High-dose melphalan and stem cell transplantation in systemic AL amyloidosis in the era of novel anti-plasma cell therapy: a comprehensive review

Screening for Systemic Light-Chain Amyloidosis in Patients Over 60 with λ Monoclonal Gammopathies

Background/Objectives: To reduce the early mortality of light-chain amyloidosis (AL), earlier diagnosis is needed. To pursue this goal, we conducted a multicenter study screening for AL λ-type (NCT04615572) in subjects > 60 years of age with λ smoldering myeloma (SMM) or monoclonal gammopathy of undetermined significance (MGUS), a light-chain differential (dFLC, λ minus κ) > 23 mg/L, and no prior amyloid diagnosis. Methods: Variables included AL-related IGVL gene usage and clonal plasma cell cytogenetic abnormalities, such as t(11;14) or gain 1q, which are present in 75% of AL cases. Here, 9 out of 33 λ IGVL genes, accounting for 90% of AL λ cases, were considered to be AL-related. Bone marrow was obtained, plasma cell cytogenetics and next generation sequencing for IGVL genes were performed, and subjects with AL-related IGVL genes were screened for AL using tissue studies. Results: From 2021 to 2023, we enrolled 30 subjects (19 M/11 F) with a median age of 68.5 years old (IQR 64.3-73), 17 SMM and 13 MGUS, with a median of 6% marrow plasma cells (range, 3.5-40). Here, 11 SMM and 4 MGUS cases had t(11;14) or gain 1q; 10/17 SMM and 12/13 MGUS had AL-related genes, and AL was ultimately confirmed by tissue biopsy in 3 with SMM. SMM, AL-related IGVL genes, and t(11;14) or gain 1q were found in 6 SMM subjects, including the 3 with AL (3/6 vs. 0/16; p < 0.05, Fisher's exact, two-tailed). Conclusions: These results justify a larger study screening for AL in SMM to develop a likelihood algorithm for AL using dFLC, IGVL gene usage, and the presence of t(11;14) or gain 1q.

Autologous stem cell transplantation in AL amyloidosis: Muddy waters

Immunoglobulin light chain (AL) amyloidosis is a malignant plasma cell dyscrasia causing multi-organ morbidity. High dose melphalan and autologous stem cell transplantation (ASCT) is a preferred consolidation approach and is safe with improved patient selection criteria. With the advent of bortezomib and daratumumab based induction therapy, nearly all patients can achieve deep hematological responses but follow up for daratumumab based induction is short. Consequently, the traditional approach of induction followed by ASCT is called into question. Given the multi-organ involvement of AL, endpoints beyond depth of response and hematological progression free survival (PFS) are important. Major organ dysfunction PFS (MOD-PFS) adds to PFS and is a composite endpoint of PFS, renal and cardiac organ progression, and overall survival. It is currently unknown which consolidative approach (ASCT or non-ASCT) will generate improved outcomes across the MOD-PFS spectrum a question the recently opened S2213 trial will attempt to answer.

Peripheral Nervous, Hepatic, and Gastrointestinal Endpoints for AL Amyloidosis Clinical Trials: Report from the Amyloidosis Forum Multi-organ System Working Group

Systemic immunoglobulin light chain (AL) amyloidosis is a heterogeneous rare disease driven by a destructive monoclonal gammopathy and typified by misfolded immunoglobulin light and/or heavy chains which aggregate and deposit in organs as insoluble amyloid fibrils. Disease heterogeneity is driven by the degree of multi-systemic involvement; cardiac, renal, neurological, and gastrointestinal (GI) systems are affected to varying degrees in different patients. While prognosis is primarily driven by hematologic response to treatment and outcomes associated with cardiac events and overall survival, the involvement of the peripheral nervous, hepatic, and GI systems can also have a significant impact on patients. The Amyloidosis Forum ( https://amyloidosisforum.org ) is a public-private partnership between the nonprofit Amyloidosis Research Consortium ( www.arci.org ) and the US Food and Drug Administration (FDA) Center for Drug Evaluation and Research formed to advance drug development for the treatment of systemic amyloid disorders. A series of virtual workshops focused on the development of novel, patient-relevant endpoint components and analytical strategies for clinical trials in AL amyloidosis. This review summarizes the proceedings and recommendations of the Multi-Systemic Working Group which identified, reviewed, and prioritized endpoints relevant to the impacts of AL amyloidosis on the peripheral nervous, hepatic, and GI systems. The Working Group comprised amyloidosis experts, patient representatives, statisticians, and representatives from the FDA, Medicines and Healthcare products Regulatory Agency (MHRA), and pharmaceutical companies. Prioritized neuropathy/autonomic endpoints included a modified form of the Neuropathy Impairment Score (NIS + 7) and the Composite Autonomic Symptom Score (COMPASS-31), respectively. Alkaline phosphatase was identified as the most relevant indicator of liver involvement and disease progression. Following extensive review of potential GI endpoints, the Working Group identified multiple exploratory endpoints. These recommended components will be further explored through evaluation of clinical trial datasets and possible integration into composite endpoint analysis.

Health-Related Quality of Life Instruments for Clinical Trials in AL Amyloidosis: Report from the Amyloidosis Forum HRQOL Working Group

Systemic AL (light chain) amyloidosis is a rare protein misfolding disorder associated with plasma cell dyscrasia affecting various organs leading to organ dysfunction and failure. The Amyloidosis Forum is a public-private partnership between the Amyloidosis Research Consortium and the US Food and Drug Administration Center for Drug Evaluation and Research with the goal of accelerating the development of effective treatments for AL amyloidosis. In recognition of this goal, 6 individual working groups were formed to identify and/or provide recommendations related to various aspects of patient-relevant clinical trial endpoints. This review summarizes the methods, findings, and recommendations of the Health-Related Quality of Life (HRQOL) Working Group. The HRQOL Working Group sought to identify existing patient-reported outcome (PRO) assessments of HRQOL for use in clinical trials and practice deemed relevant across a broad spectrum of patients with AL amyloidosis. A systematic review of the AL amyloidosis literature identified 1) additional signs/symptoms not currently part of an existing conceptual model, and 2) relevant PRO instruments used to measure HRQOL. The Working Group mapped content from each identified instrument to areas of impact in the conceptual model to determine which instrument(s) provide coverage of relevant concepts. The SF-36v2^® Health Survey (SF-36v2; QualityMetric Incorporated, LLC) and Patient-Reported Outcomes Measurement Information System-29 Profile (PROMIS-29; HealthMeasures) were identified as instruments relevant to patients with AL amyloidosis. Existing evidence of reliability and validity was evaluated with a recommendation for future work focused on estimating clinically meaningful within-patient change thresholds for these instruments. For sponsors, the context of use-including specific research objectives, trial population, and investigational product under study-should inherently drive selection of the appropriate PRO instrument and endpoint definitions to detect meaningful change and enable patient-focused drug development.

Vincristine, Doxorubicin, and Dexamethasone Induction before Autologous Stem Cell Transplantation in Patients with AL Amyloidosis: A Retrospective Comparison with Frontline Stem Cell Transplantation

Objective High-dose melphalan and autologous stem cell transplantation (ASCT) therapy for AL amyloidosis are now associated with reduced mortality based on the application of strict criteria. However, there is no long-term evidence concerning the performance of induction therapy with newer agents, such as bortezomib or daratumumab. Concerns regarding long-term relapse despite treatment with ASCT exist, and missing the opportunity to perform ASCT might occur if induction proves to not be efficacious and cardiac amyloidosis progression deprives the patients of a chance to receive ASCT. We herein report good amyloid control by vincristine, doxorubicin, and dexamethasone (VAD) induction therapy and argue the importance of induction therapy before ASCT. Methods We compared patients who underwent VAD induction and ASCT (VAD+ASCT) with patients who underwent frontline ASCT in our hospital. Patients A total of 26 patients with histologically proven AL amyloidosis were included (18 in the VAD+ASCT group and 8 in the frontline ASCT). Results In the VAD+ASCT group, the 10-year overall survival and renal response rates were 82% and 43%, respectively. The renal response rate at two years in the VAD+ASCT group was significantly better than that in the frontline ASCT group. Although there was no significant difference in the survival rates between the two groups, the time to next treatment or death was significantly better in the VAD+ASCT group than in the the frontline ASCT group. Acute kidney injury was the most frequent reason for failure to receive two courses of VAD, and early mortality was mainly due to gastrointestinal complications. Conclusion Considering that only those who underwent 2 courses of VAD experienced a 10-year renal response, induction therapy was deemed to be directly related to the long-term control of AL amyloidosis.

Proposed Cardiac End Points for Clinical Trials in Immunoglobulin Light Chain Amyloidosis: Report From the Amyloidosis Forum Cardiac Working Group

Immunoglobulin light chain amyloidosis is a rare, multisystemic, phenotypically heterogenous disease affecting cardiovascular, renal, neurological, and gastrointestinal systems to varying degrees. Its underlying cause is a plasma cell dyscrasia characterized by misfolding of monoclonal immunoglobulin light chains which leads to aggregation and deposition of insoluble amyloid fibrils in target organs. Prognosis is primarily dependent on extent of cardiac involvement and depth of hematologic response to treatment. To facilitate development of new therapies, a public-private partnership was formed between the nonprofit Amyloidosis Research Consortium and the US Food and Drug Administration Center for Drug Evaluation and Research. In 2020, the Amyloidosis Forum launched an initiative to identify novel/composite end points and analytic strategies to expedite clinical trials for development of new therapies for the primary hematologic disorder and organ system manifestations. Specialized working groups identified organ-specific end points; additional working groups reviewed health-related quality of life measures and statistical approaches to data analysis. Each working group comprised amyloidosis experts, patient representatives, statisticians, and representatives from the Food and Drug Administration, the UK Medicines and Healthcare Products Regulatory Agency, and pharmaceutical companies. This review summarizes the proceedings and recommendations of the Cardiac Working Group. Using a modified Delphi method, the group identified, reviewed, and prioritized cardiac end points relevant to immunoglobulin light chain amyloidosis in the context of an antiplasma cell therapy. Prioritized cardiovascular end points included overall survival, hospitalization, N-terminal pro-B-type natriuretic peptide level, 6-minute walk test, Kansas City Cardiac Questionnaire, and cardiac deterioration progression-free survival. These recommended components will be further explored through evaluation of clinical trial datasets and formal guidance from regulatory authorities.

Influence of anticancer agents on sexual function: an in Vivo study based on the US FDA Adverse Event Reporting System

Background

Patients with cancer are treated with chemotherapeutics that cause adverse effects, including erectile dysfunction (ED).

Objectives

We investigated erectile function in rats after the administration of anticancer agents based on data retrieved through mining of the US Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) database.

Materials and methods

The statistical signal strength for the association between anticancer drugs and ED was calculated using the reporting odds ratio (ROR). A drug–event combination was detected when the lower limit of the 95% confidence interval (CI) of the ROR exceeded 1.00. Rats were administered anticancer agents detected in the FDA AERS analysis. Erectile function was assessed using intracavernous pressure (ICP) and mean arterial pressure (MAP) analysis after electrical stimulation of the cavernous nerve. Statistical significance was determined using Welch's t‐test or two‐way ANOVA.

Results

Melphalan (L‐PAM; ROR = 4.72, 95% CI = 2.78–8.00), vincristine (VCR; ROR = 2.47, 95% CI = 1.54–3.97), docetaxel (DTX; ROR = 2.25, 95% CI = 1.28–3.95), methotrexate (MTX; ROR = 1.96, 95% CI = 1.39–2.75), and doxorubicin (DOX; ROR = 1.82, 95% CI = 1.07–3.19) enhanced ED risk. L‐PAM and MTX decreased the ICP/MAP ratio 1 week after administration. VCR and DOX decreased erectile function 4 weeks after administration. DTX decreased erectile function at all assessed time points.

Discussion and conclusion

Certain anticancer agents should be considered risk factors for ED.

Our results provide possible treatment strategies for maintaining erectile function in cancer survivors, including careful erectile function monitoring after treatment.

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.

Impact of time to diagnosis on Mayo stages, treatment outcome, and survival in patients with AL amyloidosis and cardiac involvement

OBJECTIVE

To study the impact of time to diagnosis on cardiac Mayo stages, treatment outcome, and overall survival.

METHODS

We retrospectively analyzed 77 consecutive patients diagnosed between 2015 and 2020 with AL amyloidosis and cardiac involvement. Medical history was recorded in standardized form with the help of a questionnaire.

RESULTS

Time from onset of symptoms of cardiac failure to diagnosis was correlated with the severity of cardiac involvement in modified Mayo 2004 and revised Mayo 2012 staging systems (r_s  = 0.30, 95% CI: 0.07-0.50, P = .007 and r_s  = 0.25, 95% CI: 0.01-0.45, P = .03). Patients with advanced Mayo 2004 stages received reduced-intensity regimens and had a lower probability to achieve adequate hematologic- and cardiac response after first-line treatment than patients with early stages (r_s  = 0.28, 95% CI: 0.04-0.48, P = .01 and r_s  = 0.72, 95% CI: 0.55-0.82, P < .0001) and poorer overall survival (P = .0004). Compared with patients diagnosed within the first year, patients diagnosed after 13-18 or ≥19 months from first symptoms had a 3- to 5 times higher risk of dying. Our data indicate that there is a 12-month window within which the diagnosis of AL amyloidosis needs to be established to avoid early deterioration and death.

CONCLUSIONS

Sensitizing physicians and raising awareness for the disease are crucial for timely diagnosis and may improve the outcome of the disease.

Amyloidosis with Cardiac Involvement: Identification, Characterization, and Management

PURPOSE OF REVIEW

Amyloidosis is a protein deposition disease whereby a variety of precursor proteins form insoluble fibrils that deposit in tissues, causing organ dysfunction and, many times, death. Accurate characterization of the disease based on the nature of the precursor protein, organ involvement, and extent of disease is paramount to guide management. Cardiac amyloidosis is critical to understand because of its impact on prognosis and new treatment options available.

RECENT FINDINGS

New imaging methods have proven to be considerably valuable in the identification of cardiac amyloid infiltration. For treating clinicians, a diagnostic algorithm for patients with suspected amyloidosis with or without cardiomyopathy is shown to help classify disease and to direct appropriate genetic testing and management. For patients with light chain disease, recently introduced treatments adopted from multiple myeloma therapies have significantly extended progression-free and overall survival as well as organ response. In addition, new medical interventions are now available for those with transthyretin amyloidosis. Although cardiac amyloidosis contributes significantly to the morbidity and mortality associated with systemic disease, new tools are available to assist with diagnosis, prognosis, and management.

The role of induction therapy before autologous stem cell transplantation in low disease burden AL amyloidosis patients

BACKGROUND

Induction therapy is recommended before autologous stem cell transplantation (ASCT) for AL amyloidosis patients with high disease burden [bone marrow plasma cells (BMPCs) > 10%], but the role of induction therapy before ASCT in patients with low disease burden (BMPCs ≤ 10%) is still unknown.

METHODS

A total of 227 patients with AL amyloidosis were included in this study. Among 227 patients, 124 patients received bortezomib-based induction prior to ASCT and were defined as group A, 35 patients received other chemotherapeutic induction and were defined as group B, and the other 68 patients without induction were defined as group C. We compared the differences of efficacy and prognosis between the three groups.

RESULTS

The haematological overall response rates (ORR) of groups A, B and C were 91%, 67% and 75%, respectively. The complete response rates (CR) of groups A, B and C were 50%, 25% and 20%, respectively. Both the ORR and CR rates of group A were significantly higher than those of groups B and C. The renal response rates of groups A, B and C were 64%, 46% and 47%, respectively. The cardiac response rates of groups A, B and C were 74%, 45% and 40%, respectively. The renal and cardiac responses rates of group A were also significantly higher than those of the other two groups. After a median follow-up of 44 months, the median OS was not reached. The 5-year estimated overall survival (OS) rates of groups A, B and C were 81%, 57% and 67%, respectively. The median progression-free survival (PFS) was 83 months for all patients. The 5-year estimated PFS rates of groups A, B and C were 61%, 38% and 49%, respectively. Both the OS and PFS of group A were higher than those of both group B and group C. On multivariate analysis, baseline dFLC > 50 mg/L was associated with worse survival, but induction with bortezomib was associated with better survival.

CONCLUSION

Our study demonstrated that low disease burden AL patients who are eligible for ASCT may benefit from bortezomib-based induction therapy.

Diagnosis and treatment of cardiac amyloidosis: position statement of the German Cardiac Society (DGK)

Systemic forms of amyloidosis affecting the heart are mostly light-chain (AL) and transthyretin (ATTR) amyloidoses. The latter is caused by deposition of misfolded transthyretin, either in wild-type (ATTRwt) or mutant (ATTRv) conformation. For diagnostics, specific serum biomarkers and modern non-invasive imaging techniques, such as cardiovascular magnetic resonance imaging (CMR) and scintigraphic methods, are available today. These imaging techniques do not only complement conventional echocardiography, but also allow for accurate assessment of the extent of cardiac involvement, in addition to diagnosing cardiac amyloidosis. Endomyocardial biopsy still plays a major role in the histopathological diagnosis and subtyping of cardiac amyloidosis. The main objective of the diagnostic algorithm outlined in this position statement is to detect cardiac amyloidosis as reliably and early as possible, to accurately determine its extent, and to reliably identify the underlying subtype of amyloidosis, thereby enabling subsequent targeted treatment.

AL Amyloidosis: The Effect of Maintenance Therapy on Autologous Stem Cell Transplantation Outcomes

BACKGROUND

Autologous stem cell transplantation (ASCT) remains an effective treatment option for many patients with systemic light chain (AL) amyloidosis. While maintenance post ASCT in multiple myeloma is now standard, the decision to utilize maintenance in AL amyloidosis remains largely unexplored. The present study aims to determine the prognostic significance of utilizing maintenance therapy following ASCT and assess the impact of fluorescent in situ hybridization (FISH) abnormalities, bone marrow plasma cell burden (BMPC), and degree of organ involvement on this decision.

METHODS AND RESULTS

This is a retrospective analysis of fifty AL amyloidosis patients who underwent ASCT at The Ohio State University. Twenty-eight patients received maintenance and twenty-two did not. Kaplan-Meier survival analysis was used to compare the effect of maintenance therapy with no significant difference in PFS (p = 0.66) and OS (p = 0.32) between the two groups. There was no difference in survival based on maintenance when further categorized by FISH, PFS (p = 0.15), and OS (p = 0.65); BMPC ≥ 10%, PFS (p = 0.49), and OS (p = 0.32); or with 2 or more organs involved, PFS (p = 0.34) and OS (p = 0.80).

CONCLUSION

Maintenance therapy post ASCT did not impact PFS or OS when categorized by FISH abnormalities, increasing BMPC, or ≥2 organs involved in AL amyloidosis patients.

Lousada I. The Amyloidosis Forum: a public private partnership to advance drug development in AL amyloidosis

BACKGROUND

Immunoglobulin light chain (AL) amyloidosis is a rare, multi-systemic disorder characterized by two disease processes: an underlying plasma cell dyscrasia that provides the source of pathologic light chains, and the resulting organ dysfunction caused by deposition of amyloid light chain fibrils. There are no FDA approved treatments for AL amyloidosis; regimens developed for multiple myeloma are used off-label to treat the plasma cell disorder and no therapies are directed at organ deposition. Thus, an unmet medical need persists despite advances in disease management. A public-private partnership was recently formed between the Amyloidosis Research Consortium (ARC) and the US Food and Drug Administration (FDA) to bridge scientific gaps in drug development for the treatment of AL amyloidosis.

MAIN BODY

The inaugural Amyloidosis Forum was convened at FDA on 12 November 2019 and led by a multidisciplinary panel of physicians, health outcomes professionals, and representatives from the FDA, ARC, and pharmaceutical companies. Patients provided important perspectives on the pathway to diagnosis, challenges of rigorous treatment, and the burden of disease. The panel reviewed the epidemiology, pathobiology, and clinical features of AL amyloidosis. Hematologic characteristics, staging systems, and response criteria were examined with clear consensus that a "deep response" to plasma cell-directed treatments was critical to overall survival. Emphasis was placed on the heterogeneous clinical phenotypes of AL amyloidosis, including cardiovascular, renal, neurological, and gastrointestinal system manifestations that contribute to morbidity and/or mortality, but render challenges to clinical trial endpoint selection. FDA representatives discussed regulatory perspectives regarding demonstration of clinical benefits of investigational therapies in the context of a rare disease with multi-systemic manifestations. The panel also highlighted the potential importance of well-designed health-related quality of life instruments, quantification of system organ effects, the potential of advanced imaging technologies, and survival prediction models.

CONCLUSIONS

The Amyloidosis Forum identified a clear need for novel trial designs that are scientifically rigorous, feasible, and incorporate clinically meaningful endpoints based on an understanding of the natural history of the disease in an evolving therapeutic landscape. Future forums will delve into these issues and seek to include participation from additional stakeholders.

Systemic Amyloidosis Recognition, Prognosis, and Therapy: A Systematic Review

IMPORTANCE

Many patients with systemic amyloidosis are underdiagnosed. Overall, 25% of patients with immunoglobulin light chain (AL) amyloidosis die within 6 months of diagnosis and 25% of patients with amyloid transthyretin (ATTR) amyloidosis die within 24 months of diagnosis. Effective therapy exists but is ineffective if end-organ damage is severe.

OBJECTIVE

To provide evidence-based recommendations that could allow clinicians to diagnose this rare set of diseases earlier and enable accurate staging and counseling about prognosis.

EVIDENCE REVIEW

A comprehensive literature search was conducted by a reference librarian with publication dates from January 1, 2000, to December 31, 2019. Key search terms included amyloid, amyloidosis, nephrotic syndrome, heart failure preserved ejection fraction, and peripheral neuropathy. Exclusion criteria included case reports, non-English-language text, and case series of fewer than 10 patients. The authors independently selected and appraised relevant literature.

FINDINGS

There was a total of 1769 studies in the final data set. Eighty-one articles were included in this review, of which 12 were randomized clinical trials of therapy that included 3074 patients, 9 were case series, and 3 were cohort studies. The incidence of AL amyloidosis is approximately 12 cases per million persons per year and there is an estimated prevalence of 30 000 to 45 000 cases in the US and European Union. The incidence of variant ATTR amyloidosis is estimated to be 0.3 cases per year per million persons with a prevalence estimate of 5.2 cases per million persons. Wild-type ATTR is estimated to have a prevalence of 155 to 191 cases per million persons. Amyloidosis should be considered in the differential diagnosis of adult nondiabetic nephrotic syndrome; heart failure with preserved ejection fraction, particularly if restrictive features are present; unexplained hepatomegaly without imaging abnormalities; peripheral neuropathy with distal sensory symptoms, such as numbness, paresthesia, and dysesthesias (although the autonomic manifestations occasionally may be the presenting feature); and monoclonal gammopathy of undetermined significance with atypical clinical features. Staging can be performed using blood testing only. Therapeutic decision-making for AL amyloidosis involves choosing between high-dose chemotherapy and stem cell transplant or bortezomib-based chemotherapy. There are 3 therapies approved by the US Food and Drug Administration for managing ATTR amyloidosis, depending on clinical phenotype.

CONCLUSIONS AND RELEVANCE

All forms of amyloidosis are underdiagnosed. All forms now have approved therapies that have been demonstrated to improve either survival or disability and quality of life. The diagnosis should be considered in patients that have a multisystem disorder involving the heart, kidney, liver, or nervous system.