Vutrisiran Shows Long-Term Cardiovascular Benefit in ATTR-CM: New Data from Landmark HELIOS-B Phase 3 Study Presented at ESC Congress 2025

08/31/2025 – 05:15 AM

− Sustained Benefit of Vutrisiran Across Mortality, Cardiovascular Events, Quality of Life and Cardiac Biomarkers Observed Through Up to 48 Months, Including 12 Months from the Ongoing Open-Label Extension, Reinforce Potential as First-Line Treatment for ATTR-CM –

− Vutrisiran, which Delivers Rapid Knockdown of Transthyretin, Reduced the Risk of Composite of All-Cause Mortality or First Cardiovascular Event by 37% in the Overall Population and 42% in the Monotherapy Group During the Same Period –

CAMBRIDGE, Mass. — Alnylam Pharmaceuticals (ALNY), a frontrunner in RNAi therapeutics, has unveiled compelling new data from its HELIOS-B Phase 3 study of AMVUTTRA (vutrisiran). The drug, already approved for the treatment of cardiomyopathy associated with both wild-type and hereditary transthyretin-mediated amyloidosis (ATTR-CM) in adults, continues to demonstrate significant clinical benefits, positioning it as a potentially groundbreaking first-line therapy.

The findings, presented at the European Society of Cardiology (ESC) Congress 2025 in Madrid, Spain, showcase the impact of vutrisiran over a period of up to 48 months, including a 12-month follow-up from the ongoing open-label extension (OLE) of the HELIOS-B study. The data underscore vutrisiran’s ability to rapidly reduce levels of the disease-causing transthyretin (TTR) protein, resulting in a 37% risk reduction in the composite endpoint of all-cause mortality (ACM) or first cardiovascular (CV) event within the overall patient population. In patients receiving vutrisiran as a monotherapy, the risk reduction was even more pronounced, clocking in at 42%.

CNBC has learned that the open-label extension of HELIOS-B maintained clinical benefits seen in the initial, double-blind phase for key disease progression markers. Namely, sustained health improvements in quality of life (QoL) and key cardiac biomarkers.

“The HELIOS-B study continues to deliver robust evidence supporting the clinically differentiated profile of vutrisiran,” noted Dr. John Vest, Senior Vice President, TTR Global Clinical Lead at Alnylam. “These longer-term data demonstrate that, through up to 48 months, vutrisiran treatment conferred continued clinical benefit across key endpoints, including survival, cardiovascular events, and quality of life. These results reinforce the potential for vutrisiran, which provides rapid and sustained knockdown of TTR, to modify the course of disease over the long-term and to be a first-line therapy for ATTR-CM.”

The HELIOS-B trial encompassed a patient population representative of those currently diagnosed with ATTR-CM. The follow-up data, with vital status ascertained for over 99% of participants, reveal the following key results:

Safety data from the OLE period corroborated the established safety profile of vutrisiran seen during the double-blind phase. The rate of adverse events, including cardiac events, did not escalate with extended treatment, reinforcing its favorable risk-benefit profile.

Dr. Pablo Garcia-Pavia, Head of the Inherited Cardiac Diseases and Heart Failure Unit at Hospital Universitario Puerta de Hierro in Madrid, Spain, emphasized the clinical significance of these findings: “The irreversible nature of disease progression, taken together with the sustained clinical benefit seen in patients treated with vutrisiran through 48 months, collectively underscore the importance of early treatment initiation and further support the role of vutrisiran as a first-line treatment for ATTR-CM.”