CONGRESS ABSTRACT

Background: In the phase 3 HELIOS-B trial (NCT04153149), vutrisiran reduced the risk of all-cause mortality (ACM) and recurrent cardiovascular (CV) events, and improved functional capacity and quality of life (QoL) vs placebo in patients with transthyretin amyloidosis with cardiomyopathy (ATTR-CM). Methods: This subgroup analysis assessed the effect of vutrisiran (25 mg every 3 months up to 36 months) vs placebo by baseline NYHA Class I, II, or III, and by baseline NT-proBNP levels of ≤2,000 or >2,000 pg/mL on selected HELIOS-B trial endpoints in the overall and monotherapy (not on tafamidis at baseline) populations. Endpoints analyzed included: primary endpoint of ACM and recurrent CV events up to Month 36, secondary endpoints of ACM through 42 months, change from baseline (CFB) at Month 30 in 6-minute walk test (6-MWT), and Kansas City Cardiomyopathy Questionnaire-Overall Summary score (KCCQ-OS); exploratory endpoints of CFB at Month 30 in NT-proBNP and troponin I. Results: Consistent benefits with vutrisiran vs placebo were observed in both populations for all endpoints analyzed, including ACM and recurrent CV events (Figure), 6-MWT, KCCQ-OS, NT-proBNP and troponin I, when analyzed by baseline NYHA Class or NT-proBNP level.  Conclusion: In patients with ATTR-CM, the benefits of vutrisiran vs placebo on ACM, CV events, functional capacity, health status and QoL, and cardiac biomarkers were consistent across different baseline heart failure severity groups defined by NYHA Class or NT-proBNP level.   Character count: 1,523/2,500 characters (including spaces) + 1 Figure (max 3 images)