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.).

Patisirana no tratamento de pacientes diagnosticados com amiloidose hereditária relacionada à transtirretina (ATTRh) com polineuropatia em estágio 2 ou que apresentem resposta inadequada ao tafamidis / Patisiran in the treatment of patients diagnosed with hereditary transthyretin-related amyloidosis (hATTR) with stage 2 polyneuropathy or who have an inadequate response to tafamidis

INTRODUÇÃo: Amiloidose hereditária relacionada a transtirretina é uma doença genética rara autossômica dominante, multissistêmica, progressiva e potencialmente fatal. Após o diagnóstico deve ser determinado o estágio da doença de acordo com a gravidade dos sintomas (Estágio 0 a III), sendo o estágio III o de maior gravidade. Estima-se que a ATTRh afete cerca de 50 mil pessoas no mundo todo. No Brasil, não há dados epidemiológicos publicados sobre sua prevalência. Porém, observou-se um aumento no número de casos de ATTRh registrados no país. Atualmente, o único medicamento disponibilizado pelo SUS para tratar ATTRh é o tafamidis meglumina, indicado para pacientes adultos sintomáticos em estágio inicial (estágio I) e não submetidos a transplante hepático por ATTRh. O transplante hepático deve ser realizado apenas no estágio I da doença, em razão de não ser uma medida terapêutica curativa das lesões, que surgem nos estágios mais avançados da ATTRh. PERGUNTA: O tratamento com patisirana é eficaz, efetivo e seguro para pacientes diagnosticados com amiloidose ATTRh com polineuropatia em estágio 2 ou que apresentam resposta inadequada ao tafamidis? EVIDÊNCIAS CLÍNICAS: Os estudos selecionados demonstram a eficácia do patisirana na redução da progressão neuropática da doença, evidenciada pela diminuição da pontuação na escala mNIS+7 após uso

Inotersena para o tratamento da polineuropatia amiloidótica familiar relacionada à transtirretina em pacientes adultos em estágio 2 ou pacientes não respondedores a tafamidis meglumina / Inotersena for the treatment of transthyretin-related familial amyloidotic polyneuropathy in stage 2 adult patients or patients nonresponders to tafamidis meglumine

INTRODUÇÃO: A amiloidose por transtirretina (TTR) é um distúrbio sistêmico caracterizado pela deposição extracelular de fibrilas amiloides e compostas por TTR, que é uma proteína de transporte plasmático de tiroxina e vitamina A produzida predominantemente pelo fígado. A polineuropatia amiloidótica familiar relacionada à transtirretina (PAF-TTR) é uma doença multissistêmica rara, progressiva, hereditária e altamente incapacitante. É um distúrbio autossômico dominante e até o momento mais de 100 mutações de TTR diferentes foram identificadas em todo o mundo, essas mutações desestabilizam a proteína TRR. PAF-TTR é uma doença multissintomática que pode apresentar neuropatia periférica (sensorial e motora), neuropatia autonômica, comprometimento gastrointestinal, cardiomiopatia, nefropatia ou deposição ocular. As manifestações clínicas da amiloidose sistêmica são determinadas principalmente pela proteína precursora e pelos órgãos envolvidos. No entanto, há considerável sobreposição clínica entre todos os tipos de amiloidose. Estimativas de preva

Tafamidis meglumina no tratamento de pacientes com cardiomiopatia amiloide associada à transtirretina (selvagem ou hereditária), classes NYHA II e III acima de 60 anos de idade / Tafamidis meglumina no tratamento de pacientes com cardiomiopatia amiloide associada à transtirretina (selvagem ou hereditária), classes NYHA II e III acima de 60 anos de idade

INTRODUÇÃO: A cardiomiopatia amiloide associada à transtirretina (TTR), ou CM-TTR, integra o grupo de doenças amiloides raras e sistêmicas que são caracterizadas pela deposição extracelular de proteína amiloide, que resulta em falência progressiva de órgãos. A CM-TTR pode se manifestar como dois genótipos: hereditária ou selvagem (adquirida ou senil) e em ambas a proteína amiloide pode infiltrar qualquer uma ou todas as estruturas cardiovasculares, incluindo o sistema de condução, o miocárdio atrial e ventricular, tecido valvar, as artérias e coronárias. PERGUNTA DE PESQUISA: Qual a eficácia, efetividade, segurança, custo-efetividade e impacto orçamentário do tafamidis meglumina no tratamento da cardiomiopatia amiloide associada à transtirretina (CM-TTR), selvagem ou hereditária, classe NYHA II e III, em pessoas acima de 60 anos de idade, na perspectiva do SUS? EVIDÊNCIAS CIENTÍFICAS: Foram incluídos dois estudos, um randomizado de fase III e um estudo aberto de fase II. O grupo de pacientes tratados com o medicamento mostrou superioridade na redução da mortalidade por todas as causas e hospitalizações por causas cardiovasculares ao longo de 30 meses de acompanhamento em relação ao grupo placebo. Também foi observada redução do número de hospitalizações em pacientes com classe funcional NYHA I ou II e redução do declínio da capacidade funcional e da qualidade de vida no mês 30, com diferenças observadas logo no mês seis, quando comparado com placebo. O perfil de segurança do tafamidis meglumina foi semelhante ao placebo, com menor taxa de descontinuação. AVALIAÇÃO ECONÔMICA (AE): A análise de custo-efetividade foi apresentada na perspectiva do SUS, empregando-se um modelo de estados transicionais do tipo cadeias de Markov para acompanhar os pacientes com CM-TTR nas classes funcionas II ou III, considerando-se a transição por diferentes estados de saúde. Tafamidis meglumina resultou em ganhos em anos de vida ajustados pela qualidade (AVAQ) e anos de vida ganhos (AVG) a partir de custo incremental de R$ 473.457,61 e R$ 369.124,83, respectivamente, por paciente, em um horizonte temporal lifetime de 25 anos. AVALIAÇÃO DE IMPACTO ORÇAMENTÁRIO: A população elegível ao tratamento com tafamidis meglumina foi determinada pelo método epidemiológico, empregando-se dados da literatura a partir da estimativa populacional. Como resultados da análise foi calculado um impacto orçamentário no cenário de referência de R$ 19,8 milhões no primeiro ano após incorporação do medicamento no SUS e, em um horizonte de temporal de 5 anos, e um total acumulado de aproximadamente R$ 721,7 milhões em cinco anos. MONITORAMENTO DO HORIZONTE TECNOLÓGICO: Foram realizadas buscas estruturadas nos campos de pesquisa das bases de dados ClinicalTrials.gov e Cortellis™, a fim de localizar medicamentos potenciais para o tratamento de pacientes acima de 60 anos de idade com cardiomiopatia amiloide associada à transtirretina (hereditária ou selvagem), classe NYHA II e III. A busca foi realizada no dia 12 de setembro 2022. Foram considerados estudos clínicos de fases 2, 3 ou 4 inscritos no ClinicalTrials, que testaram ou estão testando os medicamentos resultantes da busca supracitada. Os medicamentos com registro para a indicação clínica há mais de dois anos na Agência Nacional de Vigilância Sanitária (ANVISA), ou há mais de cinco anos na European Medicines Agency (EMA) ou na U.S. Food and Drug Administration (FDA) não foram considerados. Os dados da situação regulatória das tecnologias foram consultados nos sítios eletrônicos das referidas agências sanitárias. Assim, no horizonte considerado nesta análise, detectaram-se seis tecnologias para compor o esquema terapêutico da cardiomiopatia amiloide associada à transtirretina. CONSIDERAÇÕES FINAIS: As evidências analisadas foram identificadas de qualidade baixa a alta. Quanto aos desfechos, no ECR os pacientes tratados com o tafamidis meglumina mostraram superioridade na redução da mortalidade por todas as causas e hospitalizações por causas cardiovasculares ao longo de 30 meses de acompanhamento em relação ao grupo placebo, além de redução do declínio da capacidade funcional e da qualidade de vida, em comparação com o placebo. Na avaliação econômica, foi realizada uma análise de custo-efetividade (ACE). O tratamento com tafamidis resultou em ganhos em AVAQ e AVG a partir de custo incremental de, respectivamente, R$ 473.457,61 e R$ 369.124,83, por paciente por benefício ganho, em um horizonte temporal lifetime de 25 anos. Já a AIO foi estimada em um cenário base e dois alternativos, em um horizonte temporal de 5 anos. O cenário base representou um impacto orçamentário de R$ 19.828.700,39 no primeiro ano de incorporação do tafamidis e um acumulado de R$ 721,7 milhões em cinco anos. RECOMENDAÇÃO PRELIMINAR DA CONITEC: Os membros do plenário presentes na 113ª reunião ordinária, realizada no dia 06 de outubro de 2022, deliberaram por unanimidade que a matéria fosse disponibilizada em consulta pública com recomendação preliminar desfavorável à incorporação de Tafamidis meglumina no tratamento de pacientes com cardiomiopatia amiloide associada à transtirretina (selvagem ou hereditária), classes NYHA II e III acima de 60 anos de idade no SUS. Os membros do plenário concordaram que, embora a demanda envolva proposta de tratamento para uma condição clínica rara, com boa evidência, deve ser considerada a razão de custo-efetividade e o impacto orçamentário da tecnologia, visto as incertezas relacionadas a população elegível. CONSULTA PÚBLICA: Foram recebidas 643 contribuições, sendo 165 pelo formulário técnico-científico e 478 pelo formulário sobre experiência ou opinião. Todas as contribuições de cunho técnico-científico recebidas foram contra a recomendação inicial da Conitec. Das contribuições recebidas sobre experiência com a tecnologia ou opinião sobre o tema 476 foram contra a recomendação preliminar e duas concordaram. RECOMENDAÇÃO FINAL DA CONITEC: Pelo exposto, o Plenário da Conitec, em sua 115ª Reunião Ordinária, no dia 01 de dezembro de 2022, deliberou por unanimidade, recomendar a não incorporação do tafamidis meglumina no tratamento de pacientes com cardiomiopatia amiloide associada à transtirretina (selvagem ou hereditária), classes NYHA II e III acima de 60 anos de idade no SUS. Por fim, foi assinado o Registro de Deliberação nº 792/2022. DECISÃO: Não incorporar, no âmbito do Sistema Único de Saúde - SUS, o tafamidis meglumina no tratamento de pacientes com cardiomiopatia amiloide associada à transtirretina (selvagem ou hereditária), classes NYHA II e III acima de 60 anos de idade, conforme protocolo estabelecido pelo Ministério da Saúde, conforme a Portaria nº 177, publicada no Diário Oficial da União nº 240, seção 1, página 1119, em 22 de dezembro de 2022.

Long-term safety and efficacy of patisiran for hereditary transthyretin-mediated amyloidosis with polyneuropathy: 12-month results of an open-label extension study.

BACKGROUND: Hereditary transthyretin-mediated amyloidosis is a rare, inherited, progressive disease caused by mutations in the transthyretin (TTR) gene. We assessed the safety and efficacy of long-term treatment with patisiran, an RNA interference therapeutic that inhibits TTR production, in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy. METHODS: This multicentre, open-label extension (OLE) trial enrolled patients at 43 hospitals or clinical centres in 19 countries as of Sept 24, 2018. Patients were eligible if they had completed the phase 3 APOLLO or phase 2 OLE parent studies and tolerated the study drug. Eligible patients from APOLLO (patisiran and placebo groups) and the phase 2 OLE (patisiran group) studies enrolled in this global OLE trial and received patisiran 0·3 mg/kg by intravenous infusion every 3 weeks with plans to continue to do so for up to 5 years. Efficacy assessments included measures of polyneuropathy (modified Neuropathy Impairment Score +7 [mNIS+7]), quality of life, autonomic symptoms, nutritional status, disability, ambulation status, motor function, and cardiac stress, with analysis by study groups (APOLLO-placebo, APOLLO-patisiran, phase 2 OLE patisiran) based on allocation in the parent trial. The global OLE is ongoing with no new enrolment, and current findings are based on the interim analysis of the patients who had completed 12-month efficacy assessments as of the data cutoff. Safety analyses included all patients who received one or more dose of patisiran up to the data cutoff. This study is registered with ClinicalTrials.gov, NCT02510261. FINDINGS: Between July 13, 2015, and Aug 21, 2017, of 212 eligible patients, 211 were enrolled: 137 patients from the APOLLO-patisiran group, 49 from the APOLLO-placebo group, and 25 from the phase 2 OLE patisiran group. At the data cutoff on Sept 24, 2018, 126 (92%) of 137 patients from the APOLLO-patisiran group, 38 (78%) of 49 from the APOLLO-placebo group, and 25 (100%) of 25 from the phase 2 OLE patisiran group had completed 12-month assessments. At 12 months, improvements in mNIS+7 with patisiran were sustained from parent study baseline with treatment in the global OLE (APOLLO-patisiran mean change -4·0, 95 % CI -7·7 to -0·3; phase 2 OLE patisiran -4·7, -11·9 to 2·4). Mean mNIS+7 score improved from global OLE enrolment in the APOLLO-placebo group (mean change from global OLE enrolment -1·4, 95% CI -6·2 to 3·5). Overall, 204 (97%) of 211 patients reported adverse events, 82 (39%) reported serious adverse events, and there were 23 (11%) deaths. Serious adverse events were more frequent in the APOLLO-placebo group (28 [57%] of 49) than in the APOLLO-patisiran (48 [35%] of 137) or phase 2 OLE patisiran (six [24%] of 25) groups. The most common treatment-related adverse event was mild or moderate infusion-related reactions. The frequency of deaths in the global OLE was higher in the APOLLO-placebo group (13 [27%] of 49), who had a higher disease burden than the APOLLO-patisiran (ten [7%] of 137) and phase 2 OLE patisiran (0 of 25) groups. INTERPRETATION: In this interim 12-month analysis of the ongoing global OLE study, patisiran appeared to maintain efficacy with an acceptable safety profile in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy. Continued long-term follow-up will be important for the overall assessment of safety and efficacy with patisiran. FUNDING: Alnylam Pharmaceuticals.

Targeting transthyretin - Mechanism-based treatment approaches and future perspectives in hereditary amyloidosis.

The liver-derived, circulating transport protein transthyretin (TTR) is the cause of systemic hereditary (ATTRv) and wild-type (ATTRwt) amyloidosis. TTR stabilization and knockdown are approved therapies to mitigate the otherwise lethal disease course. To date, the variety in phenotypic penetrance is not fully understood. This systematic review summarizes the current literature on TTR pathophysiology with its therapeutic implications. Tetramer dissociation is the rate-limiting step of amyloidogenesis. Besides destabilizing TTR mutations, other genetic (RBP4, APCS, AR, ATX2, C1q, C3) and external (extracellular matrix, Schwann cell interaction) factors influence the type of onset and organ tropism. The approved small molecule tafamidis stabilizes the tetramer and significantly decelerates the clinical course. By sequence-specific mRNA knockdown, the approved small interfering RNA (siRNA) patisiran and antisense oligonucleotide (ASO) inotersen both significantly reduce plasma TTR levels and improve neuropathy and quality of life compared to placebo. With enhanced hepatic targeting capabilities, GalNac-conjugated siRNA and ASOs have recently entered phase III clinical trials. Bivalent TTR stabilizers occupy both binding groves in vitro, but have not been tested in trials so far. Tolcapone is another stabilizer with the potential to cross the blood-brain barrier, but its half-life is short and liver failure a potential side effect. Amyloid-directed antibodies and substances like doxycycline aim at reducing the amyloid load, however, none of the yet developed antibodies has successfully passed clinical trials. ATTR-amyloidosis has become a model disease for pathophysiology-based treatment. Further understanding of disease mechanisms will help to overcome the remaining limitations, including application burden, side effects, and blood-brain barrier permeability.

The Bioequivalence of Tafamidis 61-mg Free Acid Capsules and Tafamidis Meglumine 4 × 20-mg Capsules in Healthy Volunteers.

Tafamidis, a non-nonsteroidal anti-inflammatory benzoxazole derivative, acts as a transthyretin (TTR) stabilizer to slow progression of TTR amyloidosis (ATTR). Tafamidis meglumine, available as 20-mg capsules, is approved in more than 40 countries worldwide for the treatment of adults with early-stage symptomatic ATTR polyneuropathy. This agent, administered as an 80-mg, once-daily dose (4 × 20-mg capsules), is approved in the United States, Japan, Canada, and Brazil for the treatment of hereditary and wild-type ATTR cardiomyopathy in adults. An alternative single solid oral dosage formulation (tafamidis 61-mg free acid capsules) was developed and introduced for patient convenience (approved in the United States, United Arab Emirates, and European Union). In this single-center, open-label, randomized, 2-period, 2-sequence, crossover, multiple-dose phase 1 study, the rate and extent of absorption were compared between tafamidis 61-mg free acid capsules (test) and tafamidis meglumine 80-mg (4 × 20-mg) capsules (reference) after 7 days of repeated oral dosing under fasted conditions in 30 healthy volunteers. Ratios of adjusted geometric means (90%CI) for the test/reference formulations were 102.3 (98.0-106.8) for area under the concentration-time profile over the dosing interval and 94.1 (89.1-99.4) for the maximum observed concentration, satisfying prespecified bioequivalence acceptance criteria (90%CI, 80-125). Both tafamidis regimens had an acceptable safety/tolerability profile in this population.

Transthyretin Anti-Amyloidogenic and Fibril Disrupting Activities of Bacopa monnieri (L.) Wettst (Brahmi) Extract.

The homotetrameric plasma protein transthyretin (TTR), is responsible for a series of debilitating and often fatal disorders in humans known as transthyretin amyloidosis. Currently, there is no cure for TTR amyloidosis and treatment options are rare. Thus, the identification and development of effective and safe therapeutic agents remain a research imperative. The objective of this study was to determine the effectiveness of Bacopa monnieri extract (BME) in the modulation of TTR amyloidogenesis and disruption of preformed fibrils. Using aggregation assays and transmission electron microscopy, it was found that BME abrogated the formation of human TTR aggregates and mature fibrils but did not dis-aggregate pre-formed fibrils. Through acid-mediated and urea-mediated denaturation assays, it was revealed that BME mitigated the dissociation of folded human TTR and L55P TTR into monomers. ANS binding and glutaraldehyde cross-linking assays showed that BME binds at the thyroxine-binding site and possibly enhanced the quaternary structural stability of native TTR. Together, our results suggest that BME bioactives prevented the formation of TTR fibrils by attenuating the disassembly of tetramers into monomers. These findings open up the possibility of further exploration of BME as a potential resource of valuable anti-TTR amyloidosis therapeutic ingredients.

Biophysical characterization and modulation of Transthyretin Ala97Ser.

OBJECTIVE: Ala97Ser (A97S) is the major transthyretin (TTR) mutation in Taiwanese patients of familial amyloid polyneuropathy (FAP), characterized by a late-onset but rapidly deteriorated neuropathy. Tafamidis can restore the stability of some mutant TTR tetramers and slow down the progression of TTR-FAP. However, there is little understanding of the biophysical features of A97S-TTR mutant and the pharmacological modulation effect of tafamidis on it. This study aims to delineate the biophysical characteristics of A97S-TTR and the pharmacological modulation effect of tafamidis on this mutant. METHOD: The stability of TTR tetramers was assessed by urea denaturation and differential scanning calorimetry. Isothermal titration calorimetry (ITC) was used to measure the binding constant of tafamidis to TTR. Nuclear magnetic resonance spectroscopy (NMR) titration experiment was used to map out the tafamidis binding site. RESULTS: Chemical and thermal denaturation confirmed the destabilization effect of A97S. Consistent with other the amyloidogenic mutant, A97S-TTR has slightly lower conformational stability. NMR revealed the binding site of A97S-TTR with tafamidis is at the thyroxine binding pocket. The ITC experiments documented the high affinity of the binding which can effectively stabilize the A97S-TTR tetramer. INTERPRETATION: This study confirmed the structural modulation effect of tafamidis on A97S-TTR and implied the potential therapeutic benefit of tafamidis for A97S TTR-FAP. This approach can be applied to investigate the modulation effect of tafamidis on other rare TTR variants and help to make individualized choices of available treatments for FAP patients.

Nicotine Acts on Cholinergic Signaling Mechanisms to Directly Modulate Choroid Plexus Function.

Neuronal cholinergic circuits have been implicated in cognitive function and neurological disease, but the role of cholinergic signaling in other cellular populations within the brain has not been as fully defined. Here, we show that cholinergic signaling mechanisms are involved in mediating the function of the choroid plexus, the brain structure responsible for generating CSF and releasing various factors into the brain. The choroid plexus was found to express markers of endogenous cholinergic signaling, including multiple nicotinic acetylcholine receptor (nAChR) subtypes in a region-specific manner, and application of nicotine was found to induce cellular activation, as evidenced by calcium influx in primary tissue. During intravenous nicotine self-administration in male rats, nicotine increased expression of transthyretin, a protein selectively produced and released by the choroid plexus, and microRNA-204 (mir-204), a transcript found in high levels in the choroid plexus and CSF. Finally, human choroid plexus tissue from both sexes was found to exhibit similar nAChR, transthyretin and mir-204 expression profiles, supporting the translational relevance of the findings. Together, these studies demonstrate functionally active cholinergic signaling mechanisms in the choroid plexus, the resulting effects on transthyretin and mir-204 expression, and reveal the direct mechanism by which nicotine modulates function of this tissue.

Association of Patisiran, an RNA Interference Therapeutic, With Regional Left Ventricular Myocardial Strain in Hereditary Transthyretin Amyloidosis: The APOLLO Study.

Importance: Patients with cardiac amyloidosis demonstrate reduced myocardial strain with associated sparing of the cardiac apex. In the APOLLO randomized clinical trial, patisiran, an RNA interference therapeutic that inhibits transthyretin synthesis, improved left ventricular (LV) global longitudinal strain (LV GLS) compared with placebo in patients with hereditary transthyretin-mediated (hATTR) amyloidosis with polyneuropathy and evidence of cardiac involvement. Objective: To evaluate the treatment association of patisiran with regional LV myocardial strain in cardiac manifestation in hATTR amyloidosis. Design, Setting, and Participants: This exploratory analysis of APOLLO, a randomized, double-blind, placebo-controlled, phase 3, multicenter international clinical trial that was conducted from December 2013 to January 2016, included patients with hATTR amyloidosis with polyneuropathy who were randomized 2:1 to receive patisiran or placebo. The prespecified cardiac subpopulation (126 of 225 [56%]) comprised patients with a baseline LV wall thickness of 13 mm or more and no history of hypertension or aortic valve disease. This post hoc data analysis was performed between September 2018 and January 2019. Intervention: Placebo or patisiran, 0.3 mg/kg, via intravenous infusion once every 3 weeks for 18 months. Main Outcomes and Measures: The association of patisiran with LV regional longitudinal strain at 18 months. Results: Of the 126 patients included in the prespecified cardiac subpopulation, 36 patients (28.6%) received placebo (median [interquartile range] age, 62 [57-72] years) and 90 patients (71.4%) received patisiran (median [interquartile range] age, 60 [54-66] years); 98 (77.8%) were men, 28 (22.2%) were from North America, and 43 (34.1%) were from Western Europe. At baseline, LV GLS was impaired and regional longitudinal strains were lowest in the basal segments with apical sparing. There were no differences in regional longitudinal strains between the treatment groups at baseline. Patisiran improved the absolute GLS (least-squares mean [SE] difference, 1.4% [0.6%]; 95% CI, 0.3%-2.5%; P = .02) compared with placebo at 18 months, with the greatest differential increase observed in the basal region (overall least-squares mean [SE] difference, 2.1% [0.8%]; 95% CI, 0.6%-3.6%; P = .006) and no significant differences in the mid and apical regions among groups. Conclusions and Relevance: Patisiran prevented the deterioration of LV GLS over 18 months, driven primarily by attenuating disease progression in the basal region, suggesting that basal longitudinal strain may be a more sensitive marker of treatment associations with the cardiac manifestation in hATTR amyloidosis and that basal region may be influenced by disease-modifying therapies more than other ventricular regions. Trial Registration: ClinicalTrials.gov identifier: NCT01960348.

Transthyretin deposition in the eye in the era of effective therapy for hereditary ATTRV30M amyloidosis.

BACKGROUND: Ocular abnormalities have been known to occur in hereditary amyloidotic polyneuropathy since the 1950s. While vitreous opacities and scalloped pupils were described early it has become evident that every component of the eye from the conjunctiva to the retinal vasculature can be involved. Reports from the major centres in Japan, Portugal and Sweden, which primarily treat patients with ATTRV30M, have indicated that with the increased longevity seen in patients treated with liver transplantation the frequency of the more severe eye findings, notably vitreous opacities and subsequent glaucoma, are being detected more frequently. METHODS: In an attempt to confirm that the experience was similar in a broader range of locales we performed a survey of ten treatment centres in eight countries to determine the frequency of severe ocular abnormalities (vitreous opacities and glaucoma) in 804 patients with V30M disease and whether there was any relationship to treatment with liver transplantation or the transthyretin stabilizer tafamidis. RESULTS: The data indicate that the frequency of these abnormalities increases with increasing duration of disease. In patients broadly matched for duration of disease the frequency was higher in subjects who had undergone liver transplantation than in those who were untreated. CONCLUSIONS: Retrospective surveys are subject to a number of potential biases. In this case, the major potential confounders were defining the time of disease onset and physician bias in choice of therapy, particularly regarding the choice of patients and the time in their course when they should undergo liver transplantation, and when and whether they should receive tafamidis. Nonetheless it appears that the incidence of severe ocular abnormalities in V30M subjects from centres around the world is similar to those found in centres in the areas endemic for this variant protein. The incidence increased with duration of disease regardless of therapy with the highest frequencies seen in patients more than ten years after diagnosis who had undergone liver transplantation.

Inhibition of the mechano-enzymatic amyloidogenesis of transthyretin: role of ligand affinity, binding cooperativity and occupancy of the inner channel.

Dissociation of the native transthyretin (TTR) tetramer is widely accepted as the critical step in TTR amyloid fibrillogenesis. It is modelled by exposure of the protein to non-physiological low pH in vitro and is inhibited by small molecule compounds, such as the drug tafamidis. We have recently identified a new mechano-enzymatic pathway of TTR fibrillogenesis in vitro, catalysed by selective proteolytic cleavage, which produces a high yield of genuine amyloid fibrils. This pathway is efficiently inhibited only by ligands that occupy both binding sites in TTR. Tolcapone, which is bound with similar high affinity in both TTR binding sites without the usual negative cooperativity, is therefore of interest. Here we show that TTR fibrillogenesis by the mechano-enzymatic pathway is indeed more potently inhibited by tolcapone than by tafamidis but neither, even in large molar excess, completely prevents amyloid fibril formation. In contrast, mds84, the prototype of our previously reported bivalent ligand TTR 'superstabiliser' family, is notably more potent than the monovalent ligands and we show here that this apparently reflects the critical additional interactions of its linker within the TTR central channel. Our findings have major implications for therapeutic approaches in TTR amyloidosis.

Repositioning tolcapone as a potent inhibitor of transthyretin amyloidogenesis and associated cellular toxicity.

Transthyretin (TTR) is a plasma homotetrameric protein implicated in fatal systemic amyloidoses. TTR tetramer dissociation precedes pathological TTR aggregation. Native state stabilizers are promising drugs to treat TTR amyloidoses. Here we repurpose tolcapone, an FDA-approved molecule for Parkinson's disease, as a potent TTR aggregation inhibitor. Tolcapone binds specifically to TTR in human plasma, stabilizes the native tetramer in vivo in mice and humans and inhibits TTR cytotoxicity. Crystal structures of tolcapone bound to wild-type TTR and to the V122I cardiomyopathy-associated variant show that it docks better into the TTR T4 pocket than tafamidis, so far the only drug on the market to treat TTR amyloidoses. These data indicate that tolcapone, already in clinical trials for familial amyloid polyneuropathy, is a strong candidate for therapeutic intervention in these diseases, including those affecting the central nervous system, for which no small-molecule therapy exists.

Hippocampal Gene Expression Is Highly Responsive to Estradiol Replacement in Middle-Aged Female Rats.

In the hippocampus, estrogens are powerful modulators of neurotransmission, synaptic plasticity and neurogenesis. In women, menopause is associated with increased risk of memory disturbances, which can be attenuated by timely estrogen therapy. In animal models of menopause, 17ß-estradiol (E2) replacement improves hippocampus-dependent spatial memory. Here, we explored the effect of E2 replacement on hippocampal gene expression in a rat menopause model. Middle-aged ovariectomized female rats were treated continuously for 29 days with E2, and then, the hippocampal transcriptome was investigated with Affymetrix expression arrays. Microarray data were analyzed by Bioconductor packages and web-based softwares, and verified with quantitative PCR. At standard fold change selection criterion, 156 genes responded to E2. All alterations but 4 were transcriptional activation. Robust activation (fold change > 10) occurred in the case of transthyretin, klotho, claudin 2, prolactin receptor, ectodin, coagulation factor V, Igf2, Igfbp2, and sodium/sulfate symporter. Classification of the 156 genes revealed major groups, including signaling (35 genes), metabolism (31 genes), extracellular matrix (17 genes), and transcription (16 genes). We selected 33 genes for further studies, and all changes were confirmed by real-time PCR. The results suggest that E2 promotes retinoid, growth factor, homeoprotein, neurohormone, and neurotransmitter signaling, changes metabolism, extracellular matrix composition, and transcription, and induces protective mechanisms via genomic effects. We propose that these mechanisms contribute to effects of E2 on neurogenesis, neural plasticity, and memory functions. Our findings provide further support for the rationale to develop safe estrogen receptor ligands for the maintenance of cognitive performance in postmenopausal women.

The diversity of mechanisms influenced by transthyretin in neurobiology: development, disease and endocrine disruption.

Transthyretin (TTR) is a protein that binds and distributes thyroid hormones (THs). TTR synthesised in the liver is secreted into the bloodstream and distributes THs around the body, whereas TTR synthesised in the choroid plexus is involved in movement of thyroxine from the blood into the cerebrospinal fluid and the distribution of THs in the brain. This is important because an adequate amount of TH is required for normal development of the brain. Nevertheless, there has been heated debate on the role of TTR synthesised by the choroid plexus during the past 20 years. We present both sides of the debate and how they can be reconciled by the discovery of TH transporters. New roles for TTR have been suggested, including the promotion of neuroregeneration, protection against neurodegeneration, and involvement in schizophrenia, behaviour, memory and learning. Recently, TTR synthesis was revealed in neurones and peripheral Schwann cells. Thus, the synthesis of TTR in the central nervous system (CNS) is more extensive than previously considered and bolsters the hypothesis that TTR may play wide roles in neurobiological function. Given the high conservation of TTR structure, function and tissue specificity and timing of gene expression, this implies that TTR has a fundamental role, during development and in the adult, across vertebrates. An alarming number of 'unnatural' chemicals can bind to TTR, thus potentially interfering with its functions in the brain. One role of TTR is delivery of THs throughout the CNS. Reduced TH availability during brain development results in a reduced IQ. The combination of the newly discovered sites of TTR synthesis in the CNS, the increasing number of neurological diseases being associated with TTR, the newly discovered functions of TTR and the awareness of the chemicals that can interfere with TTR biology render this a timely review on TTR in neurobiology.

Emerging treatments for amyloidosis.

Amyloidosis results from protein misfolding, and ongoing amyloid deposition can ultimately lead to organ failure and death. Historically, this is a group of diseases with limited treatment options and frequently poor prognosis. However, there are now 'targeted' therapeutics emerging in the form of stabilizers of the precursor protein, inhibitors of fibrillogenesis, fibril disruptors, and blockers of protein translation, transcription, and immunotherapy. We review many of these approaches that are currently being assessed in clinical trials.

A woman with a rare p.Glu74Gly transthyretin mutation presenting exclusively with a rapidly progressive neuropathy: a case report.

INTRODUCTION: Familial amyloid polyneuropathy is a rare autosomal dominant disorder caused by mutations in the transthyretin gene, TTR. Diagnosis can be challenging, especially if other family members are not affected or an obvious systemic involvement is lacking. The patients are often misdiagnosed, leading to a delay in the initiation of therapy. CASE PRESENTATION: A 35-year-old woman of Turkish origin presented to our outpatient clinic with severe polyneuropathy associated with distally pronounced tetraparesis and hypesthesia of 2 to 3 years' duration. In addition, small nerve fiber involvement with impaired detection of cold temperatures and tingling pain in the lower legs was reported. She did not complain of autonomic dysfunction or visual disturbance. Her family history was empty regarding neuromuscular disorders. The routine diagnostic work-up was unremarkable. A sural nerve biopsy disclosed amyloid deposits, which led to the identification of a rare heterozygous transthyretin mutation (p.Glu74Gly; old classification: p.Glu54Gly). CONCLUSIONS: Few cases with this very heterozygous mutation can be found in the literature. In contrast to the case of our patient, all of the previously described patients in the literature presented with additional severe autonomic symptoms, involvement of the eyes and a positive family history. In this case report, we emphasize that, in patients with progressive neuropathy with small fiber involvement, an amyloid neuropathy should be considered in the differential diagnosis, even if the family history is empty and other organs are not affected.

Inhibitory activities of propolis and its promising component, caffeic acid phenethyl ester, against amyloidogenesis of human transthyretin.

Transthyretin (TTR) is a homotetrameric serum protein associated with amyloidoses such as familial amyloid polyneuropathy and senile systemic amyloidosis. The amyloid fibril formation of TTR can be inhibited through stabilization of the TTR tetramer by the binding of small molecules. In this study, we examined the inhibitory potency of caffeic acid phenethyl ester (CAPE) and its derivatives. Thioflavin T assay showed that CAPE suppressed the amyloid fibril formation of TTR. Comparative analysis of the inhibitory potencies revealed that phenethyl ferulate was the most potent among the CAPE derivatives. The binding of phenethyl ferulate and the selected compounds to TTR were confirmed by the 8-anilino-1-naphthalenesulfonic acid displacement and X-ray crystallography. It was also demonstrated that Bio 30, which is a CAPE-rich commercially available New Zealand propolis, inhibited TTR amyloidogenesis and stabilized the TTR tetramer. These results suggested that a propolis may be efficient for preventing TTR amyloidosis.