Rituximab versus cyclophosphamide as first steroid-sparing agent in childhood frequently relapsing and steroid-dependent nephrotic syndrome

Immunosuppressive agents for frequently relapsing/steroid-dependent nephrotic syndrome in children: a systematic review and network meta-analysis

Aim

This study aimed to systematically compare the efficacy of various immunosuppressive agents in treating pediatric frequently relapsing or steroid-dependent nephrotic syndrome (FRSDNS).

Methods

We conducted systematic searches of PubMed, Embase, the Cochrane Library, and the Web of Science up to May 23, 2023. Outcome measures included relapses within 1 year, mean cumulative exposure to corticosteroids, patients with treatment failure at 1 year, relapse-free survival during 1 year, and adverse events. The quality of the included studies was evaluated using the modified Jadad scale, the Methodological Index for Non-Randomized Studies (MINORS), and the modified Newcastle-Ottawa Scale (NOS).

Results

Rituximab was found to be the most likely (92.44%) to be associated with the fewest relapses within 1 year and was also most likely (99.99%) to result in the lowest mean cumulative exposure to corticosteroids. Rituximab had the highest likelihood (45.98%) of being associated with the smallest number of patients experiencing treatment failure at 1 year. CsA was most likely (57.93%) to achieve the highest relapse-free survival during 1 year, followed by tacrolimus (26.47%) and rituximab (30.48%). Rituximab showed no association with serious side effects and had comparable adverse effects to ofatumumab and tacrolimus.

Conclusion

Rituximab may be the most favorable immunosuppressive agent for treating pediatric FRSDNS. Nephrologists should consider this drug, along with their clinical experience, patient characteristics, and cost considerations, when choosing a treatment approach.

Predictive factors of long-term disease remission after rituximab administration in patients with childhood-onset complicated steroid-dependent nephrotic syndrome: a single-center retrospective study

BACKGROUND

Despite the fact that rituximab (RTX)-associated adverse events may be relatively frequent in younger patients, recent studies have reported RTX as a suitable first-line steroid-sparing agent for maintaining remission in children with steroid-dependent nephrotic syndrome (SDNS). However, the impact of age at RTX initiation on the long-term outcome remains unknown in this cohort.

METHODS

We retrospectively reviewed the clinical course of 61 patients with complicated SDNS who received a single dose of RTX (375 mg/m2) followed by maintenance immunosuppressive agents (IS) from January 2008 to March 2021. In patients who achieved > 12 months of prednisolone-free remission, IS tapering within 6 months was tried to achieve. The primary endpoint was the probability of achieving long-term treatment-free remission at the last follow-up.

RESULTS

After RTX initiation, 52 patients (85.2%) relapsed after a median of 665 days, and 44 patients (72.1%) received additional RTX doses (total, 226 infusions). At the last follow-up (median observation period, 8.3 years; median age, 18.3 years), 16 patients (26.2%) achieved long-term remission. Multivariate analysis showed that older age at RTX initiation was the independent predictive factor for achieving long-term remission (odds ratio, 1.25; p < 0.05). The proportion of those who achieved long-term remission was significantly higher in patients aged ≥ 13.5 years than in those aged < 13.5 years at RTX initiation (52.6 vs 14.3%, p < 0.05). Persistent severe hypogammaglobulinemia did not develop in older children (≥ 13.5 years) at RTX initiation.

CONCLUSION

For older children with complicated SDNS, RTX appeared to be a suitable disease-modifying therapy without persistent adverse events.

Childhood nephrotic syndrome

Idiopathic nephrotic syndrome is the most common glomerular disease in children. Corticosteroids are the cornerstone of its treatment, and steroid response is the main prognostic factor. Most children respond to a cycle of oral steroids, and are defined as having steroid-sensitive nephrotic syndrome. Among the children who do not respond, defined as having steroid-resistant nephrotic syndrome, most respond to second-line immunosuppression, mainly with calcineurin inhibitors, and children in whom a response is not observed are described as multidrug resistant. The pathophysiology of nephrotic syndrome remains elusive. In cases of immune-mediated origin, dysregulation of immune cells and production of circulating factors that damage the glomerular filtration barrier have been described. Conversely, up to a third of cases of steroid-resistant nephrotic syndrome have a monogenic origin. Multidrug resistant nephrotic syndrome often leads to kidney failure and can cause relapse after kidney transplant. Although steroid-sensitive nephrotic syndrome does not affect renal function, most children with steroid-sensitive nephrotic syndrome have a relapsing course that requires repeated steroid cycles with significant side-effects. To minimise morbidity, some patients require steroid-sparing immunosuppressive agents, including levamisole, mycophenolate mofetil, calcineurin inhibitors, anti-CD20 monoclonal antibodies, and cyclophosphamide. Close monitoring and preventive measures are warranted at onset and during relapse to prevent acute complications (eg, hypovolaemia, acute kidney injury, infections, and thrombosis), whereas long-term management requires minimising treatment-related side-effects. A subset of patients have active disease into adulthood.

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.

IPNA clinical practice recommendations for the diagnosis and management of children with steroid-sensitive nephrotic syndrome

Idiopathic nephrotic syndrome is the most frequent pediatric glomerular disease, affecting from 1.15 to 16.9 per 100,000 children per year globally. It is characterized by massive proteinuria, hypoalbuminemia, and/or concomitant edema. Approximately 85-90% of patients attain complete remission of proteinuria within 4-6 weeks of treatment with glucocorticoids, and therefore, have steroid-sensitive nephrotic syndrome (SSNS). Among those patients who are steroid sensitive, 70-80% will have at least one relapse during follow-up, and up to 50% of these patients will experience frequent relapses or become dependent on glucocorticoids to maintain remission. The dose and duration of steroid treatment to prolong time between relapses remains a subject of much debate, and patients continue to experience a high prevalence of steroid-related morbidity. Various steroid-sparing immunosuppressive drugs have been used in clinical practice; however, there is marked practice variation in the selection of these drugs and timing of their introduction during the course of the disease. Therefore, international evidence-based clinical practice recommendations (CPRs) are needed to guide clinical practice and reduce practice variation. The International Pediatric Nephrology Association (IPNA) convened a team of experts including pediatric nephrologists, an adult nephrologist, and a patient representative to develop comprehensive CPRs on the diagnosis and management of SSNS in children. After performing a systematic literature review on 12 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, recommendations were formulated and formally graded at several virtual consensus meetings. New definitions for treatment outcomes to help guide change of therapy and recommendations for important research questions are given.

Oral cyclophosphamide therapy in 100 children with steroid-sensitive nephrotic syndrome: experience from a developing country

BACKGROUND

Oral cyclophosphamide (CYP) is an important therapeutic agent in treatment of steroid-sensitive nephrotic syndrome having a steroid-dependent (SD) or frequent relapsing (FR) course. This retrospective observational study aimed to determine response to oral CYP and factors associated with positive response in these patients.

METHODS

We studied 100 children (male; 75) with FR (19%) and SD (81%) NS treated with CYP in the Pediatric Nephrology clinic. Responders were defined as children in whom steroids were stopped for at least 6 months following CYP and factors affecting response were analysed. Relapse-free survival was estimated by Kaplan-Meier method.

RESULTS

Median age at onset of NS was 3 years (IQR 2-5.2). Median age at CYP was 5.7 years (IQR 3.7-7.9). Fifty percent of patients were in the responder group at 6 months of CYP. Relapse-free survival post CYP therapy was 31% at 1 year, 11% at 2 years. Factors predicting good response were age at onset of NS > 3 years with 61.2% response at 6 months (p = 0.028) and older age at CYP initiation (> 5 years) with 61% response (p = 0.008). Multivariate regression analysis showed age at start of CYP > 5 years was an independent factor for good response (p = 0.044, OR = 2.903, CI -1.03 to 8.18).

CONCLUSIONS

Judicious selection of patients, especially with age of onset of NS more than 3 years and initiation of CYP after age of 5 years, can predict better response in this group of patents.

Pediatric idiopathic steroid-sensitive nephrotic syndrome: diagnosis and therapy -short version of the updated German best practice guideline (S2e) - AWMF register no. 166-001, 6/2020

Idiopathic nephrotic syndrome is the most frequent glomerular disease in children in most parts of the world. Children with steroid-sensitive nephrotic syndrome (SSNS) generally have a good prognosis regarding the maintenance of normal kidney function even in the case of frequent relapses. The course of SSNS is often complicated by a high rate of relapses and the associated side effects of repeated glucocorticoid (steroid) therapy. The following recommendations for the treatment of SSNS are based on the comprehensive consideration of published evidence by a working group of the German Society for Pediatric Nephrology (GPN) based on the systematic Cochrane reviews on SSNS and the guidelines of the KDIGO working group (Kidney Disease - Improving Global Outcomes).

Rhabdomyosarcoma in a child with nephrotic syndrome treated with cyclosporine: a case report with literature review

Background

In patients with frequently relapsing nephrotic syndrome, immunosuppressive therapy such as cyclosporine are often required to maintain remission. Cyclosporine has been noted to have tumorgenesis effects. In this case report, we present a child with relapsing nephrotic syndrom developed a rhabdomyosarcoma on her tongue after adout 4 years of continual immunosuppressive therapy.

Case presentation

A 2-year-old female child had nephrotic syndrome (urine protein-creatinine ratio 749.1 mg/mg; blood urea nitrogen 11 mg/dL; serum creatinine 0.3 mg/dL; and serum albumin 1.8 g/dL.) Proteinuria resolved on treatment with daily prednisolone for 4 weeks at the dose of 45 mg (2.5 mg/kg/day) but recurred with taper from 25 mg/day to 10 mg/day. At least five more episodes of relapse occurred within about a 3-year period. After the third relapse, she was treated with prednisolone and cyclosporine (at initial dose of 50 mg/day [1.7 mg/kg/day]) for immunosuppression. About 4 years after the diagnosis of nephrotic syndrome had been made, an embryonal rhabdomyosarcoma developed on her tongue. The cancer was treated with TPOG-RMS-LR protocol, with vincristine, actinomycin, and cyclophosphamide. Magnetic resonance imaging scan, performed about 3 years after the start of TPOG-RMS-LR therapy, revealed complete remission of the cancer.

Conclusions

Although treatment with cyclosporine cannot be conclusively implicated as the cause the rhabdomyosarcoma in this patient, the association should prompt consideration of its use in the treatment of frequently relapsing nephrotic syndrome in children.