Lentzsch, Suzanne

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 The B-cell maturation antigen (BCMA)–targeting bispecific T-cell engager pavurutamab (AMG 701) directs the cytotoxic T-cell response toward multiple myeloma (MM) cells. This phase 1/1b, open-label, dose-exploration and dose-expansion study evaluated the safety, tolerability, and efficacy of pavurutamab monotherapy in patients with triple-class relapsed/refractory MM (RRMM). Pavurutamab (5-18 000 μg) was administered IV weekly with step-up dosing in week 1. Overall, 172 patients received at least 1 dose of pavurutamab; 73 received the recommended phase 2 dose (RP2D; 18 000 μg), with 2 different step-up dosing regimens in phase 1b. Twelve patients had dose-limiting toxicities, which included cytokine release syndrome (CRS) and increased transaminases; none of which occurred at the RP2D. The most frequently reported treatment-emergent adverse events included CRS (74.4%), anemia (61.0%), neutropenia (47.1%), and hypophosphatemia (45.3%). Grade ≥3 infections were noted in 60 patients (34.9%). The overall response rate (ORR) was 46.5% among all patients and 65.8% (very good partial response [VGPR] or better, 60.3%) among 73 patients treated at the RP2D. At median follow-up of 17.2 months, median duration of response (DOR) was 36.6 months (95% confidence interval [CI], 22.3 to not estimable). Median progression-free survival (PFS) for all patients was 5.5 months (95% CI, 2.8-10.1) and 16.8 months (95% CI, 5.0 to not estimable) with the RP2D. Pavurutamab exposure generally increased in a dose-proportional manner, with high soluble BCMA levels correlating with lower exposure level. The acceptable safety profile, pharmacokinetics, and preliminary efficacy of pavurutamab supports anti-BCMA T-cell engager therapy in heavily pretreated patients with RRMM. This trial was registered at www.clinicaltrials.gov as NCT03287908.

PURPOSE Binary cardiac response assessment using cardiac biomarkers is prognostic in light chain amyloidosis. Previous studies suggested four-level cardiac responses using N-terminal prohormone of brain natiuretic peptide improves prognostic prediction. This study was designed to validate graded cardiac response criteria using N-terminal prohormone of brain natiuretic peptide/brain natiuretic peptide. PATIENTS AND METHODS This retrospective, multicenter study included patients with light chain amyloidosis who achieved at least a hematologic partial response (PR) and were evaluable for cardiac response. Four response criteria were tested on the basis of natriuretic peptide response depth: cardiac complete response (CarCR), cardiac very good partial response (CarVGPR), cardiac PR (CarPR), and cardiac no response (CarNR). Response was classified as best response and at fixed time points (6, 12, and 24 months from therapy initiation). The study primary outcome was overall survival. RESULTS 651 patients were included. Best CarCR, CarVGPR, CarPR, and CarNR were achieved in 16%, 26.4%, 22.9%, and 34.7% of patients, respectively. Patients in cardiac stage II were more likely to achieve CarCR than patients in cardiac stage IIIA and IIIB (22% v 13.5% v 3.2%; P < .001). A deeper cardiac response was associated with a longer survival (5-year overall survival 93%, 79%, 65%, and 33% for CarCR, CarVGPR, CarPR, and CarNR, respectively; P < .001). Fixed time-point analyses and time-varying covariates Cox regression analysis, to minimize survivorship bias, affirmed the independent survival advantage of deeper cardiac responses. Four-level response performed better than two-level response as early as 12 months from therapy initiation. CONCLUSION Graded cardiac response criteria allow better assessment of cardiac improvement compared with the traditional binary response system. The study re-emphasizes the importance of early diagnosis, which increases the likelihood of deep cardiac responses.