Alnylam Pharmaceuticals Inc. (NASDAQ: ALNY) presented new analyses from its HELIOS-B Phase 3 study of vutrisiran at Heart Failure 2026, showing consistent clinical benefits across patient populations with transthyretin-mediated amyloidosis cardiomyopathy (ATTR-CM).

The data demonstrated that vutrisiran reduced all-cause mortality and recurrent cardiovascular events across key patient subgroups, including those with atrial fibrillation, low systolic blood pressure, and high comorbidity burden. The treatment effects remained consistent in patients receiving background therapies including TTR stabilizers and heart failure medications.

In patients with atrial fibrillation, representing approximately 65% of the study population, vutrisiran significantly reduced the risk of all-cause mortality and recurrent cardiovascular events compared with placebo. Clinical benefits were maintained regardless of concomitant use of medications such as SGLT2 inhibitors, MRAs, beta-blockers and ACE inhibitors.

A separate pooled analysis evaluated safety data from more than 25,000 patient-years of treatment exposure across vutrisiran and patisiran programs. The analysis found that rates of ocular adverse events potentially associated with vitamin A deficiency were low and comparable to placebo, with no cases of clinically meaningful vitamin A deficiency observed.

Alnylam also presented the design of the DemonsTTRate study, a global observational study expected to enroll more than 2,000 patients with ATTR-CM and follow them for up to five years to generate real-world outcomes data.

Worldwide experience with vutrisiran across ATTR-CM and hereditary transthyretin-mediated amyloidosis with polyneuropathy exceeds 13,000 patient-years. Vutrisiran is approved for treatment of both conditions and is administered quarterly via subcutaneous injection.