New Findings from Landmark HELIOS-B Phase 3 Study Show Vutrisiran's Long-Term Cardiovascular Benefits in ATTR-CM at ESC Congress 2025

Vutrisiran's Clinical Efficacy and Safety

• Long-term Benefits: Vutrisiran has demonstrated sustained clinical benefits across mortality, cardiovascular events, quality of life, and cardiac biomarkers over a period of up to 48 months, including 12 months from the ongoing open-label extension (OLE) of the HELIOS-B Phase 3 study.
• Risk Reduction: The treatment reduced the risk of composite all-cause mortality or first cardiovascular event by 37% in the overall population and 42% in the monotherapy group, with statistical significance (p<0.001).

Study Details and Findings

• HELIOS-B Study Overview: The HELIOS-B trial involved 654 patients, with 466 entering the OLE period. The study's findings were presented at the European Society of Cardiology (ESC) Congress 2025.
• Key Clinical Measures: Continued treatment with vutrisiran maintained improvements in quality of life, as measured by the Kansas City Cardiomyopathy Questionnaire Overall Summary (KCCQ-OS), and showed significant reductions in cardiac biomarkers such as NT-proBNP and Troponin I.

Safety Profile

• Adverse Events: The safety profile of vutrisiran during the OLE period was consistent with previous reports, with no new safety concerns identified. The rates of adverse events, including serious adverse events, remained stable over time.

Practical Impact of Treatment

• Days Lost to Death and Hospitalization: A post hoc analysis indicated that vutrisiran was associated with a reduction of 32.2 days lost to death and/or hospitalization over three years compared to placebo, highlighting its practical benefits in managing the disease.

Regulatory Approvals and Market Presence

• Global Approvals: Vutrisiran has received approvals in multiple regions, including the US, EU, Japan, and the UK, for treating both the cardiomyopathy and polyneuropathy manifestations of hereditary transthyretin-mediated amyloidosis (hATTR).
• Patient Experience: The treatment has accumulated over 8,000 patient-years of experience worldwide, establishing its role as a first-line therapy for ATTR-CM.

Conclusion and Future Implications

• Clinical Significance: The ongoing evidence from the HELIOS-B study supports the potential of vutrisiran to modify the course of ATTR-CM, emphasizing the importance of early treatment initiation.
• Alnylam's Commitment: Alnylam Pharmaceuticals continues to focus on delivering transformative RNAi therapeutics, with a robust pipeline aimed at addressing unmet medical needs in rare and prevalent diseases.