Alnylam reports new data from HELIOS-B Phase 3 study

Alnylam (ALNY) Pharmaceuticals announced results of new analyses from the HELIOS-B Phase 3 study of AMVUTTRA, an RNAi therapeutic approved for the treatment of the cardiomyopathy of wild-type or hereditary transthyretin-mediated amyloidosis in adults. Data from the 12-month follow-up of the ongoing open-label extension period of HELIOS-B were presented during an oral session at the European Society of Cardiology Congress 2025 held in Madrid, Spain. These data reflect outcomes of treatment through up to 48 months, including the initial double-blind period of 33-36 months, and highlight the ongoing clinical benefit of vutrisiran, which causes rapid knockdown of the disease-causing transthyretin protein, including a 37% risk reduction in the composite endpoint of all-cause mortality or first cardiovascular event in the overall population and a 42% risk reduction in the monotherapy group, reinforcing vutrisiran’s potential as a first-line treatment for patients with ATTR-CM. Vutrisiran also reduced the risk of ACM alone by 37% in the overall population and 39% in the monotherapy group during this same period. “The findings from the ongoing HELIOS-B study show that the clinical benefits seen during the double-blind period of 33-36 months across key clinical measures of disease progression, including quality of life as measured by the Kansas City Cardiomyopathy Questionnaire Overall Summary and cardiac biomarkers, were maintained with continued vutrisiran treatment during the 12-month OLE period. The long-term safety and tolerability profile during the OLE period was consistent with the established profile of vutrisiran. Additionally, a post hoc analysis of the HELIOS-B trial presented during a poster session highlighted reductions in days lost to death and/or hospitalization and improvements in functional and QoL outcomes compared to placebo. Vutrisiran was associated with a reduction in mean DLDH of more than one month versus placebo over a three-year period, with a greater effect observed when accounting for impaired function and QoL,” the company stated.