An Extension Study to Assess Long-Term Safety of Eplontersen in Adults With Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR-CM)

An Open-Label Extension Study to Assess the Long-Term Safety of Eplontersen (ION-682884) in Patients With Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR-CM)

Status

Enrolling by invitation

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT05667493

Enrollment

1400

Registered

2022-12-28

Start date

2022-11-30

Completion date

2029-08-01

Last updated

2026-04-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR CM)

Keywords

Amyloidosis

Brief summary

The purpose of this study is to evaluate the safety and tolerability of extended dosing with eplontersen in participants with ATTR-CM.

Detailed description

This is a multicenter, open-label extension, Phase 3 study in up to approximately 1400 participants from the 682884-CS2 study. Eligible participants will receive eplontersen once every 4 weeks for up to 36 months or until after eplontersen is approved and available in the site's country, whichever occurs first. Participants will also receive daily supplemental doses of the recommended daily allowance (RDA) of vitamin A.

Interventions

DRUGEplontersen

Eplontersen will be administered by SC injection.

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

1. Satisfactory completion of Treatment Period and the End of Treatment Visit of the Index Study (ION-682884-CS2) OR diagnosis of ATTR-CM and satisfactory participation on ISIS 420915- CS101 study as judged by the Investigator and Sponsor. 2. Investigator is willing to treat the participant with open-label eplontersen. 3. Willingness to adhere to vitamin A supplementation per protocol.

Exclusion criteria

1. Permanently discontinued study drug administration while participating in the Index Study (ION 682884-CS2) or IST (ISIS 420915-CS101 Study). 2. Have any new condition or worsening of an existing condition that in the opinion of the Investigator or Sponsor would make the participant unsuitable for enrolment, or which could interfere with the participant participating in or completing the study, including the need for treatment with medications disallowed in the Index Study.

Design outcomes

Primary

Measure	Time frame
Number of Participants With Adverse Events (AE) and Serious Adverse Events (SAE)	Baseline up to 36 months
Change From Baseline in Platelet Count	Baseline up to 36 months
Change From Baseline in Estimated Glomerular Filtration Rate (eGFR)	Baseline up to 36 months
Change From Baseline in Urine Protein Creatinine Ratio (UPCR)	Baseline up to 36 months

Secondary

Measure	Time frame
Change From Baseline in Transthyretin (TTR) Serum Levels	Baseline up to 36 months
Change From Baseline in 6-minute Walk Test (6MWT)	Baseline up to 36 months
Change From Baseline in Kansas City Cardiomyopathy Questionnaire (KCCQ)	Baseline up to 36 months

Countries

Argentina, Australia, Austria, Belgium, Brazil, Canada, Czechia, Denmark, France, Germany, Greece, Israel, Italy, Japan, Poland, Portugal, Spain, Sweden, United Kingdom, United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Apr 18, 2026