Ofatumumab treatment for nephrotic syndrome recurrence after pediatric renal transplantation

Clinical characteristics and favorable treatment responses of recurrent focal segmental glomerulosclerosis or steroid-resistant nephrotic syndrome in children after kidney transplantation

BACKGROUND

Recurrence of focal segmental glomerulosclerosis (FSGS) or steroid-resistant nephrotic syndrome (SRNS) after kidney transplant leads to significant morbidity and potentially earlier allograft loss. To date however, reported rates, risk factors and treatment outcomes have varied widely.

METHODS

We applied computational phenotypes to a multicenter aggregation of electronic health records data from 7 large pediatric health systems in the USA, to identify recurrence rates, risk factors, and treatment outcomes. We refined the data collection by chart review.

RESULTS

From > 7 million patients, we compared children with primary FSGS/SRNS who received a kidney transplant between 2009 and 2020 and who either developed recurrence (n = 67/165; 40.6%) or did not (n = 98/165). Serum albumin level at time of transplant was significantly lower and recipient HLA DR7 presence was significantly higher in the recurrence group. By 36 months post-transplant, complete remission occurred in 58.2% and partial remission in 17.9%. Through 6 years post-transplant, no remission after recurrence was associated with an increased risk of allograft loss over time (p < 0.0001), but any remission showed similar allograft survival and function decline to those with no recurrence. Since treatments were used in non-random fashion, using spline curves and multivariable non-linear analyses, complete + partial remission chance was significantly higher with greater plasmapheresis sessions, CTLA4-Ig doses or LDL-apheresis sessions. Only treatment with anti-CD20, CTLA4-Ig agents, or LDL-apheresis sessions were associated with complete remission. Excluding 25 patients with mutations did not significantly change our results.

CONCLUSIONS

Our contemporary high-risk cohort had higher favorable response rates than most prior reports, from combinations of agents.

Current approaches to overcome recurrent focal segmental glomerulosclerosis after kidney transplantation

PURPOSE OF REVIEW

Recurrent focal segmental glomerulosclerosis (FSGS) presents with nephrotic syndrome shortly after kidney transplantation. This review will overview the role of circulating permeability factors in disease pathogenesis and treatment options for recurrent FSGS.

RECENT FINDINGS

Novel circulating permeability factors have been identified in serum samples. Current research is focused on detection of permeability factors as a marker of treatment response. Furthermore, novel monoclonal antibodies are being utilized to further induce remission.

SUMMARY

Posttransplant recurrent FSGS can have a deleterious effect on allograft. Early detection of disease recurrence with prompt treatment is optimal for clinical remission. Plasmapheresis with anti-B cell therapy is considered the mainstay of treatment. Newer B cell therapies and detection of circulating factors in serum may help in providing targeted treatment in a subset of patients.

Pathogenesis and management of immune dysfunction secondary to B cell haematological malignancies

Malignancies of the B-lymphocyte lineage are among the most diagnosed haematological malignancies in clinical practice. In our community, multiple myeloma (MM) and its precursor condition monoclonal gammopathy of undetermined significance are the commonest, accounting for ~12% of diagnoses, followed by chronic lymphocytic leukaemia (CLL) and its precursor condition monoclonal B lymphocytosis, ~9%. Along with diffuse large B cell lymphoma, follicular lymphoma and marginal zone lymphoma, these conditions comprise around a third of all haematological malignancies diagnosed. Infection remains an important cause of mortality and morbidity in the management of patients with these conditions. This is in part treatment-related but also reflective of disease-related immune dysfunction. Infectious complications account for up to 50% of early mortality in patients with myeloma and up to 50% of all mortality in patients with CLL. A variety of strategies are available to decrease the morbidity and mortality of infectious complications; however, practices vary between countries and often between treating physicians. Treatment options have evolved significantly over the last decade, with the introduction of monoclonal antibodies, small molecule inhibitors, second- and third-generation immunomodulatory agents and CAR-T cell therapy. Much of the data that inform clinical practice in infection management predates current therapeutic approaches. This is in part because of the rapid development of new therapies but also reflective of the long natural history of many of these diseases and the need for prolonged periods of observation. In this article, we review the aspects of disease and treatment that contribute to immune dysfunction in MM, CLL and B-cell non-Hodgkin lymphoma and review the current strategies used to manage immune dysfunction and infection.

Biologics in steroid resistant nephrotic syndrome in childhood: review and new hypothesis-driven treatment

Nephrotic syndrome affects about 2-7 per 100,000 children yearly and accounts for less than 15% of end stage kidney disease. Steroids still represent the cornerstone of therapy achieving remission in 75-90% of the cases The remaining part result as steroid resistant nephrotic syndrome, characterized by the elevated risk of developing end stage kidney disease and frequently presenting disease recurrence in case of kidney transplant. The pathogenesis of nephrotic syndrome is still far to be elucidated, however, efficacy of immune treatments provided the basis to suggest the involvement of the immune system in the pathogenesis of the disease. Based on these substrates, more immune drugs, further than steroids, were administered in steroid resistant nephrotic syndrome, such as antiproliferative and alkylating agents or calcineurin inhibitors. However, such treatments failed in inducing a sustained remission. In last two decades, the developments of monoclonal antibodies, including the anti-CD20 rituximab and inhibitor of B7-1 abatacept, represented a valid opportunity of treatment. However, also the effectiveness of biologics resulted limited. We here propose a new hypothesis-driven treatment based on the combining administration of rituximab with the anti-CD38 monoclonal antibody daratumumab (NCT05704400), sustained by the hypothesis to target the entire B-cells subtypes pool, including the long-lived plasmacells.

[Diagnosis and treatment of focal-segmental glomerulosclerosis-2023]

The histopathological term focal-segmental glomerulosclerosis comprises different pathogenic processes with the unifying features of a high proteinuria and the name-giving glomerular lesion pattern seen on light microscopy. A differentiation according to the underlying cause into primary, secondary and genetic forms is therefore of utmost importance. The pathogenesis of primary focal-segmental glomerulosclerosis remains unknown but, like minimal-change disease, an autoimmune-mediated process leading to podocyte damage is assumed. Consequently, the unifying term "podocytopathy" is increasingly being used for both entities. Supportive treatment measures to preserve kidney function are important in all subtypes. In contrast, immunosuppressive treatment is only indicated in primary focal-segmental glomerulosclerosis. Steroid-dependence, steroid-resistance and frequently relapsing disease often complicate disease management and necessitate alternative treatment strategies. Here, the Austrian Society of Nephrology (ÖGN) provides consensus recommendations on how to best diagnose and manage patients with focal-segmental glomerulosclerosis.

Implications of rituximab pharmacokinetic and pharmacodynamic alterations in various immune-mediated glomerulopathies and potential anti-CD20 therapy alternatives

The specific B-cell depleting anti-CD20 monoclonal antibody rituximab (RTX) is effective in terms of the treatment of various immune-mediated glomerulopathies. The administration of RTX has been shown to be reliable and highly effective particularly in patients with ANCA-associated vasculitis, which is manifested predominantly with non-nephrotic proteinuria. Stable long-term B-cell depletion is usually readily attained in such patients using standard dosing regimens. However, in patients with nephrotic syndrome and non-selective proteinuria, the RTX pharmacokinetics is altered profoundly and RTX does not maintain high enough levels for a sufficiently long period, which may render RTX treatment ineffective. Since complement-derived cytotoxicity is one of the important modes of action of RTX, hypocomplementemia, frequently associated with systemic lupus erythematodes, may act to hamper the efficacy of RTX in the treatment of patients with lupus nephritis. This review provides a description of RTX pharmacokinetics and pharmacodynamics in several selected glomerulopathies, as well as the impact of proteinuria, anti-drug antibodies and other clinical variables on the clearance and volume of distribution of RTX. The impact of plasmapheresis and peritoneal dialysis on the clearance of RTX is also discussed in the paper. A review is provided of the potential association between pharmacokinetic and pharmacodynamic alterations in various kidney-affecting glomerular diseases, the sustainability of B-cell depletion and the clinical efficacy of RTX, with proposals for potential dosing implications. The role of therapeutic drug monitoring in treatment tailoring is also discussed, and various previously tested RTX dosing schedules are compared in terms of their clinical and laboratory treatment responses. Since alternative anti-CD20 molecules may prove effective in RTX unresponsive patients, their pharmacokinetics, pharmacodynamics and current role in the treatment of glomerulopathies are also mentioned.

The immunopathogenesis of idiopathic nephrotic syndrome: a narrative review of the literature

Idiopathic nephrotic syndrome (INS) is a common glomerular disease in childhood, and the immunological involvement in the pathogenesis of non-genetic INS, although not fully elucidated, is evident. This narrative review aims to offer a concise and in-depth view of the current knowledge on the immunological mechanisms of the development of INS as well as the role of the immunological components of the disease in the responsiveness to treatment. T cell immunity appears to play a major role in the INS immunopathogenesis and has been the first to be linked to the disease. Various T cell immunophenotypes are implicated in INS, including T-helper-1, T-helper-2, T-helper-17, and T regulatory cells, and various cytokines have been proposed as surrogate biomarkers of the disease; however, no distinct T helper or cytokine profile has been conclusively linked to the disease. More recently, the recognition of the role of B cell mediated immunity and the various B cell subsets that are dysregulated in patients with INS have led to new hypotheses on the underlying immunological causes of INS. Finally, the disambiguation of the exact mechanisms of the INS development in the future may be the key to the development of more targeted personalized approaches in managing INS.

CONCLUSIONS

INS demonstrates particularly interesting immunopathogenetic pathways, in which multiple interactions between T cell and B cell immunity and the podocyte are involved. The disambiguation of these pathways will provide promising novel therapeutic targets in INS.

WHAT IS KNOWN

• INS is the most common glomerular disease in the paediatric population, and its onset and relapses have been linked to various immunological triggers. • Multiple immunological mechanisms have been implicated in the pathogenesis of INS; however, no single distinct immunological profile has been recognized.

WHAT IS NEW

• Th17 cells and Treg cells play an important role in the immune dysregulation in INS. • Transitional B cell levels as well as the transitional/memory B cell ratio have been correlated to nephrotic relapses and have been proposed as biomarkers of INS relapses in SSNS patients.

Use of ofatumumab and eplerenone in post-transplant recurrence of FSGS

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) predisposes patients for risk of recurrent disease in allografts.

METHODS

We report a case of a recipient of an unrelated living donor renal transplant and discuss considerations for utilization of ofatumumab and eplerenone in treatment for recurrent FSGS.

RESULTS

The recipient was initially managed with scheduled plasmapheresis, intravenous immunoglobulin (IVIG), and rituximab post-transplant during index hospitalization. With notable recurrence of FSGS noted on kidney transplant biopsy, she was initially treated with additional plasmapheresis sessions leading to downtrend in proteinuria. The patient was then transitioned to LDL-A pheresis, which resulted again in uptrend in proteinuria. This prompted return to scheduled plasmapheresis sessions weekly, leading again to a downtrend in proteinuria. Albumin levels remained within normal range throughout her course. Following initiation of eplerenone and ofatumumab, the patient demonstrated normalization of urine protein:creatinine ratio and remission of FSGS recurrence without need for additional apheresis.

CONCLUSIONS

With notable risk of recurrence of FSGS in kidney transplants leading to allograft failure, the use of ofatumumab and eplerenone in conjunction should be considered for management to induce remission.

New and Old Anti-CD20 Monoclonal Antibodies for Nephrotic Syndrome. Where We Are?

Nephrotic proteinuria is the hallmark of several glomerulonephritis determined by different pathogenetic mechanisms, including autoimmune, degenerative and inflammatory. Some conditions such as Minimal Change Nephropathy (MCN) and Focal Segmental Glomerulosclerosis (FSGS) are of uncertain pathogenesis. Chimeric anti-CD20 monoclonal antibodies have been used with success in a part of proteinuric conditions while some are resistant. New human and humanized monoclonal anti-CD 20 antibodies offer some advantages based on stronger effects on CD20 cell subtypes and have been already administered in hematology and oncology areas as substitutes of chimeric molecules. Here, we revised the literature on the use of human and humanized anti-CD 20 monoclonal antibodies in different proteinuric conditions, resulting effective in those conditions resistant to rituximab. Literature on the use of human anti-CD 20 monoclonal antibodies in different proteinuric diseases is mainly limited to ofatumumab, with several protocols and doses. Studies already performed with ofatumumab given in standard doses of 1,500 mg 1.73m² suggest no superiority compared to rituximab in children and young adults with steroid dependent nephrotic syndrome. Ofatumumab given in very high doses (300 mg/1.73m² followed by five infusion 2,000 mg/1.73 m²) seems more effective in patients who are not responsive to common therapies. The question of dose remains unresolved and the literature is not concordant on positive effects of high dose ofatumumab in patients with FSGS prior and after renal transplantation. Obinutuzumab may offer some advantages. In the unique study performed in patients with multidrug dependent nephrotic syndrome reporting positive effects, obinutuzumab was associated with the anti-CD38 monoclonal antibody daratumumab proposing the unexplored frontier of combined therapies. Obinutuzumab represent an evolution also in the treatment of autoimmune glomerulonephritis, such as membranous nephrotahy and lupus nephritis. Results of randomized trials, now in progress, are awaited to add new possibilities in those cases that are resistant to other drugs. The aim of the present review is to open a discussion among nephrologists, with the hope to achieve shared approaches in terms of type of antibodies and doses in the different proteinuric renal conditions.

UK experience of ofatumumab in recurrence of focal segmental glomerulosclerosis post-kidney transplant

BACKGROUND

Steroid-resistant nephrotic syndrome (SRNS), commonly caused by focal segmental glomerulosclerosis (FSGS), is associated with progression to stage 5 chronic kidney disease, requirement for kidney replacement therapy and a risk of disease recurrence post-kidney transplantation. Ofatumumab (OFA) is a fully humanised monoclonal antibody to CD20, with similar mechanisms of action to rituximab (RTX).

METHODS

We report a case series of seven UK patients (five paediatric, two adult), all of whom developed FSGS recurrence after kidney transplantation and received OFA as part of their therapeutic intervention. All also received concomitant plasmapheresis. The 2-year outcome of these seven patients is reported, describing clinical course, kidney function and proteinuria.

RESULTS

Four patients (all paediatric) achieved complete urinary remission with minimal proteinuria 12 months post-treatment. Three of those four also had normal graft function. Two patients showed partial remission-brief improvement to non-nephrotic proteinuria (197 mg/mmol) in one patient, maintained improvement in kidney function (estimated glomerular filtration rate 76 ml/min/1.73 m²) in the other. One patient did not demonstrate any response.

CONCLUSIONS

OFA may represent a useful addition to therapeutic options in the management of FSGS recurrence post-transplantation, including where RTX has shown no benefit. Concomitant plasmapheresis in all patients prevents any definitive conclusion that OFA was the beneficial intervention.

Clinical practice recommendations for recurrence of focal and segmental glomerulosclerosis/steroid-resistant nephrotic syndrome

Recurrence of primary disease is one of the major risks for allograft loss after pediatric RTx. The risk of recurrence of FSGS/SRNS after pediatric RTx in particular can be up to 86% in idiopathic cases. There is a need for consensus recommendations on its prevention and treatment. The CERTAIN study group has therefore performed a thorough literature search based on the PICO model of clinical questions to formulate educated statements to guide the clinician in the process of decision-making. A set of educated statements on prevention and treatment of FSGS/SRNS after pediatric RTx has been generated after careful evaluation of available evidence and thorough panel discussion. We do not recommend routine nephrectomy prior to transplantation; neither do we recommend abstaining from living donation. Special attendance needs to be given to those patients who had already experienced graft loss due to FSGS/SRNS recurrence. Early PE or IA with or without high-dose CsA and/or rituximab seems to be most promising to induce remission. The educated statements presented here acknowledge that FSGS/SRNS recurrence after pediatric RTx remains a major concern and is associated with shorter graft survival or even graft loss. The value of any recommendation needs to take into account that evidence is based on cohorts that differ in ethnicity, pre-transplant history, immunosuppressive regimen, definition of recurrence (eg, clinical and/or histological diagnosis) and treatment modalities of recurrence.