Effect of Acoramidis on Recurrent and Cumulative Cardiovascular Outcomes in ATTR-CM: Exploratory Analysis From ATTRibute-CM.

Abstract

Transthyretin (TTR) amyloid cardiomyopathy (ATTR-CM) is a progressive disease with a significant burden of recurrent cardiovascular (CV) events. Acoramidis, an approved oral therapy for ATTR-CM, achieves early, near-complete (≥90%) TTR stabilization. In the phase 3 ATTRibute-CM (Efficacy and Safety of Acoramidis in Participants with Transthyretin Amyloid Cardiomyopathy) study, acoramidis significantly reduced the composite of all-cause mortality or first CV-related hospitalization (CVH), with an effect observed at month 3. Its efficacy on the burden of cumulative CV outcome events has not been reported. This study was a post hoc exploratory recurrent-event analysis of the efficacy of acoramidis on the cumulative incidence of CV outcomes from ATTRibute-CM and its open-label extension. Cumulative incidences of centrally adjudicated CV-related mortality (CVM) or recurrent CVH (first and, if applicable, subsequent CVH), recurrent CVH alone (month 30), and CVM (month 42) were measured in the modified intention-to-treat population (acoramidis, n = 409; placebo, n = 202). Mean cumulative events by treatment, and the difference between treatment groups were estimated by using a modified Andersen-Gill model. Acoramidis significantly reduced the cumulative risk of CVM or recurrent CVH through month 30 vs placebo (HR: 0.51; 95% CI: 0.43-0.62; P < 0.0001). A notable proportion of CV outcome events (19% of CVM or recurrent CVH events, 22% of CVH) occurred within the first 6 months. Numerically fewer cumulative events were observed with acoramidis compared with placebo at month 1, and the difference increased progressively, resulting at month 30 in 53 events avoided per 100 treated participants (95% CI: 29-79). At month 42, CVM was reduced with continuous acoramidis vs placebo-to-acoramidis (HR: 0.55; 95% CI: 0.39-0.79; P = 0.0011). The annualized frequency of recurrent CVH was significantly decreased through month 30 (relative risk ratio: 0.50; 95% CI: 0.35-0.69; P < 0.0001). Acoramidis significantly reduced the cumulative burden of CV outcomes in ATTR-CM over 30 months. Numerically fewer events were observed with acoramidis vs placebo by month 1, and the difference increased progressively over time, resulting in 53 events avoided per 100 treated patients at month 30. Almost one-fourth of the cumulative CV events occurred within the first 6 months. These exploratory findings suggest that cumulative event burden may occur early, highlighting the importance of timely evaluation, diagnosis and treatment in ATTR-CM.