Alnylam Pharmaceuticals has shared positive new results from a late-stage trial of its RNAi therapeutic Amvuttra (vutrisiran) in transthyretin amyloid cardiomyopathy (ATTR-CM), an under-diagnosed and rapidly progressive disease of the heart muscle.
ATTR-CM, in which misfolded transthyretin (TTR) protein builds up and causes irreversible cardiovascular damage over time, is estimated to affect over 300,000 people worldwide.
Given quarterly via a subcutaneous injection, Alnylam’s Amvuttra works with the body’s natural system to rapidly knock down TTR, and received approval from the US Food and Drug Administration in March to treat cardiomyopathy of wild-type or hereditary ATTR-CM.
The US regulator’s decision was supported by results from the phase 3 HELIOS-B trial, in which Alnylam’s drug reduced the risk of all-cause mortality (ACM) and recurrent cardiovascular events by 28% in the overall study population during the double-blind treatment period of up to 36 months.
New data from HELIOS-B presented at the European Society of Cardiology’s Heart Failure Congress showed that Amvuttra reduces key cardiovascular (CV) events such as CV hospitalisations and heart failure hospitalisations, which often come before ACM and are key indicators of disease progression.
By month 42, the risk of ACM was reduced by 36% and the risk of CV mortality was reduced by 33% in the overall population compared to placebo. Additionally, urgent heart failure visits were reduced by 46%.
Alnylam’s chief medical officer, Pushkal Garg, said: “From the primary analysis of HELIOS-B, we know that Amvuttra profoundly impacts ACM, while preserving patients’ functional capacity and quality of life.”
He continued: “I remain impressed by the HELIOS-B results, which are noteworthy given the substantial use of heart failure treatments in the study population, and I believe they continue to reinforce Amvuttra as a clinically differentiated, first-line option for patients with ATTR-CM.”
Alongside ATTR-CM, Amvuttra already holds approvals to treat the polyneuropathy of hereditary TTR-mediated amyloidosis.
The drug has also been recommended by the European Medicines Agency’s human medicines committee to treat ATTR-CM, with a decision from the European Commission expected by the third quarter of 2025.
