Immunoglobulin Light Chain Amyloidosis Research Articles

Advancing precision medicine in immunoglobulin light-chain amyloidosis: a novel prognostic model incorporating multi-organ indicators.

To develop a more accurate prognostic model that incorporates indicators of multi-organ involvement for immunoglobulin light-chain (AL) Amyloidosis patients. Biopsy-proven AL amyloidosis patients between January 1, 2012, and February 28, 2023, were enrolled and randomly divided into a training set and a test set at a ratio of 7:3. Prognostic indicators that comprehensively cover cardiac, renal, and hepatic involvement were identified in the training set by random survival forest (RSF). Then, RSF and Cox models were established. The Concordance index (C-index) and integrated brier scores (IBS) were applied to evaluate the models' performance in the test set. Besides, the net reclassification index (NRI) and integrated discrimination improvement (IDI) were calculated. A total of 173 eligible patients were included. After a median follow-up of 25.9 (9.2, 50.3) months, 48 (27.7%) patients died. Creatine kinase-MB, estimated glomerular filtration rate ≤ 50mL/min/1.73m2, interventricular septum ≥ 15mm, ejection fraction, alanine aminotransferase and Live involved were selected to develop prediction models. The RSF model based on the above indicators achieved C-index and IBS values of 0.834 (95% CI 0.725-0.915) and 0.151 (95% CI 0.1402-0.181), respectively. At last, the NRI and IDI of the RSF model were 0.301 (95% CI 0.048-0.546, P = 0.012) and 0.157 (95% CI 0.041-0.269, P < 0.001) at 5-year by comparing the RSF model with the Cox model which is based on the Mayo 2012 staging system. The RSF model that incorporates indicators of multi-organ involvement had a great performance, which may be helpful for physicians' decision-making and more accurate overall survival prediction.

Serum monoclonal immunoglobulin light-chain detection differs between immunofixation electrophoresis methods in patients with AL amyloidosis.

Serum immunofixation electrophoresis (IFE) is often performed for screening monoclonal proteins (M proteins) in immunoglobulin light-chain amyloidosis (AL amyloidosis). However, the performance of serum IFE for detecting M protein in AL amyloidosis patients is often insufficient. In this study, we examined the detection rate of serum M protein in newly diagnosed AL amyloidosis patients and analyzed differences in M protein detection between IFE methods. Among 60 patients newly diagnosed with AL amyloidosis, 22 had undetectable serum M protein by IFE with the Epalyzer2 system. Samples with undetectable M protein had significantly lower involved serum-free light-chain (iFLC) and a smaller difference between involved and uninvolved serum-free light-chain (dFLC) values than samples with IFE-detectable monoclonal light chains. When samples that tested negative for M protein by the Epalyzer2 system were retested by IFE with the HYDRASYS 2 system, 50% had IFE-detectable monoclonal light chains. The IFE system and reagents used may affect serum monoclonal immunoglobulin light-chain detection in AL amyloidosis patients, especially those with low iFLC or low dFLC samples. More attention should be paid to the performance of IFE systems, since it may affect the diagnostic and therapeutic evaluation of AL amyloidosis patients.

The real-world data on patients with cardiac stage IIIb AL amyloidosis

BackgroundMorbidity and mortality of patients with immunoglobulin light chain (AL) amyloidosis are strongly associated with the severity of cardiac involvement, especial in patients with cardiac stage IIIb, but the real-world data on these patients is still limited. Patients and MethodsA retrospective analysis was conducted on 77 patients diagnosed with cardiac stage IIIb AL amyloidosis at our center. We analyzed the clinical characteristics, treatment and outcome of the patients. ResultsThe median age of patients was 57 years and 49.4% were male. Median serum N-Terminal Pro-Brain Natriuretic Peptide (NT-proBNP) and cardiac troponin T (cTnT) were 13384 ng/L and 0.166 ug/L, and 42(54.5%) patients had heart failure at diagnosis. Fifty-seven (74.0%) patients received anti-plasma cell treatment, and the main treatment options include bortezomib or thalidomide combined with dexamethasone. The hematologic overall response rate was 70% (28/40), and at 6-month landmark analysis, patients with hematologic responses had a higher survival rate. Cardiac and renal responses were achieved in 14(37.8%) and 13(32.5%) patients, respectively. After a median follow-up of 10 months (range 1-115 months), median overall survival (OS) was 18 months, and the estimated survival rates at 3, 6, and 12 months were 79.9%, 75.6%, and 54.5%, respectively. In Cox regression models, age, hypotension and cTnT were independently predictive of mortality after adjusting for heart failure. ConclusionThe hematologic, cardiac and renal responses were relative lower in patients with cardiac stage IIIb AL amyloidosis. The overall prognosis of patients was poor, and age, hypotension, and cTnT can be used to predict mortality. Micro-abstractThe clinical characteristics, treatment modalities and outcomes of Chinese patients with cardiac stage IIIb AL amyloidosis have not been fully investigated. Through consulting the electronic medical record system and telephone follow-up, we documented hematologic and organ responses after treatment in 77 patients diagnosed at our center. The unsatisfactory prognosis of these patients suggests that a rapid-acting and safe therapy is needed for these patients.

Primary Data on ATTR-Amyloidosis Prevalence Among Elderly Patients With Left Ventricular Hypertrophy in Russia.

To estimate the prevalence of amyloid cardiomyopathy (CM) caused by transthyretin amyloidosis (ATTR) and immunoglobulin light chain (AL) amyloidosis among patients aged &gt;65 years with interventricular septal (IVS) hypertrophy of ≥14 mm. From January through August 2023, 60 patients (mean age 7.2±7.3 years, 34 (56.67%) men) were enrolled. Patients meeting the inclusion criteria underwent an echocardiographic study with determining the myocardial longitudinal strain, myocardial scintigraphy with 99mTc-pyrfotech, myocardial single-photon emission computed tomography, measurement of N-terminal fragment of brain natriuretic peptide and troponin I, and the immunochemical study of serum and urine proteins with measurement of free light chains. In the presence of grades 2 and 3 radiopharmaceutical uptake according to scintigraphy, a molecular genetic study was performed for differential diagnosis of wild-type transthyretin amyloidosis (wtATTR) and hereditary/variant (hATTR) ATTR-CM. According to data of myocardial scintigraphy with 99mTc-pyrfotech, grade 3 uptake in the absence of monoclonal secretion was detected in 5 (8.3%) cases and grade 2 radiotracer uptake in the absence of monoclonal secretion was detected in 6 (10%) patients. Myeloma complicated by AL amyloidosis and primary AL amyloidosis were found in 5 (8.3%) patients. Among patients aged ≥65 years with IVS hypertrophy ≥14 mm, amyloid CM was detected in 20% of cases (12 patients), including 5 cases (8.3%) of AL amyloidosis and 7 cases (11.7%) of ATTR amyloidosis.

Oxidative damage in immunoglobulin light chain and transthyretin cardiac amyloidosis – a closer look

Heart failure is a progressive disease, representing a growing cause of morbidity, hospitalization, and mortality. An increasingly common type of heart failure with preserved ejection fraction (HFpEF) is an immunoglobulin light chain and transthyretin cardiac amyloidosis, in the pathophysiology of which oxidative damage appears to exert a strong impact. Reactive oxygen and nitrogen species have physiological signaling functions, but their overaccumulation, as in cardiac amyloidosis, leads to cardiomyocyte damage and apoptosis, and to cardiac hypertrophy and fibrosis. Moreover, such pathological processes worsen the redox damage with the perpetuation of an inflammatory state, in a vicious cycle. Here, the role of oxidative damage in the transthyretin and immunoglobulin light chain cardiac amyloidosis, the underlying pathogenic mechanisms, the therapeutic implications, and possible future strategies are reviewed.

Clonal hematopoiesis of indeterminate potential in patients with immunoglobulin light-chain AL amyloidosis

AbstractImmunoglobulin light-chain (AL) amyloidosis is characterized by the deposition of misfolded monoclonal free light chains, with cardiac complications accounting for patient mortality. Clonal hematopoiesis of indeterminate potential (CHIP) has been associated with worse cardiovascular outcomes in the general population. Its significance in AL amyloidosis remains unclear. We collected clinical information and outcome data on 76 patients with a diagnosis of AL amyloidosis who underwent deep targeted sequencing for myeloid neoplasia–associated mutations between April 2018 and August 2023. Variant allele fraction was set at 2% to call CHIP-associated mutations. CHIP mutations were present in patients with AL amyloidosis at a higher frequency compared with age-matched control individuals. Sixteen patients (21%) had at least 1 CHIP mutation. DNMT3A was the most frequent mutation (7/16; 44%). Compared with patients without CHIP, patients with CHIP had a higher prevalence of t(11;14) translocation (69% vs 25%, respectively; P = .004). Furthermore, among patients with renal involvement, those with CHIP had a lower Palladini renal stage (P = .001). At a median follow-up of 32.5 months, the presence of CHIP was not associated with worse overall survival or major organ dysfunction progression-free survival. Larger studies and longer follow-up are needed to better define the impact of CHIP in patients with AL amyloidosis.

WCN24-2458 Renal response to treatment in patients with immunoglobulin light chain amyloidosis

WCN24-2458 Renal response to treatment in patients with immunoglobulin light chain amyloidosis

A validated LC-MS/MS method for the quantitation of daratumumab in rat serum using rapid tryptic digestion without IgG purification and reduction

Daratumumab, a humanized monoclonal antibody utilized in treating immunoglobulin light-chain amyloidosis and relapsed/refractory multiple myeloma, was quantified in rat serum through a simple, economical and effective liquid chromatography tandem-mass spectrometry (LC-MS/MS) method. A surrogate peptide, LLIYDASNR, derived from trypsin hydrolysis, was quantitatively analyzed with LLIYDASN [13C6, 15N4] RAT as an internal standard. This corrected variations from sample pretreatment and mass spectrometry response, involving denaturation and trypsin hydrolysis in a two-step process lasting approximately 1 hour. Methodological validation demonstrated a linear range of 1 µg/mL to 1000 µg/mL in rat serum. Precision, accuracy, matrix effect, sensitivity, stability, selectivity, carryover, and interference met acceptance criteria. The validated LC-MS/MS approach was successfully applied to a pharmacokinetic study of daratumumab in rats at an intravenous dose of 15 mg/kg.

A clinical case of transthyretin amyloidosis with manifestations of seronegative arthritis

A clinical case of transthyretin amyloidosis with manifestations of seronegative arthritis

A new staging system using right atrial strain in patients with immunoglobulin light-chain cardiac amyloidosis.

There are minimal data on the prognostic impact of right atrial strain during the reservoir phase (RASr) in patients with immunoglobulin light-chain (AL) cardiac amyloidosis. Among 78 patients who were diagnosed with AL cardiac amyloidosis at Kumamoto University Hospital from 2007 to 2022, 72 patients with sufficient two-dimensional speckle tracking imaging data without chemotherapy before the diagnosis were retrospectively analysed. During a median follow-up of 403days, 31 deaths occurred. Age and the rate of male sex were not significantly different between the all-cause death group and the survival group (age, 70.4±8.8years vs. 67.0±10.0years, P=0.14, male sex, 65% vs. 66%, P=0.91). The estimated glomerular filtration rate (eGFR) was significantly lower, and B-type natriuretic peptide (BNP) and high sensitivity cardiac troponin T (hs-cTnT) were significantly higher, in the all-cause death group versus the survival group (eGFR, 48.2±21.0mL/min/1.73m2 vs. 59.4±24.4mL/min/1.73m2 , P<0.05, BNP, 725 [360-1312] pg/mL vs. 123 [81-310] pg/mL, P<0.01, hs-cTnT, 0.12 [0.07-0.18] ng/mL vs. 0.05 [0.03-0.08] ng/mL, P<0.01). Left ventricular (LV) global longitudinal strain (GLS) (LV-GLS), left atrial strain during the reservoir phase (LASr), right ventricular GLS (RV-GLS), and RASr were significantly lower in the all-cause death group versus the survival group (LV-GLS, 8.5±4.3% vs. 11.8±3.8%, P<0.01, LASr, 8.8±7.1% vs. 14.3±8.1%, P<0.01, RV-GLS, 11.6±5.1% vs. 16.4±3.9%, P<0.01, RASr, 10.2±7.3% vs. 20.7±9.5%, P<0.01). RASr was significantly associated with all-cause death after adjusting for RV-GLS, LV-GLS and LASr (hazard ratio [HR]: 0.91, 95% confidence interval [95% CI]: 0.83-0.99, P<0.05). RASr and log-transformed BNP were significantly associated with all-cause death after adjusting for log-transformed troponin T and eGFR (RASr, HR: 0.93, 95% CI: 0.87-1.00, P<0.05; log-transformed BNP, HR: 2.10, 95% CI: 1.17-3.79, P<0.05). The optimal cut-off values were RASr: 16.4% (sensitivity: 66%, specificity: 84%, area under curve [AUC]: 0.81) and BNP: 311.2pg/mL (sensitivity: 83%, specificity: 78%, AUC: 0.82) to predict all-cause mortality using ROC analysis. Kaplan-Meier analysis revealed that patients with low RASr (<16.4%) or high BNP (>311.2pg/mL) had a significantly high probability of all-cause death (both, P<0.01). We devised a new staging score by adding 1 point if RASr decreased or BNP levels increased more than each cut-off value. The HR for all-cause death using score 0 as a reference was 5.95 (95% CI: 1.19-29.79; P<0.05) for score 1 and 23.29 (95% CI: 5.37-100.98; P<0.01) for score 2. The new staging system using RASr and BNP predicted prognosis in patients with AL cardiac amyloidosis.

Complexities of Coexisting Cardiac Amyloidosis and Coronary Artery Disease: A Contemporary Review of Diagnostic and Treatment Approaches.

Cardiac amyloidosis (CA) represents an emerging challenge in cardiovascular medicine, with notable clinical overlaps and diagnostic complexities when coexisting with coronary artery disease (CAD). This integrative review navigates the intricate terrain of CA and CAD, elucidating epidemiology, clinical presentations, and diagnostic considerations. Examining both immunoglobulin light chain amyloidosis (AL) and transthyretin amyloidosis, we underscore their shared demographic associations, diagnostic intricacies, and potential diagnostic confounders with CAD. Notably, we emphasize the impact of CA on epicardial coronary arteries and the consequential implications for coronary microcirculation. Further exploration reveals the connection between CA and acute myocardial infarction, emphasizing early recognition as pivotal. In terms of differential diagnosis, we underscore the significance of clinical symptoms, electrocardiography, echocardiography, cardiac magnetic resonance, and bone scintigraphy. Additionally, we scrutinize the intricate realm of treatment, encompassing medication selection, antithrombotic strategies, and revascularization modalities. Our review addresses the distinctive challenges posed by CA patients' limited tolerance for conventional therapies. This comprehensive synthesis serves as an invaluable resource for clinicians confronting the intricate intersection of CA and CAD. By offering insights into diagnostic refinement and innovative therapeutic avenues, we aim to enhance patient outcomes and quality of life within this complex clinical landscape.

Biophysical characterization of human-cell-expressed, full-length κI O18/O8, AL-09, λ6a, and Wil immunoglobulin light chains

Immunoglobulin light chain (AL) amyloidosis involves the deposition of insoluble monoclonal AL protein fibrils in the extracellular space of different organs leading to dysfunction and death. Development of methods to efficiently express and purify AL proteins with acceptable standards of homogeneity and structural integrity has become critical to understand the in vitro and in vivo aspects of AL protein aggregation, and thus the disease progression. In this study, we report the biophysical characterization of His-tagged and untagged versions of AL full-length (FL) κI and λ6 subgroup proteins and their mutants expressed from the Expi293F human cell line. We used an array of biophysical and biochemical methods to analyze the structure and stability of the monomers, oligomerization states, and thermodynamic characteristics of the purified FL proteins and how they compare with the bacterially expressed FL proteins. Our results demonstrate that the tagged and untagged versions of FL proteins have comparable stability to proteins expressed in bacterial cells but exhibit multiple unfolding transitions and reversibility. Non-reducing SDS-PAGE and analytical ultracentrifugation analysis showed presence of monomers and dimers, with an insignificant amount of higher-order oligomers, in the purified fraction of all proteins. Overall, the FL proteins were expressed with sufficient yields for biophysical studies and can replace bacterial expression systems.

Chinese consensus on the diagnosis and treatment of immunoglobulin light-chain cardiac amyloidosis.

Chinese consensus on the diagnosis and treatment of immunoglobulin light-chain cardiac amyloidosis.

Immunoglobulin light chain amyloidosis: 2024 update on diagnosis, prognosis, and treatment.

Immunoglobulin light chain amyloidosis is a clonal, nonproliferative plasma cell disorder in which fragments of immunoglobulin light or heavy chain are deposited in tissues. Clinical features depend on organs involved but can include heart failure with preserved ejection fraction, nephrotic syndrome, hepatic dysfunction, peripheral/autonomic neuropathy, and "atypical smoldering multiple myeloma or MGUS." Tissue biopsy stained with Congo red demonstrating amyloid deposits with apple-green birefringence is required for the diagnosis of AL amyloidosis. Organ biopsy is not required in 85% of patients. Verification that amyloid is composed of immunoglobulin light chains is mandatory. The gold standard is laser capture mass spectroscopy. N-terminal pro-brain natriuretic peptide (NT-proBNP or BNP), serum troponin T(or I), and difference between involved and uninvolved immunoglobulin free light chain values are used to classify patients into four stages; 5-year survivals are 82%, 62%, 34%, and 20%, respectively. All patients with a systemic amyloid syndrome require therapy to prevent deposition of amyloid in other organs and prevent progressive organ failure. Current first-line therapy with the best outcome is daratumumab, bortezomib, cyclophosphamide, and dexamethasone. The goal of therapy is a ≥VGPR. In patients failing to achieve this depth of response options for consolidation include pomalidomide, stem cell transplantation, venetoclax, and bendamustine. Delayed diagnosis remains a major obstacle to initiating effective therapy prior to the development of end-stage organ failure. Trials of antibodies to deplete deposited fibrils are underway.

Composition and Dynamic Evolution of the Bone Marrow Microenvironment in AL Amyloidosis during Daratumumab Based Therapy

Background: Immunoglobulin light chain (AL) amyloidosis is caused by clonal B or plasma cells proliferating in the bone marrow that produce immunoglobulin (MIg) proteins that misfold and aggregate in tissue(s), leading to multi-organ failure. The monoclonal antibody targeting CD38, daratumumab is an approved and very efficient treatment in multiple myeloma and AL Amyloidosis by inducing plasma cell death through immune mediated mechanisms including complement and antibody-dependent cytotoxicity, direct apoptosis and T cell subsets modifications. While the role of the bone marrow microenvironment (BME) as a major oncogenic actor in multiple myeloma (MM) is well established, the BME composition and role in AL Amyloidosis is largely undefined. Here, we used single-cell RNA-seq combined with CITE-seq and TCR sequencing to characterize the immune ecosystem and microenvironment in AL amyloidosis in comparison to healthy donors, as well as in comparison to other plasma cell disorders including monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM) and multiple myeloma (MM). Methods: BM aspirates from 6 AL amyloidosis patients were collected at diagnosis or before treatment with daratumumab based therapy and 12 months post-treatment, alongside samples from 13 healthy donors, 5 MGUS, 9 SMM and 8 MM patients at diagnosis. We performed unbiased mRNA profiling (5' sequencing) and feature barcoding for cell surface proteins (CITE-seq) of bone marrow mononuclear cells using 10x Genomics. We processed data via the Cell Ranger pipeline, which grouped T cells into clonotypes based on shared TCR α/β sequences. Further data processing was done with Seurat, scRepertoire and Immunarch. Overall, 83703 cells were sequenced from 45 samples, including 3065 plasma cells and 80639 BME cells. Results: Compared to other plasma cell disorders (PCD) at diagnosis, AL BME had more cellular diversity and its plasma cells were more similar to normal plasma cells. They also had more TCR diversity than other PCD samples. When compared to healthy samples, AL BME had a trend towards more CD8+ T cells (p value = 0.078) at diagnosis, which became more pronounced 12 months post-treatment (p value = 0.012), and a trend towards fewer monocytes (p value = 0.036). When compared to PCD samples, AL BME tended to have more hematopoietic stem cells (p value = 0.018 vs MGUS, 0.052 vs SMM and 0.02 vs MM) and fewer NK cells (p values respectively 0.03, 0.059, 0.05) and CD4+ T cells (p values respectively 0.05, 0.018, 0.02) (Figure 1). The number of memory T cells and exhausted T cells were similar. Importantly, AL samples were significantly enriched in early/young CD4 memory T cells (p value &amp;lt; 2.6e-16) and NK/T like CD8+ T cells (p value = 7.99e-11) suggesting an ongoing and active T cell mediated immune response. We next analyzed serial samples from 4 AL patients at diagnosis and ~12 months after Daratumumab-based therapy, with half the patients achieving complete hematologic and organ responses (CR) and half with incomplete responses. We found broad changes in the BME, but in particular, there were more CD4+ and CD8+ T cells at 12 months expressing cytokine signaling genes (p value 1.19e-35) and adaptive immune system pathway genes (p value = 2.59e-33). Importantly, the distributions of CD8+ cells and T cell clonotypes were different between patients achieving CR and those who did not, underlying the role of the immune microenvironment and especially CD8+ T cells in the pathogenesis of the disease and response to Daratumumab based treatment. Conclusion: We identified unique characteristics of the BME in AL amyloidosis and dynamic changes within the T cell compartment following Daratumumab based therapy. Further validations are needed to evaluate the potential of BME profiling to diagnose the disease, predict treatment response and potentially develop new therapeutic strategies in AL Amyloidosis.

Association of p16, a Biomarker of Cellular Senescence, with Receipt of Therapy for Plasma Cell Disorders

Introduction Multiple myeloma (MM) and immunoglobulin light chain (AL) amyloidosis are clonal plasma cell disorders (PCDs) of aging, with median ages at diagnosis of 69 and 76 years, respectively. The care of adults with these disorders is often challenging due to the higher prevalence of vulnerabilities with advancing age. We examined patterns of senescence biomarkers and associations with therapy receipt among adults treated for plasma cell disorders. Methods Adults undergoing treatment for PCDs were recruited to a longitudinal observational study (NCT03717844) from 2018 to 2020. Study participants provided blood samples and completed study assessments at pre-specified intervals. Cellular senescence was quantified by measuring mRNA expression of p16 in peripheral blood T lymphocytes. Expression of p16 is reported as log2 arbitrary units. A linear regression formula previously derived from p16 expression in 633 subjects was utilized to translate p16 expression levels into an age equivalent. These values were used to calculate the p16AgeGap, a difference between an individual's p16 expression and their chronological age. Subjects with p16 levels below the age-appropriate population mean have a negative p16AgeGap, and those with p16 above the population mean have a positive p16AgeGap. Exposures included both treatment receipt and duration of therapy. Treatment was assessed via categorical classification of treatment intensity, and treatment duration was quantified from diagnosis to time of p16 blood draw. Descriptive statistics were calculated for baseline demographic and disease characteristic variables. The p16 and p16AgeGap variables were summarized in terms of means and 95% confidence intervals (CI). The significance of associations between p16/p16AgeGap and categorical variables was assessed via Kruskal-Wallis or Wilcoxon rank-sum tests. Associations between continuous variables were assessed via calculation of Pearson correlation coefficients. Results The cohort consisted of 109 individuals (88 with multiple myeloma and 21 with other plasma cell disorders). Mean age was 68 years (range 39-91). The sample was predominantly male (56.9%) and White (70.6%). Samples for p16 were drawn prior to any treatment in 20 subjects. The remainder had received prior therapy and 36 had relapsed/refractory disease. There was a significant association between the treatment receipt and p16 as well as between the treatment receipt and p16AgeGap (Figure 1). We observed a significant modest positive correlation between the duration of treatment and p16 (correlation coefficient 0.27, p=0.007) and p16AgeGap (0.22, p=0.03). Among those who had undergone transplant, we observed higher mean p16 (mean 12.84 [95% CI 12.46-13.23] vs 11.81 [11.51-12.11] for non-recipients, p=0.0001) and p16AgeGap (mean 50.6 [39.6-61.6] vs 16.9 [8.4-25.4], p &amp;lt;0.0001). There was a significant association between receipt of bortezomib-containing regimens with both p16 levels p16AgeGap, with higher mean p16 &amp; mean p16AgeGap for those who did not receive bortezomib. For the subset of patients with transplant date before the p16 collection date (N=38), there was no significant association between time since transplant and either p16 level or p16AgeGap. Conclusion This study elucidates the relationship between markers of cellular senescence, specifically p16 levels and the p16AgeGap, and the impact of treatment receipt and duration in a cohort of patients undergoing treatment for plasma cell disorders. There was a clear significant association between the receipt of treatment and both markers of senescence, along with a modest positive correlation between the duration of treatment and these markers. Further analyses involving this cohort will evaluate the relationship between these biomarkers and patient-centered endpoints, including disease-related symptoms and functional outcomes.

Systemic Amyloid Response in Patients with AL Amyloidosis Assessed By Serial Iodine ( 124I) Evuzamitide PET/CT Imaging

Background: Immunoglobulin light chain (AL) amyloidosis is a systemic disorder. Fibrillar aggregates of monoclonal free light chains, or fragments thereof, can deposit in any organ or tissue. Invariably, more than one anatomic site is involved, including the heart, liver, spleen, kidneys, pancreas, nerves, gastrointestinal tract and vasculature. Cardiac and renal amyloidosis are clinically most ominous; however, amyloid in other sites significantly impacts quality of life and may cause other heretofore unappreciated clinical sequelae. This is also true of the other 17 types of systemic amyloidosis. The degree of amyloid distribution and the tissue-specific amyloid load can only be achieved by nuclear imaging. Moreover, monitoring changes in amyloid load in response to therapy would benefit from whole body quantitative molecular imaging techniques. Here we report a pilot study of eight ( n=8) patients with AL amyloidosis who underwent serial PET/CT imaging using a novel amyloid-binding, iodine-124-labelled peptide, designated iodine-124-evuzamitide. Data from a cohort of ten ( n=10) patients with transthyretin associated (ATTR) amyloidosis are also described for comparison (NCT05968846). Methods: The study plans to enroll 20 ( n=20) patients with AL ( n=10) and ATTR ( n=10) amyloidosis who were previously imaged more than 12 months prior and who had positive uptake of 124I-evuzamitide in the heart. To date, eight ( n=8) patients with AL and ten ( n=10) with ATTR amyloidosis have undergone repeat imaging since 2019. Between imaging sessions, patients with AL received immunotherapy ( n=2/8) or were untreated ( n=6/8). Patients were administered 37 or 74 MBq 124I-evuzamitide, and PET/CT imaging was performed at ~5 h post injection. Clinical chemistry parameters were collected contemporaneously. Images were interpreted by a single reviewer, experienced in evaluating this tracer, for positive uptake. A fully manual 2D region of interest (ROI) analysis was performed on three representative image views of the heart in the transaxial plane as well as the liver, spleen, and kidneys. The blood pool was used as a reference tissue to determine standard uptake value ratios (SUVR mean). Cardiac uptake of radiotracer was compared with serum NT-proBNP measurements. Pearson and Spearman correlations were used to test for associations. Results: The mean time between imaging sessions for patients with AL amyloidosis was 3.21±0.95 years and 2.96±0.87 years for the entire cohort. In the AL amyloid cohort, 88% ( n=7/8) had a reduction in cardiac radiotracer uptake. In one ( n=1) patient, a 92.9% increase in cardiac uptake was seen, which was readily visible in scaled maximum intensity PET images. In this patient, the liver, spleen, and kidney uptake also increased. In contrast to the heart, renal uptake of the radiotracer was increased in 62.5% ( n=5/8) of patients with AL, with three ( n=3) patients showing a &amp;gt;20% increase in the SUVR mean. A strongly positive, significant correlation between the change in the liver and spleen uptake was observed (Pearson r=0.88, p=0.004). The change in the cardiac radiotracer uptake correlated strongly with that of the spleen (Pearson r=0.74, p=0.04). For the entire cohort, AL and ATTR patients ( n=18), there was a significant moderate correlation between the change in cardiac SUVR mean and change in single point serum NTproBNP concentration (Spearman rho=0.57, p=0.01). Conclusion: AL amyloidosis, and indeed all types of systemic amyloid disease, is a complex systemic disorder. The amyloid response to treatment, or disease progression, remains enigmatic as compared to the hematologic and biomarker responses. Appreciating the changes in amyloid load may not only improve clinical management but may also illuminate aspects of pathogenesis. PET/CT imaging using 124I-evuzamitide may, therefore, play a valuable role in understanding, diagnosing, and monitoring changes in organ-specific amyloid load and amyloid response. Additional longitudinal imaging studies are needed to investigate these possibilities further.

First Report on the Effects of Lisaftoclax (APG-2575) in Combination with Novel Therapeutic Regimens in Patients with Relapsed or Refractory Multiple Myeloma (R/R MM) or Immunoglobulin Light-Chain (Amyloid Light-Chain [AL]) Amyloidosis

*Drs. Yifan Zhai and Sikander Ailawadhi are co-corresponding authors Background R/R MM is an incurable condition, with virtually inevitable relapse. AL amyloidosis is a rare disease that may cause serious illness and even death. Lisaftoclax is a novel, potent, selective BCL-2 inhibitor under clinical development for treatment of patients with hematologic malignancies or solid tumors, and has shown clinical antitumor benefits. In a previous study on chronic lymphocytic leukemia, lisaftoclax was shown to require only a short (daily vs weekly) dose ramp-up to mitigate tumor lysis syndrome and was associated with a low incidence of adverse events (AEs) (Ailawadhi et al. J Clin Oncol 2021;39:abstract 7502; Davids et al. Blood 2022;140[suppl 1]:2326-2328). Methods This multicenter study evaluated lisaftoclax combined with pomalidomide and dexamethasone (Arms A and C) or daratumumab, lenalidomide, and dexamethasone (Arm B) in patients with R/R MM (Arm A and B) or R/R amyloidosis (Arm C). Eligible patients had an ECOG performance status ≤ 2; ≥ 1 prior line of therapy; and adequate organ function. Patients with R/R amyloidosis also needed confirmed symptomatic organ involvement, in addition to purpura and/or carpal tunnel syndrome. Lisaftoclax was administered orally daily (QD) at 5 dose levels (400, 600, 800, 1,000, and 1,200 mg) without ramp-up in repeated 28-day cycles. Pomalidomide, daratumumab, and lenalidomide were administered per label use. Dexamethasone 40 mg (20 mg for patients aged &amp;gt; 75 years) was administered on Days 1, 8, 15, and 22 of 28-day cycles. Study objectives were safety and efficacy assessments of the combination treatments. Results As of July 3, 2023, a total of 30 patients were enrolled: 22 in Arm A at dose levels of 400 (n = 3), 600 (n = 4), 800 (n = 3), 1,000 (n = 6), and 1,200 mg (n = 6); 3 in Arm B at 600 mg; and 5 in Arm C at 400 (n = 1) and 600 mg (n = 4). A total of 66.7% of patients were male, and the median (range) age was 70.5 (24-88) years, with 66.7% of patients above the age of 65. The median (range) lines of prior therapies was 4 (1-19), and median (range) time from diagnosis to first dose was 5.2 (1-29) years. The median (range) number of treatment cycles was 4 (1-19). A total of 18 patients were triple-class-exposed, 7 had received pomalidomide, and 3 harbored t(11;14) at baseline. A total of 19 patients reported experiencing any-grade lisaftoclax treatment-related adverse events (TRAEs), including neutropenia or nausea (16.7% each); and thrombocytopenia, leukopenia, abdominal distension, constipation, or diarrhea (6.7% each). Seven patients experienced grade ≥ 3 TRAEs, including neutropenia (10%) and febrile neutropenia, iron deficiency anemia, thrombocytopenia, prolonged electrocardiogram QT interval, and acute kidney injury (3.3% each). Two patients experienced lisaftoclax-related serious AEs, of which 1 was febrile neutropenia and 1 acute kidney injury. In Arm B, 1 patient experienced a dose-limiting toxicity (prolonged QT interval). A total of 12 patients discontinued treatment because of disease progression (n = 8), an AE (n = 1), noncompliance (n = 1), and investigator/patient decision (n = 2). In Arm A, 21 patients with R/R MM were evaluable, of whom 9 experienced a partial response (PR) and 5 a very good PR (VGPR). The overall response rate (ORR [PR or better]) was 66.7%, with a median (range) time to response of 1.2 (1-3) months. After a median (range) time to response of 1.4 (1-2) months, 2 patients with R/R MM in Arm B achieved a PR (n = 1) or VGPR (n = 1). In Arm C, 3 patients with R/R amyloidosis achieved a hematologic VGPR; the ORR was 60%; the median (range) time to response was 0.9 (1-1) month; and 1 patient experienced organ function improvement. Conclusion Lisaftoclax, combined with novel therapeutic regimens, was well tolerated and has demonstrated preliminary antitumor activity in patients with AL amyloidosis or R/R MM. Internal study identifier: APG-2575-MU101; clinical trial registration: NCT04942067.

Immune Checkpoint Expression Patterns on T Cell Subsets in Light-Chain Amyloidosis: VISTA, PD-1, and Tigit As Potential Therapeutic Targets

Abstract Background: Systemic immunoglobulin light chain amyloidosis (AL amyloidosis) is a rare plasma cell dyscrasia with a poor prognosis. T-cell exhaustion can lead to impaired T cell-mediated antitumor immunity, but there is limited information available regarding the T-cell immunodeficiency status in AL amyloidosis. This study aims to investigate the T-cell immune checkpoint expression patterns in AL amyloidosis and its relationship with clinicobiological characteristics. Methods: Using multi-color fluorescent flow cytometry, we examined the expression levels of V-domain immunoglobulin suppressor of T cell activation (VISTA), programmed death 1 (PD-1), T cell immunoglobulin and mucin-domain-containing-3 (Tim-3), T cell immunoreceptor with Ig and ITIM domains (TIGIT) on CD3+, CD4+, CD8+ T-cell, and regulatory T cell (Treg) in peripheral blood (PB) and bone marrow (BM) from 19 patients with newly diagnosed AL amyloidosis. We used 36 PB and BM samples from patients with newly diagnosed multiple myeloma (MM) and 19 PB and 10 BM samples from healthy individuals (HIs) as controls. Results: Our results showed that PB from patients with AL amyloidosis had significantly higher percentages of VISTA+ and PD-1+ subsets within CD3+, CD4+, CD8+ T cells and Tregs when compared to HIs. No statistical differences for frequency of VISTA+, PD-1+, Tim-3+ and TIGIT+ T-cell in BM were observed between the two groups. The percentages of double-positive VISTA+ PD-1+, VISTA+ Tim-3+, VISTA+ TIGIT+, PD-1+ Tim-3+ and PD-1+ TIGIT+ T cells in PB from the patients with AL amyloidosis were also considerably higher than those in the HIs. Moreover, we discovered that the patients with renal involvement had greater percentages of PD-1+ or TIGIT+ subsets within CD3+, CD4+ T cells and Tregs than the individuals without renal involvement. Additionally, PD-1+CD3+%, PD-1+CD4+%, and PD-1+Treg% were found to be positively correlated with 24-hour proteinuria levels. Furthermore, we observed that the AL amyloidosis patients had significantly higher counts of PD-1+ Treg in PB than the MM patients, while the MM patients had significantly higher counts of TIGIT+ subsets within CD3+, CD4+ and CD8+ T cells than the AL amyloidosis patients. Conclusions: Our findings suggest that there are elevated proportions of VISTA+ and PD-1+ T cells in PB of AL amyloidosis patients, which are indicators of an immunosuppressive milieu. The rise in PD-1+ or TIGIT+ T cells was associated with renal damage. Notably, MM and AL amyloidosis have very distinct immunosuppressive patterns based on immune checkpoint alteration. Overall, VISTA, PD-1, and TIGIT may be considered as potential targets for reversing T cell exhaustion and enhancing T cell activity in AL amyloidosis.

Value of nuclide scintigraphy in the diagnosis and prognosis of cardiac amyloidosis.

Amyloidosis is a local or systemic disease caused by the deposition of misfolded proteins outside the cell, with rapid progression, and dire prognosis. Common types of cardiac amyloidosis are monoclonal immunoglobulin light chain amyloidosis (AL-CA) and transthyretin cardiac amyloidosis (ATTR-CA). Nuclear medicine examinations can be accurate, rapid, and non-invasive to help diagnose diseases and can effectively predict the prognosis of patients with CA. Technetium (99Tcm)-labeled bisphosphonate imaging has been included in the consensus of experts and has become the first-line imaging method for the diagnosis of ATTR-CA. 123I-metaiodoenzylguanidine (MIBG) as a norepinephrine analogue can effectively assess cardiac sympathetic innervation in patients with CA. Aβ- amyloid imaging agents such as 11C-pittsburgh compound B and 18F-flubetaben are expected to be new techniques for diagnosing AL-CA and incorporating them into cardiac staging systems for AL-CA patients in the future. New imaging agents such as 18F-NaF has been widely used in the diagnosis, treatment response monitoring, and prognosis assessment of CA. Summarizing the research value of nuclide imaging in CA may provide new ideas for clinical realization of early detection of CA and accurate assessment of disease prognosis.