Alnylam Presents New Data at ESC Congress 2026 Reinforcing Strength in RNAi-Powered TTR Silencing Across ATTR-CM Patient Populations and Treatment Settings

– Late-Breaking Prespecified Subgroup Analysis of HELIOS-B Demonstrates that Vutrisiran Provided Consistent Clinical Benefit Across All-Cause Mortality and Recurrent Cardiovascular Events in Patients With or Without Tafamidis Use at Baseline –

– Additional Post Hoc Analyses Highlight Positive Impact of Vutrisiran in Addressing the Multisystemic Manifestations of ATTR-CM –

– Pooled Analysis Across Four Positive Phase 3 Studies of Vutrisiran and Patisiran Shows Consistent Treatment Effect Across Sexes –

– New Subgroup Analysis from KARDIA-3 Phase 2 Study of Zilebesiran Highlights Potential to Provide Enhanced Blood Pressure Control –

CAMBRIDGE, Mass., August 30, 2026--Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), the leading RNAi therapeutics company, today announced new data at the European Society of Cardiology (ESC) Congress 2026 demonstrating the strength of RNAi-powered silencing for cardiovascular disease. The findings further reinforce the clinical profile of AMVUTTRA® (vutrisiran) across transthyretin amyloidosis (ATTR) patient populations, treatment settings, and manifestations of disease. Additionally, the data expand the potential application of RNAi to uncontrolled hypertension, the world's leading cause of cardiovascular disease.

"With the power of our RNAi therapeutics platform, we have the potential to make a transformational impact on cardiovascular care," said Pushkal Garg, M.D., Chief Research and Development Officer at Alnylam. "The data presented at ESC demonstrate the consistency of clinical outcomes achieved by RNAi-powered TTR silencing, reinforcing our conviction in AMVUTTRA as a first-line treatment option for ATTR-CM. With zilebesiran, we have the potential to extend the precision and durability of RNAi to uncontrolled hypertension. Together, these programs reflect our ambition to change the course of cardiovascular disease for patients with high unmet need."

Vutrisiran Analyses

HELIOS-B Prespecified Subgroup Analysis Demonstrates Consistent Clinical Benefit with Vutrisiran Across Contemporary ATTR-CM Treatment Settings

A late-breaking oral presentation featured a prespecified subgroup analysis of the HELIOS-B Phase 3 clinical trial evaluating the treatment effect of vutrisiran according to baseline tafamidis use. The results were simultaneously published in the Journal of the American College of Cardiology.

Among 654 randomized and treated patients in HELIOS-B, 259 patients (40%) were receiving tafamidis at baseline. The treatment effect for vutrisiran on the primary composite endpoint of all-cause mortality and recurrent cardiovascular events through 33-36 months was consistent irrespective of baseline tafamidis use, suggesting clinical benefits across broad patient populations, including those receiving stabilizers.