The HELIOS-A study has reported positive results of 18 months of treatment with vutrisiran treatment for patients with hereditary transthyretin-mediated amyloidosis (hATTR). The study, published in Archives of Cardiovascular Disease Supplements, reported improved NT-proBNP levels and echocardiographic characteristics compared with patients given placebo.

“HELIOS-A assessed the efficacy of vutrisiran, an investigational RNAi, in patients with hATTR amyloidosis with polyneuropathy,” the authors wrote. “[Vutrisiran] also reduced cardiac uptake of 99mTc, potentially suggesting reduction in cardiac amyloid.”

hATTR is a rare, underdiagnosed, progressive, and hereditary disease caused by a mutation in the transthyretin (TTR) gene. It leads to the accumulation of misfolded amyloid protein deposits in multiple organs including the heart, eyes, kidneys, peripheral nervous system, and gastrointestinal tract.

Vutrisiran is an investigational RNAi therapy that inhibits TTR production in the liver, thereby reducing overall TTR in the blood. It is administered subcutaneously every 3 months. It has not yet been approved by the US Food and Drug Administration or the European Medicines Agency but it is under review. A phase 1 study on 80 healthy volunteers demonstrated an acceptable safety profile, with reduced serum TTR levels for at least 90 days after 1 dose of vutrisiran.

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The open-label, global phase 3 HELIOS-A study randomized 164 patients 3:1 to 25 mg vutrisiran every 3 months, 0.3 mg/kg patisiran every 3 weeks, or placebo, with a primary endpoint of change from baseline in the modified neuropathy impairment score. Cardiac endpoints included changes in NT-proBNP levels, 99mTc scintigraphy, and echocardiography parameters at 18 months.

A trend towards improvements in NT-proBNP levels, cardiac output, and 99mTc scintigraphy was observed. No cardiac safety concerns were found with the treatment.


Pavia P, Gillmore JD, Kale P, et al. HELIOS-A: 18-month exploratory cardiac results from the phase 3 study of vutrisiran in patients with hereditary transthyretin-mediated amyloidosis. Arch Cardiovasc Disease Supp. 2023;15(1). doi: 10.1016/j.acvdsp.2022.10.056