Daratumumab in first-line treatment of patients with light chain amyloidosis and Mayo stage IIIb improves treatment response and overall survival.

Treatment of patients with Mayo stage IIIb light chain (AL) amyloidosis is still challenging, and the prognosis remains very poor. Mayo stage IIIb patients were excluded from the pivotal trial leading to the approval of daratumumab in combination with bortezomib-cyclophosphamide-dexamethasone. This retrospective, multicenter study evaluates the addition of daratumumab to first-line therapy in patients with newly diagnosed stage IIIb AL amyloidosis. In total, data from 119 consecutive patients were analyzed, 27 patients received an upfront treatment including daratumumab, 63 a bortezomibbased regimen without daratumumab, eight received therapies other than daratumumab or bortezomib and 21 pretreated patients or deceased prior to treatment were excluded. In the daratumumab group, median overall survival was not reached after a median follow-up time of 14.5 months, while it was significantly worse in the bortezomib- and the otherwise treated group (6.6 and 2.2 months, respectively) (P=0.002). Overall hematologic response rate at 2 and 6 months was better in the daratumumab group compared to the bortezomib group (59% vs. 37%, P=0.12, 67% vs. 41%, P=0.04, respectively). Landmark survival analyses revealed a significantly improved overall survival in patients with partial hematologic response or better, compared to non-responders. Cardiac response at 6 months was 46%, 21%, 0% in the daratumumab-, bortezomib- and otherwise treated groups, respectively (P=0.04). A landmark survival analysis revealed markedly improved overall survival in patients with cardiac very good partial response vs. cardiac non-responders (P=0.002). This study demonstrates for the first time the superiority of an upfront treatment with daratumumab over standard-of-care in stage IIIb AL amyloidosis.

Corneal confocal microscopy identifies corneal nerve loss and increased Langerhans cells in presymptomatic carriers and patients with hereditary transthyretin amyloidosis.

BACKGROUND: Hereditary transthyretin amyloidosis (ATTRv amyloidosis) is a rare, but life-threatening protein misfolding disorder due to TTR gene mutations. Cardiomyopathy (ATTRv-CM) and polyneuropathy (ATTRv-PN) with early small nerve fibre involvement are the most common manifestations. Timely diagnosis and treatment initiation are key to limiting progression of disease. Corneal confocal microscopy (CCM) is a non-invasive method to quantify corneal small nerve fibres and immune cell infiltrates in vivo. METHODS: This cross-sectional study investigated the utility of CCM in 20 patients with ATTRv amyloidosis (ATTRv-CM, n = 6; ATTRv-PN, n = 14) and presymptomatic carriers (n = 5) compared to 20 age- and sex-matched healthy controls. Corneal nerve fibre density, corneal nerve fibre length, corneal nerve branch density, and cell infiltrates were assessed. RESULTS: Corneal nerve fibre density and nerve fibre length were significantly lower in patients with ATTRv amyloidosis compared to healthy controls regardless of the clinical phenotype (ATTRv-CM, ATTRv-PN) and corneal nerve fibre density was significantly lower in presymptomatic carriers. Immune cell infiltrates were only evident in patients with ATTRv amyloidosis, which correlated with reduced corneal nerve fibre density. CONCLUSIONS: CCM identifies small nerve fibre damage in presymptomatic carriers and symptomatic patients with ATTRv amyloidosis and may serve as a predictive surrogate marker to identify individuals at risk of developing symptomatic amyloidosis. Furthermore, increased corneal cell infiltration suggests an immune-mediated mechanism in the pathogenesis of amyloid neuropathy.

Quantitative 99mTc-DPD-SPECT/CT assessment of cardiac amyloidosis.

INTRODUCTION: Transthyretin (ATTR) amyloidosis is responsible for the majority of cardiac amyloidosis (CA) cases and can be reliably diagnosed with bone scintigraphy and the visual Perugini score. We aimed to implement a quantification method of cardiac amyloid deposits in patients with suspected cardiac amyloidosis and to compare performance to visual scoring. METHODS AND MATERIALS: 136 patients received 99mTc-DPD-bone scintigraphy including SPECT/CT of the thorax in case of suspicion of cardiac amyloidosis. Imaging phantom studies were performed to determine the scaling factor for standardized uptake value (SUV) quantification from SPECT/CT. Myocardial tracer uptake was quantified in a whole heart volume of interest. RESULTS: Forty-five patients were diagnosed with CA. A strong relationship between cardiac SUVmax and Perugini score was found (Spearman r 0.75, p < 0.0001). Additionally, tracer uptake in bone decreased with increasing cardiac SUVmax and Perugini score (p < 0.0001). ROC analysis revealed good performance of the SUVmax for the detection of ATTR-CA with AUC of 0.96 ± 0.02 (p < 0.0001) with sensitivity 98.7% and specificity 87.2%. CONCLUSION: We demonstrate an accessible and accurate quantitative SPECT approach in CA. Quantitative assessment of the cardiac tracer uptake may improve diagnostic accuracy and risk classification. This method may enable monitoring and assessment of therapy response in patients with ATTR amyloidosis.

A novel TTR mutation (p.Ala65Val) underlying late-onset hereditary transthyretin (ATTRv) amyloidosis with mixed cardiac and neuropathic phenotype: a case report.

BACKGROUND: Hereditary transthyretin (ATTRv) amyloidosis is a rare, genetically heterogeneous and phenotypically variable systemic disease characterized by deposition of misfolded transthyretin fibrils in various tissues. ATTRv cardiomyopathy and progressive axonal polyneuropathy are the most common manifestations, leading to severe disability and ultimately death within approximately ten years. As disease-modifying treatment options evolve, timely diagnosis and treatment initiation are crucial to prevent rapid disease progression. CASE PRESENTATION: Here, we report on a 73-year old patient initially diagnosed with cardiac wild-type ATTR (ATTRwt) amyloidosis by endomyocardial biopsy. Molecular genetic analysis revealed a novel TTR sequence variant (p.Ala65Val) that is highly likely to be amyloidogenic in light of previously reported TTR mutations and the patient's clinical presentation and family history. CONCLUSIONS: Our findings expand the spectrum of known pathogenic TTR mutations and underline the importance of a thorough diagnostic workup in amyloidosis patients including careful genetic testing to avoid misdiagnosis and missing of treatment opportunities and to enable cascade testing and tracking of carriers.

Prevalence and predictors of neurological manifestations in systemic AL amyloidosis.

INTRODUCTION: Immunoglobulin light chain (AL) amyloidosis is a life-threatening systemic disease due to plasma cell dyscrasias, which is characterized by amyloid deposition in various tissues. Neurological manifestations, in particular peripheral nervous system involvement, play a major role for quality of life and treatment decisions as frequently potentially neurotoxic drugs are used. METHODS: We retrospectively investigated the prevalence of neurological manifestations, its risk factors and prognostic value in 155 consecutive patients with AL amyloidosis in a single German tertiary center between 2010 and 2021. Multiple logistic regression was performed to identify predictors of amyloid neuropathy and the impact of peripheral neuropathy on patient survival was assessed by Cox proportional hazard regression analysis. RESULTS: Nearly half of patients showed at least one of four neurological manifestations of AL amyloidosis which were frequent in our study: peripheral neuropathy (36.8%), carpal tunnel syndrome (12.9%), lumbar spinal stenosis (7.1%), and amyloid myopathy (3.9%). Male sex (OR 2.943, CI 1.152-8.139, p = 0.029) and cardiac involvement (OR 6.186, CI 1.449-43.38, p = 0.028) were independent predictors of peripheral neuropathy which was closely related to autonomic dysfunction in patients with AL amyloidosis. Peripheral neuropathy had no impact on survival (HR 0.952, CI 0.517-1.754, p = 0.876). CONCLUSIONS: Neurological involvement is common in systemic AL amyloidosis. Treatment decisions should take into account peripheral neuropathy, in particular in male patients with amyloid cardiomyopathy, but also amyloid myopathy that seems to be not as rare as previously suggested.

Mitochondrial Kv1.3 Channels as Target for Treatment of Multiple Myeloma.

Despite several new developments in the treatment of multiple myeloma, all available therapies are only palliative without curative potential and all patients ultimately relapse. Thus, novel therapeutic options are urgently required to prolong survival of or to even cure myeloma. Here, we show that multiple myeloma cells express the potassium channel Kv1.3 in their mitochondria. The mitochondrial Kv1.3 inhibitors PAPTP and PCARBTP are efficient against two tested human multiple myeloma cell lines (L-363 and RPMI-8226) and against ex vivo cultured, patient-derived myeloma cells, while healthy bone marrow cells are spared from toxicity. Cell death after treatment with PAPTP and PCARBTP occurs via the mitochondrial apoptotic pathway. In addition, we identify up-regulation of the multidrug resistance pump MDR-1 as the main potential resistance mechanism. Combination with ABT-199 (venetoclax), an inhibitor of Bcl2, has a synergistic effect, suggesting that mitochondrial Kv1.3 inhibitors could potentially be used as combination partner to venetoclax, even in the treatment of t(11;14) negative multiple myeloma, which represent the major part of cases and are rather resistant to venetoclax alone. We thus identify mitochondrial Kv1.3 channels as druggable targets against multiple myeloma.

Corneal confocal microscopy to detect early immune-mediated small nerve fibre loss in AL amyloidosis.

OBJECTIVE: Light chain (AL) amyloidosis is a life-threatening disorder characterised by extracellular deposition of amyloid leading to dysfunction of multiple organs. Peripheral nerve involvement, particularly small fibre neuropathy, may be associated with poorer survival. Corneal confocal microscopy (CCM) is a rapid and non-invasive imaging technique to quantify corneal small nerve fibres and immune cells in vivo. We aimed to evaluate CCM as a tool for early diagnosis of peripheral nerve involvement in AL amyloidosis. METHODS: CCM and nerve conduction studies (NCS) were undertaken in 21 newly diagnosed, treatment-naïve AL amyloidosis patients and 21 age- and sex-matched healthy controls. Corneal nerve fibre density (CNFD), corneal nerve branch density and fibre length, and cell infiltrates were quantified in the sub-basal layer of the cornea. RESULTS: There was a significant reduction in CNFD and nerve fibre length, even without large fibre affection and an increase in cell density, particularly around corneal nerve fibres in patients with AL amyloidosis compared to controls. Additionally, cell infiltration correlated with reduced nerve fibre density in patients with AL amyloidosis, but reduced CNFD did not correlate with laboratory parameters of organ dysfunction. INTERPRETATION: Our study is the first to show that CCM allows rapid non-invasive identification of early small nerve fibre damage associated with immune cell infiltration in patients with AL amyloidosis. CCM detects peripheral nerve involvement more sensitively than NCS.

Clinical features and predictors of atrial fibrillation in patients with light-chain or transthyretin cardiac amyloidosis.

AIMS: The study aimed to investigate the prevalence, phenotypic characteristics, and predictors of atrial fibrillation (AF) in patients presenting with cardiac amyloidosis (CA) of light-chain (AL) or transthyretin (ATTR) type. METHODS AND RESULTS: Clinical, biochemical, and echocardiographic data of patients presenting with CA between 2005 and 2020 were retrospectively collected. CA staging was based on established biomarker systems. Binomial logistic regression was run to analyse the effects of clinical variables on the likelihood of AF. The study included 133 patients [53% AL, 41% wild-type (wt) ATTR-CA, & 6% hereditary ATTR-CA]. Mean age was 71 years, and 80% were male patients. AF was diagnosed in 64 (48%) patients (28% in AL-CA, 80% in wtATTR, 13% in hATTR, P < 0.001). Patients with AF were older (74 vs. 69 years, P < 0.001), more likely to have wtATTR-CA (67 vs. 16%, P < 0.001), exhibited more often New York Heart Association ≥ III symptoms (66 vs. 45%, P = 0.02) and carried a higher burden of comorbidities. AF patients had lower left ventricular ejection fraction (47 vs. 53%, P < 0.005), higher left atrial volume index (54 vs. 46 mL/m2 , P = 0.007), higher pulmonary artery pressure (42 vs. 31 mmHg, P = 0.008), and worse tricuspid annular plane systolic excursion values (17 vs. 20 mm, P = 0.01). Mitral regurgitation ≥ Grade 2 was more frequent in AF (56 vs. 25%, P < 0.001). Higher ATTR-CA stage was associated with higher AF prevalence (47% vs. 74% vs. 94%, P < 0.001, for Stages I, II, & III, respectively). Higher AL-CA stage was associated with lower AF prevalence (0% vs. 40% vs. 31% vs. 18%, P < 0.001, for Stages I, II, IIIa, & IIIb, respectively). Three independent predictors for AF were identified in a multivariate logistic regression model with 81.5% classification accuracy: AL type [odds ratio (OR) 0.1, confidence interval (CI) 0.01-0.29, P = 0.001], estimated glomerular filtration rate (OR 0.9, CI 0.93-0.99, P = 0.03), and body mass index (OR 1.3, CI 1.07-1.66, P = 0.01). ATTR amyloidosis was associated with a 10-fold higher risk of AF. During 1 year follow-up, only one episode of ischaemic stroke was reported. CONCLUSIONS: Atrial fibrillation affects nearly half of all patients with CA. Patients presenting with AF have more severe symptoms and higher burden of comorbidities. ATTR type of amyloidosis is the strongest predictor of AF. Prospective screening for occult AF may be considered in ATTR-CA.

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

OBJECTIVE: To study the impact of time to diagnosis on cardiac Mayo stages, treatment outcome, and overall survival. METHODS: We retrospectively analyzed 77 consecutive patients diagnosed between 2015 and 2020 with AL amyloidosis and cardiac involvement. Medical history was recorded in standardized form with the help of a questionnaire. RESULTS: Time from onset of symptoms of cardiac failure to diagnosis was correlated with the severity of cardiac involvement in modified Mayo 2004 and revised Mayo 2012 staging systems (rs  = 0.30, 95% CI: 0.07-0.50, P = .007 and rs  = 0.25, 95% CI: 0.01-0.45, P = .03). Patients with advanced Mayo 2004 stages received reduced-intensity regimens and had a lower probability to achieve adequate hematologic- and cardiac response after first-line treatment than patients with early stages (rs  = 0.28, 95% CI: 0.04-0.48, P = .01 and rs  = 0.72, 95% CI: 0.55-0.82, P < .0001) and poorer overall survival (P = .0004). Compared with patients diagnosed within the first year, patients diagnosed after 13-18 or ≥19 months from first symptoms had a 3- to 5 times higher risk of dying. Our data indicate that there is a 12-month window within which the diagnosis of AL amyloidosis needs to be established to avoid early deterioration and death. CONCLUSIONS: Sensitizing physicians and raising awareness for the disease are crucial for timely diagnosis and may improve the outcome of the disease.