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Abstract: The survival of patients achieving a cardiac complete response in light chain amyloidosis, defined as N-terminal pro B-type natriuretic peptide ≤350 pg/mL or B-type natriuretic peptide ≤80 pg/mL, was similar to that of a matched general population, with estimated 5-year survival rates of 93% and 95%, respectively., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Amyloid light-chain (AL) amyloidosis is a rare, typically fatal disease characterized by the accumulation of misfolded immunoglobulin light chains (LCs). Birtamimab is an investigational humanized monoclonal antibody designed to neutralize toxic LC aggregates and deplete insoluble organ-deposited amyloid via macrophage-induced phagocytosis. VITAL was a phase 3 randomized, double-blind, placebo-controlled clinical trial assessing the efficacy and safety of birtamimab + standard of care (SOC) in 260 newly diagnosed, treatment-naive patients with AL amyloidosis. Patients received 24 mg/kg IV birtamimab + SOC or placebo + SOC every 28 days. The primary composite end point was the time to all-cause mortality (ACM) or centrally adjudicated cardiac hospitalization ≥91 days after the first study drug infusion. The trial was terminated early after an interim futility analysis; there was no significant difference in the primary composite end point (hazard ratio [HR], 0.826; 95% confidence interval [CI], 0.574-1.189; log-rank P = .303). A post hoc analysis of patients with Mayo stage IV AL amyloidosis, those at the highest risk of early mortality, showed significant improvement in the time to ACM with birtamimab at month 9 (HR, 0.413; 95% CI, 0.191-0.895; log-rank P = .021). At month 9, 74% of patients with Mayo stage IV AL amyloidosis treated with birtamimab and 49% of those given placebo survived. Overall, the rates of treatment-emergent adverse events (TEAEs) and serious TEAEs were generally similar between treatment arms. A confirmatory phase 3 randomized, double-blind, placebo-controlled clinical trial of birtamimab in patients with Mayo stage IV AL amyloidosis (AFFIRM-AL; NCT04973137) is currently enrolling. The VITAL trial was registered at www.clinicaltrials.gov as #NCT02312206., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Patients with immunoglobulin light chain (AL) amyloidosis and stage IIIb cardiac involvement have a dismal outcome despite the introduction of novel treatments. However, a rapid hematologic response translates in better survival. We evaluated the impact of early cardiac response and its depth on outcome in 249 patients with newly diagnosed stage IIIb cardiac AL amyloidosis. Hematologic and cardiac responses were evaluated by intent to treat. After a median follow-up of 52 months, 219 (84%) patients died, and median survival was 4.2 months. The 30- and 90-day hematologic response rates were 22% (at least very good partial response [VGPR] in 9%) and 24% (at least VGPR in 15%), respectively. Early hematologic response resulted in better survival. At 90 days, 21 (8%) patients achieved a cardiac response (cardiac very good partial response [cardiac VGPR] in 12 cases and cardiac partial response [cardiac PR] in 9). At the 90-day landmark analysis, cardiac response resulted in longer survival (median, 54 months), also in those patients who have achieved at least VGPR (median, 62 vs 26 months, P = .011). Patients with cardiac VGPR had a longer survival than those with cardiac PR (median, 92 vs 24 months; P = .027), whereas patients without cardiac response had a poor survival (median, 6 months). A baseline difference of involved/uninvolved free light chains > 50 mg/L (odds ratio [OR], 0.21, P = .024) and a bone marrow plasma cell infiltrate > 10% (OR, 0.23, P = .040) were negative predictors of 90-day cardiac response. Early cardiac responses are rare but possible in stage IIIb AL amyloidosis and translate to longer survival., (© 2022 by The American Society of Hematology.)

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 presymptomatic 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., (© 2022 by The American Society of Hematology.)

In amyloid light chain (AL) amyloidosis, a small B-cell clone, most commonly a plasma cell clone, produces monoclonal light chains that exert organ toxicity and deposit in tissue in the form of amyloid fibrils. Organ involvement determines the clinical manifestations, but symptoms are usually recognized late. Patients with disease diagnosed at advanced stages, particularly when heart involvement is present, are at high risk of death within a few months. However, symptoms are always preceded by a detectable monoclonal gammopathy and by elevated biomarkers of organ involvement, and hematologists can screen subjects who have known monoclonal gammopathy for amyloid organ dysfunction and damage, allowing for a presymptomatic diagnosis. Discriminating patients with other forms of amyloidosis is difficult but necessary, and tissue typing with adequate technology available at referral centers, is mandatory to confirm AL amyloidosis. Treatment targets the underlying clone and should be risk adapted to rapidly administer the most effective therapy patients can safely tolerate. In approximately one-fifth of patients, autologous stem cell transplantation can be considered up front or after bortezomib-based conditioning. Bortezomib can improve the depth of response after transplantation and is the backbone of treatment of patients who are not eligible for transplantation. The daratumumab+bortezomib combination is emerging as a novel standard of care in AL amyloidosis. Treatment should be aimed at achieving early and profound hematologic response and organ response in the long term. Close monitoring of hematologic response is vital to shifting nonresponders to rescue treatments. Patients with relapsed/refractory disease are generally treated with immune-modulatory drugs, but daratumumab is also an effective option., (© 2020 by The American Society of Hematology.)

Although no therapies are approved for light chain (AL) amyloidosis, cyclophosphamide, bortezomib, and dexamethasone (CyBorD) is considered standard of care. Based on outcomes of daratumumab in multiple myeloma (MM), the phase 3 ANDROMEDA study (NCT03201965) is evaluating daratumumab-CyBorD vs CyBorD in newly diagnosed AL amyloidosis. We report results of the 28-patient safety run-in. Patients received subcutaneous daratumumab (DARA SC) weekly in cycles 1 to 2, every 2 weeks in cycles 3 to 6, and every 4 weeks thereafter for up to 2 years. CyBorD was given weekly for 6 cycles. Patients had a median of 2 involved organs (kidney, 68%; cardiac, 61%). Patients received a median of 16 (range, 1-23) treatment cycles. Treatment-emergent adverse events were consistent with DARA SC in MM and CyBorD. Infusion-related reactions occurred in 1 patient (grade 1). No grade 5 treatment-emergent adverse events occurred; 5 patients died, including 3 after transplant. Overall hematologic response rate was 96%, with a complete hematologic response in 15 (54%) patients; at least partial response occurred in 20, 22, and 17 patients at 1, 3, and 6 months, respectively. Renal response occurred in 6 of 16, 7 of 15, and 10 of 15 patients, and cardiac response occurred in 6 of 16, 6 of 13, and 8 of 13 patients at 3, 6, and 12 months, respectively. Hepatic response occurred in 2 of 3 patients at 12 months. Daratumumab-CyBorD was well tolerated, with no new safety concerns versus the intravenous formulation, and demonstrated robust hematologic and organ responses. This trial was registered at www.clinicaltrials.gov as #NCT03201965., (© 2020 by The American Society of Hematology.)

Daratumumab is a human monoclonal antibody targeting CD38, an antigen uniformly expressed by plasma cells in multiple myeloma and light-chain amyloidosis (AL). We report the results of a prospective multicenter phase 2 study of daratumumab monotherapy in AL (NCT02816476). Forty previously treated AL patients with a difference between involved and uninvolved free light chains (dFLC) >50 mg/L were included in 15 centers between September of 2016 and April of 2018. Patients received 6 28-day cycles of IV daratumumab, every week for cycles 1 and 2 and every 2 weeks for cycles 3 through 6. Median age was 69 years (range, 45-83). Twenty-six patients had ≥2 organs involved, with heart in 24 and kidney in 26. Median time from diagnosis to enrollment was 23 months (interquartile range, 4-122), with a median of 3 prior therapies (range, 1-5). At data cutoff (September of 2019), all patients discontinued therapy; 33 received the planned 6 cycles. Overall, 22 patients had hematological response, and 19 patients (47.5%) achieved very good partial response (dFLC <40 mg/L) or better. Median time to hematological response was 1 week. Patients with no response after 4 doses were unlikely to respond further. Renal and cardiac responses occurred in 8 and 7 patients, respectively. Daratumumab was well tolerated, with no unexpected adverse events. With a median follow-up of 26 months, the 2-year overall survival rate was 74% (95% confidence interval, 62-81). Daratumumab monotherapy is associated with deep and rapid hematological responses in previously treated AL patients, with a good safety profile. Further studies of daratumumab in combination regimens are warranted., (© 2020 by The American Society of Hematology.)

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., (© 2018 by The American Society of Hematology.)

Growth differentiation factor-15 (GDF-15) improves prognostication in patients with cardiovascular disorders in addition to conventional cardiac markers (N-terminal pro B-type natriuretic peptide [NT-proBNP], troponins [Tns]) and has shown prognostic value in patients with renal diseases. In patients with light chain (AL) amyloidosis, cardiac involvement is the major determinant of prognosis, and cardiac markers define prognosis, whereas biomarkers of renal involvement stratify renal risk. We explored the prognostic importance of serum level of GDF-15 in patients with AL amyloidosis in 2 independent cohorts. The prognostic value of GDF-15 level was initially evaluated in a cohort of 107 consecutive previously untreated patients with AL amyloidosis from Athens, Greece, and was then validated in a second cohort of 202 consecutive previously untreated patients from Pavia, Italy. High GDF-15 level was associated with a higher risk of early death and poor overall survival independently of NT-proBNP and high-sensitivity TnT (hsTnT) or hsTnI levels. At the 6-month landmark, reduction of GDF-15 level ≥25% was associated with improved outcome. GDF-15 level ≥4000 pg/mL was associated with a high risk of progression to dialysis, independently of renal risk defined by estimated glomerular filtration rate and proteinuria, in both cohorts; failure to reduce GDF-15 below this level was associated with increased risk at either the 3- or 6-month landmark, independently of the established renal response or progression criteria. In conclusion, GDF-15 has prognostic implications for different outcomes in patients with AL and adds prognostic information independent of that provided by cardiac and renal risk biomarkers., (© 2018 by The American Society of Hematology.)

Competing Interests: Conflict-of-interest disclosure: G.P. received honoraria from Janssen-Cilag, honoraria and travel support from Prothena, and travel support from Celgene. G.M. is a consultant for Millennium Pharmaceuticals, Inc., Pfizer, Janssen, Prothena, and IONIS.

The management of light chain (AL) amyloidosis has improved in recent years thanks to accurate biomarker-based staging systems and response criteria and availability of novel effective therapies. However, previous studies have focused on newly diagnosed patients, and little is known on relapsed patients, despite the fact that trials of new agents are often performed in this setting. In the present study, we report the outcome of 259 patients who responded to up-front therapy. Ninety-two patients (35%) needed second-line therapy after a median of 49 months. Cardiac and renal progression were observed in 22% and 12% of patients who received second-line therapy, respectively. Complete response after up-front treatment and frontline therapy with combined bortezomib, melphalan, and dexamethasone independently prolonged time to second-line therapy. Median survival of relapsing patients was 59 months. Patients who had a "high-risk dFLC progression," which we defined as a difference between involved and uninvolved free light chains (dFLC) of >20 mg/L, a level >20% of baseline value, and a >50% increase from the value reached at best response, had a shorter survival after initiation of second-line therapy on univariate, but not on multivariate, analysis, where cardiac progression was the only independent predictor of survival after starting rescue treatment. Patients with AL amyloidosis who need second-line therapy after response to up-front treatment generally have a good outcome. A "high-risk dFLC progression" should trigger rescue treatment, and cardiac progression should not be awaited., (© 2018 by The American Society of Hematology.)

This phase 1/2 study assessed the safety, tolerability, and preliminary efficacy of the oral proteasome inhibitor (PI) ixazomib in patients with relapsed/refractory immunoglobulin light chain (AL) amyloidosis. Ixazomib was administered to adult patients with relapsed/refractory AL amyloidosis after 1 or more prior lines of therapy (including bortezomib) on days 1, 8, and 15 of 28-day cycles, for up to 12 cycles. Patients with less than partial response after 3 cycles received oral dexamethasone (40 mg, days 1-4) from cycle 4. A 3+3 dose-escalation phase was followed by 2 expansion cohorts (PI-naive and PI-exposed patients) at the maximum tolerated dose (MTD). Twenty-seven patients were enrolled: 11 during dose escalation (6 at 4.0 mg and 5 at 5.5 mg) and 16 during dose expansion (4.0 mg). Three patients experienced dose-limiting toxicities: 1 at 4.0 mg and 2 at 5.5 mg; the MTD was determined as 4.0 mg. Most common adverse events (AEs) included nausea, skin and subcutaneous tissue disorders (SSTD), diarrhea, and fatigue; grade 3 or higher AEs included dyspnea, fatigue, and SSTD. Overall, the hematologic response rate was 52% in patients treated at the MTD (n = 21). Organ responses were seen in 56% of patients (5 cardiac, 5 renal). Median hematologic progression-free survival was 14.8 months; 1-year progression-free and overall survival rates were 60% and 85%, respectively (median follow-up, 16.9 months). Weekly oral ixazomib appears to be active in patients with relapsed/refractory AL amyloidosis, with a generally manageable safety profile. The study was registered at clinicaltrials.gov as #NCT01318902 A phase 3 study is ongoing (#NCT01659658)., (© 2017 by The American Society of Hematology.)

The validated criteria of hematologic response in light-chain (AL) amyloidosis are based on the measurement of circulating free light chains (FLCs). Patients with a difference between involved and uninvolved FLC (dFLC) <50 mg/L cannot be assessed for response and are excluded from clinical trials. We compared the clinical characteristics and outcome of 203 newly diagnosed patients with dFLC <50 mg/L (low dFLC) with 866 patients with measurable dFLC (high dFLC) evaluated between 2004 and 2015. Heart involvement was significantly less common and less advanced in the low-dFLC group (43% vs 83% and Mayo stage III 45% vs 15%, both P < .001), whereas renal involvement was more frequent (77% vs 63%, P < .001) and more severe (renal stage III 26% vs 18%, P = .001). Overall survival (OS) was significantly better in the low-dFLC group (median 117 vs 21 months, P < .001), whereas no difference was seen in renal survival (RS). Within each Mayo stage, patients with low dFLC had a longer survival. In the low-dFLC group, complete response was associated with a significant advantage in OS (median not reached vs 117 months, P = .005) and with a better RS. A reduction in dFLC after therapy of <10 mg/L was associated with a better OS and RS in patients with at least a dFLC >20 mg/L baseline. Nineteen percent of newly diagnosed patients with AL amyloidosis have low dFLC and had a better outcome. Hematologic response assessed with adapted criteria predicts OS and RS in these patients, who can thus be assessed for response and included in clinical trials with appropriate stratification., (© 2017 by The American Society of Hematology.)

Immunomodulatory drugs are active agents in light-chain (AL) amyloidosis. However, previous studies could not show a survival advantage for patients with AL amyloidosis responding to salvage treatment with pomalidomide. In this phase 2 trial, we assessed the safety and efficacy of pomalidomide and dexamethasone (PDex) in patients with AL amyloidosis who were previously exposed to bortezomib, alkylators, and other immunomodulatory drugs. Twenty-eight patients were enrolled. Three patients received pomalidomide 2 mg/d with no dose-limiting toxicity. The remaining patients received 4 mg/d. Pomalidomide was administered continuously and dexamethasone was given once per week at a dose of 20 or 40 mg. Fifteen patients experienced grade 3 to 4 adverse events; the most common were fluid retention and infection. Hematologic response was observed in 68% of patients (very good partial response or complete response in 29%), as well as improved survival. Median time to response was 1 month. PDex is a rapidly active regimen and improves survival in responding, heavily pretreated patients with AL amyloidosis. This trial was registered at www.clinicaltrials.gov as #NCT01510613., (© 2017 by The American Society of Hematology.)

Systemic light chain (AL) amyloidosis is caused by the clonal production of an unstable immunoglobulin light chain (LC), which affects organ function systemically. Although pathogenic LCs have been characterized biochemically, little is known about the biology of amyloidogenic plasma cells (PCs). Intrigued by the unique response rates of AL amyloidosis patients to the first-in-class proteasome inhibitor (PI) bortezomib, we purified and investigated patient-derived AL PCs, in comparison with primary multiple myeloma (MM) PCs, the prototypical PI-responsive cells. Functional, biochemical, and morphological characterization revealed an unprecedented intrinsic sensitivity of AL PCs to PIs, even higher than that of MM PCs, associated with distinctive organellar features and expression patterns indicative of cellular stress. These consisted of expanded endoplasmic reticulum (ER), perinuclear mitochondria, and a higher abundance of stress-related transcripts, and were consistent with reduced autophagic control of organelle homeostasis. To test whether PI sensitivity stems from AL LC production, we engineered PC lines that can be induced to express amyloidogenic and nonamyloidogenic LCs, and found that AL LC expression alters cell growth and proteostasis and confers PI sensitivity. Our study discloses amyloidogenic LC production as an intrinsic PC stressor, and identifies stress-responsive pathways as novel potential therapeutic targets. Moreover, we contribute a cellular disease model to dissect the biology of AL PCs., (© 2017 by The American Society of Hematology.)

In this phase 2 multicenter trial, we evaluated the efficacy of the combination of bortezomib, dexamethasone, and rituximab (BDR) in 59 previously untreated symptomatic patients with Waldenström macroglobulinemia (WM), most of which were of advanced age and with adverse prognostic factors. BDR consisted of a single 21-day cycle of bortezomib alone (1.3 mg/m 2 IV on days 1, 4, 8, and 11), followed by weekly IV bortezomib (1.6 mg/m 2 on days 1, 8, 15, and 22) for 4 additional 35-day cycles, with IV dexamethasone (40 mg) and IV rituximab (375 mg/m 2 ) on cycles 2 and 5, for a total treatment duration of 23 weeks. On intent to treat, 85% responded (3% complete response, 7% very good partial response, 58% partial response). After a minimum follow-up of 6 years, median progression-free survival was 43 months and median duration of response for patients with at least partial response was 64.5 months. Overall survival at 7 years was 66%. No patient had developed secondary myelodysplasia, whereas transformation to high-grade lymphoma occurred in 3 patients who had received chemoimmunotherapy after BDR. Thus, BDR is a very active, fixed-duration, chemotherapy-free regimen, inducing durable responses and with a favorable long-term toxicity profile (www.ClinicalTrials.gov #NCT00981708)., (© 2017 by The American Society of Hematology.)

Waldenström macroglobulinemia (WM) is a distinct B-cell lymphoproliferative disorder for which clearly defined criteria for the diagnosis, initiation of therapy, and treatment strategy have been proposed as part of the consensus panels of the International Workshop on Waldenström's Macroglobulinemia (IWWM). At IWWM-8, a task force for treatment recommendations was impanelled to review recently published and ongoing clinical trial data as well as the impact of new mutations (MYD88 and CXCR4) on treatment decisions, indications for B-cell receptor and proteasome inhibitors, and future clinical trial initiatives for WM patients. The panel concluded that therapeutic strategies in WM should be based on individual patient and disease characteristics. Chemoimmunotherapy combinations with rituximab and cyclophosphamide-dexamethasone, bendamustine, or bortezomib-dexamethasone provide durable responses and are still indicated in most patients. Approval of the BTK inhibitor ibrutinib in the United States and Europe represents a novel and effective treatment option for both treatment-naive and relapsing patients. Other B-cell receptor inhibitors, second-generation proteasome inhibitors (eg, carfilzomib), and mammalian target of rapamycin inhibitors are promising and may increase future treatment options. Active enrollment in clinical trials whenever possible was endorsed by the panel for most patients with WM., (© 2016 by The American Society of Hematology.)

Light chain (AL) amyloidosis is caused by a usually small plasma cell clone producing a misfolded light chain that deposits in tissues. Survival is mostly determined by the severity of heart involvement. Recent studies are clarifying the mechanisms of cardiac damage, pointing to a toxic effect of amyloidogenic light chains and offering new potential therapeutic targets. The diagnosis requires adequate technology, available at referral centers, for amyloid typing. Late diagnosis results in approximately 30% of patients presenting with advanced, irreversible organ involvement and dying in a few months despite modern treatments. The availability of accurate biomarkers of clonal and organ disease is reshaping the approach to patients with AL amyloidosis. Screening of early organ damage based on biomarkers can help identify patients with monoclonal gammopathy of undetermined significance who are developing AL amyloidosis before they become symptomatic. Staging systems and response assessment based on biomarkers facilitate the design and conduction of clinical trials, guide the therapeutic strategy, and allow the timely identification of refractory patients to be switched to rescue therapy. Treatment should be risk-adapted. Recent studies are linking specific characteristics of the plasma cell clone to response to different types of treatment, moving toward patient-tailored therapy. In addition, novel anti-amyloid treatments are being developed that might be combined with anti-plasma cell chemotherapy., (© 2016 by The American Society of Hematology.)

The combination of cyclophosphamide/bortezomib/dexamethasone (CyBorD) showed early promise of high rates of hematologic responses tempered by studies showing the inability to overcome poor prognosis of advanced cardiac amyloidosis. Large studies are needed to clarify its role in light chain (AL) amyloidosis. We report the outcome of 230 patients treated frontline with CyBorD. Overall hematologic response rate was 60%, and in the 201 patients with measurable disease it was 62%, with 43% achieving at least very good partial response (VGPR). Cardiac response was reached in 17% of patients and renal response in 25% of patients. Advanced cardiac stage III patients (amino-terminal pro-natriuretic peptide type B >8500 ng/L) had lower response rates (42%, ≥ VGPR 23%) and poorer survival (median, 7 months). Nevertheless, hematologic response improved survival in these subjects (67% at 2 years), showing the importance of striving for a good response even in this group., (© 2015 by The American Society of Hematology.)

Accurate diagnosis of systemic amyloidosis is necessary both for assessing the prognosis and for delineating the appropriate treatment. It is based on histologic evidence of amyloid deposits and characterization of the amyloidogenic protein. We prospectively evaluated the diagnostic performance of immunoelectron microscopy (IEM) of abdominal fat aspirates from 745 consecutive patients with suspected systemic amyloidoses. All cases were extensively investigated with clinical and laboratory data, with a follow-up of at least 18 months. The 423 (56.8%) cases with confirmed systemic forms were used to estimate the diagnostic performance of IEM. Compared with Congo-red-based light microscopy, IEM was equally sensitive (75% to 80%) but significantly more specific (100% vs 80%; P < .001). In amyloid light-chain (AL) amyloidosis, κ cases were more difficult to diagnose (sensitivity 71%), whereas the analysis of abdominal aspirate was informative in only 40% of patients with transthyretin amyloidosis. We found a high prevalence (20%) of a monoclonal component in patients with non-AL amyloidosis, highlighting the risk of misdiagnosis and the need for unequivocal amyloid typing. Notably, IEM identified correctly the specific form of amyloidosis in >99% of the cases. IEM of abdominal fat aspirates is an effective tool in the routine diagnosis of systemic amyloidoses., (© 2015 by The American Society of Hematology.)

CAN2007 was a phase 1/2 study of once- and twice-weekly single-agent bortezomib in relapsed primary systemic amyloid light chain amyloidosis (AL) amyloidosis. Seventy patients were treated, including 18 and 34 patients at the maximum planned doses on the once- and twice-weekly schedules. This prespecified final analysis provides mature response and long-term outcomes data after 3-year additional follow-up since the last report. In the once-weekly 1.6 mg/m(2) and twice-weekly 1.3 mg/m(2) bortezomib groups, final hematologic response rates were 68.8% and 66.7%; 80% of patients in each group sustained their response for ≥1 year. One-year progression-free rates were 72.2% and 76.8%. Median overall survival (OS) was 62.1 months and not reached; 4-year OS rates were 75.0% and 63.0%. Low baseline difference in κ/λ free light-chain level was associated with higher hematologic complete response rates and longer OS. At data cutoff, 40 (57%) patients had received subsequent therapy, including 19 (27%) retreated with bortezomib, 11 (58%) of whom achieved complete or partial hematologic responses. Four patients received prolonged bortezomib for between 3.5 and 5.6 years, with no new safety concerns, highlighting the feasibility of long-term therapy. Single-agent bortezomib produced durable hematologic responses and promising long-term OS in relapsed AL amyloidosis. This trial was registered at www.clinicaltrials.gov as #NCT00298766., (© 2014 by The American Society of Hematology.)

The kidney is involved in 70% of patients with immunoglobulin light-chain (AL) amyloidosis, but little is known on progression or reversibility of renal involvement, and criteria for renal response have never been validated. Newly diagnosed patients from the Pavia (n = 461, testing cohort) and Heidelberg (n = 271, validation cohort) centers were included. Proteinuria >5 g/24 h and estimated glomerular filtration rate (eGFR) <50 mL/min predicted progression to dialysis best. Proteinuria below and eGFR above the thresholds indicated low risk (0 and 4% at 3 years in the testing and validation cohorts, respectively). High proteinuria and low eGFR indicated high risk (60% and 85% at 3 years). At 6 months, a ≥25% eGFR decrease predicted poor renal survival in both cohorts and was adopted as criterion for renal progression. A decrease in proteinuria by ≥30% or below 0.5 g/24 h without renal progression was the criterion for renal response, being associated with longer renal survival in the testing and validation populations. Hematologic very good partial or complete remission at 6 months improved renal outcome in both populations. We identified and validated a staging system for renal involvement and criteria for early assessment of renal response and progression in AL amyloidosis that should be used in clinical practice and trial design., (© 2014 by The American Society of Hematology.)

Waldenström macroglobulinemia (WM) is a distinct B-cell lymphoproliferative disorder for which clearly defined criteria for the diagnosis, initiation of therapy, and treatment strategy have been proposed as part of the consensus panels of International Workshops on WM (IWWM). As part of the IWWM-7 and based on recently published and ongoing clinical trials, the panels updated treatment recommendations. Therapeutic strategy in WM should be based on individual patient and disease characteristics (age, comorbidities, need for rapid disease control, candidacy for autologous transplantation, cytopenias, IgM-related complications, hyperviscosity, and neuropathy). Mature data show that rituximab combinations with cyclophosphamide/dexamethasone, bendamustine, or bortezomib/dexamethasone provided durable responses and are indicated for most patients. New monoclonal antibodies (ofatumumab), second-generation proteasome inhibitors (carfilzomib), mammalian target of rapamycin inhibitors, and Bruton's tyrosine kinase inhibitors are promising and may expand future treatment options. A different regimen is typically recommended for relapsed or refractory disease. In selected patients with relapsed disease after long-lasting remission, reuse of a prior effective regimen may be appropriate. Autologous stem cell transplantation may be considered in young patients with chemosensitive disease and in newly diagnosed patients with very-high-risk features. Active enrollment of patients with WM in clinical trials is encouraged.

Poor prognosis and limited therapeutic options characterize immunoglobulin light-chain (AL) amyloidosis with major heart involvement. Reliable experimental models are needed to study light-chain (LC)/heart interactions and to explore strategies for prevention of cardiac damage. We have exploited the nematode Caenorhabditis elegans as a novel tool, because its pharynx is evolutionarily related to the vertebrate heart. Our data demonstrate that the pharyngeal pumping of C elegans is significantly and selectively reduced by LCs from AL patients suffering from cardiomyopathy, but not by amyloid LCs with different organ tropism or nonamyloidogenic LCs from multiple myeloma. This functional alteration is dependent on the LC concentration and results in persistent pharyngeal dysfunction and in a significant reduction of the worms' lifespan. These manifestations are paralleled by an increase of mitochondrial reactive oxygen species and can be prevented by treatment with antioxidant agents. In conclusion, these data indicate that this nematode-based assay is a promising surrogate model for investigating the heart-specific toxicity of amyloidogenic LCs and for a rapid screening of new therapeutic strategies., (© 2014 by The American Society of Hematology.)

In this issue of Blood, Turesson et al study the risk of progression of monoclonal gammopathy of undetermined significance (MGUS) to lymphoplasmacellular and myeloid malignancies in a large population, validating current risk factors and adding immunoparesis as a predictor of progression.

In this phase 2 multicenter trial, we evaluated the activity of bortezomib, dexamethasone, and rituximab (BDR) combination in previously untreated symptomatic patients with Waldenström macroglobulinemia (WM). To prevent immunoglobulin M (IgM) "flare," single agent bortezomib (1.3 mg/m(2) IV days 1, 4, 8, and 11; 21-day cycle), was followed by weekly IV bortezomib (1.6 mg/m(2) days 1, 8, 15, and 22) every 35 days for 4 additional cycles, followed by IV dexamethasone (40 mg) and IV rituximab (375 mg/m(2)) in cycles 2 and 5. Fifty-nine patients were treated; 45.5% and 40% were high and intermediate risk per the International Prognostic Scoring System for WM. On intent to treat, 85% responded (3% complete response, 7% very good partial response, 58% partial response [PR]). In 11% of patients, an increase of IgM ≥25% was observed after rituximab; no patient required plasmapheresis. After a minimum follow-up of 32 months, median progression-free survival was 42 months, 3-year duration of response for patients with ≥PR was 70%, and 3-year survival was 81%. Peripheral neuropathy occurred in 46% (grade ≥3 in 7%); only 8% discontinued bortezomib due to neuropathy. BDR is rapidly acting, well tolerated, and nonmyelotoxic, inducing durable responses in previously untreated WM.

In immunoglobulin light chain amyloidosis a small, indolent plasma cell clone synthesizes light chains that cause devastating organ damage. Early diagnosis, based on prompt recognition of "red-flags" before advanced cardiomyopathy ensues, is essential for improving outcomes. Differentiation from other systemic amyloidoses may require advanced technologies. Prognosis depends on the extent of cardiac involvement, and cardiac biomarkers guide the choice of therapy. The protean clinical presentation requires individualized treatment. Close monitoring of clonal and organ response guides therapy changes and duration. Conventional or high-dose alkylator-based chemotherapy is effective in almost two-thirds of patients. Combinations of proteasome inhibitors, dexamethasone, and alkylators achieve high response rates, although controlled studies are needed. Risk-adapted stem cell transplant and consolidation with novel agents may be considered in selected patients. Immune-modulatory drugs are good options for refractory/relapsed patients. Novel agents and therapeutic targets are expected to be exploited, in an integrated, more effective and less toxic treatment strategy.

Treatment outcomes of patients with cardiac stage III light chain (AL) amyloidosis remain poorly studied. Such cases have been excluded from most clinical studies due to perceived dismal prognosis. We report treatment outcomes of 346 patients with stage III AL amyloidosis from the United Kingdom, Italy, Germany, and Greece. Median overall survival (OS) was 7 months with OS at 3, 6, 12, and 24 months of 73%, 55%, 46%, and 29%, respectively; 42% died before first response evaluation. On an intention-to-treat basis, the overall hematologic response rate was 33%, including a complete response rate of 12%. OS rates at 12 and 24 months, respectively, for 201 response evaluable patients were 88% and 85% for complete responders, 74% and 53% for partial responders, and 39% and 22% for nonresponders. Forty-five percent of responders achieved an organ response. Amino-terminal fragment of brain-type natriuretic peptide (NT-proBNP) >8500 ng/L and systolic blood pressure (SBP) <100 mm Hg were the only factors that independently impacted OS and identified an especially poor prognosis subgroup of patients with a median OS of only 3 months. Outcome and organ function of stage III AL amyloidosis without very elevated NT-proBNP and low SBP is improved by a very good hematologic response to chemotherapy.

Considering the important advances in treating specific types of systemic amyloidoses, unequivocal typing of amyloid deposits is now essential. Subcutaneous abdominal fat aspiration is the easiest, most common diagnostic procedure. We developed a novel, automated approach, based on Multidimensional Protein Identification Technology, for typing amyloidosis. Fat aspirates were obtained from patients with the most common systemic amyloidoses (ALλ, ALκ, transthyretin, and reactive amyloidosis), with Congo red score more than or equal to 3+, and nonaffected controls. Peptides from extracted and digested proteins were analyzed by Multidimensional Protein Identification Technology. On semiquantitative differential analysis (patients vs controls) of mass spectrometry data, specific proteins up-represented in patients were identified and used as deposit biomarkers. An algorithm was developed to classify patients according to type and abundance of amyloidogenic proteins in samples; in all cases, proteomic characterization was concordant with fibril identification by immunoelectron microscopy and consistent with clinical presentation. Our approach allows reliable amyloid classification using readily available fat aspirates.

Monoclonal Ig light chains (LC) can be responsible for pathologic conditions in humans, as in systemic amyloid light amyloidosis. Protean clinical manifestations characterize this disorder with the most varied combination of symptoms generated by different degrees of diverse organ involvement. Kidney and heart are most frequently interested, with major heart involvement as the most relevant prognostic factor. The identification of the underlying mechanism involved in organ targeting is of major relevance for the pathobiology of this disorder. To this aim, we characterized the repertoire of variable region germline genes of λ LC preferentially targeting the heart and compared it with the repertoire of LC that do not in a case-control study. We found that the repertoires were highly restricted, showing preferential use of the same few germline genes but with a different frequency pattern. A single gene, IGVL1-44, was found associated with a 5-fold increase in the odds of dominant heart involvement (after adjusting for confounders in a multivariable logistic model). These results support an involvement of LC genetics in the determination of organ targeting. Study of the characteristics of IGVL1-44-LC with, and of the minority without, heart involvement might lead to identification of LC/tissue interactions.

This first prospective phase 2 study of single-agent bortezomib in relapsed primary systemic AL amyloidosis evaluated the recommended (maximum planned) doses identified in phase 1 testing (1.6 mg/m² once weekly [days 1, 8, 15, and 22; 35-day cycles]; 1.3 mg/m² twice weekly [days 1, 4, 8, and 11; 21-day cycles]). Among all 70 patients enrolled in the study, 44% had ≥ 3 organs involved, including 73% and 56% with renal and cardiac involvement. In the 1.6 mg/m² once-weekly and 1.3 mg/m² twice-weekly groups, the hematologic response rate was 68.8% and 66.7% (37.5% and 24.2% complete responses, respectively); median time to first/best response was 2.1/3.2 and 0.7/1.2 months, and 78.8% and 75.5% had response durations of ≥ 1 year, respectively. One-year hematologic progression-free rates were 72.2% and 74.6%, and 1-year survival rates were 93.8% and 84.0%, respectively. Outcomes appeared similar in patients with cardiac involvement. Among all 70 patients, organ responses included 29% renal and 13% cardiac responses. Rates of grade ≥ 3 toxicities (79% vs 50%) and discontinuations/dose reductions (38%/53% vs 28%/22%) resulting from toxicities appeared higher with 1.3 mg/m² twice-weekly versus 1.6 mg/m² once-weekly dosing. Both bortezomib dose schedules represent active, well-tolerated regimens in relapsed AL amyloidosis. This study was registered at www.clinicaltrials.gov as #NCT00298766.

In light-chain (AL) amyloidosis, prognosis is dictated by cardiac dysfunction. N-terminal natriuretic peptide type B (NT-proBNP) and cardiac troponins (cTn) are used to assess the severity of cardiac damage. We evaluated the prognostic relevance of a high-sensitivity (hs) cTnT assay, NT-proBNP, and cardiac troponin I in 171 consecutive patients with AL amyloidosis at presentation and 6 months after treatment. Response and progression of NT-proBNP were defined as more than 30% and more than 300 ng/L changes. All 3 markers predicted survival, but the best multivariable model included hs-cTnT. The hs-cTnT prognostic cutoff was 77 ng/L (median survival 10.6 months for patients with hs-cTnT above the cutoff). After treatment, response and progression of NT-proBNP and a more than 75% increase of hs-cTnT were independent prognostic determinant. In AL amyloidosis, hs-cTnT is the best baseline prognostic marker. Therapy should be aimed at preventing progression of cardiac biomarkers, whereas NT-proBNP response confers an additional survival benefit.

New treatment options are required for primary systemic AL amyloidosis (AL). This phase 1 dose-escalation component of a phase 1/2 study in relapsed AL aimed to determine the maximum tolerated dose (MTD) of bortezomib once weekly (0.7-1.6 mg/m(2); days 1, 8, 15, and 22; 35-day cycles) and twice weekly (0.7-1.3 mg/m(2); days 1, 4, 8, and 11; 21-day cycles) and assess preliminary hematologic responses. Thirty-one patients with relapsed AL were enrolled across 7 cohorts. Dose-limiting toxicity included grade 3 congestive heart failure in 2 patients (1 at once weekly, 1.6 mg/m(2), and 1 at twice weekly, 1.0 mg/m(2)). MTD was not defined for either schedule; the maximum doses of 1.6 mg/m(2) (once weekly) and 1.3 mg/m(2) (twice weekly) are being used in phase 2 evaluation. Most commonly reported toxicities on both schedules included gastrointestinal events, fatigue, and nervous system disorders. Discontinuations and dose reductions for toxicity were reported in 12 and 4 patients, respectively. No treatment-related deaths occurred. Hematologic responses occurred in 15 (50%) of 30 evaluable patients, including 6 (20%) complete responses. Median time to first response was 1.2 months. Once-weekly and twice-weekly bortezomib appear generally well tolerated in relapsed AL, with promising hematologic responses. This study is registered with http://ClinicalTrials.Gov under identifier NCT00298766.

Recently, many new drugs have been developed for the treatment of Waldenström macroglobulinemia (WM). To optimize the treatment according to the prognosis and to facilitate the comparison of trials, we developed an International Prognostic Scoring System for WM in a series of 587 patients with clearly defined criteria for diagnosis and for initiation of treatment. The median survival after treatment initiation was 87 months. Five adverse covariates were identified: advanced age (>65 years), hemoglobin less than or equal to 11.5 g/dL, platelet count less than or equal to 100 x 10(9)/L, beta2-microglobulin more than 3 mg/L, and serum monoclonal protein concentration more than 7.0 g/dL. Low-risk patients (27%) presented with no or 1 of the adverse characteristics and advanced age, intermediate-risk patients (38%) with 2 adverse characteristics or only advanced age, and high-risk patients (35%) with more than 2 adverse characteristics. Five-year survival rates were 87%, 68%, and 36%, respectively (P < .001). The ISSWM retained its prognostic significance in subgroups defined by age, treatment with alkylating agent, and purine analog. Thus, the ISSWM may provide a means to design risk-adapted studies. However, independent validation and new biologic markers may enhance its significance.

The detection of a monoclonal immunoglobulin in serum or urine usually raises concerns about the size of the underlying B-cell-derived clone and possible systemic effects caused by its expansion. However, a small clone can synthesize a very toxic protein, producing devastating systemic damage and protean clinical presentations. The resulting "monoclonal component-related diseases," although difficult to diagnose, may be progressive and even fatal. The monoclonal protein can aggregate and deposit systemically as occurs in light-chain amyloidosis, monoclonal immunoglobulin deposition disease, crystal-storing histiocytosis, and monoclonal cryoglobulinemia. Alternatively, some monoclonal proteins possess antibody activity toward autogenous antigens and cause chronic cold agglutinin disease, mixed cryoglobulinemia, and peripheral neuropathies. Other humoral mediators may contribute to neuropathy in variant disorders such as the POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome. The clone synthesizing the noxious monoclonal proteins is often small, and sensitive techniques may be required to detect these immunoglobulins. A delay in diagnosis can allow irreversible organ damage and dramatically shorten survival. Prompt recognition of suggestive signs and symptoms should trigger a thorough diagnostic approach to reach the correct diagnosis quickly, because this is the key to effective therapy. Although the treatment of these conditions is not optimal, significant advances have been made, improving the duration and quality of life.

N-terminal natriuretic peptide type B (NT-proBNP) is a marker of cardiac dysfunction in light chain amyloidosis (AL) and a powerful prognostic determinant. Serum NT-proBNP and circulating free light chains (FLCs) were measured at enrollment and after 3 cycles of chemotherapy in 51 patients with cardiac AL. In patients (n = 22, 43%) in whom FLCs decreased by more than 50% (hematologic response), NT-proBNP concentration decreased by a median of 48%, whereas in the remaining patients it increased by 47% (P = .01). The reduction of NT-proBNP was greater in patients (n = 9) in whom amyloidogenic FLCs disappeared at immunofixation (median 53%), than in the remaining responding patients (median 31%, P = .04). Left ventricular wall thickness decreased by at least 2 mm in 3 of 20 patients in whom NT-proBNP improved. Fifteen patients died. Thirteen of them, in whom NT-proBNP and FLCs did not improve, died after a median of 1.8 months. The decrease of FLCs translates into a simultaneous decrease of NT-proBNP and improved survival. Patients in whom chemotherapy fails to induce such a decrease are at risk of early death. Cardiac function in AL can rapidly improve due to a reduction of the circulating amyloidogenic precursor, despite the amount of cardiac amyloid deposits remaining apparently unaltered, as measured by echocardiography.

Based on the efficacy of thalidomide in multiple myeloma and on its synergy with dexamethasone on myeloma plasma cells, we evaluated the combination of thalidomide (100 mg/d, with 100-mg increments every 2 weeks, up to 400 mg) and dexamethasone (20 mg on days 1-4) every 21 days in 31 patients with primary amyloidosis (AL) whose disease was refractory to or had relapsed after first-line therapy. Eleven (35%) patients tolerated the 400 mg/d thalidomide dose. Overall, 15 (48%) patients achieved hematologic response, with 6 (19%) complete remissions and 8 (26%) organ responses. Median time to response was 3.6 months (range, 2.5-8.0 months). Treatment-related toxicity was frequent (65%), and symptomatic bradycardia was a common (26%) adverse reaction. The combination of thalidomide and dexamethasone is rapidly effective and may represent a valuable second-line treatment for AL.

The most efficient therapeutic approach for immunoglobulin light chain amyloidosis (AL) is autologous stem cell transplantation (ASCT); however, the toxicity of ASCT limits its feasibility to a minority of patients. Patients ineligible for ASCT are usually treated with standard oral melphalan and prednisone, but the response rate to this regimen is unsatisfactory, and time to response is long. High-dose dexamethasone provides a rapid response time in patients with AL. We evaluated the combination of oral melphalan and high-dose dexamethasone (M-Dex) in 46 patients with AL ineligible for ASCT. Thirty-one (67%) achieved a hematologic response and 15 (33%) a complete remission. In 22 (48%) of the responsive patients functional improvement of the organs involved was observed. Five patients (11%) experienced severe adverse events, 3 required hospitalization, and no treatment-related deaths were observed. M-Dex represents a feasible and effective therapeutic option for patients with advanced AL who are ineligible for ASCT.

Primary (AL) amyloidosis is a plasma cell dyscrasia characterized by extracellular deposition of monoclonal light-chain variable region (V) fragments in the form of amyloid fibrils. Light-chain amyloid is rare, and it is not fully understood why it occurs in only a fraction of patients with a circulating monoclonal component and why it typically associates with lambda isotype and lambdaVI family light-chain proteins. To provide insights into these issues, we obtained complete nucleotide sequences of monoclonal V(lambda) regions from 55 consecutive unselected cases of primary amyloidosis and the results were compared with the light-chain expression profile of polyclonal marrow plasma cells from 3 healthy donors (a total of 264 sequences). We demonstrated that: (1) the lambdaIII family is the most frequently used both in amyloidosis (47%) and in polyclonality (43%); (2) both conditions are characterized by gene restriction; (3) a very skewed repertoire is a feature of amyloidosis, because just 2 germline genes belonging to the lambdaIII and lambdaVI families, namely 3r (22% of cases, lambdaIII) and 6a (20%, lambdaVI), contributed equally to encode 42% of amyloid V(lambda) regions; (4) these same 2 gene segments have a strong association with amyloidosis if their prevalences are compared with those in polyclonal conditions (3r, 8.3%, P =.024; 6a, 2.3%, P =.0008, chi2 test); (5) the J(lambda)2/3 segment, encoding the fourth framework region, appears to be slightly overrepresented in AL (83% versus 67%, P =.03), and this might be related to preferential J(lambda)2/3 rearrangement in amyloid (11 of 12 cases) versus polyclonal 3r light chains (13 of 22 cases). These findings demonstrate that V(lambda)-J(lambda) expression is more restricted in plasma cells from amyloidosis than from polyclonal bone marrow and identify 3r as a new disease-associated gene segment. Overusage of just 2 gene segments, 3r and 6a, can thus account for the lambda light-chain overrepresentation typical of this disorder.