Complete responses in AL amyloidosis are unequal: the impact of free light chain mass spectrometry in AL amyloidosis.

ABSTRACT: Amyloidogenic serum free light chains (sFLCs) drive disease progression in AL amyloidosis. Matrix-assisted laser desorption/ionization time of flight mass spectrometry-based FLC assay (FLC-MS) has greater sensitivity than conventional sFLC assays allowing for the detection of serological residual disease. We report the utility of FLC-MS in a large series of patients with AL amyloidosis assessing the impact of FLC-MS negativity after treatment on overall survival (OS) and organ response rates. Serum samples were analyzed using FLC-MS at diagnosis and at 6 and 12 months after treatment. The impact of FLC-MS negativity over standard hematologic responses on survival and organ response was assessed. A total of 487 patients were included; 290 (59%) and 349 (71.5%) had cardiac and renal involvement, respectively. There was 100% concordance between the light chain (LC) fibril type and LC isotype identified by FLC-MS. At 6 and 12 months, 81 (16.6%) and 101 (20.7%) were FLC-MS negative. Of those achieving a conventional hematologic complete response (CR) at 6 and 12 months, 45 (27.7%) and 64 (39%) were FLC-MS negative. At 12 months, median OS for CR + FLC-MS negative was not reached vs 108 months in CR + FLC-MS positive (P = .024). At 12 months, 70% of patients with FLC-MS negativity (vs 50% FLC-MS positive) achieved a cardiac response (P = .015). In a multivariate analysis, FLC-MS negativity at 12 months was an independent predictor of better outcomes. FLC-MS can detect persistent monoclonal light chains in a significant proportion of patients in a conventional hematologic CR. FLC-MS assessment promises to be a new standard for response assessment in AL amyloidosis.

Response rates to second-line treatment with daratumumab bortezomib dexamethasone (DVD) in relapsed/refractory light chain amyloidosis (AL) after initial Bortezomib-based regime.

Bortezomib is regularly used as frontline therapy for systemic AL amyloidosis. We assess the efficacy of second-line daratumumab-bortezomib-dexamethasone (DVD) in AL amyloidosis in bortezomib-exposed patients. A total of 116 patients treated with second-line DVD were identified from a prospective observational study of newly diagnosed AL amyloidosis (ALchemy). DVD was initiated in both the relapsed setting or where there was an inadequate response defined as very good partial response (VGPR) or VGPR with organ progression/lack of organ improvement. A complete response (CR)/VGPR to second-line DVD was achieved in 81 (69.8%) patients. A CR/VGPR was achieved in 67 (79.7%) in those who achieved a VGPR/CR to first line versus 14/32 (43.8%) in those who did not. Where DVD was initiated due to an inadequate response to first line (vs. at relapse), the median event-free survival (EFS) was 18 vs. 34 months (p = 0.002). If a CR/VGPR was achieved to DVD, the 2-year EFS was still lower in those with prior inadequate response 54% vs. 66% (p = 0.062). DVD is an efficacious second-line treatment in systemic AL amyloidosis in a bortezomib-exposed population. However, the response to DVD is poorer in those with an inadequate response to first-line bortezomib.

Linking changes in quality of life to haematologic response and survival in systemic immunoglobulin light-chain amyloidosis.

This study reports health-related quality of life (HRQL) among newly-diagnosed immunoglobulin light-chain (AL) patients (n = 914) treated with a bortezomib-based regimen and its association with response depth and survival. Haematologic response/HRQL were assessed over 24 months in an ongoing, prospective study. HRQL change was calculated across haematologic/cardiac response levels. The relationship between baseline HRQL and survival was evaluated by the Cox proportional-hazard model (PH). Shared-random-effects models (SREMs) estimated time-to-death conditional on current HRQL/longitudinal HRQL trajectory. At 3 months, there was consistent decline in 5/8 HRQL domains across all haematologic response levels. By 12 months, 3/5 declining domains improved among complete response (CR) patients. In contrast, the mean change in less-than-CR patients did not indicate improvement. Under the Cox PH, having a baseline HRQL score five points higher than the sample mean was associated with 20% lower mortality risk. SREMs indicated a five-point greater HRQL score at the event time correlated with an approximately 30% decrease in mortality risk. For each one-point increase in HRQL score trajectory slope, mortality risk decreased by approximately 88%. Only CR patients had HRQL improvement, while partial response patients had less decline but no meaningful improvements. These data show the importance of HRQL serial assessments of AL patients and its importance as an end-point.

Longitudinal strain is an independent predictor of survival and response to therapy in patients with systemic AL amyloidosis.

AIMS: Cardiac involvement, a major determinant of prognosis in AL (light-chain immunoglobulin) amyloidosis, is characterized by an impairment of longitudinal strain (LS%). We sought to evaluate the utility of LS% in a prospectively observed series of patients. METHODS AND RESULTS: A total of 915 serial newly diagnosed AL patients with comprehensive baseline assessments, inclusive of echocardiography, were included. A total of 628/915 (68.6%) patients had cardiac involvement. The LS% worsened with advancing cardiac stage with mean -21.1%, -17.1%, -12.9%, and -12.1% for stages I, II, IIIa, and IIIb, respectively (P < 0.0001). There was a highly significant worsening of overall survival (OS) with worsening LS% quartile: LS% ≤-16.2%: 80 months, -16.1% to -12.2%: 36 [95% confidence interval (CI) 20.9-51.1] months, -12.1% to -9.1%: 22 (95% CI 9.1-34.9) months, and ≥-9.0%: 5 (95% CI 3.2-6.8) months (P < 0.0001). Improvement in LS% was seen at 12 months in patients achieving a haematological complete response (CR) (median improvement from -13.8% to -14.9% in those with CR and difference between involved and uninvolved light chain <10 mg/L). Strain improvement was associated with improved OS (median not reached at 53 months vs. 72 months in patients without strain improvement, P = 0.007). Patients achieving an LS% improvement and a standard N-terminal pro-brain natriuretic peptide-based cardiac response survived longer than those achieving a biomarker-based cardiac response alone (P < 0.0001). CONCLUSION: Baseline LS% is a functional marker that correlates with worsening cardiac involvement and is predictive of survival. Baseline LS% and an absolute improvement in LS% are useful additional measures of prognosis and response to therapy in cardiac AL amyloidosis, respectively.

Haematologic responses and survival do not significantly decrease with subsequent lines of therapy in systemic immunoglobulin light chain amyloidosis: results from an analysis of real-world longitudinal data.

Systemic immunoglobulin light chain amyloidosis (AL) is an incurable disorder, and the natural history is incompletely understood. In this study, we describe its natural history based on an analysis of real-world longitudinal data. All patients seen at the National Amyloidosis Centre, UK, between February 2010 and August 2019 and treated with up-front bortezomib are included. In all, 1 276 patients received the first-line treatment; 259, 85, and 32 patients received second, third, and fourth treatment lines, respectively. Among patients requiring further treatment after the first line, 77·2% started the second line within two years of the first line; 50·5%, 50·6%, 40·1% and 40·6% of patients had achieved at least very good partial response after the first, second, third and fourth treatment lines. Median overall survival (OS) from first, second, third and fourth lines was 45 months, 56 months, 37 months and not reached, respectively (P = 0·109). In summary, although relapses occur in AL amyloidosis, the outcomes and responses do not worsen with each subsequent relapse, making it attractive to design therapeutics with curative intent.

Urinary retinol binding protein predicts renal outcome in systemic immunoglobulin light-chain (AL) amyloidosis.

Renal risk stratification in systemic immunoglobulin light-chain (AL) amyloidosis is according to estimated glomerular filtration rate (eGFR) and urinary protein creatinine ratio (uPCR), the latter attributed to glomerular dysfunction, with proximal tubular dysfunction (PTD) little studied. Urinary retinol binding protein 4 (uRBP), a low molecular weight tubular protein and highly sensitive marker of PTD, was prospectively measured in 285 newly diagnosed, untreated patients with systemic AL amyloidosis between August 2017 to August 2018. At diagnosis, the uRBP/creatinine ratio (uRBPCR) correlated with serum creatinine (r = 0·618, P < 0·0001), uPCR (r = 0·422, P < 0·0001) as well as both fractional excretion of phosphate and urate (r = 0·563, P < 0·0001). Log uRBPCR at diagnosis was a strong independent predictor of end-stage renal disease {hazard ratio [HR] 2·65, [95% confidence interval (CI) 1·06-6·64]; P = 0·038}, particularly in patients with an eGFR >30 ml/min/1.73 m2 [HR 4·11, (95% CI 1·45-11·65); P = 0·008] and those who failed to achieve a deep haematological response to chemotherapy within 3 months of diagnosis [HR 6·72, (95% CI 1·83-24·74); P = 0·004], and also predicted renal progression [HR 1·91, (95% CI 1·18-3·07); P = 0·008]. Elevated uRBPCR indicates PTD and predicts renal outcomes independently of eGFR, uPCR and clonal response in systemic AL amyloidosis. The role of uRBPCR as a novel prognostic biomarker merits further study, particularly in monoclonal gammopathies of renal significance.

A prospective observational study of 915 patients with systemic AL amyloidosis treated with upfront bortezomib.

Bortezomib is a standard therapy in light-chain amyloidosis (AL), but little is known about response duration. A difference in involved amyloidogenic and uninvolved serum-free light chains (dFLC) < 10 mg/L (low dFLC response) predicts survival in AL patients with low presenting dFLC (20-50 mg/L). We report outcomes in the largest AL cohort treated with upfront bortezomib and explore the impact of posttreatment dFLC < 10 mg/L ("stringent dFLC response"). A total of 915 newly diagnosed AL patients treated with bortezomib and assessed at our center were included. Hematologic responses, 6-month dFLC, organ responses, overall survival (OS), and time-to-next-treatment (TNT) (excluded patients who died without starting second-line treatment) were evaluated. Overall response rate (intent-to-treat) was 65%, with 49% complete response (CR)/very good partial response/low dFLC response and with a stringent dFLC response, dFLC 10-40 mg/L, and dFLC > 40 mg/L was 30%, 22%, and 48%, respectively. Median OS was 72 months. A total of 289 patients died without progressing to second-line treatment. Median TNT was not reached, and 55% had not progressed to further treatment at 7 years. Patients with stringent dFLC responses had significantly better OS and TNT than did those with lesser responses. A total of 72% of CR patients did not progress to further treatment at 3 years compared with 84% with stringent dFLC responses. Cardiac responses were better in those with stringent dFLC responses (61%) compared with lesser responses (45%; P = .005). Upfront bortezomib confers durable hematologic responses. A stringent dFLC response predicts prolonged TNT and impressive organ responses.

Cardiorenal AL amyloidosis: risk stratification and outcomes based upon cardiac and renal biomarkers.

Systemic AL amyloidosis is a cause of type 5 cardiorenal syndrome. Response to treatment is currently reported according to organ-specific amyloidosis consensus criteria (ACC), which are not validated in cardiorenal AL amyloidosis. Of 1000 patients prospectively enrolled into the UK ALchemy study, 318 (32%) had combined cardiac and renal amyloidotic organ dysfunction at diagnosis, among whom 199 (63%) died; median survival by Kaplan-Meier analysis was 18·5 months. Fifty (16%) patients required renal replacement therapy (RRT). At diagnosis, independent predictors of death and dialysis were N-terminal pro-B-type natriuretic peptide (NT-proBNP) >8500 ng/l (hazard ratio [HR] 3·30, P < 0·001; HR 3·00, P < 0·001), and estimated glomerular filtration rate (eGFR) < 30 ml/min/1·73 m2 (HR 1·89, P = 0·011; HR 6·37, P < 0·001). At 6 months, an increase in NT-proBNP of >30% and a reduction in eGFR of ≥25% were independent predictors of death (HR 2·17, P = 0·009) and dialysis (HR 3·07, P = 0·002), respectively. At 12 months, an increase in NT-proBNP >30% was highly predictive of death (HR 3·67, P < 0·001) and dialysis (HR 2·85, P = 0·010), whereas ACC renal response was predictive of neither. Cardiorenal AL amyloidosis is associated with high early mortality. Outcomes are dictated by NT-proBNP and eGFR at diagnosis rather than proteinuria, and thereafter predominantly by changes in NT-proBNP concentration.

Prolonged renal survival in light chain amyloidosis: speed and magnitude of light chain reduction is the crucial factor.

Renal involvement causing progressive chronic kidney disease (CKD) is present in 70% of patients with systemic Ig light-chain (AL) amyloidosis at diagnosis. Chemotherapy that substantially suppresses free light chain production is associated with improved patient survival, but its benefit in delaying the onset of renal replacement therapy among patients who present with established advanced CKD has not been studied. To evaluate this, we studied 1000 patients enrolled in the prospective UK AL amyloidosis chemotherapy study (ALchemy). Of these, 84 patients had advanced amyloid-related CKD defined by an estimated glomerular filtration rate (eGFR) under 20 ml/min/1.73 m2. We determined outcomes among these 84 patients, who had a median eGFR of 10 ml/min/1.73 m2, in relation to response to chemotherapy evaluated at three, six, and 12 months from baseline. Patients who achieved suppression of 90% or more in their amyloidogenic free light chain (dFLC) within three months of baseline had significantly better overall survival, prolonged time to dialysis, and prolonged time to the composite endpoint of 'death or dialysis' compared to those who achieved lesser degrees of clonal response at the same time point. Even when this target of greater than 90% dFLC response was achieved but was delayed beyond 3 months, it was associated with worse outcomes. Cox regression analyses confirmed that a 90% or better dFLC response within 3 months was the only significant independent predictor of all three of these outcome measures. Thus, renal survival among patients with systemic immunologic light chain amyloidosis who present with advanced CKD is strongly dependent upon the magnitude and speed with which the underlying hematologic disorder is suppressed by chemotherapy.

A European collaborative study of treatment outcomes in 346 patients with cardiac stage III AL amyloidosis.

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.

Clinical profile and treatment outcome of older (>75 years) patients with systemic AL amyloidosis.

Systemic AL amyloidosis, a disease with improving outcomes using novel therapies, is increasingly recognized in the elderly but treatment and outcomes have not been systematically studied in this group of patients in whom comorbidities and frailty may compound morbidity and mortality. We report the outcomes of 295 patients with systemic AL amyloidosis ≥75 years seen at the UK National Amyloidosis Centre from 2005-2012. The median age was 78.5 years. The median overall survival was 20 months. Two hundred and thirty-eight patients received chemotherapy and 57 elected for supportive care only (overall survival - 24 and 8.4 months, respectively). On intention-to-treat analysis, 44% achieved a hematologic response including a very good partial response or better in 23%. The median overall survival was 6.2 years in patients achieving very good partial response or better at the 6-month landmark analysis and 1.5 years in non-responders. Factors independently indicating a poor prognosis were: cardiac involvement, performance status ≥2; systolic blood pressure <100 mmHg and, on landmark analysis, achieving less than a very good partial response. Treatment of systemic AL amyloidosis in the elderly is challenging. Deep clonal responses are associated with excellent survival and organ responses. Achieving a response to the first-line regimen appears particularly important as outcomes of non-responders are similar to those of untreated patients. Prospective trials with lower toxicity, outpatient treatment regimens are needed.

Lenalidomide and dexamethasone for systemic AL amyloidosis following prior treatment with thalidomide or bortezomib regimens.

The outcomes and responses to treatment remain poorly studied among patients with systemic AL amyloidosis who require further treatment following prior novel agent-based therapy. We report here treatment with lenalidomide-dexamethasone in 84 AL amyloidosis patients with relapsed/refractory clonal disease following prior treatment with thalidomide (76%) and/or bortezomib (68%). On an intention-to-treat (ITT) basis, the overall haematological response rate was 61%, including 20% complete responses. The median overall survival (OS) has not been reached; 2-year OS and progression-free survival (PFS) was 84% and 73%, respectively. Achieving a free light chain (FLC) response was an independent good prognostic factor for OS in multivariate analysis. There was no impact of prior thalidomide or bortezomib therapy on response rate, OS or PFS. 16% achieved an organ response at 6 months, with a marked improvement in organ responses in patients on long term therapy (median duration 11 months) and 55% achieving renal responses by 18 months. Lenalidomide/dexamethasone therapy achieves good haematological responses in patients with AL amyloidosis with relapsed/refractory clonal disease. The rate of renal responses among patients who received prolonged treatment was unexpectedly high, raising the possibility that immunomodulatory effects of lenalidomide therapy might enhance the otherwise slow natural regression of amyloid deposits.

Cyclophosphamide, bortezomib, and dexamethasone therapy in AL amyloidosis is associated with high clonal response rates and prolonged progression-free survival.

Bortezomib has shown great promise in the treatment of amyloid light-chain (AL) amyloidosis. We present our experience of 43 patients with AL amyloidosis who received cyclophosphamide, bortezomib, and dexamethasone (CVD) upfront or at relapse. Of these, 74% had cardiac involvement and 46% were Mayo Cardiac Stage III. The overall hematologic response rate was 81.4%, including complete response (CR) in 41.9% and very good partial response with >90% decrease in difference between involved/uninvolved light chain (VGPR-dFLC) in 51.4%. Patients treated upfront had higher rates of CR (65.0%) and VGPR-dFLC (66.7%). The estimated 2-year progression-free survival was 66.5% for patients treated upfront and 41.4% for relapsed patients. Those attaining a CR or VGPR-dFLC had a significantly better progression-free survival (P=.002 and P=.026, respectively). The estimated 2-year overall survival was 97.7% (94.4% in Mayo Stage III patients). CVD is a highly effective regimen producing durable responses in AL amyloidosis; the deep clonal responses may overcome poor prognosis in advanced-stage disease.

Graded Organ Response and Progression Criteria for Kidney Immunoglobulin Light Chain Amyloidosis.

Importance: Kidney light chain (AL) amyloidosis is associated with a risk of progression to kidney replacement therapy (KRT) and death. Several studies have shown that a greater reduction in proteinuria following successful anticlonal therapy is associated with improved outcomes. Objective: To validate graded kidney response criteria and their association with kidney and overall survival (OS). Design, Setting, and Participants: This retrospective, multicenter cohort was conducted at 10 referral centers for amyloidosis from 2010 to 2015 and included patients with kidney AL amyloidosis that was evaluable for kidney response and who achieved at least hematologic partial response within 12 months of diagnosis. The median follow-up was 69 (54-88) months. Data analysis was conducted in 2023. Exposure: Four kidney response categories based on the reduction in pretreatment 24-hour urine protein (24-hour UP) levels: complete response (kidCR, 24-hour UP ≤200 mg), very good partial response (kidVGPR, >60% reduction in 24-hour UP), partial response (kidPR, 31%-60% reduction), and no response (kidNR, ≤30% reduction). Kidney response was assessed at landmark points (6, 12, and 24 months) and best kidney response. Main Outcomes and Measures: Cumulative incidence of progression to KRT and OS. Results: Seven-hundred and thirty-two patients (335 women [45.8%]) were included, with a median (IQR) age of 63 (55-69) years. The median (IQR) baseline 24-hour proteinuria and estimated glomerular filtration rate was 5.3 (2.8-8.5) g per 24 hours and 72 (48-92) mL/min/1.73m2, respectively. In a competing-risk analysis, the 5-year cumulative incidence rates of progression to KRT decreased with deeper kidney responses as early as 6 months from therapy initiation (11%, 12%, 2.1%, and 0% for kidNR, kidPR, kidVGPR, and kidCR, respectively; P = .002) and were maintained at 12 months and 24 months and best kidney response. Patients able to achieve kidCR/kidVGPR by 24 months and at best response had significantly better OS compared with kidPR/kidNR. Kidney progression, defined as a 25% or greater decrease in estimated glomerular filtration rate, was associated with cumulative incidence of progression to KRT and OS. Conclusions and Relevance: The results of this cohort study suggest that graded kidney response criteria offers clinically and prognostically meaningful information for treating patients with kidney AL amyloidosis. The response criteria potentially inform kidney survival based on the depth of reduction in 24-hour proteinuria levels and demonstrate an OS advantage for those able to achieve kidCR/kidVGPR compared with kidPR/kidNR. Taken together, achievement of at least kidVGPR by 12 months is needed to ultimately improve kidney and patient survival.

Graded Cardiac Response Criteria for Patients With Systemic Light Chain Amyloidosis.

PURPOSE: Binary cardiac response assessment using cardiac biomarkers is prognostic in light chain amyloidosis. Previous studies suggested four-level cardiac responses using N-terminal prohormone of brain natiuretic peptide improves prognostic prediction. This study was designed to validate graded cardiac response criteria using N-terminal prohormone of brain natiuretic peptide/brain natiuretic peptide. PATIENTS AND METHODS: This retrospective, multicenter study included patients with light chain amyloidosis who achieved at least a hematologic partial response (PR) and were evaluable for cardiac response. Four response criteria were tested on the basis of natriuretic peptide response depth: cardiac complete response (CarCR), cardiac very good partial response (CarVGPR), cardiac PR (CarPR), and cardiac no response (CarNR). Response was classified as best response and at fixed time points (6, 12, and 24 months from therapy initiation). The study primary outcome was overall survival. RESULTS: 651 patients were included. Best CarCR, CarVGPR, CarPR, and CarNR were achieved in 16%, 26.4%, 22.9%, and 34.7% of patients, respectively. Patients in cardiac stage II were more likely to achieve CarCR than patients in cardiac stage IIIA and IIIB (22% v 13.5% v 3.2%; P < .001). A deeper cardiac response was associated with a longer survival (5-year overall survival 93%, 79%, 65%, and 33% for CarCR, CarVGPR, CarPR, and CarNR, respectively; P < .001). Fixed time-point analyses and time-varying covariates Cox regression analysis, to minimize survivorship bias, affirmed the independent survival advantage of deeper cardiac responses. Four-level response performed better than two-level response as early as 12 months from therapy initiation. CONCLUSION: Graded cardiac response criteria allow better assessment of cardiac improvement compared with the traditional binary response system. The study re-emphasizes the importance of early diagnosis, which increases the likelihood of deep cardiac responses.