Alnylam Pharmaceuticals, Inc. Announces New Analyses from the Helios-B Phase 3 Study of Vutrisiran in Patients

Published: 2026-05-12 13:05:32 ET ALNY

Published on 05/12/2026 at 01:05 pm EDT

Alnylam Pharmaceuticals, Inc. announced new analyses from the HELIOS-B Phase 3 study of vutrisiran in patients with the cardiomyopathy of wild-type or hereditary transthyretin-mediated amyloidosis (ATTR-CM), adding to the growing body of evidence supporting vutrisiran and reinforcing the durability of transthyretin (TTR) knockdown and its well-characterized safety profile. Vutrisiran is the first and only TTR silencer approved for ATTR-CM that is designed to deliver rapid knockdown of TTR at the source. The data presented at Heart Failure 2026, the annual congress of the Heart Failure Association of the European Society of Cardiology, show consistent clinical benefit across patient populations commonly encountered in clinical practice, including those with a high disease burden, supporting its use as a first-line treatment option for this rapidly progressive and life-threatening disease.

In patients with atrial fibrillation, representing approximately 65% of the HELIOS-B study population and associated with more advanced disease, vutrisiran significantly reduced the risk of all-cause mortality and recurrent cardiovascular (CV) events compared with placebo. Treatment effects were also maintained in patients with low systolic blood pressure (SBP), a higher-risk phenotype, with vutrisiran slowing the progressive decline in SBP observed over time. Clinical benefits were similarly consistent regardless of comorbidity burden or concomitant use of disease-modifying therapies, including tafamidis and heart failure medications such as SGLT2 inhibitors, MRAs, ß-blockers and ACEi/ARB/ARNI.

Consistent effects were also observed in women, a historically underrepresented population in ATTR-CM trials. A separate pooled analysis of clinical trial and post-marketing safety data evaluated the relationship between transthyretin-lowering RNAi therapies and vitamin A deficiency-related adverse events. Patients treated with vutrisiran and patisiran are suggested to take the recommended daily allowance of vitamin A. The analysis included more than 25,000 patient-years of treatment exposure across vutrisiran and patisiran programs. Rates of ocular adverse events potentially associated with vitamin A deficiency were low and comparable to placebo.

No cases of clinically meaningful vitamin A deficiency were observed. Alnylam also presented the design and rationale of the DemonsTTRate study, a global, prospective, observational study evaluating real-world outcomes in patients with ATTR-CM. The study is expected to enroll more than 2,000 patients and follow them for up to five years, generating longitudinal data on clinical outcomes, treatment patterns and healthcare utilization across routine clinical practice.

Across ATTR-CM and hereditary transthyretin-mediated amyloidosis with polyneuropathy (hATTR-PN), worldwide experience with vutrisiran to date exceeds 13,000 patient-years, reflecting a robust and expanding body of clinical evidence across both manifestations of the disease.