First report of ibrutinib in IgM-related amyloidosis: few responses, poor tolerability, and short survival

How I use genomics and BTK inhibitors in the treatment of Waldenström macroglobulinemia

ABSTRACT

Mutations in MYD88 (95%-97%) and CXCR4 (30%-40%) are common in Waldenström macroglobulinemia (WM). TP53 is altered in 20% to 30% of patients with WM, particularly those previously treated. Mutated MYD88 activates hematopoietic cell kinase that drives Bruton tyrosine kinase (BTK) prosurvival signaling. Both nonsense and frameshift CXCR4 mutations occur in WM. Nonsense variants show greater resistance to BTK inhibitors. Covalent BTK inhibitors (cBTKi) produce major responses in 70% to 80% of patients with WM. MYD88 and CXCR4 mutation status can affect time to major response, depth of response, and/or progression-free survival (PFS) in patients with WM treated with cBTKi. The cBTKi zanubrutinib shows greater response activity and/or improved PFS in patients with WM with wild-type MYD88, mutated CXCR4, or altered TP53. Risks for adverse events, including atrial fibrillation, bleeding diathesis, and neutropenia can differ based on which BTKi is used in WM. Intolerance is also common with cBTKi, and dose reduction or switchover to another cBTKi can be considered. For patients with acquired resistance to cBTKis, newer options include pirtobrutinib or venetoclax. Combinations of BTKis with chemoimmunotherapy, CXCR4, and BCL2 antagonists are discussed. Algorithms for positioning BTKis in treatment naïve or previously treated patients with WM, based on genomics, disease characteristics, and comorbidities, are presented.

How to manage waldenström's macroglobulinemia in 2024

Clinical management of Waldenström's Macroglobulinemia has seen major progress in the recent years, triggered by our improved understanding of the biology of the disease and the development of new therapies. Based on this there are multiple treatment options available for patients with WM ranging from classical immunochemotherapy to targeted approaches blocking key enzymes involved in lymphoma growth. This review summarizes our current knowledge about diagnostics and treatment of this rare but recurrent lymphoma subtype, which often presents a major clinical challenge in daily clinical life.

Clinical and clonal characteristics of monoclonal immunoglobulin M-associated type I cryoglobulinaemia

Monoclonal immunoglobulin M-associated type I cryoglobulinaemia is poorly characterised. We screened 534 patients with monoclonal IgM disorders over a 9-year period and identified 134 patients with IgM type I cryoglobulins. Of these, 76% had Waldenström macroglobulinaemia (WM), 5% had other non-Hodgkin lymphoma (NHL) and 19% had IgM monoclonal gammopathy of undetermined significance (MGUS). Clinically relevant IgM-associated disorders (including cold agglutinin disease [CAD], anti-MAG antibodies, amyloidosis and Schnitzler syndrome) coexisted in 31%, more frequently in MGUS versus WM/NHL (72% vs. 22%/29%, p < 0.001). The majority of those with cryoglobulins and coexistent CAD/syndrome had the molecular characteristics of a CAD clone (wild-type MYD88 in 80%). A half of all patients had active manifestations at cryoglobulin detection: vasomotor (22%), cutaneous (16%), peripheral neuropathy (22%) and hyperviscosity (9%). 16/134 required treatment for cryoglobulin-related symptoms alone at a median of 38 days (range: 6-239) from cryoglobulin detection. At a median follow-up of 3 years (range: 0-10), 3-year cryoglobulinaemia-treatment-free survival was 77% (95% CI: 68%-84%). Age was the only predictor of overall survival. Predictors of cryoglobulinaemia-related treatment/death were hyperviscosity (HR: 73.01; 95% CI: 15.62-341.36, p < 0.0001) and cutaneous involvement (HR: 2.95; 95% CI: 1.13-7.71, p = 0.028). Type I IgM cryoglobulinaemia is more prevalent than previously described in IgM gammopathy and should be actively sought.

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

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

Monoclonal gammopathy of renal significance: Multidisciplinary approach to diagnosis and treatment

Monoclonal gammopathy of renal significance (MGRS) is a hemato-nephrological term referring to a heterogeneous group of kidney disorders characterized by direct or indirect kidney injury caused by a monoclonal immunoglobulin (MIg) produced by a B cell or plasma cell clone that does not meet current hematologic criteria for therapy. MGRS-associated kidney diseases are diverse and can result in the development of end stage kidney disease (ESKD). The diagnosis is typically made by nephrologists through a kidney biopsy. Many distinct pathologies have been identified and they are classified based on the site or composition of the deposited Mig, or according to histological and ultrastructural findings. Therapy is directed towards the identified underlying clonal population and treatment decisions should be coordinated between hematologists and nephrologists in a multidisciplinary fashion, depend on the type of MGRS, the degree of kidney function impairment and the risk of progression to ESKD.

Report of consensus panel 1 from the 11th International Workshop on Waldenstrom's Macroglobulinemia on management of symptomatic, treatment-naïve patients

Consensus Panel 1 (CP1) of the 11th International Workshop on Waldenstrom's Macroglobulinemia (IWWM-11) was tasked with updating guidelines for the management of symptomatic, treatment-naïve patients with WM. The panel reiterated that watchful waiting remains the gold standard for asymptomatic patients without critically elevated IgM or compromised hematopoietic function. For first-line treatment, chemoimmunotherapy (CIT) regimens such as dexamethasone, cyclophosphamide, rituximab (DRC), or bendamustine, rituximab (Benda-R) continue to play a central role in managing WM, as they are effective, of fixed duration, generally well-tolerated, and affordable. Covalent BTK inhibitors (cBTKi) offer a continuous, generally well-tolerated alternative for the primary treatment of WM patients, particularly those unsuitable for CIT. In a Phase III randomized trial updated at IWWM-11, the second-generation cBTKi, zanubrutinib, was less toxic than ibrutinib and induced deeper remissions, thus categorizing zanubrutinib as a suitable treatment option in WM. While the overall findings of a prospective, randomized trial updated at IWWM-11 did not show superiority of fixed duration rituximab maintenance over observation following attainment of a major response to Benda-R induction, a subset analysis showed benefit in patients >65 years and those with a high IPPSWM score. Whenever possible, the mutational status of MYD88 and CXCR4 should be determined before treatment initiation, as alterations in these 2 genes predict sensitivity towards cBTKi activity. Treatment approaches for WM-associated cryoglobulins, cold agglutinins, AL amyloidosis, Bing-Neel syndrome (BNS), peripheral neuropathy, and hyperviscosity syndrome follow the common principle of reducing tumor and abnormal protein burden rapidly and deeply to improve symptoms. In BNS, ibrutinib can be highly active and produce durable responses. In contrast, cBTKi are not recommended for treating AL amyloidosis. The panel emphasized that continuous improvement of treatment options for symptomatic, treatment-naïve WM patients critically depends on the participation of patients in clinical trials, whenever possible.

Report of Consensus Panel 6 from the 11 th International Workshop on Waldenström's Macroglobulinemia on Management of Waldenström's Macroglobulinemia Related Amyloidosis

Consensus Panel 6 (CP6) of the 11th International Workshop on Waldenström's Macroglobulinemia (IWWM-11) was tasked with reviewing the state of the art for diagnosis, prognosis, and therapy of AL amyloidosis associated with Waldenström macroglobulinemia (WM). Since significant advances have been made in the management of AL amyloidosis an update for this rare disease associated with WM was necessary. The key recommendations from IWWM-11 CP6 included: (1) The need to improve the diagnostic process by recognizing red flags and using biomarkers and imaging; (2) The essential tests for appropriate workup; (3) The diagnostic flowchart, including mandatory amyloid typing, that improves the differential diagnosis with transthyretin amyloidosis; (4) Criteria for therapy response assessment; (5) State of the art of the treatment including therapy of wild type transthyretin amyloidosis associated with WM.

Guidelines for non-transplant chemotherapy for treatment of systemic AL amyloidosis: EHA-ISA working group

BACKGROUND

This guideline has been developed jointly by the European Society of Haematology and International Society of Amyloidosis recommending non-transplant chemotherapy treatment for patients with AL amyloidosis.

METHODS

A review of literature and grading of evidence as well as expert recommendations by the ESH and ISA guideline committees.

RESULTS AND CONCLUSIONS

The recommendations of this committee suggest that treatment follows the clinical presentation which determines treatment tolerance tempered by potential side effects to select and modify use of drugs in AL amyloidosis. All patients with AL amyloidosis should be considered for clinical trials where available. Daratumumab-VCD is recommended from most untreated patients (VCD or VMDex if daratumumab is unavailable). At relapse, the two guiding principles are the depth and duration of initial response, use of a class of agents not previously exposed as well as the limitation imposed by patients' fitness/frailty and end organ damage. Targeted agents like venetoclax need urgent prospective evaluation. Future prospective trials should include advanced stage patients to allow for evidence-based treatment decisions. Therapies targeting amyloid fibrils or those reducing the proteotoxicity of amyloidogenic light chains/oligomers are urgently needed.

Diagnosis and Treatment of AL Amyloidosis

Systemic light chain (AL) amyloidosis is caused by an usually small B cell clone that produces a toxic light chain forming amyloid deposits in tissue. The heart and kidney are the major organs affected, but all others, with the exception of the CNS, can be involved. The disease is rapidly progressive, and it is still diagnosed late. Screening programs in patients followed by hematologists for plasma cell dyscrasias should be considered. The diagnosis requires demonstration in a tissue biopsy of amyloid deposits formed by immunoglobulin light chains. The workup of patients with AL amyloidosis requires adequate technology and expertise, and patients should be referred to specialized centers whenever possible. Stagings are based on cardiac and renal biomarkers and guides the choice of treatment. The combination of daratumumab, cyclophosphamide, bortezomib and dexamethasone (dara-CyBorD) is the current standard of care. Autologous stem cell transplant is performed in eligible patients, especially those who do not attain a satisfactory response to dara-CyBorD. Passive immunotherapy targeting the amyloid deposits combined with chemo-/immune-therapy targeting the amyloid clone is currently being tested in controlled clinical trials. Response to therapy is assessed based on validated criteria. Profound hematologic response is the early goal of treatment and should be accompanied over time by deepening organ response. Many relapsed/refractory patients are also treated with daratumumab combination, but novel regimens will be needed to rescue daratumumab-exposed subjects. Immunomodulatory drugs are the current cornerstone of rescue therapy, while immunotherapy targeting B-cell maturation antigen and inhibitors of Bcl-2 are promising alternatives.

IgM-Related Immunoglobulin Light Chain (AL) Amyloidosis

Waldenström macroglobulinemia (WM) is a rare lymphoplasmacytic disorder characterized by an IgM paraprotein. The clinical presentation of WM varies and can include common manifestations such as anemia and hyperviscosity, in addition to less common features such as cryoglobulinemia, IgM-related neuropathy, and immunoglobulin light chain (AL) amyloidosis. Amyloidosis is a protein-folding disorder in which vital organ damage occurs due to the accumulation of misfolded protein aggregates. The most common type of amyloidosis in patients with an IgM paraprotein is AL amyloidosis, although other types of amyloidosis may occur. IgM-related amyloidosis has distinct clinical features when compared with other subtypes of AL amyloidosis. This review highlights the diagnostic criteria of IgM-related AL amyloidosis, as well as the clinical characteristics and treatment options for this disorder.

Advances in the treatment of light chain amyloidosis

PURPOSE OF REVIEW

After many years, the management of systemic light chain (AL) amyloidosis is entering the era of evidence-based medicine, with three recently published randomized clinical trials, a regimen (daratumumab, cyclophosphamide, bortezomib, and dexamethasone, daratumumab-CyBorD) labeled for upfront therapy, more clinical trials ongoing, and published guidelines. In this review, we discuss how current practice is changing based on this data.

RECENT FINDINGS

Daratumumab-CyBorD grants unprecedentedly high rates of hematologic and organ response and became the novel standard-of-care in AL amyloidosis. The International Society of Amyloidosis and the European Hematology Association issued common guidelines for autologous stem cell transplant (ASCT) in this disease. Improved patient selection and effective induction regimens greatly reduced ASCT-related mortality. Venetoclax is emerging as a very effective option in patients harboring the common t(11;14) abnormality. Rapid and profound reduction of the amyloid free light chain can improve survival also at advanced stages.

SUMMARY

Daratumumab-CyBorD is being integrated into the treatment flow-chart whereas the role of ASCT is being redefined. New approaches are being tested in clinical trials. Treatment of daratumumab-refractory patients and validation of criteria of hematologic progression to be used in clinical trials and in individual patient management are current areas of research.

Immunoglobulin M Monoclonal Gammopathies of Clinical Significance

Immunoglobulin M monoclonal gammopathy of undetermined significance (MGUS) comprises 15-20% of all cases of MGUS. IgM MGUS is distinct from other forms of MGUS in that the typical primary progression events include Waldenstrom macroglobulinaemia and light chain amyloidosis. Owing to its large pentameric structure, IgM molecules have high intrinsic viscosity and precipitate more readily than other immunoglobulin subtypes. They are also more commonly associated with autoimmune phenomena, resulting in unique clinical manifestations. Organ damage attributable to the paraprotein, not fulfilling criteria for a lymphoid or plasma cell malignancy has recently been termed monoclonal gammopathy of clinical significance (MGCS) and encompasses an important family of disorders for which diagnostic and treatment algorithms are evolving. IgM related MGCS include unique entities such as cold haemagglutinin disease, IgM related neuropathies, renal manifestations and Schnitzler's syndrome. The diagnostic approach to, and management of these disorders differs significantly from other categories of MGCS. We describe a practical approach to the evaluation of these patients and our approach to their treatment. We will also elaborate on the key unmet needs in IgM MGCS and highlight potential areas for future research.

Diagnosis and management of Waldenström macroglobulinaemia-A British Society for Haematology guideline

SCOPE

The objective of this guideline is to provide healthcare professionals with clear guidance on the management of patients with Waldenström macroglobulinaemia. In individual patients, circumstances may dictate an alternative approach.

METHODOLOGY

This guideline was compiled according to the British Society for Haematology (BSH) process at http://www.b-s-h.org.uk/guidelines/proposing-and-writing-a-new-bsh-guideline/. Recommendations are based on a review of the literature using Medline, Pubmed, Embase, Central, Web of Science searches from beginning of 2013 (since the publication of the previous guidelines) up to November 2021. The following search terms were used: Waldenström('s) macroglobulin(a)emia OR lymphoplasmacytic lymphoma, IgM(-related) neuropathy OR cold h(a)emagglutinin disease OR cold agglutinin disease OR cryoglobulin(a)emia AND (for group a only) cytogenetic OR molecular OR mutation OR MYD88 OR CXCR4, management OR treatment OR transfusion OR supportive care OR plasma exchange OR plasmapheresis OR chemotherapy OR bendamustine OR bortezomib OR ibrutinib OR fludarabine OR dexamethasone OR cyclophosphamide OR rituximab OR everolimus, bone marrow transplantation OR stem cell transplantation. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) nomenclature was used to evaluate levels of evidence and to assess the strength of recommendations. The GRADE criteria can be found at http://www.gradeworkinggroup.org. Review of the manuscript was performed by the British Society for Haematology (BSH) Guidelines Committee Haemato-Oncology Task Force, the BSH Guidelines Committee and the Haemato-Oncology sounding board of BSH. It was also on the members section of the BSH website for comment. It has also been reviewed by UK Charity WMUK; these organisations do not necessarily approve or endorse the contents.

Use of BTK inhibitors with special focus on ibrutinib in Waldenström macroglobulinemia: an expert panel opinion statement

The pivotal role that ibrutinib plays in the management of Waldenström macroglobulinemia (WM) is undisputed but there are ongoing questions regarding its positioning in the therapeutic algorithm of WM as well as in some peculiar clinical situations. A panel of experts from Italy was convened to provide real world recommendations on the use of BTK inhibitors in lymphoproliferative diseases in general, and in patients with WM in particular. This position paper represents the panel's collective analysis, evaluation, and opinions and is made up of a series of questions frequently asked by practicing clinicians and answers based on currently available evidence. This article is protected by copyright. All rights reserved.

Utility of Bruton’s Tyrosine Kinase Inhibitors in Light Chain Amyloidosis Caused by Lymphoplasmacytic Lymphoma (Waldenström’s Macroglobulinemia)

Of the variety of immunoglobulin related amyloidosis (AL), immunoglobulin M (IgM) related AL represents only 6 to 10% of affected patients, and the majority of these cases are associated with underlying non-Hodgkin's Lymphoma including Waldenström's macroglobulinemia (WM). Ibrutinib, acalabrutinib, and zanubrutinib are Bruton tyrosine kinase (BTK) inhibitors approved for certain indolent B cell non-Hodgkin's lymphoma (NHL). BTK is a nonreceptor kinase involved in B-cell survival, proliferation, and interaction with the microenvironment. We retrospectively evaluated the tolerability and effectiveness of BTK inhibitors ibrutinib and acalabrutinib therapy in (n = 4) patients with IgM-related AL amyloidosis with underlying WM. Treatment was well tolerated with both hematologic and organ response in patients with AL amyloidosis in the setting of WM. Atrial fibrillation led to the discontinuation of ibrutinib in one patient, and acalabrutinib caused significant thumb hematoma needing dose reduction in another patient. All patients evaluated had the MYD88 mutation. This may explain the good response to BTK inhibitors therapy in our series. BTK inhibitors should be further investigated in larger prospective studies for treatment of AL amyloidosis in patients with lymphoplasmacytic lymphoma/WM.

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.

Managing complications secondary to Waldenström's macroglobulinemia

Introduction: Waldenström's macroglobulinemia (WM) is a rare lymphoma characterized by the accumulation of IgM-secreting lymphoplasmacytic cells in the bone marrow and other organs. Clinical sequelae relate to direct tissue infiltration by malignant cells but also to the physicochemical and immunological properties of the monoclonal IgM, resulting in a variety of disease-related complications.Areas covered: This narrative review, following a thorough Pubmed search of pertinent published literature, discusses complications secondary to WM, related to direct tumor infiltration, monoclonal IgM circulation, and deposition, as well as other less common ones. The description and pathophysiology of these complications were described together with their specific management strategies and in the context of available treatment options for WM (anti-CD20 monoclonal antibody-based combinations, proteasome inhibitors, BTK inhibitors, and other emerging ones).Expert opinion: The availability of many novel, active and less toxic regimens for the treatment of WM allows the management of the disease with strategies that depend on clinical presentation and disease-related complications, age, toxicity considerations, and presence of comorbidities.

Systemic Amyloidosis due to Low-Grade Lymphoma

Lymphoma-related amyloidosis is a rare entity. Systemic AL amyloidosis is generally caused by an underlying plasma cell clone in the bone marrow with an intact monoclonal immunoglobulin G (IgG) or IgA protein. The rarity of the lymphoma-related amyloidosis makes the generation of data in randomized trials and the determination of the optimal treatment almost impossible. Therefore, treatment recommendations discussed here are based on either retrospective or small prospective trials of single centers.

How I treat Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is an uncommon lymphoma characterized by the infiltration of the bone marrow by clonal lymphoplasmacytic cells that produce monoclonal immunoglobulin M (IgM). The disease may have an asymptomatic phase, or patients may present with symptoms and complications resulting from marrow or other tissue infiltration, or from physicochemical or immunological properties of the monoclonal IgM. Diagnosis of WM has been clearly defined, and genetic testing for somatic mutation of MYD88L265P is a useful tool for differential diagnosis from other conditions. Specific criteria that define symptomatic disease that needs treatment offer clinical guidance. The treatment of WM has evolved rapidly, with treatment options that include anti-CD20 monoclonal antibody-based combinations and BTK inhibitors. The choice of therapy is based on the need for rapid disease control, presence of specific disease complications, and patient's age. With the use of BTK inhibitors, the use of continuous therapy has been introduced as another option over fixed-duration chemoimmunotherapy. In this review, we focus on different clinical scenarios and discuss treatment options, based on the available data.

Genomic Landscape of Waldenström Macroglobulinemia and Its Impact on Treatment Strategies

Next-generation sequencing has revealed recurring somatic mutations in Waldenström macroglobulinemia (WM), including MYD88 (95%-97%), CXCR4 (30%-40%), ARID1A (17%), and CD79B (8%-15%). Deletions involving chromosome 6q are common in patients with mutated MYD88 and include genes that modulate NFKB, BCL2, Bruton tyrosine kinase (BTK), and apoptosis. Patients with wild-type MYD88 WM show an increased risk of transformation and death and exhibit many mutations found in diffuse large B-cell lymphoma. The discovery of MYD88 and CXCR4 mutations in WM has facilitated rational drug development, including the development of BTK and CXCR4 inhibitors. Responses to many agents commonly used to treat WM, including the BTK inhibitor ibrutinib, are affected by MYD88 and/or CXCR4 mutation status. The mutation status of both MYD88 and CXCR4 can be used for a precision-guided treatment approach to WM.

IgM AL amyloidosis: delineating disease biology and outcomes with clinical, genomic and bone marrow morphological features

This study evaluates newly diagnosed IgM (6%, n = 75/1174) vs. non-IgM light chain amyloidosis patients. IgM amyloid patients had lower light chains (12.5 vs. 22.5 mg/dL; p < 0.001). Heart (56% vs. 73%, p = 0.002) and >1 organ involvement (31% vs. 44%, p = 0.02) was less common in IgM amyloidosis, while soft tissue and peripheral nerve involvement was more common. t(11;14) was less common (27% vs. 50%, p = 0.008) in IgM amyloidosis. Rates of MYD88^L265P and CXCR4^WHIM mutation in IgM amyloidosis were 58% (29/50) and 17% (8/46). Diagnosis after hematopathology review in IgM amyloidosis was pure plasma cell neoplasm (PPCN) in 23% (16/70), lymphoplasmacytic neoplasm (LPL) in 63% (44/70) patients, and other (14%). LPL vs. PPCN groups had distinct genetic abnormalities: t(11;14): 0% (0/18) vs. 60% (9/15), p < 0.001; MYD88^L265P mutation: 84% (27/32) vs. 0% (0/14), p < 0.001; CXCR4 mutation: 29% (8/28) vs. 0% (0/14), p = 0.04. Overall survival was shorter in IgM AL when stratified by Mayo 2012 stage; stage 1/2 (59 vs. 125.9 months, p = 0.003) and stage 3/4 (6.5 vs. 12.9 months, p = 0.075), likely due to lower hematologic response rates (6 months: 39% vs. 59%, p = 0.008). We characterized two subtypes of IgM amyloidosis (LPL/PPCN). This can aid in therapeutic decision-making, with treatment directed at the clonal disease.

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

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

Monoclonal gammopathy of clinical significance: a novel concept with therapeutic implications

Monoclonal gammopathy is a common condition, particularly in the elderly. It can indicate symptomatic multiple myeloma or another overt malignant lymphoid disorder requiring immediate chemotherapy. More frequently, it results from a small and/or quiescent secreting B-cell clone, is completely asymptomatic, and requires regular monitoring only, defining a monoclonal gammopathy of unknown significance (MGUS). Sometimes, although quiescent and not requiring any treatment per se, the clone is associated with potentially severe organ damage due to the toxicity of the monoclonal immunoglobulin or to other mechanisms. The latter situation is increasingly observed but still poorly recognized and frequently undertreated, although it often requires rapid specific intervention to preserve involved organ function. To improve early recognition and management of these small B-cell clone–related disorders, we propose to introduce the concept of monoclonal gammopathy of clinical significance (MGCS). This report identifies the spectrum of MGCSs that are classified according to mechanisms of tissue injury. It highlights the diversity of these disorders for which diagnosis and treatment are often challenging in clinical practice and require a multidisciplinary approach. Principles of management, including main diagnostic and therapeutic procedures, are also described. Importantly, efficient control of the underlying B-cell clone usually results in organ improvement. Currently, it relies mainly on chemotherapy and other anti–B-cell/plasma cell agents, which should aim at rapidly producing the best hematological response.