Novel monoclonal antibodies: A really specific therapy for light chain amyloidosis.

Light chain amyloidosis is a rare disease caused by clonal plasma cells in the bone marrow generating an excessive amount of immunoglobulin light chains. These chains misfold and produce insoluble fibrils that deposit in various organs, including the heart, kidneys, liver, nervous system, and digestive tract. Life expectancy and symptoms during the course of the disease vary depending on which and how many organs are affected. Targeted plasma cell therapy has significantly advanced the clinical management of amyloidosis, with ongoing progress. However, current clinical studies are investigating innovative targets, drug combinations and treatment strategies to improve therapeutic outcomes by minimizing adverse effects and refining patient prognosis in these challenging hematological conditions. In this paper, we review the state of the art regarding the use of anti-amyloid antibodies, as a revolutionary and innovative approach in the current scenario of amyloid treatment.

Successful Treatment of Systemic Light Chain Amyloidosis with Liver Involvement using Low-Frequency Daratumumab: A Case Report.

BACKGROUND Systemic light chain (AL) amyloidosis is a disease characterized by the deposition of amyloid fibrils throughout tissues due to the production of misfolded immunoglobulin light chains by clonally expanded populations of CD38+ plasma cells. Some patients can have liver involvement, which typically presents with nonspecific symptoms. Daratumumab, a human CD38-targeting antibody, has shown efficacy in improving hematological parameters and organ function in patients with AL amyloidosis. Low-frequency daratumumab can reduce financial burden, but whether it is effective for patients with liver involvement has not been reported. CASE REPORT We present the case of a 64-year-old man admitted to our hospital with fatigue and recurrent fever. Histological analysis of a liver biopsy demonstrated AL amyloidosis. Bone marrow biopsy demonstrated the presence of abnormal plasma cells. Laboratory test results demonstrated increased levels of circulating free kappa (kappa) light chains, which were also seen on blood and urine immunofixation electrophoresis. Based on these findings, AL amyloidosis of the kappa light chain type with liver, cardiac, and renal involvement was diagnosed. The patient ultimately achieved hematological stringent complete response, liver remission, renal complete response, and cardiac very good partial response after 2 cycles of the low-frequency daratumumab, bortezomib, and dexamethasone regimen and 4 cycles of daratumumab and dexamethasone regimen chemotherapy. CONCLUSIONS The case indicates that low-frequency daratumumab treatment can have efficacy in AL amyloidosis with liver involvement.

Daratumumab in first-line treatment of patients with light chain amyloidosis and Mayo stage IIIb improves treatment response and overall survival.

Treatment of patients with Mayo stage IIIb light chain (AL) amyloidosis is still challenging, and the prognosis remains very poor. Mayo stage IIIb patients were excluded from the pivotal trial leading to the approval of daratumumab in combination with bortezomib-cyclophosphamide-dexamethasone. This retrospective, multicenter study evaluates the addition of daratumumab to first-line therapy in patients with newly diagnosed stage IIIb AL amyloidosis. In total, data from 119 consecutive patients were analyzed, 27 patients received an upfront treatment including daratumumab, 63 a bortezomibbased regimen without daratumumab, eight received therapies other than daratumumab or bortezomib and 21 pretreated patients or deceased prior to treatment were excluded. In the daratumumab group, median overall survival was not reached after a median follow-up time of 14.5 months, while it was significantly worse in the bortezomib- and the otherwise treated group (6.6 and 2.2 months, respectively) (P=0.002). Overall hematologic response rate at 2 and 6 months was better in the daratumumab group compared to the bortezomib group (59% vs. 37%, P=0.12, 67% vs. 41%, P=0.04, respectively). Landmark survival analyses revealed a significantly improved overall survival in patients with partial hematologic response or better, compared to non-responders. Cardiac response at 6 months was 46%, 21%, 0% in the daratumumab-, bortezomib- and otherwise treated groups, respectively (P=0.04). A landmark survival analysis revealed markedly improved overall survival in patients with cardiac very good partial response vs. cardiac non-responders (P=0.002). This study demonstrates for the first time the superiority of an upfront treatment with daratumumab over standard-of-care in stage IIIb AL amyloidosis.

Risk factors, treatments and outcomes of patients with light chain amyloidosis who relapse after autologous stem cell transplantation.

Relapse after ASCT is an important factor affecting the long-term prognosis of patients with AL amyloidosis. However, the risk factors of relapse are unknown and there are limited studies on treatment outcomes of these patients. We retrospectively reviewed 170 patients with AL amyloidosis who underwent ASCT between 2010 and 2021. Seventy-six patients confirmed as relapse and the median time from ASCT to relapse was 39 months. On multivariate analysis of variables before and after ASCT, lambda restricted, dFLC >30 mg/L pre ASCT, reduced dose melphalan and dFLC >10 mg/L at 6 months after ASCT were independent risk factors for relapse, and achieving CR after induction therapy and renal response after ASCT were protective factors. Most relapsed patients were treated with bortezomib-based regimens (50%) followed by daratumumab-based regimens (22.2%) and other chemotherapy regimens (13.9%). The overall hematological response in evaluable patients was 68.2% with 56.8% achieving CR/VGPR. The median PFS and OS from post-transplant relapse were 25 months and 81 months, respectively. Patients receiving bortezomib or daratumumab showed a better survival compared to other chemotherapy regimens. In conclusion, this study identified independent risk factors of post-transplant relapse and demonstrated the superiority of bortezomib or daratumumab treatment for these patients. CLINICAL TRIAL REGISTRATION: NCT04210791.

¿Qué hay de nuevo en el tratamiento de amiloidosis por cadenas livianas? Parte 1: cadenas livianas / What is new in light chain amyloidosis treatment? Part 1: lightweight chains

La amiloidosis AL es una enfermedad debida al depósito, en órganos y tejidos, de fibrillas formadas por cadenas livianas producidas de forma patológica por plasmocitos clonales. Su tratamiento actualmente está orientado a erradicar el clon de células plasmáticas; este históricamente se extrapoló de tratamientos disponibles y estudiados para otras discrasias sanguíneas. En el año 2020, el Grupo de Estudio de Amiloidosis (GEA) confeccionó distintas guías de práctica clínica para el tratamiento de la amiloidosis AL. Desde entonces se han publicado ensayos clínicos que arrojan contundencia al conocimiento disponible hasta el momento, y están en desarrollo nuevas líneas de investigación que robustecen y estimulan el estudio en el área. En esta revisión se realiza una actualización de las guías existentes en lo que respecta al tratamiento de la amiloidosis por cadenas livianas.Como evidencia de relevancia, en el último año estuvieron disponibles resultados de ensayos clínicos que respaldan el uso de esquemas basados en daratumumab (un anticuerpo monoclonal anti-CD38+) para pacientes con diagnóstico reciente de amiloidosis AL como primera línea. Además, para el tratamiento de la amiloidosis AL refractaria o recaída, la disponibilidad de bibliografía respaldatoria es escasa y extrapolada del tratamiento del mieloma múltiple; sin embargo, actualmente existe evidencia de calidad para recomendar el uso de ixazomib, un inhibidor de proteosoma reversible por vía oral disponible en la Argentina desde 2020. Por último, se mencionan algunas líneas de investigación con otros anticuerpos monoclonales y terapéuticas basadas en el uso de CAR-T cells. (AU)

AL amyloidosis is a disease caused by the deposit in different organs and tissues of protein fibrils formed by light chains synthetized by pathological clonal plasma cells. Its treatment is currently aimed at eradicating this plasma cell clone and it has been historically extrapolated from available and validated treatments for other blood dyscrasias. In 2020, the Amyloidosis Study Group prepared different clinical practice guidelines for the treatment of AL amyloidosis.Since then, clinical trials have been published that confirm and strengthen the knowledge available up to now, and new lines of research are being developed that stimulate study in the area. In this review, an update of the existing guidelines regarding the treatment of AL amyloidosis is made. As relevant evidence, in the last year, results of clinical trials have been made available that support the use of regimens based on Daratumumab (an anti-CD38+ monoclonal antibody) for patients with newly diagnosed AL amyloidosis as first line therapy. In addition, for the treatment of refractory or relapsed AL amyloidosis, where the availability of supporting literature is scant and extrapolated from the treatment of multiple myeloma, there is currently quality evidence to recommend the use of ixazomib, an oral reversible proteasome inhibitor, only available in Argentina since 2020. Finally, some research lines exploring the efficacy of other monoclonal antibodies and therapeutic experiments based on the use of CAR-T cells are mentioned. (AU)

Clinical characterization and outcomes of a cohort of colombian patients with AL Amyloidosis.

Background: Amyloid light chain (AL) amyloidosis is characterized by amyloid fibril deposition derived from monoclonal immunoglobulin light chains, resulting in multiorgan dysfunction. Limited data exist on the clinical features of AL amyloidosis. Objective: This study aims to describe the clinical characteristics, treatments, and outcomes in Colombian patients with AL amyloidosis. Methods: A retrospective descriptive study was conducted at three high-complexity centers in Medellín, Colombia. Adults with AL amyloidosis diagnosed between 2012 and 2022 were included. Clinical, laboratory, histological, treatment, and survival data were analyzed. Results: The study included 63 patients. Renal involvement was most prevalent (66%), followed by cardiac involvement (61%). Multiorgan involvement occurred in 61% of patients. Amyloid deposition was most commonly detected in renal biopsy (40%). Bortezomib-based therapy was used in 68%, and 23.8% received high-dose chemotherapy with autologous hematopoietic stem cell transplantation (HDCT-ASCT). Hematological response was observed in 95% of patients with available data. Cardiac and renal organ responses were 15% and 14%, respectively. Median overall survival was 45.1 months (95% CI: 22.2-63.8). In multivariate analysis, cardiac involvement was significantly associated with inferior overall survival (HR 3.27; 95% CI: 1.23-8.73; p=0.018), HDCT-ASCT had a non-significant trend towards improved overall survival (HR 0.25; 95% CI: 0.06-1.09; p=0.065). Conclusions: In this study of Colombian patients with AL amyloidosis, renal involvement was more frequent than cardiac involvement. Overall survival and multiorgan involvement were consistent with data from other regions of the world. Multivariate analysis identified cardiac involvement and HDCT-AHCT as possible prognostic factors.

Antecedentes: La amiloidosis por amiloide de cadenas ligeras (AL) se caracteriza por el depósito de fibrillas amiloides derivadas de cadenas ligeras de inmunoglobulinas monoclonales, lo que resulta en disfunción multiorgánica. Existen datos limitados sobre las características clínicas de la amiloidosis AL. Objetivo: Este estudio tiene como objetivo describir las características clínicas, tratamientos y desenlaces en pacientes colombianos con amiloidosis AL. Métodos: Se llevó a cabo un estudio descriptivo retrospectivo en tres centros de alta complejidad en Medellín, Colombia. Se incluyeron adultos con diagnóstico de amiloidosis AL entre 2012 y 2022. Se analizaron datos clínicos, de laboratorio, histológicos, de tratamiento y de supervivencia. Resultados: El estudio incluyó 63 pacientes. La afectación renal fue más prevalente (66%), seguida de la afectación cardíaca (61%). El 61% de los pacientes presentaron afectación multiorgánica. El depósito amiloide se detectó con mayor frecuencia en la biopsia renal (40%). El tratamiento basado en bortezomib se utilizó en el 68%, y el 23.8% recibió altas dosis de quimioterapia con trasplante autólogo de progenitores hematopoyéticos (ADQT-TAPH). Se observó respuesta hematológica en el 95% de los pacientes con datos disponibles. La respuesta de órgano cardíaca y renal fue del 15% y 14%, respectivamente. La mediana de la supervivencia global fue de 45.1 meses (IC del 95%: 22.2-63.8). En el análisis multivariado, la afectación cardíaca se asoció significativamente con una supervivencia global inferior (HR 3.27; IC del 95%: 1.23-8.73; p=0.018), ADQT-TAPH mostró una tendencia no significativa hacia una mejora en la supervivencia global (HR 0.25; IC 95%: 0.06-1.09; p=0.065). Conclusiones: En este estudio de pacientes colombianos con amiloidosis AL, la afectación renal fue más frecuente que la afectación cardíaca. La supervivencia global y la afectación multiorgánica fueron consistentes con datos de otras regiones del mundo. El análisis multivariado identificó la afectación cardíaca y ADQT-TAPH como posibles factores pronósticos.

Role of autologous haematopoietic cell transplantation in the treatment of systemic light chain amyloidosis in the era of anti-CD38 monoclonal antibodies.

The primary goal of the initial treatment in systemic light chain amyloidosis is to obtain a rapid and profound haematological response as safely as possible, coupled with supportive care by a multidisciplinary team. The treatment landscape has evolved with the introduction of highly effective therapies targeting the plasma cell clones, which can attain high rates of haematological complete response with minimal treatment-related morbidity and mortality. Consequently, the role of high-dose melphalan followed by autologous haematopoietic cell transplantation (HDM-AHCT) is being analysed, particularly considering the absence of randomised controlled trial data supporting its superiority over standard-dose therapies in systemic light chain amyloidosis treatment. In this Viewpoint, we will explore the role of HDM-AHCT in the management of patients with systemic light chain amyloidosis who are eligible for transplantation, and the unresolved questions surrounding HDM-AHCT use as both front-line and salvage therapy.

Safety and Efficacy of Propylene Glycol-Free Melphalan in Patients with AL Amyloidosis Undergoing Autologous Stem Cell Transplantation: Results of a Phase II Study.

Patients with systemic light chain (AL) amyloidosis undergoing treatment with high-dose melphalan and autologous stem cell transplantation (HDM/SCT) may develop renal and cardiac toxicities potentially exacerbated by the co-solvent propylene glycol in conventional melphalan formulations. We investigated the safety and efficacy of propylene glycol-free melphalan (PGF-Mel) during HDM/SCT in patients with AL amyloidosis (ClinicalTrials.gov identifier NCT02994784). The primary objective of this phase II, open-label study was evaluation for renal dysfunction, new cardiac arrhythmias, and postural hypotension related to autonomic dysfunction. Secondary objectives included time to neutrophil and platelet engraftment, treatment-related mortality (TRM), overall hematologic response, organ response, and number of peritransplantation hospitalizations. Twenty-eight patients with AL amyloidosis enrolled, of whom 27 underwent HDM/SCT. PGF-Mel at 140 to 200 mg/m2 was administered i.v. in 2 equally divided doses. Patients were monitored for up to 30 days after the last administration of PGF-Mel to assess for treatment-related toxicity. Patients were followed for 12 months from the time of treatment with HDM/SCT for evaluation of hematologic and organ responses. Kaplan-Meier analysis was used to estimate progression-free survival. Two patients (7%) developed renal dysfunction, 5 (19%) experienced new cardiac arrhythmias, and 3 (11%) developed orthostatic hypotension. All patients achieved neutrophil and platelet engraftment, at a median of 10 days and 17 days post-HDM/SCT, respectively. TRM on day +100 was 0%. Peritransplantation hospitalization was required for 23 patients (85%). The most common nonhematologic adverse events were diarrhea (93%), fatigue (82%), and nausea (74%). At 6 months post-HDM/SCT, hematologic complete response or very good partial response occurred in 66% of the patients. At 12 months post-HDM/SCT, renal response occurred in 12 of 23 (52%) patients with renal involvement, and cardiac response occurred in 3 of 11 (27%) patients with evaluable cardiac involvement. Our data indicate that PGF-Mel is safe and efficacious as a high-dose conditioning regimen for autologous SCT in patients with AL amyloidosis.

A retrospective analysis of clinical features and treatment outcome in 21 patients with immunoglobulin M-related light-chain amyloidosis in Japan: a study from the Amyloidosis Research Committee.

We retrospectively gathered data of 21 patients (13 male and 8 female; median age 65 years) diagnosed with immunoglobulin M (IgM)-related light-chain (AL) amyloidosis in Japan to investigate characteristics of IgM-AL amyloidosis and its optimal treatment strategy. Median IgM and difference free light chain (FLC) at diagnosis were 1257 mg/dl and 34.3 mg/l, respectively. Organ involvement was observed in the heart in 7 patients (33%), kidneys in 15 (71%), and lymph nodes in 5 (24%). Initial treatments were melphalan/dexamethasone in 7 patients, bortezomib/cyclophosphamide/dexamethasone in 3, autologous stem cell transplantation in 3, rituximab/bendamustine in 1, other in 3, and none in 4. Hematological responses among 15 evaluable patients were as follows: 3 reached complete response (CR), 4 partial response (PR), and 1 very good PR (VGPR), making the overall response rate of PR or better 40%. Median overall survival (OS) was 14.0 months and 1-year OS was 71.4%. Prognosis was significantly poorer in patients with cardiac involvement than those with non-cardiac involvement (1-year OS 27.8% vs. 85.7%, p = 0.0468). The involved FLC value was low in several patients and therapeutic response was difficult to assess. Further study is necessary to determine the optimal treatment for IgM-AL amyloidosis.

Heparin-resistance in AL amyloidosis: a case report.

BACKGROUND: Non-AT-III mediated heparin-resistance during CPB occurs by complex-forming with heparin-binding proteins. Currently, there are no specific recommendations for non-AT-III mediated heparin-resistance. CASE PRESENTATION: We present a fatal case of a 70-yr-old male-patient undergoing cardiac-surgery in which refractory heparin-resistance was observed. The massive AL amyloidosis found at autopsy is thought to be responsible and illustrates that awareness and knowledge of the etiology and perioperative strategies of non-AT-III mediated heparin-resistance is important. CONCLUSION: For anticoagulation during cardiopulmonary bypass surgery in case of a non-AT-III medicated heparin resistance, we refer to the decision tree added to this manuscript and if necessary to consider direct thrombin inhibitors, such as bivalirudin or argatroban, as it bypasses the complexing pathway.

Birtamimab plus standard of care in light-chain amyloidosis: the phase 3 randomized placebo-controlled VITAL trial.

Amyloid light-chain (AL) amyloidosis is a rare, typically fatal disease characterized by the accumulation of misfolded immunoglobulin light chains (LCs). Birtamimab is an investigational humanized monoclonal antibody designed to neutralize toxic LC aggregates and deplete insoluble organ-deposited amyloid via macrophage-induced phagocytosis. VITAL was a phase 3 randomized, double-blind, placebo-controlled clinical trial assessing the efficacy and safety of birtamimab + standard of care (SOC) in 260 newly diagnosed, treatment-naive patients with AL amyloidosis. Patients received 24 mg/kg IV birtamimab + SOC or placebo + SOC every 28 days. The primary composite end point was the time to all-cause mortality (ACM) or centrally adjudicated cardiac hospitalization ≥91 days after the first study drug infusion. The trial was terminated early after an interim futility analysis; there was no significant difference in the primary composite end point (hazard ratio [HR], 0.826; 95% confidence interval [CI], 0.574-1.189; log-rank P = .303). A post hoc analysis of patients with Mayo stage IV AL amyloidosis, those at the highest risk of early mortality, showed significant improvement in the time to ACM with birtamimab at month 9 (HR, 0.413; 95% CI, 0.191-0.895; log-rank P = .021). At month 9, 74% of patients with Mayo stage IV AL amyloidosis treated with birtamimab and 49% of those given placebo survived. Overall, the rates of treatment-emergent adverse events (TEAEs) and serious TEAEs were generally similar between treatment arms. A confirmatory phase 3 randomized, double-blind, placebo-controlled clinical trial of birtamimab in patients with Mayo stage IV AL amyloidosis (AFFIRM-AL; NCT04973137) is currently enrolling. The VITAL trial was registered at www.clinicaltrials.gov as #NCT02312206.

A phase 1b dose-escalation study of carfilzomib in combination with thalidomide and dexamethasone in patients with relapsed/refractory systemic immunoglobulin light chain amyloidosis.

INTRODUCTION: Proteasome inhibitors are the backbone of AL amyloidosis treatment - bortezomib being most widely used. Carfilzomib is a proteasome inhibitor licenced to treat multiple myeloma; autonomic and peripheral neuropathy are uncommon toxicities with carfilzomib. There is limited data on the use of carfilzomib in AL amyloidosis. Here, we report the results of a phase Ib dose-escalation study of Carfilzomib-Thalidomide-Dexamethasone (KTD) in relapsed/refractory AL amyloidosis. RESULTS: The trial registered 11 patients from 6 UK centres from September 2017 to January 2019; 10 patients received at least one dose of trial treatment. 80 adverse events were reported from 10 patients in the 1st three cycles. One patient experienced dose-limiting toxicity (acute kidney injury) at a dose of 45 mg/m2, and another patient had a SAR (fever). Five patients experienced an AE ≥ grade 3. There were no haematologic, infectious, or cardiac AE ≥ grade 3. The overall haematological response rate (ORR) at the end of three cycles of treatment was 60%. CONCLUSION: Carfilzomib 45 mg/m2 weekly can be safely given with thalidomide and dexamethasone. The efficacy and tolerability profile appears comparable to other agents in relapsed AL amyloidosis. These data provide a framework for further studies of carfilzomib combinations in AL amyloidosis.

Systemic AL amyloidosis: current approach and future direction.

Systemic Light chain (AL) amyloidosis is a monoclonal plasma cell proliferative disorder characterized by deposition of amyloidogenic monoclonal light chain fragments causing organ dysfunction. It is a fatal disease and if not diagnosed and treated early can lead to organ failure and potentially death. The renal system along with the cardiovascular system are the most common organs involved but other organs such as gut and liver can be involved as well. The initial evaluation of patients requires confirming the diagnosis with tissue biopsy and staining with Congo red followed by confirmatory typing with mass spectrometry of the Congo red positive tissue. Then establishing the extent of the organs involvement by various staging and biomarkers testing. The treatment options and the tolerability of therapy depend on the disease staging, frailty, and co-morbidities. The autologous hematopoietic cell transplantation (HCT) after high dose melphalan therapy is an effective strategy which is usually done after initial bortezomib induction therapy. Unfortunately, most systemic AL amyloidosis patients are not candidate for HCT due to frailty, old age, multi-organ involvement, renal and heart failure at the time of diagnosis. While it is widely accepted that the patients need to be treated until they achieve complete hematologic response, the maintenance therapy after HCT is not well established in AL amyloidosis. In this review, we report the literature on the latest treatment updates of AL amyloidosis and the ongoing clinical trials highlighting the future treatments.

Outcomes for patients with systemic light chain amyloidosis and Mayo stage 3B disease.

Patients with cardiac light chain amyloidosis and Mayo stage 3b disease define a high-risk population with very poor prognosis. Here, we report treatment outcomes of 80 consecutive patients with newly diagnosed AL and Mayo 3b who received novel regimens. Early mortality (<1 month) rate was 12.5%. On intention-to-treat, overall hematologic response rate was 40%, with complete response (CR)/very good partial response (VGPR) in 25% and partial response (PR) in 15%. At 1- and 3- month landmark analysis CR or VGPR/PR rates were 25%/23.5% and 34%/25.5%, respectively. Among patients that were treated with daratumumab-based therapies, 52.6% and 85.7% achieved at least VGPR within one 1 and 3 months, respectively. Three-month cardiac response rate was 11.3% and 6-month was 18.8%. At least hemVGPR at 3 months was associated with cardiac response at 6 months (p = 0.034). Median overall survival (OS) was 6.3 months. At 1-month landmark at least hemPR was associated with better median OS (24.1 vs. 4.9 months, p = 0.017) and at 3-month landmark, at least hemVGPR was associated with a median OS of 40.7 versus 17 months for hemPR and 7.4 months for those without hematologic response (p = 0.028). Cardiac response at 3 months was associated with longer median OS (59.7 vs. 10.9 months, p = 0.044). Factors associated with poorer survival were κ-light chain amyloidosis (median OS 2.9 vs. 7.4 months, p = 0.028), peripheral nerve involvement (3.4 vs. 10.45 months, p = 0.024), systolic blood pressure <90 mmHg (2 vs. 8 months, p = 0.002), baseline LVEF <55% (median OS 3.4 vs. 32 months, p = 0.29) and New York Heart Association (NYHA) class (2.7 months for NYHA 3B-4 vs. 8 months for NYHA 2-3A, p = 0.02). Twenty-one patients (26.3%) received salvage therapy and ORR was 57.1%. Median OS for patients who received second line therapy was 24 months. In conclusion, patients with Mayo 3b disease benefit from early hematologic response but cardiac response rates remain low.