Long-term follow-up from a phase 1/2 study of single-agent bortezomib in relapsed systemic 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.

Emerging therapeutic avenues in cardiac amyloidosis

Cardiac Amyloidosis (CA) is a toxic infiltrative cardiomyopathy occurred by the deposition of the amyloid fibres in the extracellular matrix of the myocardium. This results in severe clinical complications such as increased left ventricular wall thickness and interventricular stiffness, a decrease in left ventricular stroke volume and cardiac output, diastolic dysfunction, arrhythmia, etc. In a prolonged period, this condition progresses into heart failure. The amyloid fibres affecting the heart include immunoglobulin light chain (AL - amyloidosis) and transthyretin protein (ATTR - amyloidosis) misfolded amyloid fibres. ATTRwt has the highest prevalence of 155 to 191 cases per million while ATTRv has an estimated prevalence of 5.2 cases per million. The pathological findings and therapeutic approaches developed recently have aided in the treatment regimen of cardiac amyloidosis patients. In recent years, understanding the pathophysiology of amyloid fibres formation and mechanistic pathways triggered in both types of cardiac amyloidosis has led to the development of new therapeutic approaches and agents. This review focuses on the current status of emerging therapeutic agents in clinical trials. Earlier, melphalan and bortezomib in combination with alkylating agents and immunomodulatory drugs were used as a standard therapy for AL amyloidosis. Tafamidis, approved recently by FDA is used as a standard for ATTR amyloidosis. However, the emerging therapeutic agents under development for the treatment of AL and ATTR cardiac amyloidosis have shown a potent and rapid effect with a safety profile.

Predictors of hematologic response and survival with stem cell transplantation in AL amyloidosis: a 25-year longitudinal study

High-dose melphalan and stem cell transplantation (HDM/SCT) is an effective treatment for selected patients with AL amyloidosis. We report the long-term outcomes of 648 patients with AL amyloidosis treated with HDM/SCT over 25 years. Hematologic CR was achieved by 39% of patients. The median duration of hematologic CR was 12.3 years, and 45% of patients with a hematologic CR had no evidence of a recurrent plasma cell dyscrasia at 15 years after HDM/SCT. With a median follow-up interval of 8 years, the median event-free survival (EFS) and overall survival (OS) were 3.3 and 7.6 years, respectively. Patients with a hematologic CR had a median OS of 15 years, and 30% of these patients survived >20 years. On multivariable analysis, dFLC >180 mg/L and BM plasma cells >10% were independently associated with shorter EFS, whereas BNP >81 pg/mL, troponin I >0.1 ng/mL, and serum creatinine >2.0 mg/dL were independently associated with shorter OS. We developed a prognostic score for EFS, which incorporated dFLC >180 mg/L and BMPC% >10% as adverse risk factors. Patients with low-risk (0 factors), intermediate-risk (1 factor), and high-risk (2 factors) disease had median EFS estimates of 5.3, 2.8, and 1.0 years, respectively (p<0.001). The 100-day treatment-related mortality rate was 3% in the latest treatment period (2012-2021), and the 25-year risk of t-MDS/AML was 3%. We conclude that HDM/SCT induces durable hematologic responses and prolonged survival with improved safety in selected patients with AL amyloidosis. This article is protected by copyright. All rights reserved.

Treatment and outcomes of patients with light chain amyloidosis who received a second line of therapy post autologous stem cell transplantation

We retrospectively reviewed 292 patients who received a second line of therapy post ASCT for their light chain amyloidosis. Most patients (40%) were treated with an alkylator + PI ± dex or PI ± dex followed by an alkylator + 2nd-gen IMiD ± dex or 2nd-gen IMiD ± dex (26%), an alkylator ± steroid or steroid monotherapy (19%), a 2nd-gen IMiD + PI ± dex (6%), an alkylator + thalidomide ± dex (5%), or daratumumab-based therapy (4%). The rate of CR or VGPR was 70% among the daratumumab-based group, 62% in the alkylator + PI ± dex or PI ± dex group, 55% in the alkylator + 2nd-gen IMiD ± dex or 2nd-gen IMiD ± dex group, 47% in the 2nd-gen IMiD + PI ± dex group, 24% in the alkylator ± steroid or steroid monotherapy group, and 18% in the alkylator + thalidomide ± dex group. The median OS was NR for the 2nd-gen IMiD + PI ± dex group and the daratumumab group, 130.4 months in the alkylator + 2nd-gen IMiD ± dex or 2nd-gen IMiD ± dex group, 100 months for the alkylator + PI ± dex or PI ± dex group, 36 months for the alkylator ± steroid or steroid monotherapy group, and 21 months for the alkylator + thalidomide ± dex group (P < 0.0001). The median OS was 100 months in patients who received melphalan 200 mg/m² compared to 41 months in the 140 mg/m² group (P < 0.0001). In conclusion, patients receiving novel therapy post ASCT and melphalan conditioning dosing at 200 mg/m² at diagnosis had better outcomes.

Update on the Contemporary Treatment of Light Chain Amyloidosis Including Stem Cell Transplantation

The management of immunoglobulin light chain (AL) amyloidosis is complex. Emerging data have shown promising results for several novel agents. We review the management of AL amyloidosis, including factors that determine transplant eligibility, treatment options for transplant-ineligible patients, and treatment options for relapsed/refractory AL amyloidosis. For carefully selected patients, high-dose melphalan and stem cell transplantation is recommended. Transplant eligibility criteria generally include biopsy-proven amyloidosis, evidence of a plasma cell dyscrasia, involvement of at least one major organ, and adequate performance status. For transplant-ineligible patients, bortezomib-based regimens are recommended, including: 1) bortezomib, oral melphalan, and dexamethasone (BMDex); 2) bortezomib, cyclophosphamide, and dexamethasone (CyBorD or VCd); and 3) subcutaneous daratumumab (DARA SC) and VCd. The latter option is based on a landmark trial that led to the first US Food and Drug Administration-approved therapy for AL amyloidosis. For relapsed/refractory disease, novel therapeutics including proteosome inhibitors, immunomodulatory agents, and monoclonal antibodies have shown promising results. In this review, we summarize data for various therapeutics in different clinical scenarios of AL amyloidosis.

Fixed duration vs. prolonged duration treatment after first line therapy in patients with systemic light chain amyloidosis

BACKGROUND

The main objective of treatment in systemic light chain amyloidosis (AL amyloidosis) is to achieve the best hematological response. Deeper responses are associated with better organ responses and survival. In this study, we analysed the efficacy of prolonged duration treatment after first line in patients with AL amyloidosis.

METHODS

Retrospective analysis that included patients older than 18 years with AL amyloidosis. We excluded patients with more than 30% marrow plasmacytosis or concurrent multiple myeloma. Two cohorts identified accordingly if they received or not prolonged treatment after the first line. Survival analysis regarding progression free survival (PFS) and overall survival (OS) estimated with Kaplan-Meier and comparisons between groups with log-rank.

RESULTS

Thirty-eight patients were included in the analysis with a median age of 55 years. Twenty-one patients received prolonged duration treatment and 17 did not. In the prolonged duration group, after a median duration of 12 months, the median PFS was 58.8 months. In the fixed duration treatment group, PFS was 30.6 months. The difference was significant with p = .0045 favouring prolonged duration treatment. Organ response was sustained for a longer period in the prolonged duration treatment group. For OS, the difference was not significant.

CONCLUSIONS

Prolonged duration treatment in patients with systemic light chain amyloidosis correlated with better PFS and deeper organ responses. Prospective studies are needed to analyse this further.

A randomized phase 3 study of ixazomib-dexamethasone versus physician's choice in relapsed or refractory AL amyloidosis

In the first phase 3 study in relapsed/refractory AL amyloidosis (TOURMALINE-AL1 NCT01659658), 168 patients with relapsed/refractory AL amyloidosis after 1-2 prior lines were randomized to ixazomib (4 mg, days 1, 8, 15) plus dexamethasone (20 mg, days 1, 8, 15, 22; n = 85) or physician's choice (dexamethasone ± melphalan, cyclophosphamide, thalidomide, or lenalidomide; n = 83) in 28-day cycles until progression or toxicity. Primary endpoints were hematologic response rate and 2-year vital organ deterioration or mortality rate. Only the first primary endpoint was formally tested at this interim analysis. Best hematologic response rate was 53% with ixazomib-dexamethasone vs 51% with physician's choice (p = 0.76). Complete response rate was 26 vs 18% (p = 0.22). Median time to vital organ deterioration or mortality was 34.8 vs 26.1 months (hazard ratio 0.53; 95% CI, 0.32-0.87; p = 0.01). Median treatment duration was 11.7 vs 5.0 months. Adverse events of clinical importance included diarrhea (34 vs 30%), rash (33 vs 20%), cardiac arrhythmias (26 vs 15%), nausea (24 vs 14%). Despite not meeting the first primary endpoint, all time-to-event data favored ixazomib-dexamethasone. These results are clinically relevant to this relapsed/refractory patient population with no approved treatment options.

AL-amyloidosis with cardiac involvement. Diagnostic capabilities of non-invasive methods

There are presented the literature data and a description of the clinical course of the disease in isolated/predominant cardiac amyloidosis. Amyloid cardiomyopathy is the most common phenocopy of hypertrophic cardiomyopathy. The modern possibilities of non-invasive diagnostics using osteoscintigraphy for the differential diagnosis between amyloid cardiomyopathy caused by AL- and transthyretin amyloidosis are described in detail.

Safety, tolerability, and response rates of daratumumab in relapsed AL amyloidosis: results of a phase 2 study

Daratumumab, a monoclonal CD38 antibody, is approved in the treatment of myeloma, but its efficacy and safety in light-chain (AL) amyloidosis has not been formally studied. This prospective phase 2 trial of daratumumab monotherapy for the treatment of AL amyloidosis was designed to determine the safety, tolerability, and hematologic and clinical response. Daratumumab 16 mg/kg was administered by IV infusion once weekly for weeks 1 to 8, every 2 weeks for weeks 9 to 24, and every 4 weeks thereafter until progression or unacceptable toxicity, for up to 24 months. Twenty-two patients with previously treated AL amyloidosis were enrolled. The majority of the patients had received high-dose melphalan and stem cell transplantation and/or treatment with a proteasome inhibitor. The median time between prior therapy and trial enrollment was 9 months (range, 1-180 months). No grade 3-4 infusion-related reactions occurred. The most common grade ≥3 adverse events included respiratory infections (n = 4; 18%) and atrial fibrillation (n = 4, 18%). Hematologic complete and very-good-partial response occurred in 86% of patients. The median time to first and best hematologic response was 4 weeks and 3 months, respectively. Renal response occurred in 10 of 15 patients (67%) with renal involvement and cardiac response occurred in 7 of 14 patients (50%) with cardiac involvement. In summary, daratumumab is well tolerated in patients with relapsed AL amyloidosis and leads to rapid and deep hematologic responses and organ responses. This trial was registered at www.clinicaltrials.gov as #NCT02841033.

A pharmacist's review of the treatment of systemic light chain amyloidosis

OBJECTIVE

Systemic light-chain (AL) amyloidosis is an uncommon hematologic plasma cell dyscrasia that is becoming increasingly recognized. Therapeutic agents used in AL amyloidosis overlap with those used in multiple myeloma; however, differences in disease features change treatment efficacy and tolerance. Pharmacists must be cognizant of these distinctions. Herein, this review article provides an up-to-date guide to treatment considerations for systemic AL amyloidosis in both the front-line and relapsed settings.Data sources: A comprehensive literature search was performed using the PubMed/Medline database for articles published through (June 2020) regarding treatments for AL amyloidosis. Search criteria included therapies that are FDA approved for multiple myeloma, as well as investigational agents. This review of chemotherapeutic agents reflects the current clinical practice guidelines endorsed by NCCN along with commentary based on the experience of pharmacists from a tertiary-referral center treating many patients with AL amyloidosis. Data consists of randomized controlled trials, observational cohorts, case reports, and ongoing clinical trials.Data summary: Frontline options discussed here include high-dose melphalan with autologous stem cell transplantation and bortezomib-based regimens. Regarding the relapsed setting, supporting data are compiled and summarized for: bortezomib, ixazomib, carfilzomib, lenalidomide, pomalidomide, daratumumab, elotuzumab, isatuximab, venetoclax, NEOD001, and melflufen.

CONCLUSIONS

The treatment platform for AL amyloidosis is expanding with novel agents traditionally used in multiple myeloma being adopted and modified for use in AL amyloidosis. The pharmacist's familiarity with the clinical evidence base for these agents and how they fit into standard protocols for AL amyloidosis is critical as dosing and monitoring recommendations are unique from multiple myeloma.

Bortezomib, Melphalan, and Dexamethasone for Light-Chain Amyloidosis

PURPOSE

Oral melphalan and dexamethasone (MDex) were considered a standard of care in light-chain (AL) amyloidosis. In the past decade, bortezomib has been increasingly used in combination with alkylating agents and dexamethasone. We prospectively compared the efficacy and safety of MDex and MDex with the addition of bortezomib (BMDex).

METHODS

This was a phase III, multicenter, randomized, open-label trial. Patients were stratified according to cardiac stage. Patients with advanced cardiac stage (stage IIIb) amyloidosis were not eligible. The primary end point was hematologic response rate at 3 months. This trial is registered with ClinicalTrials.gov identifier NCT01277016.

RESULTS

A total of 109 patients, 53 in the BMDex and 56 in the MDex group, received ≥ 1 dose of therapy (from January 2011 to February 2016). Hematologic response rate at 3 months was higher in the BMDex arm (79% v 52%; P = .002). Higher rates of very good partial or complete response rates (64% v 39%; hazard ratio [HR], 2.47; 95% CI, 1.30 to 4.71) and improved overall survival, with a 2-fold decrease in mortality rate (HR, 0.50; 95% CI, 0.27 to 0.90), were observed in the BMDex arm. Grade 3 and 4 adverse events (the most common being cytopenia, peripheral neuropathy, and heart failure) were more common in the BMDex arm, occurring in 20% versus 10% of cycles performed.

CONCLUSION

BMDex improved hematologic response rate and overall survival. To our knowledge, this is the first time a controlled study has demonstrated a survival advantage in AL amyloidosis. BMDex should be considered a new standard of care for AL amyloidosis.

Novel challenges in the management of immunoglobulin light chain amyloidosis: from the bench to the bedside

INTRODUCTION

Immunoglobulin light chain (AL) amyloidosis is one of the most frequent systemic amyloidosis in Western countries. It is caused by a B-cell clone producing a misfolded light chain (LC) that deposits in organs.

AREAS COVERED

The review examines recent findings on pathophysiology and clinical management of AL amyloidosis. It contains an update on the recent hot topics as novel therapeutic approaches, definition of relapse, and hematologic response assessment. To review literature on AL amyloidosis, a bibliographic search was performed using PubMed.

EXPERT OPINION

Due to the proteotoxicity of amyloidogenic LCs, the therapeutic goal is a rapid and profound decrease in their concentration. The standard treatment is a risk-adapted chemotherapy targeting the B-cell clone. Novel, promising drugs, as daratumumab, are currently under evaluation in newly-diagnosed and relapsed/refractory patients. New sensitive techniques, as mass spectrometry approach and bone marrow minimal residual disease assessment, are available to evaluate depth of response. After first-line therapy, increase in LC concentration may precede worsening of organ dysfunction and should be considered carefully. Further clarification of molecular mechanisms of the disease are shedding light on new possible therapeutic targets. Innovative treatment strategies and novel technologies will improve our ability to treat AL amyloidosis, preventing organ deterioration.

Outcomes with early vs. deferred stem cell transplantation in light chain amyloidosis

In the presence of effective treatment options for systemic light chain (AL) amyloidosis, autologous stem cell transplantation (ASCT) is sometimes deferred after stem cell collection. We designed this retrospective study to compare overall survival (OS) between patients who proceed directly to ASCT after stem cell collection and those who defer ASCT. We included patients with AL amyloidosis who had stem cell collection at Mayo Clinic, Minnesota, from 2004 to 2018. ASCT was considered "early" if performed within 90 days of collection, and "deferred" if performed after 90 days, or not done by last follow up. We included 651 patients; 527 underwent early ASCT and 124 deferred ASCT. There was no difference in OS with early vs. deferred ASCT (median OS: 13.0 vs. 11.4 years, respectively, P = 0.28). There was no difference in OS between the 2 groups among patients with early or advanced Mayo Stage. Among patients who achieved ≥very good partial response at the time of collection, OS in the early and deferred groups was 14.2 and 13.4 years, respectively (P = 0.06). Survival outcomes are similar with early and deferred ASCT. Further studies are needed to identify patients who would benefit from each approach.

The efficacy and safety of bortezomib-based chemotherapy for immunoglobulin light chain amyloidosis: A systematic review and meta-analysis

BACKGROUND

The role of bortezomib in the treatment of immunoglobulin light chain (AL) amyloidosis is not well defined. We performed this meta-analysis to evaluate the efficacy and safety of bortezomib-based regimens in patients with AL amyloidosis who are not eligible for or refuse autologous stem cell transplantation.

METHODS

A systematic search of Medline, Embase, and the Cochrane Library was conducted to identify related studies.

RESULTS

Twenty-four studies with 1238 patients were included. The pooled overall response rate (ORR) and complete hematological response rate (CHR) were 0.72 (95% CI, 0.67-0.77) and 0.35 (95% CI, 0.30-0.40), respectively. Bortezomib significantly improved the outcome of ORR compared to other regimens (RR 1.28, 95% CI, 1.04-1.57, P = .02). Similar results were observed in CHR (RR 1.90, 95% CI, 1.45-2.50, P < .001) and cardiac response (RR 2.03, 95% CI, 1.31-3.13, P = .002), but not in overall survival (HR 0.82, 95% CI, 0.62-1.09, P = .17). In addition, once-weekly bortezomib was associated with improved overall survival compared with twice-weekly bortezomib (HR 0.52, 95% CI, 0.27-0.99, P = .05). Peripheral neuropathy was the most widely reported adverse event. Incorporation of bortezomib into the standard melphalan + dexamethasone setting showed a trend of increased serious adverse events, though this was not statistically significant (RR 1.29, 95% CI, 0.95-1.75, P = .10).

CONCLUSIONS

Current evidence indicates that bortezomib-based regimens might be effective and safe therapies for patients with AL amyloidosis. There is a great need to conduct more well-designed randomized controlled trials to provide high-quality evidence.

AL Amyloidosis: Unfolding a Complex Disease

Light chain (AL) amyloidosis is a rare plasma cell dyscrasia. An estimated 12,000 people live with the disease in the United States. AL amyloidosis occurs from the misfolding of proteins that deposit in organs (heart, kidneys, digestive tract, tongue, lungs, and nervous system), leading to progressive organ damage and impairment of quality of life. The treatment of AL amyloidosis has improved greatly over the past several years, with new treatments currently in development. This article will focus on the pathophysiology, diagnosis, and treatment of AL amyloidosis.

Treatment Options For Relapsed/refractory Systemic Light-Chain (AL) Amyloidosis: Current Perspectives

Systemic immunoglobulin light chain (AL) amyloidosis is a disorder characterized by the production of clonal serum free light chains that misfold, aggregate, and deposit in vital organs. Treatment of this disease is typically targeted at the abnormal plasma cell clone in the bone marrow which is the source of the amyloidogenic light chain. First-line therapies in this disease are well established, but in the relapsed or refractory setting, there are many treatment options, including immunomodulatory agents, proteasome inhibitors, alkylating agents, and monoclonal antibodies. Decisions regarding treatment choice should be made by a multidisciplinary team with consideration of the patient's functional status, disease stage, degree of organ dysfunction, and potential treatment toxicities. Herein we review the current treatment options available for patients with relapsed or refractory AL amyloidosis.

Bortezomib-based chemotherapy reduces early mortality and improves outcomes in patients with ultra-high-risk light-chain amyloidosis: a retrospective case control study

Background: Patients with amyloid light-chain (AL) amyloidosis who have advanced cardiac damage are at risk of premature mortality. Currently, bortezomib is the mainstay in the treatment of AL amyloidosis, but the benefits of bortezomib in patients with ultra-high-risk (2004 Mayo stage IIIb or 2012 Mayo stage IV) AL amyloidosis have not been proved definitively. Methods: We performed a retrospective analysis of patients newly diagnosed with ultra-high-risk AL amyloidosis who received a bortezomib-based regimen or supportive treatment. We aimed to establish the effects of bortezomib on early mortality and long-term outcomes in this high-risk population. Results: Patients receiving bortezomib-containing chemotherapy (n = 62) and patients receiving no chemotherapy (n = 24) were included. Median overall survival (OS) was 30 months in the bortezomib group and 2 months in the control group (p < .001), and median progression-free survival (PFS) was 15.8 months (bortezomib) and 2 months (control; p < .001). The early-death rate (within 6 months of treatment) was 32.3% (bortezomib) and 66.7% (control; p < .001). In a landmark analysis assessing outcomes in patients surviving beyond 6 months, the 2-year OS and PFS in the bortezomib group were 77.3% and 65.8%, respectively. Conclusions: Bortezomib-based regimens can help to reduce early mortality and improve long-term survival in patients with ultra-high-risk AL amyloidosis.

Induction Therapy with Bortezomib and Dexamethasone and Conditioning with High-Dose Melphalan and Bortezomib Followed by Autologous Stem Cell Transplantation for Immunoglobulin Light Chain Amyloidosis: Long-Term Follow-Up Analysis

In immunoglobulin light-chain (AL) amyloidosis, the depth of hematologic response to treatment is associated with improved survival and organ responses. We conducted a clinical trial using bortezomib in induction and in conditioning with melphalan before stem cell transplantation (SCT) for AL amyloidosis. The results of this clinical trial with a median follow-up of 36 months have been reported previously. Here we report the long-term results of this clinical trial with a median follow-up of 77 months. We describe survival, durability of hematologic and organ responses, and relapse rates. Thirty-five patients were enrolled between 2010 and 2013. Hematologic complete response and very good partial response (VGPR) were noted in 100% (27 of 27) of the evaluable patients at 6 months post-SCT. Four patients (15%) had hematologic relapse at a median of 42 months, and 1 patient (3.7%) had organ progression despite maintaining a VGPR at 37 months. The median overall survival and progression-free survival have not yet been reached at the time of this report. Renal and cardiac responses occurred in 65% and 88%, respectively, at 5 years post-SCT. The median time to renal and cardiac response was 12 months and 6 months, respectively. In conclusion, incorporating bortezomib into induction and conditioning yielded durable hematologic responses of AL amyloidosis, with corresponding organ responses and prolonged survival.

Treatment Tolerability in Patients with Immunoglobulin Light-Chain Amyloidosis

BACKGROUND

Immunoglobulin light-chain amyloidosis (AL amyloidosis) is a rare and often fatal disease for which there is currently no treatment approved by the US Food and Drug Administration or the European Medicines Agency. Treatment options, which are typically based on therapies for multiple myeloma and are used off-label, are associated with substantial adverse events (AEs). Because the severity of AEs is often determined by clinicians, evaluations of treatment tolerability may not fully consider patients' own experience with treatment.

OBJECTIVES

To explore the prevalence of AEs and treatment tolerability problems as reported by patients who received therapies for AL amyloidosis, and to examine the effects of AEs on treatment continuation and on health-related quality of life (HRQOL).

METHODS

Patients with AL amyloidosis were recruited for this noninterventional, longitudinal, online survey. The patients responded to survey items regarding demographics, disease characteristics, most recent AL amyloidosis treatment, and HRQOL. The study analyses are based on data collected during the 6-month follow-up survey and are restricted to patients who completed the baseline and 6-month surveys and received treatment for AL amyloidosis within 6 months before the follow-up survey.

RESULTS

A total of 100 patients met the inclusion criteria and were included in the study. The patients self-reported having a variety of AEs, which ranged in severity. Overall, 69.4% of patients had problems tolerating their treatment in the past 6 months, of whom 22% discontinued at least 1 therapy. In addition, approximately 33% of patients reduced their AL amyloidosis treatment because of AEs. Most often reported AEs included fatigue (83%), shortness of breath (53%), nausea (52%), and diarrhea (51%). Overall, 50% of the patients reported that their treatment was moderately well-tolerated and 41% said it was very well-tolerated. Those whose treatment was not well-tolerated had significantly worse HRQOL than patients whose treatment was well-tolerated.

CONCLUSIONS

Patient-reported experiences should be considered by clinicians when making treatment-related decisions. More research is needed to explore additional factors that may contribute to treatment discontinuation in patients with AL amyloidosis.

Novel Therapies in Light Chain Amyloidosis

Light chain (AL) amyloidosis is the most common form of amyloidosis involving the kidney. It is characterized by albuminuria, progressing to overt nephrotic syndrome and eventually end-stage renal failure if diagnosed late or ineffectively treated, and in most cases by concomitant heart involvement. Cardiac amyloidosis is the main determinant of survival, whereas the risk of dialysis is predicted by baseline proteinuria and glomerular filtration rate, and by response to therapy. The backbone of treatment is chemotherapy targeting the underlying plasma cell clone, that needs to be risk-adapted due to the frailty of patients with AL amyloidosis who have cardiac and/or multiorgan involvement. Low-risk patients (∼20%) can be considered for autologous stem cell transplantation that can be preceded by induction and/or followed by consolidation with bortezomib-based regimens. Bortezomib combined with alkylators, such as melphalan, preferred in patients harboring t(11;14), or cyclophosphamide, is used in most intermediate-risk patients, and with cautious dose escalation in high-risk subjects. Novel, powerful anti-plasma cell agents, such as pomalidomide, ixazomib, and daratumumab, prove effective in the relapsed/refractory setting, and are being moved to upfront therapy in clinical trials. Novel approaches based on small molecules interfering with the amyloidogenic process and on antibodies targeting the amyloid deposits gave promising results in preliminary uncontrolled studies, are being tested in controlled trials, and will likely prove powerful complements to chemotherapy. Finally, improvements in the understanding of the molecular mechanisms of organ damage are unveiling novel potential treatment targets, moving toward a cure for this dreadful disease.

The proteasome and proteasome inhibitors in multiple myeloma

Proteasome inhibitors are one of the most important classes of agents to have emerged for the treatment of multiple myeloma in the past two decades, and now form one of the backbones of treatment. Three agents in this class have been approved by the United States Food and Drug Administration-the first-in-class compound bortezomib, the second-generation agent carfilzomib, and the first oral proteasome inhibitor, ixazomib. The success of this class of agents is due to the exquisite sensitivity of myeloma cells to the inhibition of the 26S proteasome, which plays a critical role in the pathogenesis and proliferation of the disease. Proteasome inhibition results in multiple downstream effects, including the inhibition of NF-κB signaling, the accumulation of misfolded and unfolded proteins, resulting in endoplasmic reticulum stress and leading to the unfolded protein response, the downregulation of growth factor receptors, suppression of adhesion molecule expression, and inhibition of angiogenesis; resistance to proteasome inhibition may arise through cellular responses mediating these downstream effects. These multiple biologic consequences of proteasome inhibition result in synergistic or additive activity with other chemotherapeutic and targeted agents for myeloma, and proteasome inhibitor-based combination regimens have become established as a cornerstone of therapy throughout the myeloma treatment algorithm, incorporating agents from the other key classes of antimyeloma agents, including the immunomodulatory drugs, monoclonal antibodies, and histone deacetylase inhibitors. This review gives an overview of the critical role of the proteasome in myeloma and the characteristics of the different proteasome inhibitors and provides a comprehensive summary of key clinical efficacy and safety data with the currently approved proteasome inhibitors.

The Effect and Safety of Bortezomib in the Treatment of AL Amyloidosis: A Systematic Review and Meta-Analysis

Bortezomib began to be used in the treatment of light chain (AL) amyloidosis in recent years. We performed the first meta-analysis of randomized clinical trials and clinical controlled trials to evaluate the effect and safety of bortezomib treatment for AL amyloidosis. We conducted a search (until July 2016) in electronic databases (PubMed databases and the Cochrane Central Register of Controlled Trials bases from the year 2003). There were 205 records we searched and eight studies was included (n = 617 persons). We demonstrated that bortezomib treatment significantly improved overall response rate (ORR), complete response, a cardiac response rate, 2-year overall survival and the risk of neuropathy and reduced overall mortality compared to controls without bortezomib therapy. From the comparison and subgroup analysis of ORR between bortezomib group and no bortezomib group, the patients with bortezomib had a higher ORR, especially patients pretreated with bortezomib before high-dose melphalan followed by autologous stem cell transplant compared to no pretreatment. In addition, patients with bortezomib in standard dosage had significantly higher ORR. According to our results, bortezomib should be used in AL amyloidosis patients to improve response rate and survival rate and future relevant randomized controlled trials require to be performed.

Light Chain Amyloidosis

Light chain (AL) amyloidosis is caused by a usually small plasma-cell clone that is able to produce the amyloidogenic light chains. They are able to misfold and aggregate, deposit in tissues in the form of amyloid fibrils and lead to irreversible organ dysfunction and eventually death if treatment is late or ineffective. Cardiac damage is the most important prognostic determinant. The risk of dialysis is predicted by the severity of renal involvement, defined by the baseline proteinuria and glomerular filtration rate, and by the response to therapy. The specific treatment is chemotherapy targeting the underlying plasma-cell clone. It needs to be risk-adapted, according to the severity of cardiac and/or multi-organ involvement. Autologous stem cell transplant (preceded by induction and/or followed by consolidation with bortezomib-based regimens) can be considered for low-risk patients (~20%). Bortezomib combined with alkylators is used in the majority of intermediate-risk patients, and with possible dose escalation in high-risk subjects. Novel, powerful anti-plasma cell agents were investigated in the relapsed/refractory setting, and are being moved to upfront therapy in clinical trials. In addition, the use of novel approaches based on antibodies targeting the amyloid deposits or small molecules interfering with the amyloidogenic process gave promising results in preliminary studies. Some of them are under evaluation in controlled trials. These molecules will probably add powerful complements to standard chemotherapy. The understanding of the specific molecular mechanisms of cardiac damage and the characteristics of the amyloidogenic clone are unveiling novel potential treatment approaches, moving towards a cure for this dreadful disease.

Systemic amyloidosis: novel therapies and role of biomarkers

Systemic amyloidosis is caused by misfolding and extracellular deposition of one of an ever-growing list of circulating proteins, resulting in vital organ dysfunction and eventually death. Despite different predisposing conditions, including plasma cell dyscrasias [immunoglobulin light chain (AL) amyloidosis], long-lasting inflammation [reactive (AA) amyloidosis] or mutations (hereditary amyloidoses), clinical manifestations are conspicuously overlapping and mimic more prevalent conditions, significantly complicating and often delaying the recognition of these rare, complex diseases. However, refined diagnostic and imaging approaches and the increasing role of biomarkers, which help in establishing the diagnosis, assessing the prognosis and evaluating the response to therapy, have considerably improved the management of these conditions. The pillar of anti-amyloid therapy remains the prompt reduction or elimination of the amyloidogenic precursor. This is accomplished by targeting the underlying condition, and recent improvements in the treatment of plasma cell disorders and chronic inflammatory conditions have positively reverberated onto the management of AL and AA amyloidosis, respectively. Moreover, recent, substantial improvements in the understanding of the molecular underpinnings of systemic amyloidosis have unveiled different key steps in the amyloidogenic cascade which can be valid therapeutic targets. These include stabilizers of the native conformation of the amyloidogenic precursor, inhibitors of fibrillogenesis, amyloid fibril disruptors and promoters of amyloid clearance. Innovative pharmacological strategies, including rational, structure-based drug design, gene knockdown and immunotherapy, but also repurposing of old, safe drugs with newly recognized anti-amyloid properties, are currently being pursued already in the clinical setting, holding the promise of dramatically improving the outcome of these dismal conditions in the near future.

At least partial hematological response after first cycle of treatment predicts organ response and long-term survival for patients with AL amyloidosis receiving bortezomib-based treatment

AL amyloidosis is a rare plasma cell dyscrasia characterized by multi-organ involvement and poor prognosis. We retrospectively evaluated the organ response (OR) and long-term survival of newly diagnosed AL amyloidosis patients who received first-line bortezomib-containing induction therapy, aiming to identify the clinical indication of a 50% reduction in the difference between involved and uninvolved free light chains (dFLC) after first cycle of treatment. Among the 89 patients included, 78.7% had cardiac involvement and 42.7% were diagnosed with 2004 Mayo stage III disease, while 75.3% of patients achieved a hematological response, including 37.1% with complete response and a median response time of 1 month. Cardiac and renal responses were observed in 44.3 and 53.1% of patients, respectively. Sixty-one (68.5%) patients achieved at least 50% reduction in dFLC after the first cycle of therapy. After a median follow-up duration of 12 months, the estimated 3-year progression-free survival (PFS) and overall survival (OS) rates were 61.3 and 61.7% respectively. At least 50% reduction in dFLC after the first cycle of therapy was predictive of achieving an OR (p = 0.002), as well as superior PFS (HR = 0.119; 95% CI = 0.045-0.313; p < 0.001) and OS (HR = 0.206; 95% CI = 0.078-0.541; p = 0.001). Additionally, the median PFS and OS were not reached for patients with rapid reduction of dFLC. These results demonstrated that early reduction of dFLC after the first cycle of treatment is predictive of achieving an OR and long-term survival in AL patients receiving bortezomib.

Disease burden of systemic light-chain amyloidosis: a systematic literature review

INTRODUCTION

A systematic literature review on systemic light chain (AL) amyloidosis was conducted in order to understand the disease burden, and identify unmet medical needs and knowledge gaps.

METHODS

MEDLINE, Embase and Cochrane databases were searched for English language studies published in the last 10 years using search terms that focused on the clinical, economic, and patient-reported outcome (PRO) aspects of AL amyloidosis. There was a low yield of articles in the economic and PRO categories and additional searches were conducted in clinical conference proceedings, and using Google and Google Scholar. After review, there were 65 articles included for data extraction.

RESULTS

AL amyloidosis is a rare disorder without any FDA or EMA approved indications for drug therapy. Using off-label therapies, there is a high rate, 42-64%, of non-response or progression, and an associated high mortality. Toxicities during therapy are common with estimates of up to 30-40% of patients experiencing severity of grade 3 or higher. Patients with AL amyloidosis report severe psychological distress, anxiety and clinical depression.

CONCLUSIONS

There is a deficiency in the literature on the economic costs associated with AL amyloidosis, and information on costs has been derived from studies that examined multiple myeloma or other disease or treatment components common to AL amyloidosis.

A phase 1/2 study of the oral proteasome inhibitor ixazomib in relapsed or refractory AL amyloidosis

This phase 1/2 study assessed the safety, tolerability, and preliminary efficacy of the oral proteasome inhibitor (PI) ixazomib in patients with relapsed/refractory immunoglobulin light chain (AL) amyloidosis. Ixazomib was administered to adult patients with relapsed/refractory AL amyloidosis after 1 or more prior lines of therapy (including bortezomib) on days 1, 8, and 15 of 28-day cycles, for up to 12 cycles. Patients with less than partial response after 3 cycles received oral dexamethasone (40 mg, days 1-4) from cycle 4. A 3+3 dose-escalation phase was followed by 2 expansion cohorts (PI-naive and PI-exposed patients) at the maximum tolerated dose (MTD). Twenty-seven patients were enrolled: 11 during dose escalation (6 at 4.0 mg and 5 at 5.5 mg) and 16 during dose expansion (4.0 mg). Three patients experienced dose-limiting toxicities: 1 at 4.0 mg and 2 at 5.5 mg; the MTD was determined as 4.0 mg. Most common adverse events (AEs) included nausea, skin and subcutaneous tissue disorders (SSTD), diarrhea, and fatigue; grade 3 or higher AEs included dyspnea, fatigue, and SSTD. Overall, the hematologic response rate was 52% in patients treated at the MTD (n = 21). Organ responses were seen in 56% of patients (5 cardiac, 5 renal). Median hematologic progression-free survival was 14.8 months; 1-year progression-free and overall survival rates were 60% and 85%, respectively (median follow-up, 16.9 months). Weekly oral ixazomib appears to be active in patients with relapsed/refractory AL amyloidosis, with a generally manageable safety profile. The study was registered at clinicaltrials.gov as #NCT01318902 A phase 3 study is ongoing (#NCT01659658).

The amyloidogenic light chain is a stressor that sensitizes plasma cells to proteasome inhibitor toxicity

Amyloidogenic PCs show unique PI susceptibility and altered organelle homeostasis, consistent with defective autophagy. Amyloidogenic LC production is an intrinsic cellular stressor that sensitizes to PI toxicity.

Addressing Common Questions Encountered in the Diagnosis and Management of Cardiac Amyloidosis

Advances in cardiac imaging have resulted in greater recognition of cardiac amyloidosis in everyday clinical practice, but the diagnosis continues to be made in patients with late-stage disease, suggesting that more needs to be done to improve awareness of its clinical manifestations and the potential of therapeutic intervention to improve prognosis. Light chain cardiac amyloidosis, in particular, if recognized early and treated with targeted plasma cell therapy, can be managed very effectively. For patients with transthyretin amyloidosis, there are numerous therapies that are currently in late-phase clinical trials. In this review, we address common questions encountered in clinical practice regarding etiology, clinical presentation, diagnosis, and management of cardiac amyloidosis, focusing on recent important developments in cardiac imaging and biochemical diagnosis. The aim is to show how a systematic approach to the evaluation of suspected cardiac amyloidosis can impact the prognosis of patients in the modern era.

Epigallocatechin-3-gallate preferentially induces aggregation of amyloidogenic immunoglobulin light chains

Antibody light chain amyloidosis is a rare disease caused by fibril formation of secreted immunoglobulin light chains (LCs). The huge variety of antibody sequences puts a serious challenge to drug discovery. The green tea polyphenol epigallocatechin-3-gallate (EGCG) is known to interfere with fibril formation in general. Here we present solution- and solid-state NMR studies as well as MD simulations to characterise the interaction of EGCG with LC variable domains. We identified two distinct EGCG binding sites, both of which include a proline as an important recognition element. The binding sites were confirmed by site-directed mutagenesis and solid-state NMR analysis. The EGCG-induced protein complexes are unstructured. We propose a general mechanistic model for EGCG binding to a conserved site in LCs. We find that EGCG reacts selectively with amyloidogenic mutants. This makes this compound a promising lead structure, that can handle the immense sequence variability of antibody LCs.

New and Evolving Concepts Regarding the Prognosis and Treatment of Cardiac Amyloidosis

Systemic amyloidoses are rare and proteiform diseases, caused by extracellular accumulation of insoluble misfolded fibrillar proteins. Prognosis is dictated by cardiac involvement, which is especially frequent in light chain (AL) and in transthyretin variants (ATTR, both mutated, (ATTRm), and wild-type, (ATTRwt)). Recently, ATTRwt has emerged as a potentially relevant cause of a heart failure with preserved ejection fraction (HFpEF). Cardiac amyloidosis is an archetypal example of restrictive cardiomyopathy, with signs and symptoms of global heart failure and diastolic dysfunction. Independent of the aetiology, cardiac amyloidosis is associated with left ventricular concentric "hypertrophy" (i.e. increased wall thickness), preserved (or mildly depressed) ejection fraction, reduced midwall fractional shortening and global longitudinal function, as well as evident diastolic dysfunction, up to an overly restrictive pattern of the left ventricular filling. Cardiac biomarkers such as troponins and natriuretic peptides are very robust and widely accepted diagnostic as well as prognostic tools. Owing to its dismal prognosis, accurate and early diagnosis is mandatory and potentially life-saving. Although pathogenesis is still not completely understood, direct cardiomyocyte toxicity of the amyloidogenic precursor proteins and/or oligomer aggregates adds on tissue architecture disruption caused by amyloid deposition. The clarification of mechanisms of cardiac damage is offering new potential therapeutic targets, and several treatment options with a relevant impact on prognosis are now available.

Phase 2 trial of daily, oral epigallocatechin gallate in patients with light-chain amyloidosis

Previous studies have suggested that an increase in mitochondrial reactive oxygen species may cause organ damage in patients with light-chain (AL) amyloidosis; however, this damage can be decreased by antioxidant-agent treatment. Epigallocatechin gallate (EGCG), the major natural catechin in green tea, has potent antioxidant activity. Because EGCG has recently been reported to have a favorable toxicity profile for treating amyloidosis, we sought to examine the clinical efficacy and toxicity of EGCG in patients with AL amyloidosis. Fifty-seven patients were randomly assigned to the EGCG and observation groups and observed for six months. There were no increases in grade 3-5 adverse events and EGCG therapy was well tolerated. Although a decrease in the urinary albumin level was found in the EGCG group in patients with obvious albuminuria after treatment initiation, its antioxidant activity may not be sufficient to clarify the potential effect of EGCG in patients with AL amyloidosis. Because some of the biological markers responsible for organ damage were well correlated to the level of antioxidant potential in patients' plasma, the status of oxidative stress in the blood may indicate the extent of organ damage in clinical situations.

Proteasome inhibitors in AL amyloidosis: focus on mechanism of action and clinical activity

Proteasome inhibitors are the backbone in the treatment of multiple myeloma with 3 of its representatives (bortezomib, carfilzomib, and ixazomib) having already been approved. There is a different situation altogether in the treatment of amyloid light chain (AL) amyloidosis where owing to the rarity of this entity neither of these drugs has currently gained approval. Amyloid light chain plasma cells are possibly more vulnerable to bortezomib than myeloma plasmocytes because of a slightly distinct mechanism of action, which is described in depth in this manuscript. Bortezomib is highly active and rapidly effective as a single agent and even more potent in combination with dexamethasone and alkylators. Bortezomib-based regimens have become a standard part of the initial treatment of AL amyloidosis in the majority of centers. We have reviewed all available data on bortezomib in various combinations and settings. Carfilzomib seems to be effective but also toxic in these fragile patients with a high rate of cardiac events. Oral ixazomib has shown a surprisingly high efficacy with manageable toxicity and has received the Food and Drug Administration Breakthrough Therapy designation in 2014 for relapsed AL amyloidosis patients. In this review we have comprehensively described the current available knowledge of these 3 proteasome inhibitors and their use in AL amyloidosis.

Prognostic impact of cytogenetic aberrations in AL amyloidosis patients after high-dose melphalan: a long-term follow-up study

Translocation t(11;14) confers a favorable prognosis in AL amyloidosis patients treated with HDM.

What is new in diagnosis and management of light chain amyloidosis?

Light chain (AL) amyloidosis is caused by a usually small plasma cell clone producing a misfolded light chain that deposits in tissues. Survival is mostly determined by the severity of heart involvement. Recent studies are clarifying the mechanisms of cardiac damage, pointing to a toxic effect of amyloidogenic light chains and offering new potential therapeutic targets. The diagnosis requires adequate technology, available at referral centers, for amyloid typing. Late diagnosis results in approximately 30% of patients presenting with advanced, irreversible organ involvement and dying in a few months despite modern treatments. The availability of accurate biomarkers of clonal and organ disease is reshaping the approach to patients with AL amyloidosis. Screening of early organ damage based on biomarkers can help identify patients with monoclonal gammopathy of undetermined significance who are developing AL amyloidosis before they become symptomatic. Staging systems and response assessment based on biomarkers facilitate the design and conduction of clinical trials, guide the therapeutic strategy, and allow the timely identification of refractory patients to be switched to rescue therapy. Treatment should be risk-adapted. Recent studies are linking specific characteristics of the plasma cell clone to response to different types of treatment, moving toward patient-tailored therapy. In addition, novel anti-amyloid treatments are being developed that might be combined with anti-plasma cell chemotherapy.

Immunoglobulin Light Chain Systemic Amyloidosis

Immunoglobulin light chain amyloidosis (AL) is a rare, complex disease caused by misfolded free light chains produced by a usually small, indolent plasma cell clone. Effective treatments exist that can alter the natural history, provided that they are started before irreversible organ damage has occurred. The cornerstones of the management of AL amyloidosis are early diagnosis, accurate typing, appropriate risk-adapted therapy, tight follow-up, and effective supportive treatment. The suppression of the amyloidogenic light chains using the cardiac biomarkers as guide to choose chemotherapy is still the mainstay of therapy. There are exciting possibilities ahead, including the study of oral proteasome inhibitors, antibodies directed at plasma cell clone, and finally antibodies attacking the amyloid deposits are entering the clinic, offering unprecedented opportunities for radically improving the care of this disease.

Novel strategies for the diagnosis and treatment of cardiac amyloidosis

Systemic amyloidoses are rare, complex diseases caused by misfolding of autologous protein. The presence of heart involvement is the most important prognostic determinant. The diagnosis of amyloid cardiac involvement relies on echocardiography and magnetic resonance imaging, while scintigraphy with bone tracers is helpful in differentiating light chain amyloidosis from other types of amyloidosis involving the heart. Although these diseases are fatal, effective treatments exist that can alter their natural history, provided that they are started before irreversible cardiac damage has occurred. Refined diagnostic techniques, accurate patients' stratification based on biomarkers of cardiac dysfunction, the availability of novel, more powerful drugs, and ultimately, the unveiling of the cellular mechanisms of cardiac damage created a favorable environment for a dramatic improvement in the treatment of this disease that we expect in the next few years.

Treatment of Immunoglobulin Light Chain Amyloidosis: Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) Consensus Statement

Immunoglobulin light chain amyloidosis (AL amyloidosis) has an incidence of approximately 1 case per 100,000 person-years in Western countries. The rarity of the condition not only poses a challenge for making a prompt diagnosis but also makes evidenced decision making about treatment even more challenging. Physicians caring for patients with AL amyloidosis have been borrowing and customizing the therapies used for patients with multiple myeloma with varying degrees of success. One of the biggest failings in the science of the treatment of AL amyloidosis is the paucity of prospective trials, especially phase 3 trials. Herein, we present an extensive review of the literature with an aim of making recommendations in the context of the best evidence and expert opinion.

A European collaborative study of cyclophosphamide, bortezomib, and dexamethasone in upfront treatment of systemic AL amyloidosis

CyBorD achieves excellent outcome in noncardiac patients with AL amyloidosis and can rescue subjects with reversible heart damage. The outcome of high-risk patients remains poor, but response to CyBorD can also improve survival in this group.

A mouse model recapitulating human monoclonal heavy chain deposition disease evidences the relevance of proteasome inhibitor therapy

Randall-type heavy chain deposition disease (HCDD) is a rare disorder characterized by glomerular and peritubular amorphous deposits of a truncated monoclonal immunoglobulin heavy chain (HC) bearing a deletion of the first constant domain (CH1). We created a transgenic mouse model of HCDD using targeted insertion in the immunoglobulin κ locus of a human HC extracted from a HCDD patient. Our strategy allows the efficient expression of the human HC in mouse B and plasma cells, and conditional deletion of the CH1 domain reproduces the major event underlying HCDD. We show that the deletion of the CH1 domain dramatically reduced serum HC levels. Strikingly, even with very low serum level of truncated monoclonal HC, histologic studies revealed typical Randall-type renal lesions that were absent in mice expressing the complete human HC. Bortezomib-based treatment resulted in a strong decrease of renal deposits. We further demonstrated that this efficient response to proteasome inhibitors mostly relies on the presence of the isolated truncated HC that sensitizes plasma cells to bortezomib through an elevated unfolded protein response (UPR). This new transgenic model of HCDD efficiently recapitulates the pathophysiologic features of the disease and demonstrates that the renal damage in HCDD relies on the production of an isolated truncated HC, which, in the absence of a LC partner, displays a high propensity to aggregate even at very low concentration. It also brings new insights into the efficacy of proteasome inhibitor-based therapy in this pathology.