Efficacy of Acoramidis in Wild-Type and Variant Transthyretin Amyloid Cardiomyopathy: Results From ATTRibute-CM and Its Open-Label Extension.

Abstract

Transthyretin amyloid cardiomyopathy (ATTR-CM), a progressive disease caused by misfolded transthyretin (TTR), occurs as wild-type (ATTRwt-CM) or variant (ATTRv-CM) forms. p.Val142Ile is the most common variant in the US, linked to rapid progression and increased mortality. Acoramidis achieves near-complete (≥90%) TTR stabilization and showed clinical benefit in the 30-month ATTRibute-CM trial and through month 42 in the ongoing open-label extension (OLE). To evaluate the efficacy of acoramidis in ATTRwt-CM, ATTRv-CM, and variant subgroups (p.Val142Ile and non-p.Val142Ile). This international, multicenter, phase 3, randomized placebo-controlled study took place from April 2019 to May 2023 with ongoing OLE (month 42). ATTRibute-CM enrolled 632 participants with ATTR-CM; 611 of 632 were included in the modified intention-to-treat (mITT) population. There were 380 participants who continued into the OLE. These data were analyzed from January 2025 to July 2025. Oral acoramidis, 712 mg, or placebo twice daily for 30 months, followed by 12 months of open-label treatment. All-cause mortality (ACM), cardiovascular-related hospitalizations (CVH), serum TTR, 6-minute walk distance, Kansas City Cardiomyopathy Questionnaire Overall Summary score, and N-terminal pro B-type natriuretic peptide in participants with ATTRwt-CM and ATTRv-CM. Post-hoc analyses were conducted in variant subgroups, including p.Val142Ile. Overall, 552 participants with wild-type ATTR-CM (mean [SD] age, 78 [6.3] years; 92.0% male and 8.0% female) and 59 participants with variant ATTR-CM (mean [SD] age, 73 [7.7] years; 77.3% male and 22.7% female) were randomized (mITT population), including 35 with p.Val142Ile. Consistent efficacy was observed in wild-type and variant subgroups for ACM/CVH through month 30 and ACM through month 42. At month 30, acoramidis reduced the risk of ACM/first CVH vs placebo by 31% in ATTRwt-CM (hazard ratio [HR], 0.69; 95% CI, 0.52-0.90; P = .007) and by 59% in ATTRv-CM (HR, 0.41; 95% CI, 0.21-0.81; P = .01). ACM was reduced through month 42 with HRs of 0.70 (95% CI, 0.50-0.98; P = .04) and 0.41 (95% CI, 0.19-0.93; P = .03) in the ATTRwt-CM and ATTRv-CM groups, respectively. Consistent treatment benefit was observed in participants with ATTRwt-CM and ATTRv-CM for secondary end points. Within variant subgroups (p.Val142Ile vs non-p.Val142Ile), consistent treatment benefits were observed for ACM/CVH through month 30 and ACM through month 42. The beneficial effect of acoramidis was observed consistently in ATTRwt-CM and ATTRv-CM groups. These hypothesis-generating results indicate that further studies are warranted to better characterize the therapeutic benefit of acoramidis in variant subgroups. ClinicalTrials.gov Identifiers: NCT03860935; NCT04988386.