Vutrisiran in East Asian Patients With Transthyretin Amyloidosis With Cardiomyopathy: Post-Hoc Analysis of HELIOS-B.

BACKGROUND

In the phase III Study to Evaluate Vutrisiran in Patients With Transthyretin Amyloidosis With Cardiomyopathy (HELIOS-B), vutrisiran significantly reduced all-cause mortality and recurrent cardiovascular events and preserved functional capacity and quality of life. However, data in East Asian populations remain limited.

OBJECTIVES

The authors aimed to assess the efficacy and safety of vutrisiran in East Asian patients with transthyretin amyloidosis with cardiomyopathy (ATTR-CM) enrolled in HELIOS-B.

METHODS

This post-hoc analysis included 32 patients from Japan and South Korea randomized to vutrisiran (n = 17) or placebo (n = 15). The primary endpoint was a composite of all-cause mortality and recurrent cardiovascular events for up to 36 months. Secondary endpoints were changes from baseline to month 30 in the 6-minute walk test distance, Kansas City Cardiomyopathy Questionnaire Overall Summary (KCCQ-OS) score, and New York Heart Association (NYHA) functional class. Exploratory endpoints included changes in N-terminal pro-B-type natriuretic peptide and troponin I. Safety was also evaluated.

RESULTS

Baseline characteristics were generally similar to the overall population, although baseline tafamidis use was lower in East Asian patients. Vutrisiran reduced the risk of the composite primary endpoint vs placebo (HR: 0.20; 95% CI: 0.04-0.93). Vutrisiran attenuated declines in 6-minute walk test distance and KCCQ-OS scores, and a greater proportion of patients maintained or improved NYHA functional class. Smaller increases in N-terminal pro-B-type natriuretic peptide and troponin I levels were observed with vutrisiran vs placebo. Similar trends were observed in patients not receiving baseline tafamidis. Safety was consistent with the overall population.

CONCLUSIONS

In East Asian patients with ATTR-CM from HELIOS-B, the efficacy and safety of vutrisiran were consistent with the overall population. (HELIOS-B: A Study to Evaluate Vutrisiran in Patients With Transthyretin Amyloidosis With Cardiomyopathy; NCT04153149).