CONGRESS ABSTRACT

Background: Transthyretin amyloidosis with cardiomyopathy (ATTR-CM) progressively impairs patients’ functional capacity, health status, and quality of life (QOL). In HELIOS-B, vutrisiran reduced all-cause mortality and cardiovascular events compared with placebo in patients with ATTR-CM and demonstrated significant benefit on multiple clinical measures of disease progression. Methods: In HELIOS-B, 6-minute walk test (6MWT) and Kansas City Cardiomyopathy Questionnaire-Overall Summary (KCCQ-OS) score were secondary endpoints assessing functional capacity and health status/QOL. Here, we present further details on the efficacy of vutrisiran on patients’ functional capacity, health status, and quality of life. Results:  In the overall population at Month 30, the difference of LS-mean change from baseline (vutrisiran – placebo) was 26.46 m (95% CI 13.38, 39.55; p<0.001) for the 6MWT and 5.80 points (95% CI 2.40, 9.20; p<0.001) for the KCCQ-OS. Over 30 months, in the overall population, 64% and 47% of patients treated with vutrisiran and placebo, respectively (p<0.05) [monotherapy population; 65% and 38% (p<0.05)], had an increase or <5-point decrease in KCCQ-OS. Consistent benefits with vutrisiran were observed for both 6MWT and KCCQ-OS in prespecified subgroups, subdomains and different cut-off values/clinical thresholds. Similar trends were observed in the baseline tafamidis subgroup. Conclusion: Significantly more patients treated with vutrisiran maintained or improved functional capacity and health status/QOL compared with placebo, providing further evidence of the disease-modifying effect of vutrisiran treatment.   1637 characters = 1637/2500 characters (including spaces)