group in retrospective studies but was not in RCTs. The pooled rate of infusion reactions was 32 % (95 % CI = [19 %, 45 %]) in RCTs and 8 % (95 % CI = [3 %, 13 %]) in retrospective studies. Subgroup analyses demonstrated a lower risk of hematological events in adult NS patients (OR = 0.21, 95 % CI [0.09, 0.51]) and the 1000 mg RTX intervention (OR = 0.21, 95 % CI [0.09, 0.51]). There is no significant difference in serious AEs, infection, gastrointestinal, renal, cardiovascular, and cancer events between the two groups.

Conclusion

RTX reveals great potential in terms of safety compared to non-RTX treatments due to the relatively few AEs in our results. However, the interaction of other drugs needs to be monitored. The safety of RTX in NS patients needs to be further confirmed in high-quality clinical trials.

Immunosuppression for adult steroid-dependent or frequently relapsing nephrotic syndrome: A systematic review and meta-analysis

OBJECTIVE

There is limited evidence on which immunosuppressive agents produce the best outcomes for adult patients with steroid-dependent or frequently relapsing nephrotic syndrome (SDNS/FRNS). This review compares the remission rate and adverse effects of various immunosuppressants used.

METHODS

Studies of adult patients with biopsy-proven SDNS/FRNS, administered any immunosuppressive agents and reported complete remission results as one of the clinical outcomes were included. Articles were independently screened by two researchers. ROBINS-I was used for risk of bias assessment. Random-effects model was used for statistical analysis and corresponding 95% confidence intervals (CIs) were calculated.

RESULTS

574 patients across 28 studies were included in the analysis. Patients receiving rituximab have a complete remission rate of 89% (95% CI = 83% to 94%; τ2 = 0.0070; I2 = 62%; overall p < 0.01, low certainty) and adverse event rate of 0.26, cyclosporine (CR 40%; 95% CI = 21% to 59%; τ2 = 0.0205; I2 = 55%; overall p = 0.08, low certainty), tacrolimus (CR 84%; 95% CI = 70% to 98%; τ2 = 0.0060; I2 = 33%; overall p = 0.21, moderate certainty), mycophenolate mofetil (CR 82%; 95% CI = 74% to 90%; τ2 < 0.0001; I2 = 15%; overall p = 0.32, moderate certainty) and cyclophosphamide (CR 79%; 95% CI = 69% to 89%; τ2 = 0; I2 = 0%; overall p = 0.52, moderate certainty).

CONCLUSION

Among the commonly used immunosuppressive agents, only rituximab has a statistically significant effect in achieving complete remission among patients with SDNS/FRNS and has a relatively good safety profile, but this is limited by low quality of evidence with high degree of heterogeneity causing a lack of statistical power.

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.

Review of the Role of Rituximab in the Management of Adult Minimal Change Disease and Immune-Mediated Focal and Segmental Glomerulosclerosis

Background

Minimal change disease and primary FSGS are podocytopathies but are also immune-mediated diseases. Rituximab acts via multiple mechanisms by tilting the balance between autoreactive B and T cells in favor of regulatory B and T cells. The consequences are decreased production of cytokines, chemokines, and permeability factors by these cells. In the past decade, we have seen the discovery of autoantibodies mediating nephrotic syndrome (anti-annexin A2 antibody, anti-UCHL1 antibody, and anti-nephrin antibody), and rituximab decreases their production. Rituximab also binds to podocyte SMPDL3b and has direct podocyte actions.

Summary

Rituximab's role in managing these primary podocytopathies has been discussed in this brief review. Rituximab has been used extensively in children and adults with frequently relapsing and steroid-dependent nephrotic syndrome. However, rituximab is not very promising in adult steroid-resistant nephrotic syndrome. Although ofatumumab would cause prolonged B-cell depletion and is fully humanized, it is unclear if it is superior to rituximab in preventing relapse of nephrotic syndrome.

Key Messages

Rituximab therapy can induce prolonged remission in adults with frequently relapsing and steroid-dependent nephrotic syndrome. However, no good data exist on using rituximab in steroid-resistant nephrotic syndrome.

The Role of Rituximab in Primary Focal Segmental Glomerular Sclerosis of the Adult

INTRODUCTION

Primary focal segmental glomerular sclerosis (FSGS) is a rare, likely immune-mediated disease. Rituximab (RTX) may play a role in management, although data in adults are scanty.

METHODS

We collected cases of RTX-treated primary FSGS within the Italian Society of Nephrology Immunopathology Working Group and explored response rate (24-hour proteinuria <3.5 g and <50% compared with baseline, stable estimated glomerular filtration rate).

RESULTS

A total of 31 patients were followed for at least 12 months; further follow-up (median 17 months, interquartile range [IQR] 15-33.5) was available for 11. At first RTX administration, median creatinine and 24-hour proteinuria were 1.17 mg/dl (IQR 0.83-1.62) and 5.2 g (IQR 3.3-8.81), respectively. Response rate at 3, 6, and 12 months was 39%, 52%, and 42%, respectively. In the first 12 months, creatinine level remained stable whereas proteinuria and serum albumin level improved, with an increase in the proportion of patients tapering other immunosuppressants. There were 6 patients who were retreated with RTX within 12 months, either for proteinuria increase or refractory disease; only the 2 responders to the first RTX course experienced a further response. At univariate analysis, 6-month response was more frequent in steroid-dependent patients (odds ratio [OR] 7.7 [95% CI 1.16-52.17]) and those with proteinuria <5 g/24 h (OR 8.25 [1.45-46.86]). During long-term follow-up, 4 of 5 responders at 12 months maintained a sustained response, either without further immunosuppression (2 of 4) or with pre-emptive RTX (2 of 4); 1 relapsed and responded to RTX retreatment.

CONCLUSION

RTX may be an option in primary FSGS, especially in steroid-dependent patients, with 24-hour proteinuria <5 g and previously responders to RTX. Optimal long-term management for responders is unclear, with some patients experiencing sustained remission and others requiring RTX retreatment, either preemptive or after rising proteinuria.

Extended infusion of rituximab combined with steroids is effective in inducing remission and reducing relapse in adult minimal change disease

Background

Minimal change disease is a common cause of nephrotic syndrome in adults. Higher relapse rate put patients at risk of steroids toxicity due to long-term exposure. Rituximab has been suggested to maintain long time remission and withdraw steroids and other immunosuppressants with fewer adverse events. However, optimal dose and dosing interval have not been explored.

Methods

Twenty-five patients were enrolled from 2017-10 to 2020-03 in Nanfang Hospital in China. Clinical and biological data were extracted from medical records and laboratory databases. Therapy composed of 375mg/m² rituximab once three weeks for 3 dose and corticosteroid was applied. Complete remission was defined as reduction of proteinuria to 0.3g/d. Remission rate, relapse rate, steroids used before and after rituximab therapy and adverse effects were documented at a mean time of 14.71 months.

Results

Twenty-two patients achieved complete remission for an average of 3.26 months and only 3 patients experienced one relapse respectively during the follow-up period. The mean remission maintenance time was 11.6 months, and was 5 months after steroids withdrawal. Steroids dose at last follow-up was 6.09mg/d, which was significantly reduced compared to 28.15mg/d before rituximab. Relapse rate before and after rituximab was 1.43 and 0.1, respectively. Only four minor adverse events were recorded.

Conclusions

Therapy consisted of 375mg/m² rituximab once three weeks for 3 dose combined with corticosteroid is effective in inducing remission in adult patients with minimal change disease. Both of the relapse rate and dose of steroids used are significantly decreased with fewer side effects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02437-4.

Consolidation Treatment and Long-Term Prognosis of Rituximab in Minimal Change Disease and Focal Segmental Glomerular Sclerosis

Purpose

There is currently a lack of studies investigating long-term prognosis and the necessity of further rituximab (RTX) consolidation treatment for minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS). The aim of this study was to evaluate the efficacy of RTX for these diseases and to investigate whether a consolidation treatment can lower risks of relapse and reinforce long-term remission.

Patients and Methods

A retrospective study was conducted. The relapse and remission of 70 patients treated with 1 course of RTX treatment (4 infusions of 375 mg/m2) over a median follow-up time of 27 months (12–60 months) were analyzed. The rates of patients that were able to achieve non-relapse for a duration of 24 months between RTX consolidation therapy and non-consolidation therapy were compared.

Results

There were 67 cases (95.71%) of remission and 3 cases (4.29%) of non-remission. The average number of relapses decreased from 3.7±2.5 times before the treatment to 0.8±1.8 times after treatment (P <0.001). The average avannual number of relapses decreased from 1.3±1.2 times/year to 0.2±0.3 times/year (P <0.001). The results from the Cox proportional-hazards model showed that the risk of relapse in patients who received RTX non-consolidation treatment was significantly higher than those with consolidation treatment (odds ratios (OR) 20.9, 95% confidence intervals (CI) OR 5.7–75.7, p<0.001). The 24-month relapse-free rate was also significantly higher in patients with consolidation therapy compared with non-consolidation therapy (86.36% vs 25%, p<0.001). No adverse events were recorded.

Conclusion

RTX is highly effective in treating MCD and FSGS, and RTX consolidation therapy may be recommended to reinforce long-term remissions.

Efficacy and safety of rituximab in adult frequent-relapsing or steroid-dependent minimal change disease or focal segmental glomerulosclerosis: a systematic review and meta-analysis

Background

The efficacy and safety of rituximab (RTX) in adult frequent-relapsing (FR) or steroid-dependent (SD) nephrotic syndrome (NS), including minimal change disease (MCD) or focal segmental glomerulosclerosis (FSGS), are still inconclusive.

Methods

We performed a systematic review and meta-analysis registered in  PROSPERO (CRD42019148102) by pooling data of cohort studies or case series on adult patients with difficult-to-treat NS. Steroid-resistant NS was excluded. The primary outcomes were the complete remission (CR) rate and the relapse rate. Partial remission (PR) rate, no response (NR) rate and adverse events were the secondary outcomes. A random-effects model was performed for all the outcomes.

Results

We included 21 studies involving 382 adult MCD/FSGS subjects with a median follow-up duration from 12 to 43 months. RTX treatment induced a pooled 84.2% CR rate [95% confidence interval (CI): 67.7–96.3%], while MCD patients had a high 91.6% CR rate and FSGS patients a moderate 43% CR rate. However, 27.4% (95% CI 20.7–34.5%) of the patients relapsed during the follow-up. The pooled PR and NR rates were 5.8% (95% CI 1.2–12.5%) and 5.2% (95% CI 0.0–15.0%), respectively. RTX was associated with trivial adverse events and good tolerance.

Conclusions

In summary, by pooling results of current pilot studies, RTX may be an effective and relatively safe alternative for most adult FR or SD MCD/FSGS to displace calcineurin inhibitors or prednisone in the hierarchy of treatment. More clinical trials comparing RTX with other immunosuppressants and concerning the long-term adverse events are needed.

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.

Rituximab in maintaining remission in adults with podocytopathy

Rituximab is currently used after the conventional agents have failed in the management of steroid-dependent (SD)/ steroid-resistant (SR) podocytopathies and have a safer toxicity profile. We report 53 adults with podocytopathies who were managed effectively with CD19-targeted rituximab therapy.

METHODS

This was a prospective study carried out at a tertiary care centre in India between January 2014 and June 2019. Adults between 16 and 60 years with SD, frequently relapsing (FR), and SR nephrotic syndrome (NS) due to podocytopathy received rituximab in a CD19-targeted approach.

PRIMARY OUTCOME

Percentage of patients who were in remission at 6 and 12 months. Secondary outcome: Percentage of patients in remission at the last follow-up, rituximab dose and adverse events of rituximab therapy.

RESULTS

Fifty-three adults with SD/FR/SR NS received CD19-targeted rituximab. The median age at the time of first rituximab injection was 30.09 ± 13.21 (16.53) years. At the time of first rituximab infusion, all patients were in remission with steroids and/or calcineurin inhibitors (CNIs). Fifty (94.33%) patients were in remission at the end of 6 and 12 months and the last follow-up (median: 36 months). The mean total dose of rituximab at 1 year was 788.7 ± 128.1 (6 001 100) mg. At last follow-up (median 36 months), 42 (79%) patients did not require any additional CNI or steroids therapy. No serious adverse events to rituximab were noted.

CONCLUSION

CD19-targeted rituximab therapy is safe and efficacious in the management of SD/SR adult podocytopathy. Also, rituximab is effective in maintaining remission in treatment naïve adult SD or FR podocytopathy.

The efficacy of rituximab in the treatment of refractory nephrotic syndrome: a meta-analysis

OBJECTIVE

The evidence from epidemiological research on whether the efficacy of rituximab in treatment of refractory nephrotic syndrome (NS) is better than other agents is inconsistent. This meta-analysis aimed to assess the efficacy of rituximab in the treatment of NS compared with other immunosuppressive agents.

METHODS

Relevant literatures were identified and evaluated for quality before October 2019 through multiple search strategies on PubMed and EMBASE. Statistical evidence of the symmetry of the funnel plot obtained from Begg's test was indicated by Egger's linear regression and a sensitivity analysis identified heterogeneity. A fixed- or a random-effects model was applied to calculate the pooled SMDs and RRs.

RESULTS

A total of 12 studies, involving 383 patients and 354 controls, were included. Compared with other agents, rituximab significantly improved complete remission both in children and adults [Overall: RR = 1.313, 95% CI = 1.170-1.475, P < 0.001; Adult: RR = 1.359, 95% CI = 1.053-1.753, P = 0.019 Children: RR = 1.354, 95% CI = 1.072-1.709, P < 0.001], and dramatically decreased the relapse rate in children [Overall: RR = 0.349, 95% CI = 0.166-0.732, P < 0.001; Children: RR = 0.286, 95% CI = 0.176-0.463, P < 0.001].

CONCLUSIONS

Rituximab might be a promising treatment for refractory NS. Compared with other agents, rituximab significantly improves the complete remission and decreased the relapse rate. However, to confirm the efficacy of rituximab in the treatment of refractory NS, more high-quality, large sample, and multicenter randomized controlled trials are needed.