Randomized Trial Comparing Double Versus Triple Bortezomib-Based Regimen in Patients With Multiple Myeloma and Acute Kidney Injury Due to Cast Nephropathy

Prognosis of concurrent renal impairment at diagnosis of multiple myeloma: a systematic review

BACKGROUND

Multiple myeloma is a malignant tumour of the blood in which abnormal proliferation of plasma cells leads to bone destruction, renal impairment, anaemia, and hypercalcaemia. Renal impairment caused by multiple myeloma is a common and serious condition; however, the prognosis of multiple myeloma at the time of diagnosis remains unclear.

METHOD

We conducted searches for literature in PubMed, Web of Science, Cochrane, Embase, CNKI, Wanfang, and VIP databases up to 30 April 2023. Progression-free survival and overall survival with and without renal impairment at the time of multiple myeloma diagnosis were compared, and prognostic indicators were analysed.

RESULTS

Six studies were finally included. Among patients with multiple myeloma, 319 had renal impairment, and 1166 had no renal impairment. Compared to the control group, no significant difference was observed in overall or progression-free survival in patients with multiple myeloma complicated with renal impairment.

CONCLUSION

The limited low-quality evidence available does not support an association between prognosis and multiple myeloma complicated by kidney injury.

[Renal failure in multiple myeloma: Specific management issues]

Renal impairment is common during multiple myeloma and persistent reduction in kidney function strongly affects prognosis. Cast nephropathy, by monoclonal free light chains precipitation with uromodulin in renal tubules, is the main cause of acute kidney injury in multiple myeloma. Kidney biopsy, although not necessary for diagnosis, allows assessment of renal prognosis according to the extent of cast formation, tubular atrophy and interstitial fibrosis. Prevention and early diagnosis of acute kidney injury are essential to optimize management and avoid progression to chronic kidney disease. Rehydration, interruption of nephrotoxic treatments, correction of precipitating factors, anti-plasma cell chemotherapy can rapidly reduce the free light chains nephrotoxicity. The association of the proteasome inhibitor Bortezomib and high dose Dexamethasone is the reference treatment in newly diagnosed patients with renal impairment. Adding Cyclophosphamide or the immunomodulator Lenalidomide may improve the hematological response, but with a poorer tolerance. Use of anti-CD38 monoclonal antibodies is being evaluated in this population. Hemodialysis with high-flux or high-cut-off membranes, combined to chemotherapy, may improve renal function recovery. Management of multiple myeloma have to be adapted in patients with chronic kidney disease, dialysis or kidney transplantation. Because of improvement in global survival, kidney transplantation remains an option to consider in selected patients. Collaboration between hematologists and nephrologists is essential throughout the course of the disease.

Outcomes of therapeutic plasma exchange for the treatment of patients with multiple myeloma cast nephropathy

Current treatment guidelines of myeloma cast nephropathy (MCN) recommend the institution of plasma cell-directed therapy and consideration of therapeutic plasma exchange (TPE), with the goal of rapid reduction of the serum free light chain (sFLC). However, the role of TPE continues to remain a subject of debate. The goal of this retrospective bi-institutional study was to evaluate the clinical outcomes of TPE in combination with systemic therapy. Eighty patients were included in this analysis, of whom 72.5% had ≥50% drop in their initial involved sFLC. At 3 months from TPE initiation, the overall hematologic response rate (ORR) was 67.5% with a very good partial response or better (≥VGPR) rate of 40%. At 6 months, ORR was 57.5%, with ≥VGPR rate of 49%. The renal response rate at 3 and 6 months was 47.5% and 43.75%, respectively; the overall renal response rate was 48.75%. On multivariable analysis, every one unit increase in baseline creatinine (odds ratio [OR] 0.76, p = 0.006), and achievement of ≥VGPR (OR 21.7 p < 0.0001) were significantly associated with renal response. Also, a ≥50% drop in sFLC was favorably associated with renal response (OR 3.39, p = 0.09). With a median follow-up of 36.4 months, the median overall survival (OS) was 11 months. On multivariable analysis, achievement of renal response (hazard ratio [HR] 0.3, p < 0.0001) and newly diagnosed disease (NDMM; HR 0.43, p = 0.0055) were associated with improved OS. Among NDMM patients, those treated with daratumumab-based regimens had a trend for better OS (p = 0.15), compared to other regimens, but the difference was not significant. At the end of follow-up, an estimated 40.4% of patients who were on dialysis were able to become dialysis independent. In conclusion, our study highlights the poor survival of patients with MCN. Achievement of early renal response is crucial for prolonged OS, with daratumumab-based therapies showing promise.

Patient-Reported Outcomes in Phase 3 Clinical Trials for Blood Cancers: A Systematic Review

Importance

Published research suggests that patient-reported outcomes (PROs) are neither commonly collected nor reported in randomized clinical trials (RCTs) for solid tumors. Little is known about these practices in RCTs for hematological malignant neoplasms.

Objective

To evaluate the prevalence of PROs as prespecified end points in RCTs of hematological malignant neoplasms, and to assess reporting of PROs in associated trial publications.

Evidence Review

All issues of 8 journals known for publishing high-impact RCTs (NEJM, Lancet, Lancet Hematology, Lancet Oncology, Journal of Clinical Oncology, Blood, JAMA, and JAMA Oncology) between January 1, 2018, and December 13, 2022, were searched for primary publications of therapeutic phase 3 trials for adults with hematological malignant neoplasms. Studies that evaluated pretransplant conditioning regimens, graft-vs-host disease treatment, or radiotherapy as experimental treatment were excluded. Data regarding trial characteristics and PROs were extracted from manuscripts and trial protocols. Univariable analyses assessed associations between trial characteristics and PRO collection or reporting.

Findings

Ninety RCTs were eligible for analysis. PROs were an end point in 66 (73%) trials: in 1 trial (1%) as a primary end point, in 50 (56%) as a secondary end point, and in 15 (17%) as an exploratory end point. PRO data were reported in 26 of 66 primary publications (39%): outcomes were unchanged in 18 and improved in 8, with none reporting worse PROs with experimental treatment. Trials sponsored by for-profit entities were more likely to include PROs as an end point (49 of 55 [89%] vs 17 of 35 [49%]; P < .001) but were not significantly more likely to report PRO data (20 of 49 [41%] vs 6 of 17 [35%]; P = .69). Compared with trials involving lymphoma (18 of 29 [62%]) or leukemia or myelodysplastic syndrome (18 of 28 [64%]), those involving plasma cell disorders or multiple myeloma (27 of 30 [90%]) or myeloproliferative neoplasms (3 of 3 [100%]) were more likely to include PROs as an end point (P = .03). Similarly, compared with trials involving lymphoma (3 of 18 [17%]) or leukemia or myelodysplastic syndrome (5 of 18 [28%]), those involving plasma cell disorders or multiple myeloma (16 of 27 [59%]) or myeloproliferative neoplasms (2 of 3 [67%]) were more likely to report PROs in the primary publication (P = .01).

Conclusions and Relevance

In this systematic review, almost 3 of every 4 therapeutic RCTs for blood cancers collected PRO data; however, only 1 RCT included PROs as a primary end point. Moreover, most did not report resulting PRO data in the primary publication and when reported, PROs were either better or unchanged, raising concern for publication bias. This analysis suggests a critical gap in dissemination of data on the lived experiences of patients enrolled in RCTs for hematological malignant neoplasms.

Management of hematological patients requiring emergency chemotherapy in the intensive care unit

Hematological malignancies may require rapid-onset treatment because of their short doubling time, notably observed in acute leukemias and specific high-grade lymphomas. Furthermore, in targeted onco-hematological scenarios, chemotherapy is deemed necessary as an emergency measure when facing short-term, life-threatening complications associated with highly chemosensitive hematological malignancies. The risks inherent in the disease itself, or in the initiation of treatment, may then require admission to the intensive care unit (ICU) to optimize monitoring and initial management protocols. Hyperleukocytosis and leukostasis in acute leukemias, tumor lysis syndrome, and disseminated intravascular coagulation are the most frequent onco-hematological complications requiring the implementation of emergency chemotherapy in the ICU. Chemotherapy must also be started urgently in secondary hemophagocytic lymphohistiocytosis. Tumor-induced microangiopathic hemolytic anemia and plasma hyperviscosity due to malignant monoclonal gammopathy represent infrequent yet substantial indications for emergency chemotherapy. In all cases, the administration of emergency chemotherapy in the ICU requires close collaboration between intensivists and hematology specialists. In this review, we provide valuable insights that aid in the identification and treatment of patients requiring emergency chemotherapy in the ICU, offering diagnostic tools and guidance for their overall initial management.

The role of therapeutic plasma exchange in plasma cell disorders

Therapeutic plasma exchange (TPE) is an extracorporeal technique where patient's plasma containing pathogenic substances is separated and removed from the whole blood, while the cellular component is returned to the patient mixed with replacement solution via an apheresis machine. Due to its ability to remove pathogenic substances from plasma including immunoglobulins, TPE has proven efficacious in the management of various disorders across different medical disciplines, including plasma cell dyscrasias, which are characterized by the abundant secretion of non-functional immunoglobulins produced by an abnormally proliferating plasma cell clone. This review summarizes the current indications of TPE in plasma cell-related disorders and discusses its application, safety, and therapeutic effects.

New diagnostic strategy for multiple myeloma: A review

Multiple myeloma (MM) is the second most prevalent hematological malignancy and is distinguished by the aberrant proliferation of monoclonal plasma cells inside the bone marrow and production of M-protein. This condition frequently results in bone deterioration, acute kidney damage, anemia, and hypercalcemia. However, the clinical manifestations and accompanying symptoms of MM vary and may change as the condition evolves. Therefore, diagnosis of MM is difficult. At present, the confirmation of MM diagnosis necessitates the use of bone marrow biopsy, a procedure that is both invasive and challenging for assessing dynamic alterations in the disease. The integration of laboratory testing technologies with imaging technology has the potential to enhance the diagnostic effectiveness and provide a thorough evaluation of disease progression and prognosis in patients with MM. All the examination methods have advantages and disadvantages. Therefore, diagnosis is determined by the application of clinical characteristics, serological tests, and imaging investigations.

Kidney outcomes and prognostic factors of myeloma associated acute kidney injury in the contemporary era

Myeloma cast nephropathy (MCN) has historically been associated with poor kidney outcomes. We aimed to evaluate the kidney outcomes and identify prognostic factors of myeloma-associated acute kidney injury (M-AKI) in the contemporary era of anti-plasma cell therapy. Patients who received anti-myeloma therapy with M-AKI (January 2012 to June 2020) from a single centre were identified from electronic medical records. Diagnosis of MCN was either biopsy confirmed (BC) or clinically suspected (CS), the latter defined as acute kidney injury with reduced estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2 and involved serum free light chains (iSFLC) >500 mg/L at diagnosis. Twenty-six patients with M-AKI were identified (BC: n = 13, CS: n = 13). Median eGFR at diagnosis was 12 (interquartile range 6-20) mL/min/1.73 m2 . All six dialysis-requiring patients achieved dialysis independence after 71 (43-208) days. The best-achieved eGFR was 47 (32-67) mL/min/1.73 m2 after 120 (63-167) days post-treatment, which was maintained at 47 (33-66) mL/min/1.73 m2 12 months post-treatment. Patients with best-achieved eGFR above the median were more likely to have achieved an iSFLC of <20 mg/L (above median group 62% versus below median group 0%; p < .001) and lower best post-treatment iSFLC (20 (12-90) versus 67 (29-146) mg/L; p < .05). Best-achieved iSFLC was a prognostic factor for superior eGFR following treatment for M-AKI. Despite low eGFR at diagnosis, contemporary anti-myeloma therapy can achieve significant recovery of kidney function.

Risk nomogram for assessing renal recovery in patients with newly diagnosed multiple myeloma-related renal impairment

To determine risk factors affecting renal recovery in newly diagnosed multiple myeloma (NDMM) patients with renal impairment (RI) and establish a risk nomogram. This multi-center, retrospective cohort study included 187 NDMM patients with RI, 127 of whom were admitted to Huashan Hospital and assigned to the training cohort and 60 were admitted to Changzheng Hospital and assigned to the external validation cohort. The baseline data of the 2 cohorts were compared, and survival and renal recovery rates were analyzed. Independent risk factors affecting renal recovery were determined by binary logistic regression analysis, and a risk nomogram was established and subsequently tested in the external validation cohort. Results: The median overall survival (OS) improved in patients who achieved renal recovery etc within 6 courses of MM directed treatment compared with patients without renal recovery. Median time to renal recovery was 2.65 courses, and the cumulative renal recovery rate during the first 3 courses was 75.05%. Involved serum free light chain (sFLC) ratio of >120 at diagnosis, time from renal impairment to treatment > 60 days, and a hematologic response without a very good partial remission (VGPR) or better resulted as independent risk factors for renal recovery during the first 3 courses. The established risk nomogram had good discriminative ability and accuracy. Involved sFLC was a key factor affecting renal recovery. Starting treatment as soon as possible after detecting RI and achieving deep hematologic remission during the first 3 courses of treatment helped achieve renal recovery and improve prognosis.

Multiple Myeloma and Kidney Impairment at Diagnosis: A Nephrological Perspective from an Eastern European Country

Background and Objectives: The clinical presentation and survival factors in patients with myeloma-related kidney impairment (MRKI) at diagnosis remain a topic of ongoing research, given the complex interplay between nephrology and hematology. To date, no studies have specifically reported outcomes for these patients in Eastern Europe. Materials and Methods: We conducted a retrospective, unicentric study of consecutive newly diagnosed patients with MRKI in our tertiary nephrology service in Romania between 2015 and 2020; follow-up extended until 1 September 2022, covering a study period of 90 months. Results: We identified 89 consecutive patients with MRKI (median age 66 years, 38% male, median eGFR 5 mL/min). The majority of patients had arterial hypertension (71%) and systemic atherosclerosis (58%), and the most frequent clinical features at presentation were asthenia (75%) and bone pain (51%). Light-chain-restricted myeloma was the most common type (55%), with kappa free light chain being more frequent (53%). Among the patients, 81% presented with acute kidney injury (AKI), and 38% required hemodialysis at diagnosis. During the study period, 65% of the patients died, and hypoalbuminemia and the need for hemodialysis at diagnosis were significantly associated with mortality in multivariate analysis. Conclusions: Patients with MRKI who present to the nephrologist more frequently exhibit light chain restriction and most often present with AKI, with one-third requiring hemodialysis at diagnosis. Moreover, hypoalbuminemia and the initiation of hemodialysis at diagnosis were significantly associated with increased mortality.

Management of multiple myeloma-related renal impairment: recommendations from the International Myeloma Working Group

Here, the International Myeloma Working Group (IMWG) updates its clinical practice recommendations for the management of multiple myeloma-related renal impairment on the basis of data published until Dec 31, 2022. All patients with multiple myeloma and renal impairment should have serum creatinine, estimated glomerular filtration rate, and free light chains (FLCs) measurements together with 24-h urine total protein, electrophoresis, and immunofixation. If non-selective proteinuria (mainly albuminuria) or involved serum FLCs value less than 500 mg/L is detected, then a renal biopsy is needed. The IMWG criteria for the definition of renal response should be used. Supportive care and high-dose dexamethasone are required for all patients with myeloma-induced renal impairment. Mechanical approaches do not increase overall survival. Bortezomib-based regimens are the cornerstone of the management of patients with multiple myeloma and renal impairment at diagnosis. New quadruplet and triplet combinations, including proteasome inhibitors, immunomodulatory drugs, and anti-CD38 monoclonal antibodies, improve renal and survival outcomes in both newly diagnosed patients and those with relapsed or refractory disease. Conjugated antibodies, chimeric antigen receptor T-cells, and T-cell engagers are well tolerated and effective in patients with moderate renal impairment.

Multiple myeloma with acute light chain cast nephropathy

Light chain cast nephropathy (LCCN) is a leading cause of acute kidney injury (AKI) in patients with multiple myeloma (MM) and is now defined as a myeloma defining event. While the long-term prognosis has improved with novel agents, short-term mortality remains significantly higher in patients with LCCN especially if the renal failure is not reversed. Recovery of renal function requires a rapid and significant reduction of the involved serum free light chain. Therefore, proper treatment of these patients is of the utmost importance. In this paper, we provide an algorithm for treatment of MM patients who present with biopsy-proven LCCN or in those where other causes of AKI have been ruled out. The algorithm is based on data from randomized trial whenever possible. When trial data is not available, our recommendations is based on non-randomized data and expert opinions on best practices. We recommend that all patients should enroll in a clinical trial if available prior to resorting to the treatment algorithm we outlined.

Onconephrology 2022: An Update

Onconephrology is an upcoming and expanding subspecialty that deals with the intersections between hematology/oncology and nephrology. With the paradigm shift in the understanding of cancer immunobiology and mechanisms of oncotherapeutic drug toxicities, it is important for a nephrologist to have a sound understanding of this field. Over the last 5 years, there have been immense developments in our understanding of kidney-related adverse events from various targeted, immuno- and cellular-based therapies. Pathogenic mechanisms of electrolyte imbalance, hypertension (oncohypertension), and AKI from multiple forms of cancer therapies have been explored. Significant research has also been conducted in the field of transplant onconephrology. In this review, we have tried to assimilate the most recent updates in the last 2 years in this ever-growing and fascinating field.

Response and Dynamics of Renal Function in Transplantation-Eligible Multiple Myeloma Patients Treated with a Novel Agent: The CAREMM-2201 Study

Newly diagnosed multiple myeloma (NDMM) frequently results in renal impairment (RI), and its natural course has not been fully elucidated in the era of novel agents. We aimed to identify the dynamics of renal function after autologous stem cell transplantation (ASCT) following induction treatment using a novel agent in transplantation-eligible NDMM patients with RI (estimated glomerular filtration rate [eGFR] ≤50 mL/min/1.73 m²) at diagnosis. The factors associated with achieving a renal response based on the term renal benefit regardless of baseline eGFR were investigated as well. In a multicenter registry database including 1795 patients with plasma cell disorder, 140 transplantation-eligible NDMM patients who developed RI at the time of initiation of treatment for NDMM were identified. They received protocol-based treatment (PBT) consisting of induction treatment using proteasome inhibitors and/or immunomodulatory drugs followed by ASCT. MM and renal responses were evaluated using the International Myeloma Working Group response criteria. To evaluate the standardized improvement of renal function irrespective of baseline eGFR, renal benefit was defined as a sustained (for at least 3 months) increase in eGFR >15 mL/min/1.73 m². The mean patient age was 54.7 ± 7.4 years. With a mean baseline eGFR of 24.8 ± 13.9, the renal complete response (renalCR) and renal benefit rates were 49.3% and 67.9%, respectively. In a multivariable analysis, the 3 factors significantly associated with reduced likelihood of achieving both renalCR and renal benefit were age ≥55 years, light chain type NDMM, and failure to improve eGFR by 5 mL/min/1.73 m² with supportive care when measured 3 days prior to induction therapy and at the initiation of chemotherapy. Hypertension and advanced eGFR also were associated with poor renalCR achievement. The mean eGFR improved until the time of ASCT and then decreased gradually over time. The mean eGFR improved significantly until 4 months post-PBT compared with each eGFR at previous time points, but this significant improvement disappeared by 5 months post-PBT. In a subgroup of patients who developed RI after undergoing ASCT (n = 55), the eGFR increased temporarily at 1 month post-ASCT; however, this improvement reverted to baseline at 2 months post-ASCT. Among another subgroup of 27 patients who were dialysis-dependent at the time of initial treatment, 18 (66.7%) were no longer dialysis-dependent after a median of 60 days. The best renal response was acquired early during the PBT period, and ASCT did not have a robust impact on the renal outcome. Patients who failed to achieve a renal benefit should be provided with the best supportive care for chronic kidney disease, and this simplified criterion for evaluating the renal response needs to be validated in larger studies before it can be recommended. © 2022 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Monoclonal Gammopathy-Related Kidney Diseases

Monoclonal gammopathies occur secondary to a broad range of clonal B lymphocyte or plasma cell disorders, producing either whole or truncated monoclonal immunoglobulins. The kidneys are often affected by these monoclonal proteins, and, although not mutually exclusive, can involve the glomeruli, tubules, interstitium, and vasculature. The nephrotoxic potential of these monoclonal proteins is dependent on a variety of physicochemical characteristics that are responsible for the diverse clinicopathologic manifestations, including glomerular diseases with organized deposits, glomerular diseases with granular deposits, and other lesions, such as C3 glomerulopathy and thrombotic microangiopathy with unique pathophysiologic features. The diseases that involve primarily the tubulointerstitial and vascular compartments are light chain cast nephropathy, light chain proximal tubulopathy, crystal-storing histiocytosis, and crystalglobulin-induced nephropathy with distinct acute and chronic clinicopathologic features. The diagnosis of a monoclonal gammopathy-related kidney disease is established by identification of an underlying active or more commonly, low-grade hematologic malignancy, serologic evidence of a monoclonal gammopathy when detectable, and most importantly, monoclonal protein-induced pathologic lesions seen in a kidney biopsy, confirming the association with the monoclonal protein. Establishing a diagnosis may be challenging at times, particularly in the absence of an overt hematologic malignancy, with or without monoclonal gammopathy, such as proliferative glomerulonephritis with monoclonal immunoglobulin deposits. Overall, the treatment is directed against the underlying hematologic disorder and the potential source of the monoclonal protein.

Impact of Induction Therapy with VRD versus VCD on Outcomes in Patients with Multiple Myeloma in Partial Response or Better Undergoing Upfront Autologous Stem Cell Transplantation

Bortezomib-based triplet regimens-specifically bortezomib, lenalidomide, and dexamethasone (VRD) and bortezomib, cyclophosphamide, and dexamethasone (VCD)-are the 2 most common induction regimens used in transplantation-eligible patients with newly diagnosed multiple myeloma (NDMM), with conflicting data on comparative efficacy and outcomes in this population. We compared long-term outcomes of patients with NDMM receiving VRD induction and those receiving VCD induction prior to autologous stem cell transplantation (ASCT). Patients registered with the Center for International Blood and Marrow Transplant Registry were included if they had undergone ASCT for MM within 6 months of diagnosis between January 2013 and December 2018, received VRD or VCD induction, and achieved a pretransplantation partial or better response. Of 1135 patients, 914 received VRD and 221 received VCD. The patients receiving VCD were more likely to have renal impairment and International Staging System (ISS) stage III disease and less likely to receive full-dose melphalan (200 mg/m²) conditioning (69% versus 80%; P < .001). Very good partial response rates pretransplantation, post-transplantation, and at best response were not significantly different in the 2 groups. Maintenance use was more common after VRD induction (88% versus 76%; P < .001), with lenalidomide the most common agent (80% versus 63%). Patients in the VRD group had a higher rate of renal recovery (74% versus 43%; P < .001), possibly due to a rapid reduction of light chains in the VRD group or improvement in renal function with VCD, which allowed a switch over to VRD, as patients who switched were classified in the VRD group. Patients receiving VRD had better survival on univariate analysis, with a median progression-free survival (PFS) from transplantation of 44.6 months versus 34.1 months (P = .004) and median 5-year overall survival (OS) of 79% versus 60% (P < .001). Multivariate analysis showed no significant survival difference, with a hazard ratio for VCD versus VRD induction of 1.22 (95% CI, 0.96 to 1.55; P = .10) for PFS and 1.33 (95% CI, 0.93 to 1.92, P = .12) for OS. Maintenance use was independently associated with superior PFS and OS, along with ISS stage, cytogenetics, and pretransplantation response (PFS only). In patients with MM undergoing upfront ASCT after VRD or VCD induction, no independent survival difference was seen based on the induction therapy received after adjusting for other prognostic factors. The use of maintenance treatment was uniformly associated with superior outcomes. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Epidemiology, genetics and treatment of multiple myeloma and precursor diseases

Multiple myeloma (MM) is a hematological malignancy caused by the clonal expansion of plasma cells. The incidence of MM worldwide is increasing with greater than 140 000 people being diagnosed with MM per year. Whereas 5-year survival after a diagnosis of MM has improved from 28% in 1975 to 56% in 2012, the disease remains essentially incurable. In this review, we summarize our current understanding of MM including its epidemiology, genetics and biology. We will also provide an overview of MM management that has led to improvements in survival, including recent changes to diagnosis and therapies. Areas of unmet need include the management of patients with high-risk MM, those with reduced performance status and those refractory to standard therapies. Ongoing research into the biology and early detection of MM as well as the development of novel therapies, such as immunotherapies, has the potential to influence MM practice in the future.

Crystalline appearance in light chain cast nephropathy is associated with higher early mortality in patients with newly diagnosed multiple myeloma

BACKGROUND

Light chain cast nephropathy (LCCN) is the most common kidney lesion in multiple myeloma patients. LCCN may exhibit a crystalline appearance. The frequency and clinical significance of crystalline LCCN are not well understood. Here, we report the first retrospective study of crystalline LCCN.

METHODS

Twenty-six patients with LCCN were enrolled. We studied the clinicopathological features and outcomes of LCCN patients and compared ordinary LCCN patients (n = 18) with crystalline LCCN patients (n = 8).

RESULTS

Crystalline LCCN was not rare (8/26, 30.8%) in our study. The median age of LCCN patients was 57.5 (range, 41-75) years. No patients presented with nephrotic syndrome. No significant differences in clinical features were observed between the two groups. All crystalline LCCN patients suffered from advanced multiple myeloma and acute kidney injury. There was a dominance of the λ isotype (7/8, 87.5%) in patients with crystalline LCCN. Patients with ordinary LCCN had significantly higher scores of tubular atrophy and acute tubular injury than those with crystalline LCCN. The crystalline casts of 5 crystalline LCCN patients stained negative with antihuman Tamm-Horsfall glycoprotein. There were no significant differences in the median overall survival between the crystalline LCCN group and the ordinary LCCN group (6.0 months vs. 35.0 months, p = 0.173). However, crystalline LCCN patients had higher early mortality than ordinary LCCN patients (50.0% vs 11.1%, p = 0.03).

CONCLUSION

Crystalline LCCN patients had higher early mortality than ordinary LCCN patients. Thus, for patients with LCCN, crystalline appearance should be screened carefully.

Kidney injury and disease in patients with haematological malignancies

Acute kidney injury (AKI) is common in patients with cancer, especially in those with haematological malignancies. Kidney injury might be a direct consequence of the underlying haematological condition. For example, in the case of lymphoma infiltration or extramedullary haematopoiesis, it might be caused by a tumour product; in the case of cast nephropathy it might be due to the presence of monoclonal immunoglobulin; or it might result from tumour complications, such as hypercalcaemia. Kidney injury might also be caused by cancer treatment, as many chemotherapeutic agents are nephrotoxic. High-intensity treatments, such as high-dose chemotherapy followed by haematopoietic stem cell transplantation, not only increase the risk of infection but can also cause AKI through various mechanisms, including viral nephropathies, engraftment syndrome and sinusoidal obstruction syndrome. Some conditions, such as thrombotic microangiopathy, might also result directly from the haematological condition or the treatment. Novel immunotherapies, such as immune checkpoint inhibitors and chimeric antigen receptor T cell therapy, can also be nephrotoxic. As new therapies for haematological malignancies with increased anti-tumour efficacy and reduced toxicity are developed, the number of patients receiving these treatments will increase. Clinicians must gain a good understanding of the different mechanisms of kidney injury associated with cancer to better care for these patients.

Kinetics of Renal Function during Induction in Newly Diagnosed Multiple Myeloma: Results of Two Prospective Studies by the German Myeloma Study Group DSMM

Simple Summary

Renal insufficiency is frequently seen in newly diagnosed multiple myeloma and can be due to the disease itself but also caused by medical interventions or infections. Patients with severe renal insufficiency are known to have an adverse prognosis, but recently, it was shown that even moderately impaired kidney function can have long-term sequelae. Achieving quick disease control by effective antimyeloma therapy can lead to the recovery of renal function. We investigated the kidney-specific variables in a large cohort of 770 myeloma patients receiving three different three-drug regimens for initial myeloma treatment to learn more about the differential effects on kidney function in an early disease phase. All regimens had a positive impact on kidney function without a difference in the proportion of patients who reached normal renal function after three cycles. Interestingly, patients who received bortezomib, lenalidomide, and dexamethasone tended to have higher risk for a worse renal function following induction when compared to the initial values.

Abstract

Background: Preservation of kidney function in newly diagnosed (ND) multiple myeloma (MM) helps to prevent excess toxicity. Patients (pts) from two prospective trials were analyzed, provided postinduction (PInd) restaging was performed. Pts received three cycles with bortezomib (btz), cyclophosphamide, and dexamethasone (dex; VCD) or btz, lenalidomide (len), and dex (VRd) or len, adriamycin, and dex (RAD). The minimum required estimated glomerular filtration rate (eGFR) was >30 mL/min. We analyzed the percent change of the renal function using the International Myeloma Working Group (IMWG) criteria and Kidney Disease: Improving Global Outcomes (KDIGO)-defined categories. Results: Seven hundred and seventy-two patients were eligible. Three hundred and fifty-six received VCD, 214 VRd, and 202 RAD. VCD patients had the best baseline eGFR. The proportion of pts with eGFR <45 mL/min decreased from 7.3% at baseline to 1.9% PInd (p < 0.0001). Thirty-seven point one percent of VCD versus 49% of VRd patients had a decrease of GFR (p = 0.0872). IMWG-defined “renal complete response (CRrenal)” was achieved in 17/25 (68%) pts after VCD, 12/19 (63%) after RAD, and 14/27 (52%) after VRd (p = 0.4747). Conclusions: Analyzing a large and representative newly diagnosed myeloma (NDMM) group, we found no difference in CRrenal that occurred independently from the myeloma response across the three regimens. A trend towards deterioration of the renal function with VRd versus VCD may be explained by a better pretreatment “renal fitness” in the latter group.

Management of acute kidney injury in symptomatic multiple myeloma

Symptomatic multiple myeloma is commonly complicated by acute kidney injury through various mechanisms. The most frequent is the precipitation of monoclonal free light chains with uromodulin in the distal tubules, defining light chain cast nephropathy. Early diagnosis and identification of the cause of acute kidney injury are required for optimizing management and avoiding chronic kidney injury that strongly affects quality of life and patient survival. In light chain cast nephropathy, often manifesting with severe acute kidney injury, renal recovery requires urgent intervention based on vigorous rehydration, correction of precipitating factors, and efficient anti-plasma cell chemotherapy to rapidly reduce the secretion of nephrotoxic free light chains. Currently, the association of the proteasome inhibitor bortezomib with high-dose dexamethasone is the standard regimen in newly diagnosed patients. The addition of another drug such as cyclophosphamide or an immunodulatory agent may improve free light chain response but raises tolerance concerns in frail patients. Further studies are warranted to confirm the role of anti-CD38 monoclonal antibodies, whose efficacy and tolerance have been documented in patients without renal impairment. Despite controversial results from randomized studies, recent data suggest that in patients with light chain cast nephropathy and acute kidney injury requiring dialysis, the combination of chemotherapy with free light chain removal through high-cutoff hemodialysis may increase renal response recovery rates. Kidney biopsy may be helpful in guiding management and assessing renal prognosis that appears to depend on the extent of cast formation and interstitial fibrosis/tubular atrophy. Because of continuous improvement in life expectancy of patients with multiple myeloma, renal transplantation is likely to be increasingly considered in selected candidates.

Outcomes of lenalidomide- or bortezomib-based regimens in older patients with plasma cell myeloma

The "triplet" regimen of lenalidomide, bortezomib, and dexamethasone (RVD) showed survival advantage over lenalidomide-dexamethasone (RD) in clinical trials, but older patients with myeloma often receive doublet regimens (RD or bortezomib-dexamethasone, VD), or VD plus cyclophosphamide (VCD). We compared these first-line regimens using real-world data from Medicare beneficiaries receiving therapy between 2007 and 2015. In each comparative analysis, we balanced confounding characteristics using a propensity score. Outcomes included overall (OS) and event-free survival (EFS, reporting hazard ratios [HR] with 95% confidence intervals [CI]), adverse events, and costs. We identified 6076 patients with median age 76 and median OS of 2.6 years. In the comparison of RVD vs RD/VD doublets, RVD showed significantly better OS (HR = 0.83; 95% CI, 0.72-0.95) and EFS (HR = 0.68; 95% CI, 0.61-0.76). So, RVD was associated with more frequent hospitalizations, anemia, and neuropathy, but no increase in thromboembolism or secondary cancers. Costs were higher with RVD. In the comparison of RD vs VD, RD demonstrated better EFS (HR = 0.74; 95% CI, 0.68-0.81) and marginally better OS (HR = 0.91; 95% CI, 0.83-0.99). And, RD resulted in significantly more thromboembolic events, less neuropathy, and no significant difference in hospitalizations, transfusions, or secondary cancers. In the comparison of VCD vs VD, we observed no significant difference in any outcome. Superior survival favors RVD over doublet regimens, but even in 2015 RVD was applied for only about 25% of Medicare beneficiaries with myeloma. For patients not eligible for RVD due to toxicity, VCD offers no survival benefit over VD. Lenalidomide-dexamethasone may be the preferred line doublet considering its advantage over VD.