Clinical efficacy of high-dose dexamethasone with maintenance dexamethasone/alpha interferon in patients with primary systemic amyloidosis: results of United States Intergroup Trial Southwest Oncology Group (SWOG) S9628

Molecular Mechanism of Pathogenesis and Treatment Strategies for AL Amyloidosis

In amyloid light-chain (AL) amyloidosis, small B-cell clones (mostly plasma cell clones) present in the bone marrow proliferate and secrete unstable monoclonal free light chains (FLCs), which form amyloid fibrils that deposit in the interstitial tissue, resulting in organ injury and dysfunction. AL amyloidosis progresses much faster than other types of amyloidosis, with a slight delay in diagnosis leading to a marked exacerbation of cardiomyopathy. In some cases, the resulting heart failure is so severe that chemotherapy cannot be administered, and death sometimes occurs within a few months. To date, many clinical studies have focused on therapeutics, especially chemotherapy, to treat this disease. Because it is necessary to promptly lower FLC, the causative protein of amyloid, to achieve a hematological response, various anticancer agents targeting neoplastic plasma cells are used for the treatment of this disease. In addition, many basic studies using human specimens to elucidate the pathophysiology of AL have been conducted. Gene mutations associated with AL, the characteristics of amyloidogenic LC, and the structural specificity of amyloid fibrils have been clarified. Regarding the mechanism of cellular and tissue damage, the mass effect due to amyloid deposition, as well as the toxicity of pre-fibrillar LC, is gradually being elucidated. This review outlines the pathogenesis and treatment strategies for AL amyloidosis with respect to its molecular mechanisms.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Physiology, Diagnosis and Treatment of Cardiac Light Chain Amyloidosis

AL (light-chain) amyloidosis is a systemic disease in which amyloid fibers are formed from kappa or lambda immunoglobulin light chains, or fragments thereof, produced by a neoplastic clone of plasmocytes. The produced protein is deposited in tissues and organs in the form of extracellular deposits, which leads to impairment of their functions and, consequently, to death. Despite the development of research on pathogenesis and therapy, the mortality rate of patients with late diagnosed amyloidosis is 30%. The diagnosis is delayed due to the complex clinical picture and the slow progression of the disease. This is the type of amyloidosis that most often contributes to cardiac lesions and causes cardiac amyloidosis (CA). Early diagnosis and correct identification of the type of amyloid plays a crucial role in the planning and effectiveness of therapy. In addition to standard histological studies based on Congo red staining, diagnostics are enriched by tests to determine the degree of cardiac involvement. In this paper, we discuss current diagnostic methods used in cardiac light chain amyloidosis and the latest therapies that contribute to an improved patient prognosis.

Population Pharmacokinetics and Exposure-Response Modeling of Daratumumab Subcutaneous Administration in Patients With Light-Chain Amyloidosis

The purpose of this study is to characterize the population pharmacokinetics (popPK) of subcutaneous (SC) daratumumab in combination with bortezomib, cyclophosphamide, and dexamethasone and explore the relationship between daratumumab systemic exposure and selected efficacy and safety end points in patients with newly diagnosed systemic amyloid light-chain amyloidosis. The popPK analysis included pharmacokinetic and immunogenicity data from patients receiving daratumumab SC in combination with bortezomib, cyclophosphamide, and dexamethasone in the ANDROMEDA study (AMY3001; safety run-in, n = 28; randomized phase, n = 183). Nonlinear mixed-effects modeling was used to characterize the popPK and quantify the impact of potential covariates. The exposure-response (E-R) analysis included data from all patients in the randomized phase of ANDROMEDA (n = 388). Logistic regression and survival analysis were used to evaluate the relationships between daratumumab systemic exposure and efficacy end points. The E-R analysis on safety was conducted using quartile comparison and logistic regression analysis. The observed concentration-time data of daratumumab SC were well described by a 1-compartment popPK model with first-order absorption and parallel linear and nonlinear Michaelis-Menten elimination pathways. None of the investigated covariates were determined to be clinically meaningful. Daratumumab systemic exposure was generally similar across subgroups that achieved different levels of hematologic response, and there was no apparent relationship between daratumumab systemic exposure and the investigated safety end points. In conclusion, the popPK and E-R analyses supported the selected 1800-mg flat dose of daratumumab SC in combination with bortezomib, cyclophosphamide, and dexamethasone regimen for the treatment of light-chain amyloidosis. No dose adjustment was recommended for investigated covariates.

Pathophysiology and Therapeutic Approaches to Cardiac Amyloidosis

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

Conventional Therapy for Amyloid Light-Chain Amyloidosis

The vast majority of patients with light-chain (AL) amyloidosis are not eligible for stem cell transplant and are treated with conventional chemotherapy. Conventional regimens are based on various combinations of dexamethasone, alkylating agents, proteasome inhibitors, and immunomodulatory drugs. The choice of these regimens requires a careful risk stratification, based on the extent of amyloid organ involvement, comorbidities, and the characteristics of the amyloidogenic plasma cell clone. Most patients are treated upfront with bortezomib and dexamethasone combined with cyclophosphamide or melphalan. Cyclophosphamide does not compromise stem cell mobilization and harvest and is more manageable in renal failure. Melphalan can overcome the effect of t(11;14), which is associated with lower response rates and shorter survival in subjects treated with bortezomib and dexamethasone, or in combination with cyclophosphamide. Lenalidomide and pomalidomide are the mainstay of rescue treatment. They are effective in patients exposed to bortezomib, dexamethasone, and alkylators, but deep hematologic responses are rare. Ixazomib, alone or in combination with lenalidomide, increases the rate of complete responses in relapsed/refractory patients. Conventional chemotherapy regimens will represent the backbone for future combinations, particularly with anti-plasma-cell immunotherapy, that will further improve response rates and outcomes.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Immunoglobulin Light-Chain Amyloidosis: From Basics to New Developments in Diagnosis, Prognosis and Therapy

Immunoglobulin amyloid light-chain (AL) amyloidosis is the most common form of systemic amyloidosis, where the culprit amyloidogenic protein is immunoglobulin light chains produced by marrow clonal plasma cells. AL amyloidosis is an infrequent disease, and since presentation is variable and often nonspecific, diagnosis is often delayed. This results in cumulative organ damage and has a negative prognostic effect. AL amyloidosis can also be challenging on the diagnostic level, especially when demonstration of Congo red-positive tissue is not readily obtained. Since as many as 31 known amyloidogenic proteins have been identified to date, determination of the amyloid type is required. While several typing methods are available, mass spectrometry has become the gold standard for amyloid typing. Upon confirming the diagnosis of amyloidosis, a pursuit for organ involvement is essential, with a focus on heart involvement, even in the absence of suggestive symptoms for involvement, as this has both prognostic and treatment implications. Details regarding initial treatment options, including stem cell transplantation, are provided in this review. AL amyloidosis management requires a multidisciplinary approach with careful patient monitoring, as organ impairment has a major effect on morbidity and treatment tolerability until a response to treatment is achieved and recovery emerges.

Immunoglobulin Light Chain Systemic Amyloidosis

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

The impact of dialysis on the survival of patients with immunoglobulin light chain (AL) amyloidosis undergoing autologous stem cell transplantation

BACKGROUND

Acute renal failure requiring dialysis is associated with high mortality during autologous stem cell transplantation (ASCT). This study examined the association between acute renal failure and mortality in immunoglobulin light chain (AL) amyloidosis during ASCT.

METHODS

Between 1996 and 2010, 408 ASCT patients were evaluated. Data were collected from electronic medical records.

RESULTS

Dialysis was performed on 72 (17.6%) patients. Eight patients started dialysis >30 days prior to ASCT (Group II), 36 started ±30 days after ASCT (Group III) and 28 initiated dialysis >1 month after ASCT (Group IV). Patients who never dialyzed were assigned to Group I. There were no significant age or sex differences. Median overall survival (OS) had not been reached in Groups I and II but was 7.0 months in Group III and 48.5 months in Group IV (P < 0.001). Treatment-related mortality (TRM) was observed in 44.4% of the patients in Group III, 6-fold higher than the next highest group (P < 0.001). The most common causes of TRM were cardiac and sepsis. In the multivariate analysis, only hypoalbuminemia (<2.5 g/dL, P < 0.001) and estimated glomerular filtration rate (eGFR) <40 mL/min/1.73 m(2) (P < 0.001) were independently associated with starting dialysis within 30 days of ASCT.

CONCLUSIONS

The study found significant differences in the OS depending on when the acute renal failure occurred. Patients who required dialysis within 30 days of ASCT had the highest rate of TRM. Screening with serum albumin and eGFR may reduce the risk.

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

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

High-dose therapy with auto-SCT is feasible in high-risk cardiac amyloidosis

Cardiac involvement in light-chain amyloidosis (AL) predicts poor prognosis and is associated with higher TRM and morbidity during high-dose therapy and auto-SCT (HDT-ASCT). We studied the outcomes of 30 patients with cardiac amyloidosis undergoing HDT-ASCT at our center between January 1998 and March 2012. The median age of the patients was 53 years (range, 36-74) with a median follow-up of 35 months (range, 0.4-97 months). Twenty-seven patients (90%) had more than one organ involved besides the heart with 37% with cardiac stage ⩾3. Melphalan-based conditioning regimen (140-200 mg/m(2)) was used for HDT-ASCT. One-year TRM is 10%. Three-year OS and EFS from HDT-ASCT was 83% and 56.8%, respectively. Cumulative incidence of relapse at 3 years was 38.5%. Negative factors affecting survival included age >60 years, lack of novel induction therapy and BM plasmacytosis >10%. We conclude that HDT-ASCT is well tolerated in patients with high-risk cardiac amyloidosis and can lead to improved overall outcomes.

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

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.

18F-fluorodeoxyglucose positron emission tomography might be useful for diagnosis of hepatic amyloidosis

We report on a woman with hepatic involvement of primary systemic (immunoglobulin light chain, AL) amyloidosis. Her diagnosis was confirmed by liver biopsy. Clinical symptoms of hepatic amyloidosis are generally mild at its first stage, with most frequent findings being hepatomegaly and alkaline phosphatase elevation. Recent advances in the understanding of the pathophysiology of systemic amyloidosis have made several treatments available. However, its prognosis is occasionally poor. Because liver biopsy is not always safe, other modalities for the diagnosis are needed. Of interest was that fluorodeoxyglucose (FDG) uptake into the liver was observed, compared with that into the spleen, in this patient, indicating that FDG positron emission tomography and computed tomography might be useful for the diagnosis of hepatic amyloidosis with mild liver dysfunction.

Update on treatment of light chain amyloidosis

Light chain amyloidosis is the most common type of amyloidosis as a consequence of protein misfolding of aggregates composed of amyloid fibrils. The clinical features are dependent on the organs involved, typically cardiac, renal, hepatic, peripheral and autonomic neuropathy and soft tissue. A tissue biopsy or fat aspirate is needed to confirm the presence/type of amyloid and prognostic tools are important in a risk stratified approach to treatment. Autologous stem cell transplant eligibility should be assessed at baseline, weighing the reversible or non-reversible contraindications, toxicity of treatment and chemotherapy alternatives available. Chemotherapy options include melphalan, thalidomide, bortezomib, lenalidomide, bendamustine in combination with dexamethasone. Many studies have explored these treatment modalities, with ongoing debate about the optimal first line and sequential treatment thereafter. Attaining a very good partial response or better is the treatment goal coupled with early assessment central to optimizing treatment. One major challenge remains increasing the awareness of this disease, frequently diagnosed late as the presenting symptoms mimic many other medical conditions. This review focuses on the treatments for light chain amyloidosis, how these treatments have evolved over the years, improved patient risk stratification, toxicities encountered and future directions.

Immunoglobulin light chain amyloidosis

Primary light chain amyloidosis is the most common form of systemic amyloidosis and is caused by misfolded light chains that cause proteotoxicity and rapid decline of vital organ function. Early diagnosis is essential in order to deliver effective therapy and prevent irreversible organ damage. Accurate diagnosis requires clinical skills and advanced technologies. The disease can be halted and the function of target organs preserved by the prompt reduction and elimination of the plasma cell clone producing the toxic light chains in the bone marrow. Heart damage is the major determinant of survival, and staging with cardiac biomarkers guides treatment. Two-thirds of patients can benefit from treatment with improved quality of life and extended survival. Future efforts should be directed at early diagnosis, improving the tolerability and efficacy of anti-plasma cell therapy, accelerating recovery of organ function via promoting resorption of amyloid deposits, and developing novel approaches to counter light chain proteotoxicity.

Systemic amyloidoses: what an internist should know

Systemic amyloidoses are rare, complex diseases caused by misfolding of autologous proteins. Although these diseases are fatal, effective treatments exist that can alter their natural history, provided that they are started before irreversible organ damage has occurred. The cornerstones of the management of systemic amyloidoses are early diagnosis, accurate typing, appropriate risk-adapted therapy, tight follow-up, and effective supportive treatment. Internists play a key role in suspecting the disease, thus allowing early diagnosis, starting the diagnostic workup and selecting patients that should be referred to specialized centers, judiciously titrating supportive measures, and following patients throughout the course of the disease. Here we review the pathogenesis, diagnosis and treatment of the most common forms of systemic amyloidoses.

Oral melphalan and dexamethasone grants extended survival with minimal toxicity in AL amyloidosis: long-term results of a risk-adapted approach

The combination of oral melphalan and dexamethasone is considered standard therapy for patients with light-chain amyloidosis ineligible for autologous stem cell transplantation. However, previous trials reported different rates of response and survival, mainly because of the different proportions of high-risk patients. In the present study, including a total of 259 subjects, we treated 119 patients with full-dose melphalan and dexamethasone (dexamethasone 40 mg days 1-4), and 140 patients with advanced cardiac disease with an attenuated dexamethasone schedule (20 mg). Hematologic response rates were 76% in the full-dose group and 51% in the patients receiving the attenuated schedule; the corresponding complete response rates were 31% and 12%, respectively. The median survival was 7.4 years in the full-dose group and 20 months in the attenuated-dose group. Use of high-dose dexamethasone, amino-terminal pro-natriuretic peptide type-B >1800 ng/L, a difference between involved and uninvolved free light chains of >180 mg/L, troponin I >0.07 ng/mL, and response to therapy were independent prognostic determinants. In relapsed/refractory subjects bortezomib combinations granted high hematologic response rates (79% and 63%, respectively), proving the most effective rescue treatment after melphalan and dexamethasone. In summary, melphalan plus dexamethasone was highly effective with minimal toxicity, confirming its central role in the treatment of AL amyloidosis. Future randomized trials will clarify whether bortezomib is best used in frontline combination with melphalan and dexamethasone or as rescue treatment.

Modified high-dose melphalan and autologous SCT for AL amyloidosis or high-risk myeloma: analysis of SWOG trial S0115

We designed a trial using two sequential cycles of modified high-dose melphalan at 100 mg/m(2) and autologous SCT (mHDM/SCT) in AL amyloidosis (light-chain amyloidosis, AL), AL with myeloma (ALM) and host-based high-risk myeloma (hM) patients through SWOG-0115. The primary objective was to evaluate OS. From 2004 to 2010, 93 eligible patients were enrolled at 17 centers in the United States (59 with AL, 9 with ALM and 25 with hM). The median OS for patients with AL and ALM was 68 months and 47 months, respectively, and has not been reached for patients with hM. The median PFS for patients with AL and ALM was 38 months and 16 months, respectively, and has not been reached for patients with hM. The treatment-related mortality (TRM) was 12% (11/93) and was observed only in patients with AL after SCT. Grade 3 and higher non-hematologic adverse events were experienced by 81%, 67% and 57% of patients with AL, ALM and hM, respectively, during the first and second HDM/SCT. This experience demonstrates that with careful selection of patients and use of mHDM for SCT in patients with AL, ALM and hM, even in the setting of a multicenter study, OS can be improved with acceptable TRM and morbidity.

What do I need to know about immunoglobulin light chain (AL) amyloidosis?

Immunoglobulin light chain (AL) amyloidosis is the most common acquired systemic amyloidoses. Its presentation is often insidious and progressive, which may delay diagnosis. The interval between first symptoms and actual diagnosis along the intrinsic heterogeneity of tissue tropism create a wide spectrum of presentations, both in terms of scope and depth of symptoms and signs and functional status of patients. In this review, the authors review the pathogenesis, diagnosis and differential diagnosis of AL amyloidosis along with the prognosis and state-of-the-art management for patients with this affliction.

A phase 1/2 study of lenalidomide with low-dose oral cyclophosphamide and low-dose dexamethasone (RdC) in AL amyloidosis

In this phase 1/2 study, we explored the feasibility and activity of an oral regimen of lenalidomide with low-dose dexamethasone and low-dose oral cyclophosphamide (RdC) in patients with primary systemic light chain amyloidosis. RdC was given for up to 12 cycles in prespecified cohorts at escalated doses: 13 patients were treated in phase 1 and 24 in phase 2; 65% were previously untreated, and most had renal and/or cardiac involvement and elevated cardiac biomarkers. Lenalidomide 15 mg/d and cyclophosphamide 100 mg/d were further evaluated in phase 2. On intention to treat, 20 (55%) patients achieved a hematologic response, including 3 (8%) complete remissions. Hematologic responses were seen at all dose levels and in 4 of 5 patients who had received bortezomib previously. An organ response was recorded in 22% of patients on intention-to-treat and in 40% of patients who survived at least 6 months. The median time to progression was 10 months and the 2-year survival was 41%. Fatigue, nonneutropenic infections, and rash were the most common toxicities. The results of the present study show that RdC is an oral regimen with activity in primary systemic light chain amyloidosis and may be an additional treatment option, especially for patients with preserved organ function or for patients who cannot receive or who relapse after bortezomib. This study is registered at www.clinicaltrials.gov as NCT00981708.

Consensus guidelines for the conduct and reporting of clinical trials in systemic light-chain amyloidosis

This manuscript summarizes the recommendations that emerged from the first Roundtable on Clinical Research in Immunoglobulin Light-chain Amyloidosis (AL), a meeting sponsored by the Amyloidosis Foundation (Clarkston, MI, USA) to develop a consensus of experts on a modern framework for clinical trial design and drug development in AL. Recent diagnostic and technical advances in AL, and updated consensus guidelines for assessing hematologic and organ responses, enable us to define study populations, appropriate end points, and other criteria for all phases of clinical research. This manuscript provides a framework for the design and conduct of systematic collaborative clinical research in AL to encourage more rapid testing of therapies and to expedite new drug development and approval.

The challenge of systemic immunoglobulin light-chain amyloidosis (Al)

The cardiac involvement and associated mortality that occur in systemic AL amyloidosis remain among the most challenging aspects of the systemic amyloid-related diseases. Monoclonal immunoglobulin light chains produced by a clone of plasma cells are usually the cause of symptoms and organ dysfunction via both poorly understood toxic effects of misfolded species and accumulation of interstitial amyloid fibrils in key viscera. Treatment is aimed at eliminating the clonal cells in order to eliminate toxic light chain production. Recent advances in therapy have helped many patients with AL achieve complete hematologic responses and significant reversal of organ damage but these benefits do not extend to that 10-15 % who present with advanced cardiac involvement. Even with cardiac transplant followed by effective therapy such as stem cell transplant, outcomes for these patients remain promising at best.

Bortezomib in a phase 1 trial for patients with relapsed AL amyloidosis: cardiac responses and overall effects

BACKGROUND

Bortezomib is approved for the treatment of multiple myeloma and a role has been suggested in the treatment of systemic AL amyloidosis (AL).

METHODS

In this phase 1 dose-escalation portion of the first prospective study of single-agent bortezomib in AL, 31 patients with relapsed disease, including 14 (45%) with cardiac involvement, received bortezomib in seven dose cohorts on once-weekly (0.7, 1.0, 1.3, 1.6 mg/m(2)) and twice-weekly (0.7, 1.0, 1.3 mg/m(2)) schedules. Electrocardiographic, Holter and echocardiographic studies were evaluated in all patients to determine safety and response.

RESULTS

During therapy (median treatment period 210 days), no patient developed significant ventricular or supraventricular rhythm disturbance on 24-h Holter monitoring; however, no patient satisfied study criteria for cardiac response using echocardiographic assessment or New York Heart Association classification. Seven patients (23%) had a ≥ 10% fall in left ventricular ejection fraction, but only one met criteria for cardiac deterioration. The predominant cardiac adverse events were peripheral edema (23%), orthostatic hypotension (13%) and hypotension (10%). Two patients developed grade 3 congestive heart failure, which resolved following treatment interruption. In this Phase 1 portion, the maximum tolerated dose of bortezomib on either schedule was not reached. Hematologic responses occurred in 14 patients (45%), including seven (23%) complete responses. In non-responders mean left ventricular wall thickness increased during the course of treatment.

CONCLUSION

AL is frequently rapidly progressive; in these patients who had relapsed or progressed following previous conventional therapies, these results suggest that bortezomib may slow the progression of cardiac amyloid with limited toxicity.

Efficacy and safety of once-weekly and twice-weekly bortezomib in patients with relapsed systemic AL amyloidosis: results of a phase 1/2 study

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.

A long-term remission of renal amyloidosis with nephrotic syndrome after autologous peripheral blood stem-cell transplantation

Renal amyloidosis is typically characterized by nephrotic syndrome, often with massive proteinuria and refractory peripheral edema. We report the case of a patient with renal amyloidosis associated with nephrotic syndrome who maintained remission for 6 years after undergoing high-dose chemotherapy followed by autologous peripheral blood stem-cell transplantation (auto-PBSCT). The patient was a man aged in his 50s who had developed nephrotic syndrome. Bone marrow aspiration and kidney biopsy determined that the cause of the nephrotic syndrome was renal amyloidosis due to multiple myeloma, and the patient was admitted to our department in July 2003. After one course of chemotherapy, auto-PBSCT was performed in March 2004. Following transplantation, serum M-protein was no longer detectable from March 2005, and the patient achieved complete hematological remission. Subsequently, proteinuria decreased, serum albumin levels normalized, and nephrotic syndrome improved. As of 6 years after transplantation, in March 2010, the patient remained in remission, meaning that auto-PBSCT proved extremely effective as a treatment for renal amyloidosis in this case.

Amyloidosis: pathogenesis and new therapeutic options

The systemic amyloidoses are a group of complex diseases caused by tissue deposition of misfolded proteins that results in progressive organ damage. The most common type, immunoglobulin light chain amyloidosis (AL), is caused by clonal plasma cells that produce misfolded light chains. The purpose of this review is to provide up-to-date information on diagnosis and treatment options for AL amyloidosis. Early, accurate diagnosis is the key to effective therapy, and unequivocal identification of the amyloidogenic protein may require advanced technologies and expertise. Prognosis is dominated by the extent of cardiac involvement, and cardiac staging directs the choice of therapy. Treatment for AL amyloidosis is highly individualized, determined on the basis of age, organ dysfunction, and regimen toxicities, and should be guided by biomarkers of hematologic and cardiac response. Alkylator-based chemotherapy is effective in almost two thirds of patients. Novel agents are also active, and trials are ongoing to establish their optimal use. Treatment algorithms will continue to be refined through controlled trials. Advances in basic research have led to the identification of new drug targets and therapeutic approaches, which will be integrated with chemotherapy in the future.

Treatment of immunoglobulin light chain amyloidosis

No therapy is uniformly effective in the management of immunoglobulin light chain amyloidosis (AL amyloidosis). Despite the common generalization, therapy is highly effective. Options available to patients with AL amyloidosis include high-dose therapy, but this is applicable to only about one fourth of patients. Therapies shown to be effective are based on alkylators, dexamethasone, or combinations of an alkylator and steroids. In the past 5 years, novel agents previously shown to be effective in multiple myeloma (eg, thalidomide, lenalidomide, and bortezomib) have been shown to have efficacy in the management of AL amyloidosis. Predictors of outcome include the serum brain natriuretic peptide, the number of organs involved, and the severity of cardiac involvement detected by echocardiography. Virtually all patients are candidates for a trial of therapy, and it is possible to find a nontoxic regimen that can be administered to virtually any patient.

Systemic amyloidosis presenting as mucocutaneous bullous lesions

A 65-year-old male presented with hemorrhagic bullous skin lesions with purpura and ecchymoses. There was increased skin fragility with a strongly positive Nikolsky sign. Histopathology of the skin revealed large amounts of amyloid deposits in the dermis with a positive Congo Red staining around the dermal vessels. Examination and tests in this patient also revealed anemia, hepatomegaly, infiltrative cardiomyopathy, polyneuropathy and immunoglobulin l deposition, favoring a diagnosis of primary amyloidosis (AL type). The present case is reported in view of the rarity of the bullous variant of primary systemic amyloidosis as well as presence of mucosal lesions and a positive Nikolsky sign.

Weekly and twice-weekly bortezomib in patients with systemic AL amyloidosis: results of a phase 1 dose-escalation study

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.

Intrathecal corticosteroids might slow Alzheimer's disease progression

Anti-inflammatory drugs for treatment and prevention of Alzheimer's disease have to date proved disappointing, including a large study of low-dose prednisone, but higher dose steroids significantly reduced amyloid secretion in a small series of nondemented patients. In addition, there is a case report of a patient with amyloid angiopathy who had complete remission from two doses of dexamethasone, and very high dose steroids are already used for systemic amyloidosis. This paper presents the hypothesis that pulse-dosed intrathecal methylprednisolone or dexamethasone will produce detectable slowing of Alzheimer's progression, additive to that obtained with cholinesterase inhibitors and memantine. A protocol based on treatment regimens for multiple sclerosis and central nervous system lupus is outlined, to serve as a basis for formulating clinical trials. Ultimately intrathecal corticosteroids might become part of a multi-agent regimen for Alzheimer's disease and also have application for other neurodegenerative disorders.

Troponin T level as an exclusion criterion for stem cell transplantation in light-chain amyloidosis

The efficacy of stem cell transplantation in amyloidosis largely is determined by treatment-related mortality rates (range, 11-25%). Appropriate patient selection is essential to avoid this high mortality rate. Among 271 patients undergoing stem cell transplantation, troponin T was a powerful predictor of treatment-related mortality. Patients with troponin T levels of 0.06 microg/L or higher had a day-100 all-cause mortality rate of 28%. Patients with troponin T levels less than 0.06 microg/L had a day-100 all-cause mortality rate of 7% (P < 0.001). Troponin T levels should be measured in all patients before transplantation. Those with troponin T levels exceeding 0.06 microg/L should be considered for less toxic therapies until the clinically optimal use of stem cell transplantation is better defined by randomized clinical trials.

Deposition-associated diseases related with a monoclonal compound

Up to 3% of adults over 50 years of age show a monoclonal peak values in blood or urine. Findings and prognosis will be distinct in view of the nature of this factor. In B-cell neoplasias (multiple myeloma, Waldeström macroglobulinaemia, chronic myeloid leukaemia and non-Hodgkin lymphoma) the clinical pattern is dominated by the systemic effects produced by the expansion of the malign clone; the monoclonal protein may result in hyperviscosity syndrome or renal damage. On the other hand, there are other less frequent processes called diseases associated to monoclonal components, where the main clinical manifestations and prognosis depend of the biological effects of the monoclonal protein. With reference to this last group, which is the objective of this revision, no bone lesions, anaemia or a greater tendency to infections usually occur when compared with the first group. Even so, there are some cases of interposition between both groups: for instance, type IgM immunoglobulin present in Waldeström macroglobulinaemia may have cold agglutinin activity, and in the case of multiple myeloma, the clone may secrete amyloidogenic light chains.

An overview of high-dose melphalan and stem cell transplantation in the treatment of AL amyloidosis

AL amyloidosis is the most common form of systemic amyloidosis and is associated with an underlying plasma cell dyscrasia. This review outlines an overview of high-dose intravenous melphalan and stem cell transplantation in the treatment of AL amyloidosis. An algorithm of our recommendations for the treatment of AL amyloidosis is also outlined.

Amyloidosis

Amyloidosis is a disease in which abnormal proteins form fibrillar tissue deposits that can compromise key viscera and lead to early death. In order to treat amyloidosis, the type of abnormal protein must be identified. The most common type is monoclonal immunoglobulin light chain or AL amyloidosis; the other important type is hereditary, caused by variant forms of transthyretin and other proteins, whereas amyloid associated with chronic inflammation ("secondary") is rare in the developed world. AL can be misdiagnosed if a monoclonal gammopathy and a hereditary variant are present in the same patient. The aim of therapy in systemic AL amyloidosis is to reduce the amyloid-forming monoclonal light chain, measured with the serum free light chain assay, by suppressing the underlying plasma cell dyscrasia, while using supportive measures to sustain organ function. Amyloid deposits can be resorbed and organ function restored if the amyloid-forming precursor light chain is eliminated. The most effective treatment for systemic AL amyloidosis is risk-adapted melphalan with peripheral blood stem cell transplant (SCT). The hematologic response rate is 75% at 12 months when adjuvant therapy with thalidomide and dexamethasone is used post-SCT. Patients can achieve long-term durable remissions with organ recovery. Drugs effective in multiple myeloma are usually helpful in AL amyloidosis if tolerated. The use of novel antibody-based approaches for imaging amyloid and possibly for accelerating removal of deposits is under active investigation.

Light-chain (AL) amyloidosis: diagnosis and treatment

Light-chain (AL) amyloidosis is the most common form of systemic amyloidosis and is associated with an underlying plasma cell dyscrasia. The disease often is difficult to recognize because of its broad range of manifestations and what often are vague symptoms. The clinical syndromes at presentation include nephrotic-range proteinuria with or without renal dysfunction, hepatomegaly, congestive heart failure, and autonomic or sensory neuropathy. Recent diagnostic and prognostic advances include the serum free light-chain assay, cardiac magnetic resonance imaging, and serologic cardiac biomarkers. Treatment strategies that have evolved during the past decade are prolonging survival and preserving organ function in patients with this disease. This review outlines approaches to diagnosis, assessment of disease severity, and treatment of AL amyloidosis.