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

Cardiovascular toxicity from therapies for light chain amyloidosis

Amyloid light-chain (AL) amyloidosis is a hematological disorder characterized by abnormal proliferation of a plasma cell clone producing monoclonal free light chains that misfold and aggregate into insoluble fibrils in various tissues. Cardiac involvement is a common feature leading to restrictive cardiomyopathy and poor prognosis. Current first-line treatments aim at achieving hematological response by targeting the plasma cell clones, and these have been adapted from multiple myeloma therapy. Patients with AL amyloidosis often exhibit multiorgan involvement, making them susceptible to cancer therapy-related cardiovascular toxicity. Managing AL amyloidosis is a complex issue that requires enhanced knowledge of the cardio-oncological implications of hematological treatments. Future research should focus on implementing and validating primary and secondary prevention strategies and understanding the biochemical basis of oncological therapy-related damage to mitigate cardiovascular toxicity.

Echocardiographic phenotype for refined risk stratification and treatment selection in light chain amyloidosis with heart failure

AIMS

Light chain amyloidosis (AL) patients with heart failure (HF) are usually with revised Mayo (rMayo) stage III/IV disease and have a poor prognosis. We sought to investigate whether and what echocardiographic phenotype provides value for further risk stratification and guiding optimal risk-adapted treatment in this subgroup of AL patients.

METHODS AND RESULTS

95 AL patients who presented with HF and were on rMayo stage III/IV were retrospectively included. Of them, 51 patients (53.7%) were with stage III, 44 (46.3%) were with stage IV, and 44 (46.3%) underwent chemotherapy. Laboratory and echocardiographic measurements were acquired before the initiation of chemotherapy. The relevance of different variables with survival was assessed in the entire cohort, chemotherapy, and non-chemotherapy group. By Multivariate Cox regression analysis, right ventricular wall thickness (RVT) [HR 1.145, 95% confidence interval (CI) 1.026-1.279, P = 0.016], relative wall thickness (RWT) (HR 6.709, 95% CI 1.101-40.877, P = 0.039), and left ventricular ejection fraction (LVEF) < 50% (HR 1.939, 95% CI 1.048-3.590, P = 0.035) were found to be independently associated with survival in the entire cohort, RWT (HR 15.488, 95% CI 2.045-117.292, P = 0.008) in the non-chemotherapy group, and RVT (HR 1.331, 95% CI 1.054-1.681, P = 0.016) in the chemotherapy group, respectively. Kaplan-Meier survival analysis revealed that survival was significantly reduced in the presence of RVT ≥ 6.5 mm or LVEF < 50% in the entire cohort, and the significance of RVT ≥ 6.5 mm was irrespective of rMayo stages. In the chemotherapy group, survival was decreased if RVT ≥ 6.5 mm alone or together with RWT ≥ 0.67 were present, particularly in patients on rMayo stage IV.

CONCLUSIONS

Echocardiographic phenotype provides incremental value beyond rMayo staging for predicting survival and could further guide treatment in advanced AL with HF. Those with high-risk echocardiographic phenotypes as higher RVT and RWT and lower LVEF had a worse prognosis.

Antibodies gone bad - the molecular mechanism of light chain amyloidosis

Light chain amyloidosis (AL) is a systemic disease in which abnormally proliferating plasma cells secrete large amounts of mutated antibody light chains (LCs) that eventually form fibrils. The fibrils are deposited in various organs, most often in the heart and kidney, and impair their function. The prognosis for patients diagnosed with AL is generally poor. The disease is set apart from other amyloidoses by the huge number of patient-specific mutations in the disease-causing and fibril-forming protein. The molecular mechanisms that drive the aggregation of mutated LCs into fibrils have been enigmatic, which hindered the development of efficient diagnostics and therapies. In this review, we summarize our current knowledge on AL amyloidosis and discuss open issues.

Molecular bottlebrush prodrugs as mono- and triplex combination therapies for multiple myeloma

Cancer therapies often have narrow therapeutic indexes and involve potentially suboptimal combinations due to the dissimilar physical properties of drug molecules. Nanomedicine platforms could address these challenges, but it remains unclear whether synergistic free-drug ratios translate to nanocarriers and whether nanocarriers with multiple drugs outperform mixtures of single-drug nanocarriers at the same dose. Here we report a bottlebrush prodrug (BPD) platform designed to answer these questions in the context of multiple myeloma therapy. We show that proteasome inhibitor (bortezomib)-based BPD monotherapy slows tumour progression in vivo and that mixtures of bortezomib, pomalidomide and dexamethasone BPDs exhibit in vitro synergistic, additive or antagonistic patterns distinct from their corresponding free-drug counterparts. BPDs carrying a statistical mixture of three drugs in a synergistic ratio outperform the free-drug combination at the same ratio as well as a mixture of single-drug BPDs in the same ratio. Our results address unanswered questions in the field of nanomedicine, offering design principles for combination nanomedicines and strategies for improving current front-line monotherapies and combination therapies for multiple myeloma.

The management of light chain (AL) amyloidosis in Europe: clinical characteristics, treatment patterns, and efficacy outcomes between 2004 and 2018

Systemic light-chain (AL) amyloidosis is a rare and debilitating disease. Advances have been made in new treatments in recent years, yet real-world data on the management of the disease are scarce. EMN23 is a retrospective, observational study of patients who initiated first-line treatment in 2004-2018 in Europe, presenting the demographics, clinical characteristics, treatment patterns, and outcomes, from 4480 patients. Regimens based on bortezomib were the most frequently used as first-line therapy; only 6.2% of the patients received autologous stem cell transplant. Hematologic responses improved post-2010 (67.1% vs 55.6% pre-2010). The median overall survival (OS) was 48.8 (45.2-51.7) months; 51.4 (47.3-57.7) months pre-2010 and 46.7 (41.3-52.2) months post-2010. Early mortality was 13.4% and did not improve (11.4% vs 14.4% pre- and post-2010); furthermore, it remained high in patients with advanced cardiac disease (over 39% for stage IIIb). There was a significant improvement for stage IIIa (14.2 vs 30.7 months, p = 0.0170) but no improvement for stage IIIb patients (5.0 vs 4.5 months). This European real-world study of AL-amyloidosis emphasizes the unmet needs of early diagnosis, and the lack of improvement in survival outcomes of the frail stage IIIb population, despite the introduction of new therapies in recent years.

Contrasting presentations of the same disease: A comparison of two cases of amyloidosis presenting with eyelid involvement

Purpose

Localized amyloidosis can affect numerous tissues throughout the body and can also affect a variety of peri-ocular tissues including the conjunctiva, extra-ocular muscles, peri-orbital soft tissue, and lacrimal gland. We report two cases of amyloidosis presenting with eyelid involvement.

Observations

The first case represented a more subtle presentation of skin thickening with a pre-septal cellulitis, while the second case had a dramatic presentation of edema evolving into tissue dehiscence and spontaneous hemorrhage with ongoing angioedema and systemic coagulopathy.

Conclusions and importance

The two cases of biopsy-proven orbital/peri-ocular amyloidosis demonstrate the different clinical presentations that may go from the subtle to dramatic, depending on which peri-ocular tissues are affected and to what degree. Standards for treatment of amyloidosis remain conservative initially with surgery or radiation recommended only for refractory cases, but additional therapies are under investigation. Clinicians should have high clinical suspicion for amyloidosis with findings such as skin thickening or significant periorbital edema and should always consider tissue biopsy and further workup for amyloidosis if the findings worsen or do not resolve with treatment of more common conditions such as cellulitis.

Advanced Case of Cardiac Amyloidosis Presents With Chronic Diarrhea

Late diagnosis of light chain (AL) amyloidosis can lead to catastrophic consequences on the quality of life of affected patients and overall disease prognosis. Therefore, clinicians should have high suspicion and recognize clinical red flags for amyloidosis. This case report presents a 65-year-old female who presented to the emergency department with chronic diarrhea and significant weight loss with significant hypotension. The patient was treated four weeks prior to admission with a five-day course of nitrofurantoin for urinary tract infection. The initial workup was positive for Clostridium difficile(C.diff), which was treated medically; however, the patient started to complain of mild shortness of breath accompanied by mildly elevated brain natriuretic peptide (BNP). Later on, the patient had a cardiac arrest and was appropriately resuscitated. Subsequent ECHO showed significant left ventricular hypertrophy, raising high suspicion of myocardial infiltration. Because of persistent diarrhea despite aggressive medical management and an inconclusive workup, the patient underwent colonoscopy with duodenum biopsy, which revealed amyloid deposition confirmed by Congo red staining. The patient afterward suffered from a stroke and recurrent syncopal episodes requiring critical care admission. Due to a compromised quality of life, the patient eventually opted for hospice care. In view of insufficient prospective data spotlighting AL amyloidosis, all patients should be treated within clinical trials whenever possible and ideally evaluated for autologous hematopoietic cell transplantation (HCT) eligibility.

Phase 2 trial of ixazomib, cyclophosphamide, and dexamethasone for previously untreated light chain amyloidosis

Bortezomib, a proteasome inhibitor (PI) has shown efficacy in treatment of newly diagnosed and relapsed AL amyloidosis, and is often used in combination with cyclophosphamide and dexamethasone. Ixazomib is the first oral PI to be approved in routine practice but has not been evaluated yet in the upfront treatment setting. Newly diagnosed AL amyloidosis patients with measurable disease and adequate organ function were enrolled. The primary objective was to determine the hematologic response rate of ixazomib in combination with cyclophosphamide and dexamethasone. Treatment was given for 12 cycles, followed by ixazomib maintenance till progression. Thirty-five patients are included; median age was 67; 69% were male. Major organ involvement included heart (66%) and kidneys (54%). A median of 4 induction cycles (range 1-12) were administered. The overall hematologic response to induction was 63% and included complete response (CR) in 11.4% and very good partial response in 37.1% of patients. One patient was upstaged to CR during maintenance. The most common reason for going off study was institution of alternate therapy (61%). With a median follow-up on 29.7 months for the living patients, the 2-year PFS and OS were 74% and 78%, respectively. The median time to alternate therapy was 7.5 months. Grade ≥3 hematological and non-hematological adverse events occurred in 23% and 49% of patients, respectively. Given the favorable toxicity profile, an important advantage for the typically frail AL population, further evaluation of the ixazomib in other combinations in the upfront setting is warranted. This trial is registered at www.clinicaltrials.gov as NCT01864018.

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.

Health-related quality of life in patients with light chain amyloidosis treated with bortezomib, cyclophosphamide, and dexamethasone ± daratumumab: Results from the ANDROMEDA study

In the phase 3 ANDROMEDA trial, patients treated with daratumumab, bortezomib, cyclophosphamide, and dexamethasone (D-VCd) had significantly higher rates of organ and hematologic response compared with patients who received VCd alone. Here, we present patient-reported outcomes (PROs) from the ANDROMEDA trial. PROs were assessed through cycle 6 using three standardized questionnaires. Treatment effect through cycle 6 was measured by a repeated-measures, mixed-effects model. The magnitude of changes in PROs versus baseline was generally low, but between-group differences favored the D-VCd group. Results were generally consistent irrespective of hematologic, cardiac, or renal responses. More patients in the D-VCd group experienced meaningful improvements in PROs; median time to improvement was more rapid in the D-VCd group versus the VCd group. After cycle 6, patients in the D-VCd group received daratumumab monotherapy and their PRO assessments continued, with improvements in health-related quality of life (HRQoL) reported through cycle 19. PROs of subgroups with renal and cardiac involvement were consistent with those of the intent-to-treat population. These results demonstrate that the previously reported clinical benefits of D-VCd were achieved without decrement to patients' HRQoL and provide support of D-VCd in patients with AL amyloidosis.

Immunoglobulin light chain amyloidosis: 2022 update on diagnosis, prognosis, and treatment

DISEASE OVERVIEW

Immunoglobulin light chain amyloidosis is a clonal, nonproliferative plasma cell disorder in which fragments of immunoglobulin light or heavy chain are deposited in tissues. Clinical features depend on organs involved but can include heart failure with preserved ejection fraction, nephrotic syndrome, hepatic dysfunction, peripheral/autonomic neuropathy, and "atypical smoldering multiple myeloma or monoclonal gammopathy of undetermined significance (MGUS)."

DIAGNOSIS

Tissue biopsy stained with Congo red demonstrating amyloid deposits with apple-green birefringence is required for the diagnosis of AL amyloidosis. Invasive organ biopsy is not required in 85% of patients. Verification that amyloid is composed of immunoglobulin light chains is mandatory. The gold standard is laser capture mass spectroscopy.

PROGNOSIS

N-terminal pro-brain natriuretic peptide (NT-proBNP or BNP), serum troponin T (or I), and difference between involved and uninvolved immunoglobulin free light chain values are used to classify patients into four groups of similar size; median survivals are 73, 35, 15, and 5 months.

THERAPY

All patients with a systemic amyloid syndrome require therapy to prevent deposition of amyloid in other organs and prevent progressive organ failure. Current first-line therapy with the best outcome is daratumumab, bortezomib, cyclophosphamide, and dexamethasone. The goal of therapy is a complete response (CR). In patients failing to achieve this depth of response options for consolidation include pomalidomide, stem cell transplantation, venetoclax, and bendamustine.

FUTURE CHALLENGES

Delayed diagnosis remains a major obstacle to initiating effective therapy prior to the development of end-stage organ failure. Trials of antibodies to catabolize deposited fibrils are underway.

The Role of Microbiome in Brain Development and Neurodegenerative Diseases

Hundreds of billions of commensal microorganisms live in and on our bodies, most of which colonize the gut shortly after birth and stay there for the rest of our lives. In animal models, bidirectional communications between the central nervous system and gut microbiota (Gut-Brain Axis) have been extensively studied, and it is clear that changes in microbiota composition play a vital role in the pathogenesis of various neurodevelopmental and neurodegenerative disorders, such as Autism Spectrum Disorder, Alzheimer's disease, Parkinson's disease, Multiple Sclerosis, Amyotrophic Lateral Sclerosis, anxiety, stress, and so on. The makeup of the microbiome is impacted by a variety of factors, such as genetics, health status, method of delivery, environment, nutrition, and exercise, and the present understanding of the role of gut microbiota and its metabolites in the preservation of brain functioning and the development of the aforementioned neurological illnesses is summarized in this review article. Furthermore, we discuss current breakthroughs in the use of probiotics, prebiotics, and synbiotics to address neurological illnesses. Moreover, we also discussed the role of boron-based diet in memory, boron and microbiome relation, boron as anti-inflammatory agents, and boron in neurodegenerative diseases. In addition, in the coming years, boron reagents will play a significant role to improve dysbiosis and will open new areas for researchers.

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.

Outcomes of bortezomib combination chemotherapies in autologous stem cell transplantation-ineligible patients with AL amyloidosis

Background

Treatment protocols for light chain (AL) amyloidosis have been derived from myeloma treatment. Bortezomib is a key drug used for the treatment of myeloma and AL amyloidosis. We retrospectively investigated the efficacy and toxicity of bortezomib- based chemotherapy in patients with newly diagnosed AL amyloidosis.

Methods

We reviewed the outcomes of newly diagnosed autologous stem cell transplantation (auto-SCT)-ineligible AL amyloidosis patients who received bortezomib-based chemotherapy at a referral center between 2011 and 2017.

Results

Of 63 patients who received bortezomib-based chemotherapy, 32 were male, and the median age was 66 years (range, 42‒82 yr). The hematologic overall response rate (ORR) was 65.1%, and the chemotherapy regimen with the best hematologic response was VMP (75.7%, 28/37). Sixty patients had significant organ (heart or kidney) involvement; 28.3% of patients (N=17) had major organ responses after chemotherapy. With a median follow- up of 34 months, there was no significant difference in progression-free survival (P=0.49) or overall survival (P =0.67) according to regimen. Most hematologic and non-hematologic problems were manageable.

Conclusion

Various chemotherapy combinations based on bortezomib are currently employed in the clinical setting, but no difference was found in terms of efficacy or toxicity.

AL amyloidosis: untangling new therapies

Systemic light chain (AL) amyloidosis is a protein misfolding disorder characterized by the deposition of abnormal immunoglobulin light chains in fibrillary aggregates, resulting in end-organ damage. Several unique challenges face treating physicians, including delayed diagnosis, advanced vital organ involvement, and morbidity with treatment. Aggressive supportive care and risk-adapted application of plasma cell-directed therapies are the cornerstones of management. The therapeutic revolution in multiple myeloma will likely further expand the arsenal against plasma cells. Careful investigation of these agents will be critical to establish their role in this fragile population. The promise of fibril-directed therapies to restore organ function remains despite early disappointments. In this review, we discuss new therapies to tackle AL amyloidosis using a case-based approach.

Ubiquitin-associated protein 2 like (UBAP2L) enhances growth and metastasis of gastric cancer cells

Ubiquitin-proteasome pathway has emerged as therapeutic targets for cancer. GEPIA database analysis showed that the expression of ubiquitin-associated protein 2 like (UBAP2L) in gastric cancer specimens was significantly higher than that in non-tumor tissue, and its high expression is associated with poor survival of gastric cancer patients. This study aims to investigate the role of UBAP2L in gastric cancer. Real-time PCR and western blot results showed that UBAP2L expression was upregulated in gastric cancer cell lines. Loss- and gain-of-function experiments demonstrated that silencing of UBAP2L inhibited proliferation, migration and invasion, and induced apoptosis of gastric cancer cells, and overexpression of UBAP2L played opposite roles. Nude mice inoculated with UBAP2L-silenced gastric cancer cells generated smaller xenografted tumors in vivo. Furthermore, UBAP2L activated Wnt/β-catenin signaling - the accumulation of nuclear β-catenin and the expression of its downstream targets (cyclin D1, AXIN-2 and c-MYC) was facilitated, whereas knockdown of UBAP2L deactivated this signaling. The tumor-suppressing effect of UBAP2L silencing was abolished by forced activation of β-cateninS33A. UBAP2L has been confirmed as a novel and direct target of miR-148b-3p. The anti-tumor effect of miR-148b-3p was partly reversed by UBAP2L overexpression. The expression of miR-148b-3p was negatively correlated with that of UBAP2L in gastric cancer samples. Overall, our study indicates that UBAP2L is required to maintain malignant behavior of gastric cancer cells, which involves the activation of Wnt/β-catenin signaling pathway. We propose UBAP2L as a potential therapeutic target against gastric cancer.

AL Amyloidosis: Current Chemotherapy and Immune Therapy Treatment Strategies: JACC: CardioOncology State-of-the-Art Review

Immunoglobulin light chain (AL) amyloidosis is an incurable plasma cell disorder characterized by deposition of fibrils of misfolded immunoglobulin free light chains (FLC) in target organs, leading to failure. Cardiac involvement is common in AL amyloidosis and represents the single most adverse prognostic feature. A high index of clinical suspicion with rapid tissue diagnosis and commencement of combinatorial, highly effective cytoreductive therapy is crucial to arrest the process of amyloid deposition and preserve organ function. The clinical use of molecularly targeted drugs, such as proteasome inhibitors and immunomodulatory agents, monoclonal antibodies such as daratumumab, and risk-adjusted autologous stem cell transplant in eligible patients, has radically changed the natural history of AL amyloidosis. Here, we review the state-of-the-art treatment landscape in AL amyloidosis with an eye toward future therapeutic venues to impact the outcome of this devastating illness.

How I Treat AL Amyloidosis

The treatment of patients with systemic light chain (AL) amyloidosis is a challenge to hematologists. Despite its generally small size, the underlying clone causes a rapidly progressing, often devastating multiorgan dysfunction through the toxic light chains that form amyloid deposits. Clinical manifestations are deceitful and too often recognized at an irreversible stage. However, hematologists are in the unique position to diagnose AL amyloidosis at a pre-symptomatic stage checking biomarkers of amyloid organ involvement in patients with monoclonal gammopathies at higher risk to develop the disease. Adequate technology and expertise are needed for a prompt and correct diagnosis, particularly for ruling out non-AL amyloidoses that are now also treatable. Therapy should be carefully tailored based on severity of organ involvement and clonal characteristics, and early and continual monitoring of response is critical. Three recent randomized clinical trials moved AL amyloidosis to evidence-based era. Above all, the daratumumab-bortezomib combination is a new standard-of-care for newly diagnosed patients inducing rapid and deep responses that translate into high rates of organ response. The availability of new effective drugs allows to better personalize the therapy, reduce toxicity, and improve outcomes. Patients should be treated within clinical trials whenever possible.

Systemic Amyloidosis: a Contemporary Overview

Amyloidosis constitutes a large spectrum of diseases characterized by an extracellular deposition of a fibrillar aggregate, generating insoluble and toxic amasses that may be deposited in tissues in bundles with an abnormal cross-β-sheet conformation, known as amyloid. Amyloid may lead to a cell damage and an impairment of organ function. Several different proteins are recognized as able to produce amyloid fibrils with a different tissue tropism related to the molecular structure. The deposition of amyloid may occur as a consequence of the presence of an abnormal protein, caused by high plasma levels of a normal protein, or as a result of the aging process along with some environmental factors. Although amyloidosis is rare, amyloid deposits play a role in several conditions as degenerative diseases. Thus, the development of antiamyloid curative treatments may be a rational approach to treat neurodegenerative conditions like Alzheimer's disease in the future. Nowadays, novel treatment options are currently refined through controlled trials, as new drug targets and different therapeutic approaches have been identified and validated through modern advances in basic research. Fibril formation stabilizers, proteasome inhibitors, and immunotherapy revealed promising results in improving the outcomes of patients with systemic amyloidosis, and these novel algorithms will be effectively combined with current treatments based on chemotherapeutic regimens. The aim of this review is to provide an update on diagnosis and treatment for systemic amyloidosis.

Marked progress in AL amyloidosis survival: a 40-year longitudinal natural history study

The recent decades have ushered in considerable advancements in the diagnosis and treatment of systemic light chain (AL) amyloidosis. As disease outcomes improve, AL amyloidosis-unrelated factors may impact mortality. In this study, we evaluated survival trends and primary causes of death among 2337 individuals with AL amyloidosis referred to the Boston University Amyloidosis Center. Outcomes were analyzed according to date of diagnosis: 1980-1989 (era 1), 1990-1999 (era 2), 2000-2009 (era 3), and 2010-2019 (era 4). Overall survival increased steadily with median values of 1.4, 2.6, 3.3, and 4.6 years for eras 1–4, respectively (P < 0.001). Six-month mortality decreased over time from 23% to 13%. Wide gaps in survival persisted amid patient subgroups; those with age at diagnosis ≥70 years had marginal improvements over time. Most deaths were attributable to disease-related factors, with cardiac failure (32%) and sudden unexpected death (23%) being the leading causes. AL amyloidosis-unrelated mortality increased across eras (from 3% to 16% of deaths) and with longer-term survival (29% of deaths occurring >10 years after diagnosis). Under changing standards of care, survival improved and early mortality declined over the last 40 years. These findings support a more optimistic outlook for patients with AL amyloidosis.

Current Updates on the Management of AL Amyloidosis

Systemic immunoglobulin light chain (AL) amyloidosis is a rare but fatal disease. It results from clonal proliferation of plasma cells with excessive production of insoluble misfolded proteins that aggregate in the extracellular matrix, causing damage to the normal architecture and function of various organs. For decades, treatment for AL amyloidosis was based mainly on therapeutic agents previously studied for its more common counterpart, multiple myeloma. As the prevalence and incidence of AL amyloidosis have increased, ongoing research has been conducted with treatments typically used in myeloma with varying success. In this review, we focus on current treatment strategies and updates to clinical guidelines and therapeutics for AL amyloidosis.

Progress and challenges in the treatment of cardiac amyloidosis: a review of the literature

Cardiac amyloidosis is a restrictive cardiomyopathy determined by the accumulation of amyloid, which is represented by misfolded protein fragments in the cardiac extracellular space. The main classification of systemic amyloidosis is determined by the amyloid precursor proteins causing a very heterogeneous disease spectrum, but the main types of amyloidosis involving the heart are light chain (AL) and transthyretin amyloidosis (ATTR). AL, in which the amyloid precursor is represented by misfolded immunoglobulin light chains, can involve almost any system carrying the worst prognosis among amyloidosis patients. This has however dramatically improved in the last few years with the increased usage of the novel therapies such as proteasome inhibitors and haematopoietic cell transplantation, in the case of timely diagnosis and initiation of treatment. The treatment for AL is directed by the haematologist working closely with the cardiologist when there is a significant cardiac involvement. Transthyretin (TTR) is a protein that is produced by the liver and is involved in the transportation of thyroid hormones, especially thyroxine and retinol binding protein. ATTR results from the accumulation of transthyretin amyloid in the extracellular space of different organs and systems, especially the heart and the nervous system. Specific therapies for ATTR act at various levels of TTR, from synthesis to deposition: TTR tetramer stabilization, oligomer aggregation inhibition, genetic therapy, amyloid fibre degradation, antiserum amyloid P antibodies, and antiserum TTR antibodies. Treatment of systemic amyloidosis has dramatically evolved over the last few years in both AL and ATTR, improving disease prognosis. Moreover, recent studies revealed that timely treatment can lead to an improvement in clinical status and in a regression of amyloid myocardial infiltration showed by imaging, especially by cardiac magnetic resonance, in both AL and ATTR. However, treating cardiac amyloidosis is a complex task due to the frequent association between systemic congestion and low blood pressure, thrombo-embolic and haemorrhagic risk balance, patient frailty, and generally poor prognosis. The aim of this review is to describe the current state of knowledge regarding cardiac amyloidosis therapy in this constantly evolving field, classified as treatment of the cardiac complications of amyloidosis (heart failure, rhythm and conduction disturbances, and thrombo-embolic risk) and the disease-modifying therapy.

Acquired and inherited amyloidosis: Knowledge driving patients' care

Until recently, systemic amyloidoses were regarded as ineluctably disabling and life-threatening diseases. However, this field has witnessed major advances in the last decade, with significant improvements in therapeutic options and in the availability of accurate and non-invasive diagnostic tools. Outstanding progress includes unprecedented hematological response rates provided by risk-adapted regimens in light chain (AL) amyloidosis and the approval of innovative pharmacological agents for both hereditary and wild-type transthyretin amyloidosis (ATTR). Moreover, the incidence of secondary (AA) amyloidosis has continuously reduced, reflecting advances in therapeutics and overall management of several chronic inflammatory diseases. The identification and validation of novel therapeutic targets has grounded on a better knowledge of key molecular events underlying protein misfolding and aggregation and on the increasing availability of diagnostic, prognostic and predictive markers of organ damage and response to treatment. In this review, we focus on these recent advancements and discuss how they are translating into improved outcomes. Neurological involvement dominates the clinical picture in transthyretin and gelsolin inherited amyloidosis and has a significant impact on disease course and management in all patients. Neurologists, therefore, play a major role in improving patients' journey to diagnosis and in providing early access to treatment in order to prevent significant disability and extend survival.

Treatment of AL Amyloidosis: Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) Consensus Statement 2020 Update

Immunoglobulin light chain (AL) amyloidosis is a clonal plasma cell disorder leading to progressive and life-threatening organ failure. The heart and the kidneys are the most commonly involved organs, but almost any organ can be involved. Because of the nonspecific presentation, diagnosis delay is common, and many patients are diagnosed with advanced organ failure. In the era of effective therapies and improved outcomes for patients with AL amyloidosis, the importance of early recognition is further enhanced as the ability to reverse organ dysfunction is limited in those with a profound organ failure. As AL amyloidosis is an uncommon disorder and given patients' frailty and high early death rate, management of this complex condition is challenging. The treatment of AL amyloidosis is based on various anti-plasma cell therapies. These therapies are borrowed and customized from the treatment of multiple myeloma, a more common disorder. However, a growing number of phase 2/3 studies dedicated to the AL amyloidosis population are being performed, making treatment decisions more evidence-based. Supportive care is an integral part of management of AL amyloidosis because of the inherent organ dysfunction, limiting the delivery of effective therapy. This extensive review brings an updated summary on the management of AL amyloidosis, sectioned into the 3 pillars for survival improvement: early disease recognition, anti-plasma cell therapy, and supportive care.

Immunoglobulin light chain amyloidosis diagnosis and treatment algorithm 2021

Immunoglobulin light chain amyloidosis (AL) commonly presents with nephrotic range proteinuria, heart failure with preserved ejection fraction, nondiabetic peripheral neuropathy, unexplained hepatomegaly or diarrhea, and should be considered in patients presenting with these symptoms. More importantly, patients being monitored for smoldering multiple myeloma and a monoclonal gammopathy of undetermined significance (MGUS) are at risk for developing AL amyloidosis. MGUS and myeloma patients that have atypical features, including unexplained weight loss; lower extremity edema, early satiety, and dyspnea on exertion should be considered at risk for light chain amyloidosis. Overlooking the diagnosis of light chain amyloidosis leading to therapy delay is common, and it represents an error of diagnostic consideration. Herein we provide a review of established and investigational treatments for patients with AL amyloidosis and provide algorithms for workup and management of these patients.

Pathophysiology and Therapeutic Approaches to Cardiac Amyloidosis

Often considered a rare disease, cardiac amyloidosis is increasingly recognized by practicing clinicians. The increased rate of diagnosis is in part due the aging of the population and increasing incidence and prevalence of cardiac amyloidosis with advancing age, as well as the advent of noninvasive methods using nuclear scintigraphy to diagnose transthyretin cardiac amyloidosis due to either variant or wild type transthyretin without a biopsy. Perhaps the most important driver of the increased awareness is the elucidation of the biologic mechanisms underlying the pathogenesis of cardiac amyloidosis which have led to the development of several effective therapies with differing mechanisms of actions. In this review, the mechanisms underlying the pathogenesis of cardiac amyloidosis due to light chain (AL) or transthyretin (ATTR) amyloidosis are delineated as well as the rapidly evolving therapeutic landscape that has emerged from a better pathophysiologic understanding of disease development.

Recent advances in the diagnosis and management of amyloid cardiomyopathy

Amyloidosis is a disorder characterized by misfolded precursor proteins that form depositions of fibrillar aggregates with an abnormal cross-beta-sheet conformation, known as amyloid, in the extracellular space of several tissues. Although there are more than 30 known amyloidogenic proteins, both hereditary and non-hereditary, cardiac amyloidosis (CA) typically arises from either misfolded transthyretin (ATTR amyloidosis) or immunoglobulin light-chain aggregation (AL amyloidosis). Its prevalence is more common than previously thought, especially among patients with heart failure and preserved ejection fraction (HFpEF) and aortic stenosis. If there is a clinical suspicion of CA, focused echocardiography, laboratory screening for the presence of a monoclonal protein (serum and urinary electrophoresis with immunofixation and serum free light-chain ratio), and cardiac scintigraphy with 99mtechnetium-labeled bone-tracers are sensitive and specific initial diagnostic tests. In some cases, more advanced/invasive techniques are necessary and, in the last several years, treatment options for both AL CA and ATTR CA have rapidly expanded. It is important to note that the aims of therapy are different. Systemic AL amyloidosis requires treatment targeted against the abnormal plasma cell clone, whereas therapy for ATTR CA must be targeted to the production and stabilization of the TTR molecule. It is likely that a multistep treatment approach will be optimal for both AL CA and ATTR CA. Additionally, treatment of CA includes the management of restrictive cardiomyopathy with preserved or reduced ejection fraction in addition to treating the amyloid deposition. Future studies are necessary to define optimal management strategies for AL CA and ATTR CA and confirm cardiac response to therapy.

A safety review of drug treatments for patients with systemic immunoglobulin light chain (AL) amyloidosis

INTRODUCTION

In AL amyloidosis, a usually small plasma cell clone secretes unstable, amyloid-forming light chains, causing cytotoxicity and progressive (multi)organ function deterioration. Treatment aims at reducing/eradicating the underlying clone, to reduce/zero the supply of the amyloidogenic protein and halt the amyloidogenic cascade.

AREAS COVERED

Safety data of alkylating agents, proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies from clinical trials are reviewed.

EXPERT OPINION

Drugs used to treat AL amyloidosis are derived from experience with multiple myeloma or other B cell malignancies. However, treating AL amyloidosis is particularly challenging, as it implies delivering anti-neoplastic therapy to a hematologic malignancy directly causing (multi)organ function deterioration, often in elderly subjects with other comorbidities and polypharmacotherapy. This unique combination translates in increased patients' frailty and higher sensitivity toward treatment-related toxicities. Therefore, dose/schedule adjustments and special precautions are needed when translating treatment experience from multiple myeloma or other B cell malignancies to AL amyloidosis. Treatment of patients with AL amyloidosis should be risk adapted, tailored to individual patients' risk profile, considering the type and extent of organ involvement, and eventual comorbidity. As several classes of effective anti-plasma cell or B cell drugs are available, therapeutic choices are also influenced by individual drug's safety profile.

Cardiac amyloidosis-A review of current literature for the practicing physician

The amyloidoses are a family of diseases in which misfolded precursor proteins aggregate to form amyloid and deposit in body tissues. A very serious yet underrecognized form of this disease is cardiac amyloidosis, in which amyloid deposits into the extracellular space of the myocardium, resulting in thickening and stiffening of ventricular walls with resultant heart failure and conductive dysfunction. This review provides a discussion of the pathogenesis and clinical presentation of cardiac amyloidosis subtypes, as well as an up-to-date approach to diagnosis and treatment. Significant progress has been made in recent years regarding diagnosis and treatment of this condition, but prognosis remains heavily reliant on early detection of the disease. Two types of precursor protein are responsible for most cardiac amyloidosis cases: transthyretin amyloid, and immunoglobulin-derived light chain amyloid. An early diagnosis of cardiac amyloidosis can allow for novel treatment modalities to be initiated with the potential to improve prognosis.

Ixazomib, an oral proteasome inhibitor, exhibits potential effect in dystrophin-deficient mdx mice

Dystrophin deficiency makes the sarcolemma fragile and susceptible to degeneration in Duchenne muscular dystrophy. The proteasome is a multimeric protease complex and is central to the regulation of cellular proteins. Previous studies have shown that proteasome inhibition improved pathological changes in mdx mice. Ixazomib is the first oral proteasome inhibitor used as a therapy in multiple myeloma. This study investigated the effects of ixazomib on the dystrophic muscle of mdx mice. MDX mice were treated with ixazomib (7.5 mg/kg/wk by gavage) or 0.2 mL of saline for 12 weeks. The Kondziela test was performed to measure muscle strength. The tibialis anterior (TA) and diaphragm (DIA) muscles were used for morphological analysis, and blood samples were collected for biochemical measurement. We observed maintenance of the muscle strength in the animals treated with ixazomib. Treatment with ixazomib had no toxic effect on the mdx mouse. The morphological analysis showed a reduction in the inflammatory area and fibres with central nuclei in the TA and DIA muscles and an increase in the number of fibres with a diameter of 20 µm2 in the DIA muscle after treatment with ixazomib. There was an increase in the expression of dystrophin and utrophin in the TA and DIA muscles and a reduction in the expression of osteopontin and TGF-β in the DIA muscle of mdx mice treated with ixazomib. Ixazomib was thus shown to increase the expression of dystrophin and utrophin associated with improved pathological and functional changes in the dystrophic muscles of mdx mice.

Updates in the Diagnosis and Management of AL Amyloidosis

PURPOSE OF REVIEW

Light chain (AL) amyloidosis is an insidious progressive disease which results in significant morbidity and inevitable mortality if not diagnosed and treated promptly. This review will highlight recent developments and summarize critical clinical points and updated practice changes for the clinician in 2020.

RECENT FINDINGS

Comparative analyses of staging systems, updated prognostic tools, and treatment response criteria now allow for improved patient stratification and treatment decisions; the role of minimal residual disease in response assessment is still being assessed. Clinical and genetic predictors for long-term survivors have been highlighted. Standard-of-care front-line bortezomib and the integration of anti-CD38 monoclonal antibodies in the relapsed disease have transformed treatment approach in recent years. Various clinical trials in the pipeline include novel anti-plasma cell therapies and therapies directed against amyloid deposits which promise to further advance the treatment landscape. Diagnosis, response assessment, and treatment paradigms for AL amyloidosis have evolved significantly in the past 15 years, translating into superior outcomes and increased chances of long-term survival for AL amyloidosis.

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.

Amyloidosis and 30-Day Outcomes Among Patients With Heart Failure: A Nationwide Readmissions Database Study

BACKGROUND

The burden of amyloidosis among hospitalized patients is increasing over time. However, amyloidosis remains an underdiagnosed cause of heart failure (HF) hospitalization among older adults.

OBJECTIVES

We investigated the prevalence and prognostic implications of amyloidosis among patients hospitalized with HF.

METHODS

All hospitalizations for primary diagnosis of HF between January 1, 2010, and August 31, 2015, identified in the Nationwide Readmissions Database were categorized into those with and without a secondary diagnosis of amyloidosis. HF hospitalizations with amyloidosis were then matched in a 3:1 fashion to HF hospitalizations without amyloidosis using the year of admission, discharge quarter, age, sex, and Charlson comorbidity index. Primary outcomes were inpatient mortality and 30-day readmission. Multivariable logistic regression was used to estimate the association between HF with amyloidosis and clinical outcomes.

RESULTS

Of 1,593,360 HF hospitalizations that met inclusion criteria, 2,846 (0.18%) had HF with a secondary diagnosis of amyloidosis and were matched to 8,515 hospitalizations for HF without amyloidosis. Hospitalizations for HF with amyloidosis were associated with higher prevalence of kidney disease (56% vs. 45%), malignancy (20% vs. 4%), and higher inpatient mortality (6% vs. 3%) as compared with HF without amyloidosis. In adjusted analyses, HF with amyloidosis was associated with higher odds of in-hospital mortality (odds ratio: 1.46; 95% confidence interval [CI]: 1.17 to 1.82), 30-day readmission (odds ratio: 1.17; 95% CI: 1.05 to 1.31), and longer mean length of stay (least-squares mean difference: 1.46; 95% CI: 1.12 to 1.80).

CONCLUSIONS

In patients hospitalized with decompensated HF, presence of amyloidosis was associated with higher risk of inpatient mortality and 30-day readmission.

Pomalidomide and dexamethasone grant rapid haematologic responses in patients with relapsed and refractory AL amyloidosis: a European retrospective series of 153 patients

Pomalidomide demonstrated activity in the treatment of AL amyloidosis in three phase II clinical trials. We evaluated the safety and efficacy of 28-day cycles of pomalidomide and dexamethasone in 153 previously treated patients with systemic AL amyloidosis. Ninety-nine (65%) were refractory to the last line of therapy and 54 (35%) had relapsed. The median number of previous lines of therapy was 3 (range: 2-7): 143 patients (93%) previously received bortezomib, 124 (81%) lenalidomide, 114 (75%) oral melphalan, and 37 (24%) underwent autologous stem cell transplant. At the completion of cycle 6, 68 (44%) patients obtained at least partial haematologic response, with 5 complete responses (CR, 3%), 35 very good partial responses (VGPR, 23%). Haematologic response resulted in improved overall survival (median survival 50 vs. 27 months, p = .033) in a 6 months landmark analysis. Obtaining at least partial response was also associated with a significant improvement of the progression-free survival (median PFS 37 vs. 18 months, p < .001). Pomalidomide is an effective treatment for heavily pre-treated patients with AL amyloidosis. Haematologic responses are associated with an overall survival advantage.

Advances in pharmacotherapy for cardiac amyloidosis

INTRODUCTION

Amyloidosis is a group of progressive and devastating disorders resulting from extracellular deposition of misfolded proteins into tissues. When deposition of fibrils occurs in cardiac tissues, this systemic disease can lead to a very poor prognosis. Systemic amyloidosis can be acquired [light chain (AL) amyloidosis; AA amyloidosis], or hereditary [transthyretin (ATTR) amyloidosis]. Cardiac disease in amyloidosis is usually secondary to a systemic disease. The diagnosis of cardiac involvement is often delayed and yields an adverse prognosis.

AREAS COVERED

in this review, the authors report current literature on advances in pharmacotherapy for cardiac amyloidosis, mainly focused on AL and ATTR amyloidosis treatment.

EXPERT OPINION

Most pharmacological trials in amyloidosis patients, both AL and TTR, are directed to study the effects of drugs on polyneuropathy. However, since cardiac involvement carries a prominent negative survival impact in amyloidosis patients, future research should be more focused on amyloidosis cardiomyopathy as primary endpoint. Additionally, in AL amyloidosis therapies are mainly derived from experience on multiple myeloma treatment. In this specific setting, possible future research could particularly focus on immunotherapeutic agents able to optimize the standard chemotherapy results and, thus, allowing a larger population of patients to be treated by bone marrow stem cell transplantation.

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.

Options for Chemotherapy and Scoring Response and Relapse

Chemotherapy for amyloid light chain (AL) amyloidosis has evolved over the years. Although high-dose melphalan and stem cell transplantation remain the standard of care for eligible patients, a vast majority of the patients at the time of presentation are not eligible for this approach and require low-intensity but highly effective induction therapy, usually based on bortezomib. Immunomodulatory agents are not well tolerated, particularly by patients with AL amyloidosis cardiomyopathy, and are reserved for second-line or later therapy. Because there currently is no Food Drug and Administration-approved therapy, participation in well-designed clinical trials of high scientific merit should be considered.

The proteasome as a druggable target with multiple therapeutic potentialities: Cutting and non-cutting edges

Ubiquitin Proteasome System (UPS) is an adaptable and finely tuned system that sustains proteostasis network under a large variety of physiopathological conditions. Its dysregulation is often associated with the onset and progression of human diseases; hence, UPS modulation has emerged as a promising new avenue for the development of treatments of several relevant pathologies, such as cancer and neurodegeneration. The clinical interest in proteasome inhibition has considerably increased after the FDA approval in 2003 of bortezomib for relapsed/refractory multiple myeloma, which is now used in the front-line setting. Thereafter, two other proteasome inhibitors (carfilzomib and ixazomib), designed to overcome resistance to bortezomib, have been approved for treatment-experienced patients, and a variety of novel inhibitors are currently under preclinical and clinical investigation not only for haematological malignancies but also for solid tumours. However, since UPS collapse leads to toxic misfolded proteins accumulation, proteasome is attracting even more interest as a target for the care of neurodegenerative diseases, which are sustained by UPS impairment. Thus, conceptually, proteasome activation represents an innovative and largely unexplored target for drug development. According to a multidisciplinary approach, spanning from chemistry, biochemistry, molecular biology to pharmacology, this review will summarize the most recent available literature regarding different aspects of proteasome biology, focusing on structure, function and regulation of proteasome in physiological and pathological processes, mostly cancer and neurodegenerative diseases, connecting biochemical features and clinical studies of proteasome targeting drugs.

Emerging drugs for the treatment of light chain amyloidosis

INTRODUCTION

Systemic AL amyloidosis is a protein-misfolding disorder that is characterized by the deposition of insoluble amyloid fibrils derived from kinetically unstable light chains. Achieving a rapid and deep hematologic response is critical for long-term survival.

AREAS COVERED

This review covers the existing and emerging treatment options for systemic AL, divided into anti-plasma cell and fibril-directed therapies. The anti-CD38 monoclonal antibody daratumumab has demonstrated an unprecedented hematologic response rate and will become the new standard-of-care in newly diagnosed patients in combination with CyBorD/VCD. Other plasma cell-directed drugs that have prospective data on safety and efficacy in AL include proteasome inhibitors [bortezomib and ixazomib], immunomodulatory drugs [lenalidomide and pomalidomide], and alkylating agents [melphalan and bendamustine]. A major unmet need is the development of fibril-directed therapies with the goal of eliminating amyloid fibrils that are already deposited in vital organs.

EXPERT OPINION

The treatment of newly diagnosed AL in the future will likely include daratumumab-based therapy in conjunction with fibril-directed therapy. The most promising second line drugs are venetoclax [for t(11;14)] and pomalidomide, with several others in the pipeline, including antibody-drug conjugates. Minimal residual disease will emerge as a new endpoint for drug development and will potentially guide treatment duration.

Systemic AL Amyloidosis: Current Approaches to Diagnosis and Management

AL amyloidosis is characterized by a low-level expansion of an indolent, small plasma cell clone that produces amyloidogenic light chains. Amyloid aggregates or preceding intermediaries cause direct cell damage through their proteotoxicity, and amyloid deposits distort tissue architecture, and, eventually, lead to organ impairment. It is a rare, underdiagnosed disease with a diverse clinical presentation depending on the organ tropism of the amyloid fibrils; cardiac and renal involvement is most common, but any organ can be affected, excluding the central nervous system. A high level of awareness and a systematic approach using newly emerging screening biomarkers is required to achieve early diagnosis. Management should be multidisciplinary as supportive management tailored to management of organ dysfunction is paramount to survival and minimization of treatment-associated toxicity. The initial therapeutic aim is to rapidly eliminate the clonal plasma cell that produces the circulating amyloid precursor and achieve a complete hematologic response, and if possible with undetectable minimal residual disease as assessed by next-generation methods (flow and sequencing), with minimal toxicity. Treatment is tailored to the initial risk assessment of the patients. Treatments are based on regimens adapted from the expanding options that are available for multiple myeloma patients and hematological response rates have improved. Organ response rates are strongly associated with deeper hematologic response but usually lag behind hematological response and are also dependent on the initial organ function reserve. Agents directed against the amyloid deposits have been explored to aid amyloid clearance and improve organ function, but data are still negative.

Clinical Pharmacology of Ixazomib: The First Oral Proteasome Inhibitor

Ixazomib, the first oral proteasome inhibitor, is approved in combination with lenalidomide and dexamethasone for the treatment of patients with multiple myeloma (MM) who have received at least one prior therapy. Ixazomib is a selective, potent, and reversible inhibitor of the 20S proteasome, and preferentially binds to and inhibits the β5 chymotrypsin-like proteolytic site. Ixazomib absorption is rapid, with a median time to reach maximum plasma concentration of approximately 1 h post-dose. Ixazomib pharmacokinetics (PK) are adequately described by a three-compartment model (terminal half-life of 9.5 days) with first-order linear absorption (oral bioavailability of 58%). Plasma exposures of ixazomib increase in a dose-proportional manner. A high-fat meal decreases both the rate and extent of ixazomib absorption, supporting administration on an empty stomach. Population PK analyses demonstrated that no dose adjustment is required based on age, body size/weight, race, sex, mild-to-moderate renal impairment, or mild hepatic impairment. Results from dedicated studies indicate that a reduced starting dose (from 4 to 3 mg) is appropriate for patients with severe renal impairment, end-stage renal disease requiring dialysis, or moderate-to-severe hepatic impairment. Non-cytochrome P450 (CYP)-mediated metabolism appears to be the major clearance mechanism for ixazomib. Drug–drug interaction studies have shown no meaningful effects of strong inhibitors of CYP3A on ixazomib PK; however, the strong inducer rifampin caused a clinically relevant reduction in ixazomib exposure, supporting the recommendation to avoid concomitant administration of ixazomib with strong CYP3A inducers. Exposure–response analyses of data from the phase III TOURMALINE-MM1 registrational study demonstrate a favorable benefit–risk profile for the approved dose and regimen of weekly ixazomib 4 mg on days 1, 8, and 15 of each 28-day cycle.

Amyloidosis in Heart Failure

PURPOSE

Amyloidosis represents an increasingly recognized but still frequently missed cause of heart failure. In the light of many effective therapies for light chain (AL) amyloidosis and promising new treatment options for transthyretin (ATTR) amyloidosis, awareness among caregivers needs to be raised to screen for amyloidosis as an important and potentially treatable differential diagnosis. This review outlines the diversity of cardiac amyloidosis, its relation to heart failure, the diagnostic algorithm, and therapeutic considerations that should be applied depending on the underlying type of amyloidosis.

RECENT FINDINGS

Non-biopsy diagnosis is feasible in ATTR amyloidosis in the absence of a monoclonal component resulting in higher detection rates of cardiac ATTR amyloidosis. Biomarker-guided staging systems have been updated to facilitate risk stratification according to currently available biomarkers independent of regional differences, but have not yet prospectively been tested. Novel therapies for hereditary and wild-type ATTR amyloidosis are increasingly available. The complex treatment options for AL amyloidosis are improving continuously, resulting in better survival and quality of life. Mortality in advanced cardiac amyloidosis remains high, underlining the importance of early diagnosis and treatment initiation. Cardiac amyloidosis is characterized by etiologic and clinical heterogeneity resulting in a frequently delayed diagnosis and an inappropriately high mortality risk. New treatment options for this hitherto partially untreatable condition have become and will become available, but raise challenges regarding their implementation. Referral to specialized centers providing access to extensive and targeted diagnostic investigations and treatment initiation may help to face these challenges.

Immunoglobulin light chain amyloidosis: 2020 update on diagnosis, prognosis, and treatment

DISEASE OVERVIEW

Immunoglobulin light chain amyloidosis is a clonal, nonproliferative plasma cell disorder in which fragments of immunoglobulin light or heavy chain are deposited in tissues. Clinical features depend on organs involved but can include heart failure with preserved ejection fraction, nephrotic syndrome, hepatic dysfunction, peripheral/autonomic neuropathy, and "atypical smoldering multiple myeloma or monoclonal gammopathy undetermined significance (MGUS)."

DIAGNOSIS

Tissue biopsy stained with Congo red demonstrating amyloid deposits with apple-green birefringence is required for diagnosis. Invasive organ biopsy is not required in 85% of patients. Verification that amyloid is composed of immunoglobulin light chains is mandatory. The gold standard is laser capture mass spectroscopy.

PROGNOSIS

N-terminal pro-brain natriuretic peptide (NT-proBNP), serum troponin T, and difference between involved and uninvolved immunoglobulin free light chain (FLC) values are used to classify patients into four groups of similar size; median survivals are 94.1, 40.3, 14.0, and 5.8 months.

THERAPY

All patients with a systemic amyloid syndrome require therapy to prevent deposition of amyloid in other organs and prevent progressive organ failure. Stem cell transplant (SCT) is preferred, but only 20% of patients are eligible. Requirements for safe SCT include systolic blood pressure >90 mmHg, troponin T < 0.06 ng/mL and serum creatinine ≤1.7 mg/dL. Nontransplant candidates can be offered cyclophosphamide-bortezomib-dexamethasone or daratumumab-containing regimens as it appears to be highly active in AL amyloidosis.

FUTURE CHALLENGES

Delayed diagnosis remains a major obstacle to initiating effective therapy prior to the development of end-stage organ failure.

Diagnosis and management of systemic light chain AL amyloidosis

AL amyloidosis is a plasma cell disorder leading to the production and extracellular deposition of abnormal immunoglobulin light chains called amyloid. The pathogenesis of the disorder is driven by an abnormal plasma cell clone producing excessive monoclonal immunoglobulin light chains that undergo deposition in various organs of the body such as the heart, kidney, and gastrointestinal tract. The outcome of the disease remains poor with significant morbidity and mortality associated with organ dysfunction. In this review, we describe the current standard diagnostic features, prognosis, and current treatment paradigm of the disease.