Sperry, Brett W.

BACKGROUND: Transthyretin amyloidosis with cardiomyopathy is a progressive, fatal disease characterized by deposition of extracellular misfolded transthyretin (TTR) in the myocardium. Eplontersen is an N-acetylgalactosamine ligand–conjugated antisense oligonucleotide targeting hepatocyte TTR messenger RNA to reduce the production of circulating TTR. METHODS: CARDIO-TTRansform is a Phase 3, randomized, double-blind, placebo-controlled trial to assess the efficacy and safety of eplontersen in transthyretin amyloidosis with cardiomyopathy. Key inclusion criteria include histological evidence of amyloid deposits or grade 2 to 3 cardiac uptake on cardiac scintigraphy in the absence of plasma cell dyscrasia, New York Heart Association class I–III, and end-diastolic interventricular septum thickness >12 millimeters. Participants were randomized 1:1 to receive eplontersen 45 mg or placebo, administered subcutaneously every 4 weeks for up to 140 weeks, followed by a 20-week post-treatment evaluation period or open-label extension. Participants received locally available standard of care, including unrestricted use of TTR stabilizers. The primary end point is a composite of cardiovascular mortality and recurrent clinical cardiovascular events through 140 weeks. Secondary end points, in order of testing hierarchy, include changes from baseline in 6-minute walk distance and Kansas City Cardiomyopathy Questionnaire overall summary score, recurrent cardiovascular events, all-cause mortality, the primary end point in the patient subgroup receiving stabilizers at baseline, and cardiovascular mortality. Echocardiography was performed in all participants, with cardiovascular magnetic resonance imaging and technetium scintigraphy in a subset. CONCLUSIONS: CARDIO-TTRansform is fully enrolled, with 1432 randomized participants who were dosed with study drug or placebo. As the largest transthyretin amyloidosis with cardiomyopathy study to date, it will evaluate whether eplontersen improves cardiovascular outcomes in patients receiving locally available standard of care, including TTR stabilizers. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04136171. URL: http://ClinicalTrialsRegister.eu ; Unique identifier: EudraCT number 2019-002835-27.

Background: Atrial fibrillation (AF) significantly impacts quality of life (QoL) and is often observed in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). Acoramidis achieves near-complete (≥90%) transthyretin (TTR) stabilization and is approved in the USA, the UK, Europe and Japan for the treatment of ATTR-CM in adults. In the phase 3 ATTRibute-CM study (NCT03860935), acoramidis treatment significantly reduced the time to all-cause mortality (ACM) or first cardiovascular-related hospitalization (CVH) at Month 30, and resulted in improved 6-minute walk distance (6MWD), Kansas City Cardiomyopathy Questionnaire-Overall Summary (KCCQ-OS) scores and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels relative to placebo. The clinical efficacy of acoramidis has not yet been reported in patients with ATTR-CM and with an AF or atrial flutter (AFL) diagnosis at baseline. Research Question: How does acoramidis treatment affect ACM or first CVH, 6MWD, KCCQ-OS scores, and NT-proBNP levels at Month 30 in participants with ATTR-CM with or without AF/AFL diagnosis at baseline? Methods: The ATTRibute-CM study design has been previously published. This post hoc analysis included participants in the modified intention-to-treat population (N=611) grouped by AF/AFL diagnosis at baseline (defined as recorded AF medical history or the presence of AF or AFL on an ECG at enrollment). The rate of ACM or first CVH at Month 30 was compared between groups using a stratified Cox proportional hazards model. Changes from baseline to Month 30 in 6MWD, KCCQ-OS scores and NT-proBNP levels were summarized descriptively. Results: Overall, 62.8% (384/611) of participants had an AF/AFL diagnosis at baseline (acoramidis: 255/409, placebo: 129/202). These participants had lower mean 6MWD and KCCQ-OS scores and higher median NT-proBNP levels than those without AF/AFL diagnosis at baseline. Treatment with acoramidis reduced ACM or first CVH, slowed the decline in 6MWD and KCCQ-OS scores and blunted the rise in NT-proBNP compared with placebo, regardless of AF/AFL diagnosis at baseline ( Table ). Conclusions: Acoramidis improved clinical outcomes (ACM, CVH), functional status, QoL and NT-proBNP levels relative to placebo in participants with ATTR-CM, regardless of AF/AFL diagnosis at baseline.

ImportanceTafamidis reduced all-cause mortality and cardiovascular-related hospitalizations and minimized patient-reported health status deterioration at 30 months in patients with transthyretin (ATTR) amyloidosis. However, the clinical significance of health status changes remains unclear, particularly in patients with New York Heart Association (NYHA) class III symptoms who experienced more cardiovascular-related hospitalizations than those with NYHA class I-II symptoms.ObjectiveTo evaluate the health status of patients taking tafamidis with baseline NYHA class III symptoms.Design, Setting, and ParticipantsThis randomized clinical trial post hoc analysis evaluated data for patients with transthyretin (ATTR) cardiac amyloidosis and NYHA class I-III symptoms at baseline who were enrolled in ATTR-ACT, a placebo-controlled study of tafamidis held at 48 sites in 13 countries.InterventionsTafamidis meglumine, 80 mg or 20 mg (pooled cohort), vs placebo.Main Outcomes and MeasuresEstablished thresholds for clinical benefit on the Kansas City Cardiomyopathy Questionnaire Overall Summary (KCCQ-OS) were used to define response groups (very large decline to very large improvement); the proportion of patients in each group was calculated within each baseline NYHA class.ResultsAmong 441 patients (264 tafamidis, 177 placebo), the mean (SD) age was 74.3 (7.0) years; 398 (90%) were male and 43 (10%) were female. Mean (SD) baseline KCCQ-OS scores were 67.3 (21.4) in the tafamidis group and 65.9 (21.7) in the placebo group (range: 0-100, with 100 indicating the best health). There was a significant shift toward better KCCQ-OS scores in patients receiving tafamidis (odds ratio for 10-point improvement 2.4; 95% CI, 1.6-3.4; P < .001). More patients taking tafamidis were alive and not worse at all time points (37% vs 15% at month 30). These findings were similar in patients with NYHA class III symptoms. In patients with NYHA class III symptoms alive at 30 months, improvements in health status were more common (35% vs 10%) and declines were less common (38% vs 57%) with tafamidis vs placebo.Conclusions and RelevanceIn ATTR-ACT, although patients with baseline NYHA class III symptoms had worse overall outcomes, treatment with tafamidis yielded better health status compared with placebo.Trial RegistrationClinicalTrials.gov Identifier: NCT01994889