Maintenance therapy promotes profound organ and haematologic response in light-chain amyloidosis patients not undergoing autologous stem cell transplantation.

BACKGROUND: Evidence on maintenance therapy following frontline induction is sparse in primary light-chain amyloidosis (AL), especially for those who do not undergo autologous haematopoietic stem cell transplantation (ASCT). METHODS: We enrolled primary AL patients who achieved at least haematologic very good partial response (VGPR) by the 4th month at the frontline from December 2008 to June 2023 at Zhongshan Hospital, Fudan University. Those who followed maintenance therapy were identified as the maintenance group (n = 44), whereas those entering the observational phase were classified as the observational group (n = 24). RESULTS: After 7.2(interquartile range, 4.7-18.6) months of maintenance therapy, 9(20.5%), 14(31.8%) and 5 (11.4%) patients achieved improvement in haematologic, cardiac and renal response respectively. Five (11.4%) patients had minimal residual disease (MRD) response conversion from positive to negative based on maintenance therapy. In the observation group, none of the patients had haematologic response improvement, with 3(12.5%) and 1(4.2%) patient showing cardiac and renal response improvement during follow-up. CONCLUSION: This study identified the clinical benefits of maintenance therapy in patients with AL who did not undergo ASCT in real-world practice.

Current and Emerging Immunotherapies for Systemic AL Amyloidosis.

Systemic light-chain (AL) amyloidosis is a rare and complex clonal plasma cell neoplasm characterized by the production of misfolded and unstable immunoglobulin light-chains leading to multisystem amyloid deposition, which progresses to organ dysfunction and eventual failure. The importance and urgency of AL amyloidosis depends on its potential to induce significant organ impairment, progressive course, risk of life-threatening complications, and the limited treatment options available. Treatment options and prognosis depend on the number and severity of organ involvement at the time of diagnosis with cardiac involvement carrying the worst outcomes. The treatments aim to target eliminating the underlying clonal plasma cell neoplasm and prevent the production and deposition of amyloid precursor immunoglobulin light-chain protein in the affected vital organs. Strategies for treating systemic AL amyloidosis have incorporated anti-plasma cell therapies approved in the management of multiple myeloma due to their shared cellular derivation. Quadruplet therapy of cyclophosphamide, bortezomib, dexamethasone and daratumumab (DaraCyborD) is the currently approved first-line induction therapy for systemic AL amyloidosis. Some patients need upfront autologous hematopoietic stem cell transplantation (HSCT) after high-dose melphalan conditioning particularly if DaraCyborD is not able to achieve complete hematologic response (CHR). Additionally, a promising treatment option involves disassembling amyloid deposits from the vital organs using monoclonal antibodies such as CAEL 101 or Birtamimab with the expectation of restoring damaged tissues of the vital organs affected thereby improving or reversing patients' symptoms. Both CAEL 101 and Birtamimab are currently being tested in phase 3 clinical trials for systemic AL amyloidosis patients with advanced cardiac involvement. This comprehensive review provides an up-to-date overview of AL amyloidosis therapy, with a particular focus on recent advances and future directions of immunotherapeutic strategies.

Long-term outcomes of renal AL amyloidosis patients undergoing autologous stem cell transplantation: Validating the performance of the renal staging system.

Renal AL amyloidosis can be complicated by end-stage renal disease (ESRD) requiring renal replacement therapy (RRT). In this study, we describe the long-term outcomes of renal AL amyloidosis patients undergoing autologous stem cell transplantation (ASCT) and assess the utility of the renal staging system. Retrospective study of renal AL patients (n = 697; Mayo Clinic, Boston University) who underwent ASCT between 2003 and 2020. Renal stage was assigned based on 24-h proteinuria and estimated glomerular filtration rate measurements. Renal survival was defined as the time from ASCT until initiation of RRT, while patients who were not placed on RRT were censored at their last follow-up. With a median follow-up of 10.4 years, RRT was required in 149 patients (21%). The median time from ASCT to ESRD was 3.4 years, with late events of progression to ESRD seen >10 years from ASCT. Pre-ASCT renal stage was significantly associated with the cumulative incidence of RRT: 3-year RRT rate was 3%, 10%, and 37% for renal stages I, II, and III, respectively. However, in the 2012-2020 period subset, a significant decrease in ESRD risk was noted across all renal stages (3-year RRT 0%, 5%, and 24%, respectively). In multivariate analysis, renal survival was independently associated with the pre-ASCT renal stage, lambda isotype, bone marrow plasmacytosis ≥20%, post-ASCT hematologic response, and year of ASCT. Long-term outcomes of renal AL amyloidosis treated with ASCT are presented. Renal stage reliably predicts renal outcomes in patients with AL undergoing ASCT, despite a reduction in the proportion of patients progressing to RRT in recent years.

Improving care for systemic light-chain amyloidosis patients: is a multidisciplinary approach best?

INTRODUCTION: Light chain (AL) amyloidosis is a rare and complex disease which can affect various systems of the body. In common with many rare and multisystemic diseases, the breadth of diagnostic, clinical, and supportive expertise required to care for such patients is best met by a multidisciplinary team. AREAS COVERED: We outline different phases of the patients' journey, including diagnosis, staging, treatment, and response assessment, to highlight common clinical issues best resolved by a multidisciplinary approach. EXPERT OPINION: To extend the benefit of multidisciplinary care to the majority of patients with AL amyloidosis, innovative healthcare models such as telehealth and multisite multidisciplinary team meetings need to be implemented. The need for a multidisciplinary approach where such a wide array of healthcare skills is required also highlights the shortcomings of our current diagnostic and monitoring assays. Better access to diagnostic and subtyping assays is necessary. The ability to characterize and measure the causative amyloidogenic light chain as well as imaging techniques to accurately diagnose and monitor response to therapy is also needed and is currently an area of research focus.

Role of Autologous Stem Cell Transplantation in Systemic Light Chain Amyloidosis.

Systemic light chain (AL) amyloidosis is a multisystem disorder characterized by extracellular deposition of misfolded insoluble amyloid fibrils resulting in progressive organ dysfunction. AL. amyloidosis most commonly affects the heart, kidneys, gastrointestinal tract and peripheral nerves. Early mortality is chiefly determined by the degree of cardiac involvement. The aim of therapy is to rapidly reduce amyloidogenic light chain production by targeting the underlying clonal plasma or lymphoma cell population. High dose therapy with melphalan followed by autologous peripheral blood stem cell transplant (ASCT) continues to remain a highly effective treatment and is considered a standard of care for transplant eligible patients, which offers long term disease control in patients with AL amyloidosis. In recent years, several new therapeutic options have emerged (including anti-CD38 monoclonal antibodies) which are very effective alone or in combination in eradicating clonal plasma cells. In this review, we discuss the role of ASCT in the current setting of a rapidly evolving treatment landscape for patients with AL amyloidosis and provide our practice recommendations.

Healthcare resource utilisation and costs associated with AL amyloidosis: a retrospective matched cohort study.

We conducted a retrospective population-based, matched cohort study using the National Health Insurance Research Database to estimate healthcare resource utilisation (HRU) and costs in patients with newly diagnosed AL amyloidosis in Taiwan. Cases were matched 10:1 by age, sex, and area of residence to patients without AL amyloidosis (comparators) randomly selected from the database during the same time period. Annual all-cause HRU and costs for 3 years were quantified. AL amyloidosis-attributable costs were obtained by subtracting all-cause HRU costs incurred by comparators from cases. The mean age of all patients was 60.78 years and 59.07% were male. Co-morbidities were more frequent in cases than comparators. By 6 months after diagnosis, 12.1% of cases had died versus 0.9% of comparators. In the first year, cases had 103% more outpatient visits, 177% more emergency room visits, were hospitalised 4-times more frequently, and spent 5.5-times more days in hospital than comparators, and total healthcare costs were > sixfold higher. Costs incurred during the first year after diagnosis accounted for 55% of the 3-year cumulative cost. High HRU costs associated with delayed diagnosis and end-organ damage indicate a need for earlier diagnosis and more effective treatments for AL amyloidosis.

Digital whole-slide imaging of changes in amyloid after peripheral blood stem cell transplantation in patients with amyloid light-chain amyloidosis.

Peripheral blood stem cell transplantation (PBSCT) has made amyloid light-chain (AL) amyloidosis treatable. After PBSCT, hematological complete remission (HCR) can be achieved, leading to improved renal prognosis. The purpose of this study was to evaluate whether whole slide imaging of biopsy samples shows a post-treatment reduction in amyloid deposits in patients with AL amyloidosis. Patients were divided into three groups: Group A (n = 8), not eligible for PBSCT and treated with other therapies; Group B (n = 11), treated with PBSCT and achieved HCR; and Group C (n = 5), treated with PBSCT but did not achieve HCR. Clinical findings and amyloid deposition in glomeruli, interstitium, and blood vessels were compared before and after treatment using digital whole-slide imaging. Proteinuria and hypoalbuminemia improved more in Group B than in the other groups, and in Group B, amyloid deposition improved more in the glomeruli than in the interstitium and blood vessels. The long-term renal and survival prognosis was better in Group B than in the other groups. PBSCT can be expected to improve long-term clinical and renal histological prognosis in patients with AL amyloidosis who achieve HCR. Amyloid disappearance from renal tissue may take a long time even after clinical HCR.

Amyloid Neuropathy: From Pathophysiology to Treatment in Light-Chain Amyloidosis and Hereditary Transthyretin Amyloidosis.

Amyloid neuropathy is caused by deposition of insoluble ß-pleated amyloid sheets in the peripheral nervous system. It is most common in: (1) light-chain amyloidosis, a clonal non-proliferative plasma cell disorder in which fragments of immunoglobulin, light or heavy chain, deposit in tissues, and (2) hereditary transthyretin (ATTRv) amyloidosis, a disorder caused by autosomal dominant mutations in the TTR gene resulting in mutated protein that has a higher tendency to misfold. Amyloid fibrils deposit in the endoneurium of peripheral nerves, often extensive in the dorsal root ganglia and sympathetic ganglia, leading to atrophy of Schwann cells in proximity to amyloid fibrils and blood-nerve barrier disruption. Clinically, amyloid neuropathy is manifested as a length-dependent sensory predominant neuropathy associated with generalized autonomic failure. Small unmyelinated nerves are involved early and prominently in early-onset Val30Met ATTRv, whereas other ATTRv and light-chain amyloidosis often present with large- and small-fiber involvement. Nerve conduction studies, quantitative sudomotor axon testing, and intraepidermal nerve fiber density are useful tools to evaluate denervation. Amyloid deposition can be demonstrated by tissue biopsy of the affected organ or surrogate site, as well as bone-avid radiotracer cardiac imaging. Treatment of light-chain amyloidosis has been revolutionized by monoclonal antibodies and stem cell transplantation with improved 5-year survival up to 77%. Novel gene therapy and transthyretin stabilizers have revolutionized treatment of ATTRv, improving the course of neuropathy (less change in the modified Neuropathy Impairment Score + 7 from baseline) and quality of life. With great progress in amyloidosis therapies, early diagnosis and presymptomatic testing for ATTRv family members has become paramount. ANN NEUROL 2024;96:423-440.

Current status and prospect of anti-amyloid fibril therapy in AL amyloidosis.

Amyloid light-chain (AL) amyloidosis is a rare hematological disease that produces abnormal monoclonal immunoglobulin light chains to form amyloid fibrils that are deposited in tissues, resulting in organ damage and dysfunction. Advanced AL amyloidosis has a very poor prognosis with a high risk of early mortality. The combination of anti-plasma cell therapy and amyloid fibrils clearance is the optimal treatment strategy, which takes into account both symptoms and root causes. However, research on anti-amyloid fibrils lags far behind research on anti-plasma cells, and there is currently no approved treatment that could clear amyloid fibrils. Nevertheless, anti-amyloid fibril therapies are being actively investigated recently and have shown potential in clinical trials. In this review, we aim to outline the preclinical work and clinical efficacy of fibril-directed therapies for AL amyloidosis.

The Real-World Data on Patients With Cardiac Stage IIIb AL Amyloidosis.

BACKGROUND: Morbidity and mortality of patients with immunoglobulin light chain (AL) amyloidosis are strongly associated with the severity of cardiac involvement, especial in patients with cardiac stage IIIb, but the real-world data on these patients is still limited. PATIENTS AND METHODS: A retrospective analysis was conducted on 77 patients diagnosed with cardiac stage IIIb AL amyloidosis at our center. We analyzed the clinical characteristics, treatment and outcome of the patients. RESULTS: The median age of patients was 57 years and 49.4% were male. Median serum N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT) were 13,384 ng/L and 0.166 ug/L, and 42 (54.5%) patients had heart failure at diagnosis. Fifty-seven (74.0%) patients received antiplasma cell treatment, and the main treatment options include bortezomib or thalidomide combined with dexamethasone. The hematologic overall response rate was 70% (28/40), and at 6-month landmark analysis, patients with hematologic responses had a higher survival rate. Cardiac and renal responses were achieved in 14 (37.8%) and 13 (32.5%) patients, respectively. After a median follow-up of 10 months (range 1-115 months), median overall survival (OS) was 18 months, and the estimated survival rates at 3, 6, and 12 months were 79.9%, 75.6%, and 54.5%, respectively. In Cox regression models, age, hypotension and cTnT were independently predictive of mortality after adjusting for heart failure. CONCLUSION: The hematologic, cardiac and renal responses were relative lower in patients with cardiac stage IIIb AL amyloidosis. The overall prognosis of patients was poor, and age, hypotension, and cTnT can be used to predict mortality.

[AL Amyloidosis].

AL amyloidosis, derived from amyloidogenic immunoglobulin light chains, is a common type of systemic amyloidosis. Peripheral neuropathy has been identified in 10%-40% of patients with systemic AL amyloidosis. Definitive diagnosis requires tissue biopsies, including skin, fat, and gastrointestinal samples, as well as amyloid typing. Disease-modifying therapies have been shown to improve patient survival and prevent progressive organ dysfunction.

Acute kidney injury during autologous stem cell transplantation in light chain amyloidosis with kidney involvement and their impact on prognosis.

Acute kidney injury (AKI) is a complication related to important organ dysfunction during autologous stem cell transplantation (ASCT) in light chain (AL) amyloidosis. This study aims to validate the risk factors of AKI during different periods of ASCT and the impact of AKI on long-term outcomes. 302 patients with AL amyloidosis and kidney involvement who underwent ASCT were included. The procedures from stem cell mobilization to 30 days after transplantation were categorized into four periods: Period 0 (stem cell mobilization and harvest), Period 1 (preparation), Period 2 (conditioning and transplantation), and Period 3 (engraftment). The incidence of AKI during ASCT was 27.15% (0.66% in Period 0, 6.62% in Period 1, 15.23% in Period 2, and 6.95% in Period 3). The major causes of AKI were capillary leak syndrome in Period 0, ganciclovir or sulfamethoxazole/trimethoprim in Period 1, high-dose melphalan in Period 2, and engraftment syndrome in Period 3. AKI in different periods had distinct risk factors and predictive models. AKI was a risk factor for both kidney survival and overall survival (OS). Even recovered AKI reduced 10-year kidney survival from 91.7% to 68.4% (p = 0.002) and 10-year OS from 91.1% to 77.7% (p = 0.005).

Atrial fibrillation in the setting of cardiac amyloidosis - A review of the literature.

Cardiac amyloidosis (CA) is related to the aggregation of insoluble fibrous deposits of misfolded proteins within the myocardium. Transthyretin amyloidosis (ATTR) and immunoglobulin light-chain amyloidosis are the main forms of CA. Atrial fibrillation (AF) is a common arrhythmia in CA patients, especially in those with ATTR amyloidosis. Increased atrial preload and afterload, atrial enlargement, enhanced atrial wall stress, and autonomic dysfunction are the main mechanisms of AF in CA patients. CA is associated with the formation of endocardial thrombi and systemic embolism. The promoters of thrombogenesis include endomyocardial damage, blood stasis, and hypercoagulability. The prevalence of thrombi in patients with AF remains elevated despite long-term anticoagulation. Consequently, transesophageal ultrasound examinations before cardioversion should be performed to exclude endocardiac thrombi despite anticoagulation. Furthermore, the CHA2DS2-VASc score should not be used to assess the thromboembolic risk in CA patients with AF. Rate control is challenging in patients with CA, while rhythm control is the preferred treatment option, especially in the early stages of the disease process. Although catheter ablation is an effective treatment option, more data are needed to explore the role of the procedure in CA patients.

Systemic Amyloidosis and Kidney Transplantation: An Update.

Amyloidosis is a heterogeneous disorder characterized by abnormal protein aggregate deposition that often leads to kidney involvement and end-stage kidney disease. With advancements in diagnostic techniques and treatment options, the prevalence of patients with amyloidosis requiring chronic dialysis has increased. Kidney transplantation is a promising avenue for extending survival and enhancing quality of life in these patients. However, the complex and heterogeneous nature of amyloidosis presents challenges in determining optimal referral timing for transplantation and managing post-transplantation course. This review focuses on recent developments and outcomes of kidney transplantation for amyloidosis-related end-stage kidney disease. This review also aims to guide clinical decision-making and improve management of patients with amyloidosis-associated kidney disease, offering insights into optimizing patient selection and post-transplant care for favorable outcomes.