Daratumumab-based therapy for patients with monoclonal gammopathy of renal significance

Daratumumab for Bortezomib-Refractory Proliferative Glomerulonephritis With Monoclonal Immunoglobulin Deposits in Kidney Allograft: A Case Report

Despite treatment with immunosuppressive or clone-targeted chemotherapy, patients with proliferative glomerulonephritis with monoclonal immunoglobulin deposit (PGNMID) frequently progress into end-stage kidney failure, and early recurrence of PGNMID after kidney transplantation is common. The standard management of PGNMID has been unclear, currently based on data from small cohorts, which requires a need for additional therapeutic regimens in this disease. A human IgG monoclonal antibody that targets CD38 (daratumumab) was recently identified as a potential therapeutic option for treating PGNMID. To date, rare data on the application of daratumumab in patients with PGNMID after kidney transplantation have been reported. Herein, we first described a unique patient with recurrent PGNMID in kidney allograft who was treated with daratumumab after not responding to bortezomib-based regimens. Daratumumab was shown to successfully reduce proteinuria with stabilizing kidney function and was well-tolerated in this patient, which supports that daratumumab appears to be a viable option for treatment-resistant PGNMID.

Renal manifestations of MGUS

Kidney disease is a common complication of monoclonal immunoglobulin (MIg)-secreting B-cell disorders and predominantly occurs in patients who do not meet the criteria for an overt hematological disease. To distinguish this situation from monoclonal gammopathy of undetermined significance, which lacks organ damage, the term monoclonal gammopathy of renal significance (MGRS) was introduced to depict the association of a small, otherwise indolent B-cell clone, with renal disease induced by the secreted MIg. The spectrum of renal disorders in MGRS is wide, encompassing both tubular and glomerular disorders, classified according to the composition of deposits and their ultrastructural pattern of organization. Renal lesions, independent of the tumor burden, are mostly governed by the molecular characteristics of the MIg variable domain and involve either direct (deposition or precipitation) or indirect (autoantibody activity, complement activation) mechanisms. The diagnosis, often suggested by careful analysis of renal and extrarenal symptoms, almost always requires histological confirmation by a kidney biopsy with light, immunofluorescence, and electron microscopy studies. Most patients do not have a known monoclonal gammopathy at presentation. Hematologic investigations should include serum and urine protein electrophoresis and immunofixation, serum-free light chain measurements, and bone marrow studies with flow cytometry and cytogenetics to determine the nature of the pathogenic clone (most commonly plasmocytic). Early diagnosis before the development of severe chronic kidney disease and rapid achievement of deep hematological response through clone-targeted chemotherapy (currently based on proteasome inhibitor and monoclonal anti-CD38 antibody-based combinations for plasma cell clones) are the main factors influencing long-term renal and patient outcomes.

Clinical Presentation and Long-Term Survival Outcomes of Patients With Monoclonal Gammopathy of Renal Significance (MGRS): A Multicenter Retrospective Study

INTRODUCTION

MGRS are new rare clinical entities, whose recognition and optimal management is evolving.

METHODS

To implement real-life data, we retrospectively analysed a multicentre cohort of 60 patients with renal biopsy-proven MGRS receiving mainly novel treatments (between 2006 and 2021) in eight Italian centres. Based on renal biopsy, patients were divided into two subgroups: AL amyloidosis (70%, n = 42) and other-MGRS (30%, n = 18).

RESULTS

Baseline characteristics follow typical manifestations of MGRS disorders in terms of small clonal burden, laboratory and clinical features. More patients with AL amyloidosis had monotypic lambda light-chain disease, estimated glomerular filtration rate (eGFR) ≥ 60 mL/min and nephrotic proteinuria than other-MGRS group. The most widely used drug was bortezomib, and about one-third of patients underwent ASCT. Overall response rate was 86% with no differences in the two subgroups. However, high-quality hematologic responses ≥very good partial response (VGPR) were greater in AL amyloidosis than in other-MGRS group (67% vs 28%, p = 0.015). The depth of haematological response influenced renal response, obtained in 32 (59%) of evaluable patients, similarly in the subgroups. Indeed, 75% patients with ≥ VGPR (p = 0.049) and none with stable disease (p ≤ 0.001) obtained a renal response. No association between renal response and histotypes (p = 0.9) or type of first-line therapy (p = 0.3) was found. At a median follow-up of 54.4 months (IQR 24.8-102.8), median progression-free survival (PFS) was 100.1 months (95% CI 34.9-NR), and median overall survival not reached (95% CI 129.8-NR). No significant difference emerged between the two groups in terms of survival outcomes. Achieving ≥ VGPR was confirmed as the main independent predictor of prolonged PFS in the general population (HR = 0.29, p = 0.023) and AL amyloidosis group (HR 0.23; p = 0.023). Preserved renal function at diagnosis was predictive of improved PFS in the AL amyloidosis group (eGFR ≥ 60 mL/min: HR = 0.003; p = 0.018; eGFR 30-60 mL/min: HR = 0.04, p = 0.046).

CONCLUSION

Further research is warranted to develop standardised response criteria and treatment strategies to improve MGRS management.

Daratumumab-Based Therapeutic Approaches and Clinical Outcomes in Multiple Myeloma and other Plasma Cell Dyscrasias: Insights from a Nationwide Real-World Chart Review Study

Singapore leads Southeast Asia in the routine use of daratumumab for multiple myeloma and other plasma cell dyscrasias. This retrospective review analyzed 112 patients who received daratumumab between 2012 and 2020. Tolerability, and efficacy based on prior lines (PL) of therapy, cytogenetic risk group, and the presence of renal impairment were presented. Infusion-related reactions occurred in 26.8% of patients. Grades 1 and 2 hematological and non-hematological adverse events were observed in 14.3% and 33.9% of patients, respectively. After a median follow-up of 16.9 months, there was no significant difference in overall response rates (ORR) (86% versus 76.3%, p = 0.082) or depth of response (≥ complete response (CR), 35.1% versus 28.9%, p = 0.469) between myeloma patients with and without renal dysfunction. Newly diagnosed and relapsed/refractory patients had an ORR of 92% and 76.3%, and a ≥ VGPR (very good partial response) rate of 80% and 55.3%, respectively. Median progression-free survival (PFS) was better for patients with 0/1 PL compared to ≥ 2 PLs (19.8 versus 6.2 months, p < 0.001), with a deeper response (≥ CR, 38.5% versus 16.7%, p = 0.033). Forty-six and a half percentage of patients had high-risk FISH abnormalities, and those with 0/1 PL had a significantly better ORR than those with ≥ 2 PLs (83.3% vsersus 47.1%, p = 0.022), achieving an ORR similar to that of the general cohort (80.2%, p = 0.905). In conclusion, positioning daratumumab in earlier lines of therapy leads to better outcomes and may mitigate the impact of high-risk FISH abnormalities.

Monoclonal immunoglobulin crystalline nephropathies

Monoclonal Ig crystalline nephropathies are rare lesions resulting from precipitation of monoclonal Igs in the kidney as crystalline inclusions. They can be categorized into lesions with predominant intracellular crystals (light chain [LC] proximal tubulopathy, LC crystal-storing histiocytosis, and LC crystalline podocytopathy) and lesions with predominant extracellular crystals (crystalglobulin-induced nephropathy and crystalline variant of LC cast nephropathy). The majority of these lesions are associated with low tumor burden lymphoproliferative disorders, with the exception of crystalline variant of LC cast nephropathy. Extrarenal involvement (e.g., skin and cornea) is frequent. Kidney biopsy is the cornerstone for diagnosis, which often requires electron microscopy and antigen retrieval. A thorough hematologic workup and evaluation of extrarenal involvement is mandatory for management. Treatment of these lesions is with clone-directed therapy, with the goal of achieving hematologic very good partial response or complete response, which preserves or improves kidney function. In vitro and in vivo studies, animal models, and novel sequencing techniques have been invaluable tools to understand the pathogenesis of LC proximal tubulopathy and can be used to increase our limited knowledge of the pathogenesis of the other monoclonal Ig crystalline nephropathies. This review provides an update on the pathology, renal and hematologic characteristics, extrarenal manifestations, prognosis, treatment, and pathogenesis of monoclonal Ig crystalline nephropathies.

Monoclonal Antibodies in Smoldering Multiple Myeloma and Monoclonal Gammopathy of Undetermined Significance: Current Status and Future Directions

Monoclonal antibodies (MoAbs) targeting several cellular receptors have significantly improved the prognosis of multiple myeloma (MM). Their high effectiveness and safety raise the question of whether earlier therapeutic intervention in monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) influences the natural course of the disease. MM is preceded by clinically recognized conditions such as MGUS and SMM. Numerous studies are investigating the disease biology and immune profile of SMM and MGUS to unravel the intricate relationship between immunosurveillance and disease progression. The standard approach to MGUS and SMM remains close observation. Early studies indicate benefits in terms of progression or even survival for promptly treating high-risk SMM patients. Ongoing debates are focused on which patients with SMM and MGUS to treat, as well as on determining the optimal therapeutic approach. The first approach aims to cure by attempting to eliminate the pathological clone, while the second approach is preventive, aiming to manage disease progression to active MM and restore the immune system. In this review, we focus on the available and emerging data on early treatment, particularly with MoAbs alone or in combination with other therapies, in SMM and MGUS patients.

Clinicopathological Characteristics of Light and Heavy Chain Deposition Disease: A Case Series

RATIONALE & OBJECTIVE

Light and heavy chain deposition disease (LHCDD) is a rare form of monoclonal immunoglobulin (Ig) deposition disease, and limited clinical data are available characterizing this condition. Here we describe the clinicopathological characteristics and outcomes of LHCDD.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS

13 patients with biopsy-proven LHCDD diagnosed between January 2008 and December 2022 at one of 2 Chinese medical centers.

FINDINGS

Among the 13 patients described, 6 were men and 7 were women, with a mean age of 52.6±8.0 years. Patients presented with hypertension (76.9%), anemia (84.6%), increased serum creatinine concentrations (84.6%; median, 1.7mg/dL), proteinuria (100%; average urine protein, 3.0g/24h), nephrotic syndrome (30.8%), and microscopic hematuria (76.9%). Serum immunofixation electrophoresis showed monoclonal Ig for 11 patients (84.6%). Serum free light chain ratios were abnormal in 11 patients (84.6%), and heavy/light chain ratios were abnormal in 9 of 10 patients (90%) with available data. Five patients were diagnosed with multiple myeloma. A histological diagnosis of nodular mesangial sclerosis was made in 10 patients (76.9%). Immunofluorescence demonstrated deposits of IgG subclass in 7 patients (γ-κ, n=4; γ-λ, n=3) and IgA in 5 patients (α-κ, n=2; α-λ, n=3). Six patients underwent IgG subclass staining (γ1, n=3; γ2, n=2; γ3, n=1). The deposits of IgD-κ were confirmed by mass spectrometry in 1 patient. Among 12 patients for whom data were available during a median of 26.5 months, 11 received chemotherapy and 1 received conservative treatment. One patient died, and disease progressed to kidney failure in 3 (25%). Among the 9 patients evaluable for hematological and kidney disease progression, 5 (56%) had a hematologic response and 1 (11%) exhibited improvement in kidney disease.

LIMITATIONS

Retrospective descriptive study, limited number of patients, urine protein electrophoresis or immunofixation electrophoresis test results missing for most patients.

CONCLUSIONS

In this case series of LHCDD, light and heavy chain deposition in kidney tissues were most frequent with monoclonal IgG1-κ. Among patients with evaluable data, more than half had a hematologic response, but a kidney response was uncommon.

Successful Treatment with Daratumumab of a Patient with Monoclonal Lambda Light Chain Disease Presenting as Nephrotic Syndrome and Crescentic Glomerulonephritis

INTRODUCTION

Monoclonal immunoglobulin deposition diseases (MIDDs) are a group of systemic diseases, characterized by deposition of monoclonal immunoglobulin predominantly in the kidney. In the absence of overt hematologic disease, MIDDs are classified as a part of monoclonal gammopathy of renal significance. Patients with MIDD may present with a nephrotic syndrome and kidney function impairment. Treatment usually includes anti-plasma cell therapy.

CASE PRESENTATION

We report a case of a 54-year-old female who presented with nephrotic syndrome related to light chain deposition disease of lambda type. Due to a complicated clinical course (including cardiac injury and thromboembolic stroke), plasma cell-targeted therapy was stopped. A few months later, the patient presented with severe acute kidney injury. Kidney biopsy revealed crescentic glomerulonephritis, and immunofluorescence staining was positive for lambda chain. Treatment with daratumumab was initiated resulting in stabilization of kidney function and partial nephrotic syndrome remission.

CONCLUSION

This case highlights an uncommon histologic manifestation in a patient diagnosed with light chain deposition disease. Furthermore, it underscores the significance of plasma cell-targeted therapy and the favorable clinical and hematological response observed with daratumumab.

Non-crystalline light chain proximal tubulopathy, a morphologically protean entity

BACKGROUND

Light chain proximal tubulopathy (LCPT) is a rare form of paraprotein-related disease, occurring in two main histopathological forms: crystalline and non-crystalline. The clinicopathological features, treatment strategies and outcomes, especially of the non-crystalline form, are not well described.

METHODS

We conducted a single-centre retrospective case series of 12 LCPT patients, 5 crystalline and 7 non-crystalline, between 2005 and 2021.

RESULTS

The median age was 69.5 years (range 47-80). Ten patients presented with CKD and significant proteinuria (median estimated glomerular filtration rate of 43.5 ml/min/1.73 m2; urine protein:creatinine ratio 328 mg/mmol). Only six patients had known haematological disease at the time of renal biopsy. Multiple myeloma (MM) was diagnosed in seven patients cases and monoclonal gammopathy of renal significance (MGRS) in five patients. A clone was detected in all cases combining serum/urine electrophoresis and free light chain (LC) assays. Crystalline and non-crystalline variants had similar clinical presentations. For the non-crystalline variant, a diagnosis was reached based on a combination of CKD without another cause, haematological workup, LC restriction on immunofluorescence and abnormalities on electron microscopy (EM). Nine of 12 patients received clone-directed treatment. Patients who achieved haematological response (including all non-crystalline LCPT) had improved renal outcomes over a median follow-up of 79 months.

CONCLUSIONS

The non-crystalline variant may go unrecognised because of its subtle histopathological features and requires EM to distinguish it from 'excessive LC resorption without tubular injury'. Clone-directed treatment with good haematological response improves renal outcomes in both variants but limited data exist in MGRS. Multicentre prospective studies are needed to better define the clinicopathological characteristics associated with poor outcomes and optimize treatment strategies in patients with MGRS.

Daratumumab in the treatment of C3 glomerulopathy with monoclonal gammopathy: a case report and literature review

Although rare, C3 glomerulopathy (C3G) is increasingly recognized thanks to the currently available diagnostic skills. C3G is not a single disease but a group of disorders with distinct pathogenesis and progression. Thus, an essential step for its management remains an in-depth characterization of the specific form and the identification of underlying conditions, which may also impact treatment choices as well. Among these entities, an emerging condition is the association of C3G with monoclonal gammopathy, which confers poor outcomes. Overall, diagnosis of C3G remains challenging, and determining the appropriate treatment remains unclear. Conventional immunosuppressive therapy has proven ineffective in such cases, while clone-directed therapies have shown promising results in small interventional studies and case series. Here, we report a case of a patient affected by C3G with monoclonal gammopathy of renal significance who experienced rapid deterioration of kidney function requiring replacement therapy. After the failure of first-line treatment, a switch to the anti-CD38 therapy with daratumumab resulted in the progressive improvement of the patient's kidney function, leading to the discontinuation of hemodialysis after approximately 10 months. Serial renal biopsies were also performed to study the disease's evolution in response to the treatment. Based on the description of this single case, we have comprehensively reviewed available studies on daratumumab use in patients with C3G associated with monoclonal gammopathy to provide insights for the design of prospective studies which aim to enhance the management of such poor prognosis disease.

Monoclonal gammopathy of renal significance: Multidisciplinary approach to diagnosis and treatment

Monoclonal gammopathy of renal significance (MGRS) is a hemato-nephrological term referring to a heterogeneous group of kidney disorders characterized by direct or indirect kidney injury caused by a monoclonal immunoglobulin (MIg) produced by a B cell or plasma cell clone that does not meet current hematologic criteria for therapy. MGRS-associated kidney diseases are diverse and can result in the development of end stage kidney disease (ESKD). The diagnosis is typically made by nephrologists through a kidney biopsy. Many distinct pathologies have been identified and they are classified based on the site or composition of the deposited Mig, or according to histological and ultrastructural findings. Therapy is directed towards the identified underlying clonal population and treatment decisions should be coordinated between hematologists and nephrologists in a multidisciplinary fashion, depend on the type of MGRS, the degree of kidney function impairment and the risk of progression to ESKD.

Assessment of renal outcome following therapy in monoclonal immunoglobulin deposition disease: Emphasizing the need for a consensus approach

Monoclonal immunoglobulin deposition disease (MIDD), often associated with plasma cell dyscrasias, predominantly affects the kidneys. In this disease, hematologic response (HR) to treatment can be reliably assessed by International Myeloma Working Group (IMWG) consensus criteria, while uniform criteria for assessing renal response are lacking. We report a retrospective analysis of renal outcomes among 34 patients with MIDD. With most patients treated with bortezomib and autologous stem cell transplantation, 26 of 28 (94%) achieved very good partial HR or better. We demonstrate that both IMWG (based on estimated glomerular filtration rate, eGFR) and amyloid (based on proteinuria) criteria are needed to capture renal response: among 28 evaluable patients, 6 (21%) had isolated proteinuria, while 13 (46%) had isolated decreased eGFR. Using both criteria, which were concordant in patients with both decreased eGFR and proteinuria, 22 of 28 patients (79%) achieved a renal response, including 2 of 7 discontinuing dialyses. All 6 patients (100%) with isolated proteinuria and 7 of 13 (54%) with isolated decreased eGFR achieved renal response, suggesting that isolated proteinuria is an early manifestation of MIDD associated with reversible renal damage. Baseline eGFR predicted renal response (p = .02 by quartile) and survival (p = .02), while HR (CR vs. non-CR) did not, probably because of high HR rate. With a median follow-up of 110 months, the median overall survival was 136 months (95% CI: 79-NR) and median renal survival had not been reached. Prospective studies using uniform renal response criteria are needed to optimize the management of MIDD.

Monoclonal Gammopathies of Clinical Significance: A Critical Appraisal

Monoclonal gammopathies of clinical significance (MGCSs) represent a group of diseases featuring the association of a nonmalignant B cells or plasma cells clone, the production of an M-protein, and singularly, the existence of organ damage. They present a current framework that is difficult to approach from a practical clinical perspective. Several points should be addressed in order to move further toward a better understanding. Overall, these entities are only partially included in the international classifications of diseases. Its definition and classification remain ambiguous. Remarkably, its real incidence is unknown, provided that a diagnostic biopsy is mandatory in most cases. In fact, amyloidosis AL is the final diagnosis in a large percentage of patients with renal significance. On the other hand, many of these young entities are syndromes that are based on a dynamic set of diagnostic criteria, challenging a timely diagnosis. Moreover, a specific risk score for progression is lacking. Despite the key role of the clinical laboratory in the diagnosis and prognosis of these patients, information about laboratory biomarkers is limited. Besides, the evidence accumulated for many of these entities is scarce. Hence, national and international registries are stimulated. In particular, IgM MGCS deserves special attention. Until now, therapy is far from being standardized, and it should be planned on a risk and patient-adapted basis. Finally, a comprehensive and coordinated multidisciplinary approach is needed, and specific clinical trials are encouraged.

A case of treatment-resistant membranous nephropathy associated with graft versus host disease successfully treated with daratumumab

BACKGROUND

Membranous nephropathy (MN) is the most common cause of glomerulopathy after hematopoietic cell transplantation (HCT), most often occurring in the setting of graft versus host disease (GVHD). Twenty percent of patients will fail to respond to standard therapy and may progress to end stage renal disease. Here we present the case of a pediatric patient who developed chronic oral GVHD more than one-year post-HCT, who subsequently developed nephrotic syndrome (anasarca, nephrotic range proteinuria, hypoalbuminemia) and had a renal biopsy consistent with MN. Treated with ibrutinib for her GVHD, and steroids, tacrolimus, and rituximab for her MN, she failed to achieve even partial remission of her kidney disease after 8 months. Due to steroid toxicity and 0% CD19 cells on lymphocyte subpopulation flow cytometry, the decision was made to trial plasma cell depletion therapy with daratumumab.

METHOD

She received three doses of daratumumab at weeks 1, 4, and 17.

RESULTS

Her nephrotic syndrome resolved and her serum albumin was greater than 3.0 gm/dl by week 10. She was weaned off of both steroids and tacrolimus by week 16, at which time she had near-complete remission of her renal disease.

CONCLUSION

Daratumumab may be an important, novel therapeutic option for post-HCT MN patients who are not responsive to standard therapies.