Biophysical insight into anti-amyloidogenic nature of novel ionic Co(II)(phen)(H2O)4]+[glycinate]- chemotherapeutic drug candidate against human lysozyme aggregation.

In the recent past, there has been an ever-increasing interest in the search for metal-based therapeutic drug candidates for protein misfolding disorders (PMDs) particularly neurodegenerative disorders such as Alzheimer's, Parkinson's, Prion's diseases, and amyotrophic lateral sclerosis. Also, different amyloidogenic variants of human lysozyme (HL) are involved in hereditary systemic amyloidosis. Metallo-therapeutic agents are extensively studied as antitumor agents, however, they are relatively unexplored for the treatment of non-neuropathic amyloidoses. In this work, inhibition potential of a novel ionic cobalt(II) therapeutic agent (CoTA) of the formulation [Co(phen)(H2O)4]+[glycinate]- is evaluated against HL fibrillation. Various biophysical techniques viz., dye-binding assays, dynamic light scattering (DLS), differential scanning calorimetry (DSC), electron microscopy, and molecular docking experiments validate the proposed mechanism of inhibition of HL fibrillation by CoTA. The experimental corroborative results of these studies reveal that CoTA can suppress and slow down HL fibrillation at physiological temperature and pH. DLS and 1-anilino-8-naphthalenesulfonate (ANS) assay show that reduced fibrillation in the presence of CoTA is marked by a significant decrease in the size and hydrophobicity of the aggregates. Fluorescence quenching and molecular docking results demonstrate that CoTA binds moderately to the aggregation-prone region of HL (Kb = 6.6 × 104 M-1), thereby, inhibiting HL fibrillation. In addition, far-UV CD and DSC show that binding of CoTA to HL does not cause any change in the stability of HL. More importantly, CoTA attenuates membrane damaging effects of HL aggregates against RBCs. This study identifies inorganic metal complexes as a therapeutic intervention for systemic amyloidosis.

No major effect of dopamine receptor 1/5 antagonist SCH-23390 on epileptic activity in the Tg2576 mouse model of amyloidosis.

The excitation-inhibition imbalance manifesting as epileptic activities in Alzheimer's disease is gaining more and more attention, and several potentially involved cellular and molecular pathways are currently under investigation. Based on in vitro studies, dopamine D1-type receptors in the anterior cingulate cortex and the hippocampus have been proposed to participate in this peculiar co-morbidity in mouse models of amyloidosis. Here, we tested the implication of dopaminergic transmission in vivo in the Tg2576 mouse model of Alzheimer's disease by monitoring epileptic activities via intracranial EEG before and after treatment with dopamine antagonists. Our results show that neither the D1-like dopamine receptor antagonist SCH23390 nor the D2-like dopamine receptor antagonist haloperidol reduces the frequency of epileptic activities. While requiring further investigation, our results indicate that on a systemic level, dopamine receptors are not significantly contributing to epilepsy observed in vivo in this mouse model of Alzheimer's disease.

Amyloid ß-Peptide Segment Conjugated Side-Chain Proline-Based Polymers as Potent Inhibitors in Lysozyme Amyloidosis.

Developing effective amyloidosis inhibitors poses a significant challenge due to the dynamic nature of the protein structures, the complex interplay of interfaces in protein-protein interactions, and the irreversible nature of amyloid assembly. The interactions of amyloidogenic polypeptides with other peptides play a pivotal role in modulating amyloidosis and fibril formation. This study presents a novel approach for designing and synthesizing amyloid interaction surfaces using segments derived from the amyloid-promoting sequence of amyloid ß-peptide [VF(Aß(18-19)/FF(Aß(19-20)/LVF(Aß(17-19)/LVFF(Aß(17-20)], where VF, FF, LVF and LVFF stands for valine phenylalanine dipeptide, phenylalanine phenylalanine dipeptide, leucine valine phenylalanine tripeptide and leucine valine phenylalanine phenylalanine tetrapeptide, respectively. These segments are conjugated with side-chain proline-based methacrylate polymers serving as potent lysozyme amyloidosis inhibitors and demonstrating reduced cytotoxicity of amyloid aggregations. Di-, tri-, and tetra-peptide conjugated chain transfer agents (CTAs) were synthesized and used for the reversible addition-fragmentation chain transfer polymerization of tert-butoxycarbonyl (Boc)-proline methacryloyloxyethyl ester (Boc-Pro-HEMA). Deprotection of Boc-groups from the side-chain proline pendants resulted in water-soluble polymers with defined peptide chain ends as peptide-polymer bioconjugates. Among them, the LVFF-conjugated polymer acted as a potent inhibitor with significantly suppressed lysozyme amyloidosis, a finding supported by comprehensive spectroscopic, microscopic, and computational analyses. These results unveil the synergistic effect between the segment-derived amyloid ß-peptide and side-chain proline-based polymers, offering new prospects for targeting lysozyme amyloidosis.

Efficacy and Safety of Acoramidis in Transthyretin Amyloid Cardiomyopathy.

BACKGROUND: Transthyretin amyloid cardiomyopathy is characterized by the deposition of misfolded monomeric transthyretin (TTR) in the heart. Acoramidis is a high-affinity TTR stabilizer that acts to inhibit dissociation of tetrameric TTR and leads to more than 90% stabilization across the dosing interval as measured ex vivo. METHODS: In this phase 3, double-blind trial, we randomly assigned patients with transthyretin amyloid cardiomyopathy in a 2:1 ratio to receive acoramidis hydrochloride at a dose of 800 mg twice daily or matching placebo for 30 months. Efficacy was assessed in the patients who had an estimated glomerular filtration rate of at least 30 ml per minute per 1.73 m2 of body-surface area. The four-step primary hierarchical analysis included death from any cause, cardiovascular-related hospitalization, the change from baseline in the N-terminal pro-B-type natriuretic peptide (NT-proBNP) level, and the change from baseline in the 6-minute walk distance. We used the Finkelstein-Schoenfeld method to compare all potential pairs of patients within strata to generate a P value. Key secondary outcomes were death from any cause, the 6-minute walk distance, the score on the Kansas City Cardiomyopathy Questionnaire-Overall Summary, and the serum TTR level. RESULTS: A total of 632 patients underwent randomization. The primary analysis favored acoramidis over placebo (P<0.001); the corresponding win ratio was 1.8 (95% confidence interval [CI], 1.4 to 2.2), with 63.7% of pairwise comparisons favoring acoramidis and 35.9% favoring placebo. Together, death from any cause and cardiovascular-related hospitalization contributed more than half the wins and losses to the win ratio (58% of all pairwise comparisons); NT-proBNP pairwise comparisons yielded the highest ratio of wins to losses (23.3% vs. 7.0%). The overall incidence of adverse events was similar in the acoramidis group and the placebo group (98.1% and 97.6%, respectively); serious adverse events were reported in 54.6% and 64.9% of the patients. CONCLUSIONS: In patients with transthyretin amyloid cardiomyopathy, the receipt of acoramidis resulted in a significantly better four-step primary hierarchical outcome containing components of mortality, morbidity, and function than placebo. Adverse events were similar in the two groups. (Funded by BridgeBio Pharma; ATTRibute-CM ClinicalTrials.gov number, NCT03860935.).

Efficacy of topical gabapentin in women with primary macular amyloidosis: A side-by-side triple-blinded randomized clinical trial.

BACKGROUND: Primary cutaneous macular amyloidosis (PCMA) is a chronic pruritic cutaneous disease characterized by heterogeneous extracellular deposition of amyloid protein in the skin. AIMS: This study aimed to evaluate the efficacy of topical 6% gabapentin cream for the treatment of patients with PCMA. MATERIALS AND METHODS: In this triple-blind clinical trial, a total of 34 patients, who were diagnosed with PCMA, treated using two different strategies of topical gabapentin as the active group and vehicle cream as the control group. RESULTS: Pruritus score reduction in both groups was statistically significant compared with the baseline value (p < 0.001). There was a significant pigmentation score reduction in intervention group compared with control group after 1 month of the study (p < 0.001). The differences of pigmentation score changes between the groups were not significant at month 2 (p = 0.52) and month 3 (p = 0.22). CONCLUSIONS: The results of this study suggest that topical gabapentin cream may be effective as a topical agent in the treatment of pruritus associated with PCMA without any significant adverse effects. It is recommended to perform similar studies with a larger sample size and longer duration in both sexes.

Feasibility of PiB positron emission tomography/computed tomography for treatment monitoring with Tafamidis in a patient with transthyretin cardiac amyloidosis.

We present a 77-year-old woman with wild-type ATTR cardiac amyloidosis (ATTR-CA) who presented with dyspnea, arrhythmia, and elevated NT-pro BNP. Initial imaging including cardiac MRI, PYP scintigraphy, PiB PET/CT and NaF PET/CT revealed cardiac abnormalities. Tafamidis treatment was initiated. After 14 months, symptomatic improvement and reduced NT-pro BNP were observed. Cardiac MRI and PYP scintigraphy showed no significant change and increased NaF accumulation, while PiB PET/CT showed decreased amyloid deposition, suggesting that it may be superior to NaF PET/CT in assessing the therapeutic effect of tafamidis in ATTR-CA.

Successful Treatment of Systemic Light Chain Amyloidosis with Liver Involvement using Low-Frequency Daratumumab: A Case Report.

BACKGROUND Systemic light chain (AL) amyloidosis is a disease characterized by the deposition of amyloid fibrils throughout tissues due to the production of misfolded immunoglobulin light chains by clonally expanded populations of CD38+ plasma cells. Some patients can have liver involvement, which typically presents with nonspecific symptoms. Daratumumab, a human CD38-targeting antibody, has shown efficacy in improving hematological parameters and organ function in patients with AL amyloidosis. Low-frequency daratumumab can reduce financial burden, but whether it is effective for patients with liver involvement has not been reported. CASE REPORT We present the case of a 64-year-old man admitted to our hospital with fatigue and recurrent fever. Histological analysis of a liver biopsy demonstrated AL amyloidosis. Bone marrow biopsy demonstrated the presence of abnormal plasma cells. Laboratory test results demonstrated increased levels of circulating free kappa (kappa) light chains, which were also seen on blood and urine immunofixation electrophoresis. Based on these findings, AL amyloidosis of the kappa light chain type with liver, cardiac, and renal involvement was diagnosed. The patient ultimately achieved hematological stringent complete response, liver remission, renal complete response, and cardiac very good partial response after 2 cycles of the low-frequency daratumumab, bortezomib, and dexamethasone regimen and 4 cycles of daratumumab and dexamethasone regimen chemotherapy. CONCLUSIONS The case indicates that low-frequency daratumumab treatment can have efficacy in AL amyloidosis with liver involvement.

Exploring Peptido-Nanocomposites in the Context of Amyloid Diseases.

Therapeutic peptides are a major class of pharmaceutical drugs owing to their target-binding specificity as well as their versatility in inhibiting aberrant protein-protein interactions associated with human pathologies. Within the realm of amyloid diseases, the use of peptides and peptidomimetics tailor-designed to overcome amyloidogenesis has been an active research endeavor since the late 90s. In more recent years, incorporating nanoparticles for enhancing the biocirculation and delivery of peptide drugs has emerged as a frontier in nanomedicine, and nanoparticles have further demonstrated a potency against amyloid aggregation and cellular inflammation to rival strategies employing small molecules, peptides, and antibodies. Despite these efforts, however, a fundamental understanding of the chemistry, characteristics and function of peptido-nanocomposites is lacking, and a systematic analysis of such strategy for combating a range of amyloid pathogeneses is missing. Here we review the history, principles and evolving chemistry of constructing peptido-nanocomposites from bottom up and discuss their future application against amyloid diseases that debilitate a significant portion of the global population.

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.

A rare cause of AA amyloidosis: Glomus tumor and treatment with anakinra-Case report and literature review.

Systemic AA amyloidosis is associated with poorly controlled chronic inflammatory disorders. Chronic infections and inflammatory arthritis are the most common causes; however, they can also rarely occur as a complication of neoplastic disorders. The development of AA amyloidosis secondary to paraganglioma, which is a rare type of tumor, has rarely been reported in the literature. In this case, an 85-year-old female patient with a glomus tumor in the neck, who has been followed up over 50 years, applied with complaints of loss of appetite, nausea, and diarrhea for 5-6 months. While evaluating the patient, who had high levels of acute phase reactants, amyloidosis was diagnosed by salivary gland biopsy. No other cause was found to explain amyloidosis. The patient, who could not tolerate treatment with colchicine and azathioprine, is successfully treated with the interleukin-1 inhibitor anakinra. A rare relationship, systemic AA amyloidosis, which is thought to have developed as a result of long-standing jugular paraganglioma, is presented in this article. In addition, publications showing an association between paragangliomas and amyloidosis were reviewed.

Risk factors, treatments and outcomes of patients with light chain amyloidosis who relapse after autologous stem cell transplantation.

Relapse after ASCT is an important factor affecting the long-term prognosis of patients with AL amyloidosis. However, the risk factors of relapse are unknown and there are limited studies on treatment outcomes of these patients. We retrospectively reviewed 170 patients with AL amyloidosis who underwent ASCT between 2010 and 2021. Seventy-six patients confirmed as relapse and the median time from ASCT to relapse was 39 months. On multivariate analysis of variables before and after ASCT, lambda restricted, dFLC >30 mg/L pre ASCT, reduced dose melphalan and dFLC >10 mg/L at 6 months after ASCT were independent risk factors for relapse, and achieving CR after induction therapy and renal response after ASCT were protective factors. Most relapsed patients were treated with bortezomib-based regimens (50%) followed by daratumumab-based regimens (22.2%) and other chemotherapy regimens (13.9%). The overall hematological response in evaluable patients was 68.2% with 56.8% achieving CR/VGPR. The median PFS and OS from post-transplant relapse were 25 months and 81 months, respectively. Patients receiving bortezomib or daratumumab showed a better survival compared to other chemotherapy regimens. In conclusion, this study identified independent risk factors of post-transplant relapse and demonstrated the superiority of bortezomib or daratumumab treatment for these patients. CLINICAL TRIAL REGISTRATION: NCT04210791.

Patisiran Treatment in Patients with Transthyretin Cardiac Amyloidosis.

BACKGROUND: Transthyretin amyloidosis, also called ATTR amyloidosis, is associated with accumulation of ATTR amyloid deposits in the heart and commonly manifests as progressive cardiomyopathy. Patisiran, an RNA interference therapeutic agent, inhibits the production of hepatic transthyretin. METHODS: In this phase 3, double-blind, randomized trial, we assigned patients with hereditary, also known as variant, or wild-type ATTR cardiac amyloidosis, in a 1:1 ratio, to receive patisiran (0.3 mg per kilogram of body weight) or placebo once every 3 weeks for 12 months. A hierarchical procedure was used to test the primary and three secondary end points. The primary end point was the change from baseline in the distance covered on the 6-minute walk test at 12 months. The first secondary end point was the change from baseline to month 12 in the Kansas City Cardiomyopathy Questionnaire-Overall Summary (KCCQ-OS) score (with higher scores indicating better health status). The second secondary end point was a composite of death from any cause, cardiovascular events, and change from baseline in the 6-minute walk test distance over 12 months. The third secondary end point was a composite of death from any cause, hospitalizations for any cause, and urgent heart failure visits over 12 months. RESULTS: A total of 360 patients were randomly assigned to receive patisiran (181 patients) or placebo (179 patients). At month 12, the decline in the 6-minute walk distance was lower in the patisiran group than in the placebo group (Hodges-Lehmann estimate of median difference, 14.69 m; 95% confidence interval [CI], 0.69 to 28.69; P = 0.02); the KCCQ-OS score increased in the patisiran group and declined in the placebo group (least-squares mean difference, 3.7 points; 95% CI, 0.2 to 7.2; P = 0.04). Significant benefits were not observed for the second secondary end point. Infusion-related reactions, arthralgia, and muscle spasms occurred more often among patients in the patisiran group than among those in the placebo group. CONCLUSIONS: In this trial, administration of patisiran over a period of 12 months resulted in preserved functional capacity in patients with ATTR cardiac amyloidosis. (Funded by Alnylam Pharmaceuticals; APOLLO-B ClinicalTrials.gov number, NCT03997383.).

Emerging therapeutic avenues in cardiac amyloidosis.

Cardiac Amyloidosis (CA) is a toxic infiltrative cardiomyopathy occurred by the deposition of the amyloid fibres in the extracellular matrix of the myocardium. This results in severe clinical complications such as increased left ventricular wall thickness and interventricular stiffness, a decrease in left ventricular stroke volume and cardiac output, diastolic dysfunction, arrhythmia, etc. In a prolonged period, this condition progresses into heart failure. The amyloid fibres affecting the heart include immunoglobulin light chain (AL - amyloidosis) and transthyretin protein (ATTR - amyloidosis) misfolded amyloid fibres. ATTRwt has the highest prevalence of 155 to 191 cases per million while ATTRv has an estimated prevalence of 5.2 cases per million. The pathological findings and therapeutic approaches developed recently have aided in the treatment regimen of cardiac amyloidosis patients. In recent years, understanding the pathophysiology of amyloid fibres formation and mechanistic pathways triggered in both types of cardiac amyloidosis has led to the development of new therapeutic approaches and agents. This review focuses on the current status of emerging therapeutic agents in clinical trials. Earlier, melphalan and bortezomib in combination with alkylating agents and immunomodulatory drugs were used as a standard therapy for AL amyloidosis. Tafamidis, approved recently by FDA is used as a standard for ATTR amyloidosis. However, the emerging therapeutic agents under development for the treatment of AL and ATTR cardiac amyloidosis have shown a potent and rapid effect with a safety profile.

Why and by How Much is Insulin Absorption Reduced by Insulin-derived Amyloidosis? A Scoping Review.

Insulin therapy is one of the central treatments for diabetes mellitus. Insulin-derived localized amyloidosis (IDLA) is a known skin-related complication of insulin injection. This is one of the causes of poor glycemic control in diabetic patients on insulin therapy. The aim of this study was to review and update the findings on the extent and mechanism of reduced insulin absorption in IDLA. A literature search was conducted on decreased insulin absorption and its mechanisms, and nine references were selected, with seven of these on decreased insulin absorption and four on mechanisms. Insulin absorption at IDLA sites was reported to be 27-94% lower compared with normal sites. In addition, a comparison between nonpalpable and palpable IDLA sites revealed a significant decrease in insulin absorption at the palpable IDLA site. The mechanism of insulin malabsorption was found to be a reduction in insulin absorption at the palpable IDLA sites. Four mechanisms of decreased insulin absorption were identified: decreased subcutaneous blood flow, adsorption of administered insulin onto insulin amyloid fibers, impaired diffusion of insulin subcutaneously, and physical factors such as shaking of the insulin preparation. These mechanisms should be investigated in vivo in the future.

Role of autologous haematopoietic cell transplantation in the treatment of systemic light chain amyloidosis in the era of anti-CD38 monoclonal antibodies.

The primary goal of the initial treatment in systemic light chain amyloidosis is to obtain a rapid and profound haematological response as safely as possible, coupled with supportive care by a multidisciplinary team. The treatment landscape has evolved with the introduction of highly effective therapies targeting the plasma cell clones, which can attain high rates of haematological complete response with minimal treatment-related morbidity and mortality. Consequently, the role of high-dose melphalan followed by autologous haematopoietic cell transplantation (HDM-AHCT) is being analysed, particularly considering the absence of randomised controlled trial data supporting its superiority over standard-dose therapies in systemic light chain amyloidosis treatment. In this Viewpoint, we will explore the role of HDM-AHCT in the management of patients with systemic light chain amyloidosis who are eligible for transplantation, and the unresolved questions surrounding HDM-AHCT use as both front-line and salvage therapy.

Safety of Subcutaneous Daratumumab in Anti-CD38 Monoclonal Antibody-Naïve Patients with Plasma Cell Disorders: A Multicenter Real-Life Experience.

BACKGROUND: Daratumumab, an anti-CD38 monoclonal antibody, is used for treatment of multiple myeloma (MM) and light chain amyloidosis at an intravenous dosage of 16 mg/kg or at a subcutaneous fixed dose of 1800 mg. However, the subcutaneous formulation has only recently been approved in Europe, and real-life data on its safety are still few. OBJECTIVE: In this multicenter retrospective real-life experience, we provided evidence for the safety of subcutaneous daratumumab in plasma cell disorders. PATIENTS AND METHODS: A total of 189 patients diagnosed with MM or light chain amyloidosis were included in this retrospective study, and all subjects were daratumumab-naïve. Primary endpoint was safety of subcutaneous daratumumab, especially for infusion-related reaction (IRR) incidence and severity. All patients received premedication with dexamethasone, paracetamol, and antihistamine, with montelukast usage in 85% of cases. RESULTS: Eight patients (4%) experienced IRRs, mainly of grade I-II, and other frequent toxicities were: hematological (thrombocytopenia, 4%; neutropenia, 5%; lymphopenia, 6%) and non-hematological (pneumonia, 4%; diarrhea, 2%; and cytomegalovirus reactivation, 0.5%). In our multicenter retrospective real-life experience, subcutaneous daratumumab was well-tolerated with an excellent safety profile with a very low (4%) IRR incidence, even in frailer MM patients with severe renal impairment or increased body weight. CONCLUSIONS: Subcutaneous daratumumab was safe in a real-life setting including patients with severe renal failure and advanced disease. However, further studies on larger and prospective cohorts are required to confirm our real-life observations.