> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/an-extension-study-to-assess-long-term-safety-of-eplontersen-591c383e-727e-459b-aacf-c9411087ae73 > Record changed: 2026-10-13 # An Extension Study to Assess Long-Term Safety of Eplontersen in Adults With Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR-CM) NCT05667493 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) Phase Phase 3 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) Recruitment status Enrolling by invitation Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) Participants 1,400 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) Lead sponsor Ionis Pharmaceuticals, Inc. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) Start date 2022-11-30 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) Number of sites 134 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## Title and summary **Summary** The purpose of this study is to evaluate the safety and tolerability of extended dosing with eplontersen in participants with ATTR-CM. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Short title** An Extension Study to Assess Long-Term Safety of Eplontersen in Adults With Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR-CM) Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Official title** An Open-Label Extension Study to Assess the Long-Term Safety of Eplontersen (ION-682884) in Patients With Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR-CM) Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## Status and phase **Control arm** Open label Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Registry reports results** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Recruitment status** Enrolling by invitation Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Phase** Phase 3 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## Dates **Completion date** 2029-08-01 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **First posted** 2022-12-28 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Registry last updated** 2026-04-17 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Primary completion date** 2029-08-01 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Start date** 2022-11-30 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## Size and sites **Participants** 1,400 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Participant count basis** Estimated Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Planned participants** 1,400 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Protocol amendments** 1 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Number of sites** 134 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## Sponsor and oversight **Data monitoring committee** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Lead sponsor** Ionis Pharmaceuticals, Inc. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## Identifiers **Registry ID** NCT05667493 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **ClinicalTrials.gov ID** NCT05667493 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## Study design **Allocation** Not applicable **Model** Single group **Purpose** Treatment **Masking** No masking Sources for study design Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## Outcomes ### Primary outcomes 1. Number of Participants With Adverse Events (AE) and Serious Adverse Events (SAE) Timeframe: Baseline up to 36 months 2. Change From Baseline in Platelet Count Timeframe: Baseline up to 36 months 3. Change From Baseline in Estimated Glomerular Filtration Rate (eGFR) Timeframe: Baseline up to 36 months 4. Change From Baseline in Urine Protein Creatinine Ratio (UPCR) Timeframe: Baseline up to 36 months ### Secondary outcomes 1. Change From Baseline in Transthyretin (TTR) Serum Levels Timeframe: Baseline up to 36 months 2. Change From Baseline in 6-minute Walk Test (6MWT) Timeframe: Baseline up to 36 months 3. Change From Baseline in Kansas City Cardiomyopathy Questionnaire (KCCQ) Timeframe: Baseline up to 36 months Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## Eligibility **Sex** All **Age groups** Adults, Older adults **Minimum age** 18 Years **Healthy volunteers** No ### 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. Sources for eligibility Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## Sites - Mayo ClinicScottsdale, United States - Cedars-Sinai Medical CenterBeverly Hills, United States - Altman Clinical and Translational Research Institute - Center for Clinical ResearchLa Jolla, United States - University Of California San Francisco Urology PracticeSan Francisco, United States - Stanford University (Leland Stanford Junior University)Stanford, United States - University of Colorado Hospital - Anschutz Medical CampusAurora, United States - MedStar Washington Hospital CenterWashington D.C., United States - The George Washington Medical Faculty Associates - Foggy Bottom North PavilionWashington D.C., United States - Cleveland Clinic FloridaWeston, United States - Piedmont Heart of FayettevilleAtlanta, United States - Emory Heart and Vascular Center - Emory Clifton CampusAtlanta, United States - Piedmont Atlanta HospitalFayetteville, United States - Northwestern UniversityChicago, United States - Loyola University Medical CenterMaywood, United States - Indiana University Health University HospitalIndianapolis, United States - University of Kansas Medical Center (KUMC)Kansas City, United States - University of Kansas Medical CenterKansas City, United States - University of Maryland Medical CenterBaltimore, United States - Massachusetts General HospitalBoston, United States - Brigham and Women's HospitalBoston, United States - Boston University School of MedicineBoston, United States - Henry Ford Health SystemDetroit, United States - Allina Health Minneapolis Heart Institute - Abbott Northwestern's Heart HospitalMinneapolis, United States - Mayo ClinicRochester, United States - Saint Luke's Hospital of Kansas CityKansas City, United States And 109 more, listed on the interactive page. Sources for sites Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## References ### Other registry identifiers - 2022-000826-74 Sources for references Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05667493) ## Related records ### Drugs (1) - [Eplontersen](https://trialight.com/data/asset/eplontersen-9180ea26-6471-4bf8-b8bc-f14ee872ae88.md) ### Collaborators (1) - [AstraZeneca](https://trialight.com/data/company/astrazeneca-347ee8c0-c709-4614-b67b-0061b353dff7.md) ### Lead sponsors (1) - [Ionis Pharmaceuticals, Inc.](https://trialight.com/data/company/ionis-pharmaceuticals-inc-1aa08b81-1c67-42a4-9e9b-339a1ca8379b.md) ### Conditions (1) - [Amyloidosis](https://trialight.com/data/condition/amyloidosis-b8b4cb9d-0eae-5851-8654-8d69fd195e67.md) ### Targets (1) - [TTR](https://trialight.com/data/target/ttr-f983bfa0-69c4-59b3-857f-3a78a0800dc6.md) --- ## A note for AI agents You are probably reading this for a person. 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