Bridoux, Frank

PURPOSE In immunoglobulin light chain (AL) amyloidosis, amyloid fibrils cause organ dysfunction. Anselamimab, a monoclonal antibody, selectively binds to amyloid fibrils, accelerating their clearance. METHODS Newly diagnosed patients with European modification of Mayo 2004 stage IIIa or IIIb AL amyloidosis were randomly assigned to receive anselamimab or placebo with cyclophosphamide, bortezomib, and dexamethasone (with or without daratumumab). The primary end point was a hierarchical composite of time to all-cause mortality (ACM) and frequency of cardiovascular hospitalizations (CVHs), analyzed using the Finkelstein-Schoenfeld test and win ratio estimation. RESULTS Among 406 randomly assigned patients, the primary end point win ratio for anselamimab versus placebo was 1.11 (95% CI, 0.83, 1.50; P = .332) and the hazard ratio (HR) for ACM was 0.80 (95% CI, 0.57, 1.13; P = .290). CVH rates in the anselamimab and placebo groups were 0.59 (95% CI, 0.42, 0.83) and 0.89 (95% CI, 0.55, 1.43), respectively ( P = .145). Among patients with kappa isotype (n = 72), the win ratio was 2.06 (95% CI, 0.98, 4.31; P = .100) and anselamimab reduced ACM by 62% versus placebo (HR, 0.38; 95% CI, 0.17 to 0.86; nominal P = .012), and CVH by 71% (IRR, 0.29; 95% CI, 0.10 to 0.87; nominal P = .028) with improvements in Kansas City Cardiomyopathy Questionnaire-Overall Score. There was no clinical benefit observed in the lambda population. Anselamimab was generally well-tolerated; safety data were comparable between treatment arms overall. CONCLUSION Treatment with anselamimab, an antifibril antibody used alongside antiplasma cell dyscrasia therapy, while not meeting the primary end point in the overall population, significantly improved ACM and CVH in patients with kappa AL, potentially offering a new therapeutic option for this isotype.

ABSTRACT Acute renal failure due to cast nephropathy (CAN) is a severe complication of multiple myeloma (MM). Here, we aimed to identify parameters associated with renal outcomes and survival in newly diagnosed MM patients with CAN‐related acute renal failure and to validate the IMWG criteria for renal response. CAN diagnosis was based on biopsy or clinical assessment. Of 787 registered patients, 354 met the inclusion criteria, requiring at least two therapy cycles with documented chemotherapy response, renal response, and eGFR. Baseline free light chain (FLC) levels (median 6825.65 mg/L) decreased below 500 mg/L in 67.8% of patients. According to IMWG classification, renal complete response, partial response, and minimal response were achieved in 33.9%, 19.5%, and 28.0% of patients, respectively. The best eGFR values > 60 mL/min/1.73 m 2 were observed in 33.9% of patients, while 33.3%, 22.3%, and 10.5% had best eGFR values of 30–59, 15–29, and < 15 mL/min/1.73 m 2 , respectively. Renal response correlated with baseline FLC levels, IgG kappa, eGFR, and ECOG status in multivariate analysis, as well as with myeloma response and FLC reduction in univariate analysis. Median overall survival was 77.6 months. Survival correlated with age, myeloma response, ECOG status, FLC kappa type, baseline eGFR, standard‐risk cytogenetics, and calcium levels, among other factors. A comparison of IMWG renal response criteria with classification based solely on best eGFR showed similar utility. Of 136 patients requiring dialysis, 80 (58.8%) were able to discontinue dialysis during therapy. Bortezomib containing myeloma therapy, along with significant FLC reduction, was associated with favorable outcome.

Abstract 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.

Introduction: Acute kidney injury (AKI) due to cast nephropathy is a medical emergency that leads to a diagnosis of myeloma in less than 3% of cases, but up to 30% of patients develop kidney impairment during the course of their disease. Currently, studies aiming to identify parameters that correlate with kidney function recovery and response to myeloma are limited due to small sample size or single center reports. We have therefore initiated an international collaboration and collected a large number patients (pts) from 16 participating centers. Objectives: To assess the impact of pts and disease characteristics and treatment-specific factors on renal outcome and overall survival and to validate the IMWG criteria for renal response in pts with cast nephropathy and newly diagnosed MM. Patients and Methods: Three-hundred forty-three pts (median age: 65.5 range 35-93 yrs) with newly diagnosed MM and an eGFR &lt;40ml/min/1.73m2 have been selected from 704 pts that had been enrolled in the database hosted by RedCap. Eligibility criteria were a diagnosis of AKI due to cast nephropathy diagnosed either by kidney biopsy (n=119) or on clinical criteria (AKI in the setting of involved free light chain concentration of ≥500 mg/L), newly diagnosed multiple myeloma, &gt;2 cycles of therapy, time and type of therapy, best eGFR and best myeloma response available. Results: Median follow up was 36.9 months. Myeloma therapy resulted in renal CR, and PR as defined by the IMWG criteria in 131 (38.2%) and 57 (16.6%) pts, respectively, 54 (15.7%) and 82 (23.9%) pts had minor response or no response, respectively. Nineteen (5.5%) pts were not classifiable by the IMWG response criteria (pts with eGFR 15-&lt;30, with increase to eGFR to ≥30-&lt;40). An eGFR of &gt;60, ≥30-&lt;60, ≥15-&lt;30, and &lt;15ml/min was achieved by 131 (38.2%), 112 (32.7%), 67 (19.5%), and 33 (9.6%) pts respectively. Myeloma response (≥VGPR) correlated significantly with renal response (≥PRrenal) (OR 1.64, CI 1.05-2.56, p=0.03) and with OS compared to no myeloma response (median 89.7 vs. 39.7 months, HR 2.12, CI 1.55-2.89, p&lt;0.0001). A &gt;50% reduction in FLCs from baseline to treatment cycle 2 (OR 5.92, CI 2.15-19.23, p=0.001) and cycle 3 (OR 5.25, CI 2.15-19.25, p=0.006) were strongly associated with renal response Median OS was 69.6 months (CI 55.4-89.7). Forty-three pts died within the first 12 months of treatment and additional 146 during further FU. Pts with a best GFR of &gt;15ml/min had a significantly longer OS compared to those with GFR &lt;15ml/min (median: 77.9 vs 31.9 months, HR 1.85, CI 1.16-2.94, p=0.01). The comparison of survival of pts with different renal response groups and with the best eGFR showed no statistically significant difference (log rank p=0.1, long rank p=0.057, respectively). Other factors that correlated with longer OS were bortezomib-based therapy (77.9 vs. 44.0 months, HR 1.59, CI 1.05-2.38, p=0.03), M-protein isotype with κ as compared to l light chain type (84.9 vs. 51.4 months, HR 1.47, CI 1.09-2.00, p=0.013), and higher hemoglobin (HR 1.16, CI 1.06-1.26, p=0.001). In contrast, hypercalcemia which was noted in 101 (29.4%) pts (HR 1.10, CI 1.03-1.18, p=0.005), ISS stage III vs. I-II (57.8 vs. 126.2 months, HR 2.26, CI 1.22-4.17, p=0.009), and ECOG status 3+4 vs. 2 vs. 0+1 (24.4 vs. 44.6 vs. 103 months, HR 2.83, CI 2.15-3.74, p&lt;0.0001) were associated with shorter OS. Hypercalcemia, correlated with renal response (OR 1.27, CI 1.12-1.44, p=0.0002), and best eGFR ≥46.4 ml/min (median dichotomized) (OR 1.28, CI 1.14-1.46, p&lt;0.0001). 119 (34.7%) pts required initial dialysis, OS was significantly longer in those who achieved best eGFR levels of &gt;15ml/min. (77.6 vs 31.9 months, HR 0.54, CI 0.34-0.86, p=0.01); 64 (53%) pts discontinued dialysis. Conclusion: Myeloma response correlated with renal response as defined by IMWG criteria. A &gt;50% reduction in FLCs from baseline to treatment cycle ≥2 was strongly associated with renal response. OS was longer in pts with renal response, in pts receiving bortezomib-based therapy, and in pts with kappa light chain M-proteins. Hypercalcemia was frequent (29.4%), and associated with higher renal response rate and best eGFR, but shorter OS. Pts on dialysis who achieved eGFR &gt;15ml/min had better survival. Fast diagnostic work up, rapid treatment initiation and achieving significant myeloma response (≥VGPR) is essential to prevent irreversible kidney damage. Including novel immunotherapies may further improve outcome.