ATTR-CM-Study Design

HELIOS-B Clinical Trial

HELIOS-B was a landmark clinical trial establishing the efficacy and safety of AMVUTTRA® in ATTR-CM1

A global, randomized, double-blind, placebo-controlled, Phase 3 study1-3

Chart showing the HELIOS-B study designChart showing the HELIOS-B study design

  • Randomization was stratified according to tafamidis use at baseline (with vs without), ATTR disease type (hereditary vs wild-type), and NYHA class and age at baseline (NYHA class I or II and age <75 years vs all others)1
  • Following the double-blind (DB) period of up to 36 months, patients on placebo were eligible to transition to AMVUTTRA in the open-label extension, which lasted up to 24 months2

The monotherapy population comprised ~60% of patients in HELIOS-B and may be representative of patients receiving first-line therapy1,2

Patients in the monotherapy population were permitted to initiate tafamidis during the DB period.

*The overall population included patient cohorts with and without tafamidis use at baseline.1

†Cardiovascular events are defined as hospitalizations for cardiovascular causes or urgent visits for heart failure.1

6-MWT=6-minute walk test; ATTR=transthyretin-mediated amyloidosis; ATTR-CM=cardiomyopathy of transthyretin-mediated amyloidosis; hATTR=hereditary transthyretin-mediated amyloidosis; KCCQ‑OS=Kansas City Cardiomyopathy Questionnaire-Overall Summary; NT-proBNP=N-terminal prohormone of brain‑type natriuretic peptide; NYHA=New York Heart Association; q3m=every 3 months; SC=subcutaneous; wtATTR=wild-type transthyretin-mediated amyloidosis.

The study population was typical of present-day patients with ATTR-CM2

Patient Characteristics at Baseline
Table showing the HELIOS-B baseline characteristics for monotherapyTable showing the HELIOS-B baseline characteristics for monotherapy
 

 

Table showing the HELIOS-B baseline characteristics for monotherapy

Patients treated with AMVUTTRA had higher NT-proBNP and troponin I levels at baseline compared with placebo.2,3
IQR=interquartile range; NT-proBNP=N-terminal prohormone of brain-type natriuretic peptide; SD=standard deviation.
Patients treated with AMVUTTRA had higher NT‑proBNP and troponin I levels at baseline compared with placebo.2,3

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Important Safety Information

Reduced Serum Vitamin A Levels and Recommended Supplementation

AMVUTTRA treatment leads to a decrease in serum vitamin A levels.

Supplementation at the recommended daily allowance (RDA) of vitamin A is advised for patients taking AMVUTTRA. Higher doses than the RDA should not be given to try to achieve normal serum vitamin A levels during treatment with AMVUTTRA, as serum vitamin A levels do not reflect the total vitamin A in the body.

Patients should be referred to an ophthalmologist if they develop ocular symptoms suggestive of vitamin A deficiency (e.g., night blindness).

Adverse Reactions

In a study of patients with hATTR-PN, the most common adverse reactions that occurred in patients treated with AMVUTTRA were pain in extremity (15%), arthralgia (11%), dyspnea (7%), and vitamin A decreased (7%).

In a study of patients with ATTR-CM, no new safety issues were identified.

For additional information about AMVUTTRA, please see the full Prescribing Information.

Indications

AMVUTTRA® (vutrisiran) is indicated for the treatment of the:

  • cardiomyopathy of wild-type or hereditary transthyretin-mediated amyloidosis (ATTR-CM) in adults to reduce cardiovascular mortality, cardiovascular hospitalizations and urgent heart failure visits.
  • polyneuropathy of hereditary transthyretin-mediated amyloidosis (hATTR-PN) in adults.

For additional information about AMVUTTRA, please see the full Prescribing Information.

References

  1. AMVUTTRA Prescribing Information. Cambridge, MA: Alnylam Pharmaceuticals, Inc.
  2. Fontana et al. N Engl J Med. 2025;392(1):33-44.
  3. Fontana et al. N Engl J Med. 2025;392(1):33-44 (supplement).
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