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RecruitingNCT07654855sTTRingUpdated Sep 14, 2026

Long-term Safety of Eplontersen Treated aTTR Patients and in Liver Transplant and Severely Hepatic Impaired Subpopulations

An observational study in Transthyretin Amyloidosis, Transthyretin Amyloidosis With Cardiomyopathy and Transthyretin Amyloidosis With Polyneuropathy, sponsored by AstraZeneca. Recruiting at 6 sites in 6 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-14.

Sponsored by AstraZeneca · Observational

From the registry’s dates

  • Started Sep 2026; still recruiting 2 months later.
Study type
Observational
Model
Cohort
Time perspective
Retrospective
Enrollment
320
Ages
18 Years and older
Sex
All
01

Study summary

The aim of this observational cohort study is to characterise use of eplontersen in patients with prior liver transplant or with pre-existing severe hepatic impairment, as well as to assess long-term safety among all new users of eplontersen; all are areas of missing information

Primary objectives are:

  1. To describe demographic and clinical characteristics of patients at eplontersen initiation, including the prevalence of prior liver transplant (overall and by reason for liver transplant), and the prevalence of severe hepatic impairment; and to describe patients in these subgroups (prior liver transplant, severe hepatic impairment).
  2. To describe long-term safety in patients who initiate eplontersen treatment, including onset of new clinical events, abnormal laboratory values and serious adverse events.
Read the detailed description

Study D8450R00003 enrolls adults (≥18 years) with a confirmed ATTR diagnosis at the time of informed consent. The sTTRing study will represent a subset of D8450R00003 participants who consent to secondary research use of their data and who initiated eplontersen treatment within 1 year prior to enrollment in D8450R00003. For comparative analyses, patients not exposed to eplontersen who initiated alternative ATTR therapies during the D8450R00003 observation period will also be included.

sTTRing data collection will begin in Q3 2026 and conclude in Q1 2032. Interim analyses will be reported annually from Q3 2027 through Q3 2031, with a final report submitted in Q1 2033.

The primary endpoints supporting the primary study objective are: (1) the prevalence of patients with a history of liver transplantation, categorized by reason for liver transplant, and (2) the prevalence of severe hepatic impairment. Safety outcomes will be summarized by incidence risk and event rates across prespecified time intervals (e.g., 0-6 months and from 7 months to the end of available follow-up) and over the full duration of follow-up. These summaries will be included in interim reports as part of both primary and secondary objectives.

Cohort Event Monitoring will be used to identify safety events requiring further characterization. When more than 10 events are observed for a given outcome, cumulative hazard rates will be estimated. To optimize sample size, comparative analyses will be conducted, where feasible, at the final analysis and presented in the final report.

02

Conditions studied

  • Transthyretin Amyloidosis
  • Transthyretin Amyloidosis With Cardiomyopathy
  • Transthyretin Amyloidosis With Polyneuropathy

Keywords

  • ATTR, Transthyretin amyloidosis
03

In context

Amyloidosis, Hereditary, Transthyretin-Related

82 studies on the registry are indexed under Amyloidosis, Hereditary, Transthyretin-Related; 28 are open to participants now.

This study's planned enrollment of 320 is above the median of 100 across 40 observational studies indexed under Amyloidosis, Hereditary, Transthyretin-Related.

Browse Amyloidosis, Hereditary, Transthyretin-Related studies →

Lead sponsor

AstraZeneca is the lead sponsor of 3,499 studies on the registry; 270 are open to participants now.

Of its 368 completed or terminated interventional studies of FDA-regulated products, 178 (48%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

The D8450R00003 study cohort includes individuals with confirmed diagnosis of ATTR, aged ≥18 years at the time of providing the informed consent. The sTTRing study population will be a subset of the D8450R00003 cohort who meet the additional criteria below.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. D8450R00003 participants who consented to have their data used for future related research studies.
  2. D8450R00003 participants who initiated eplontersen treatment up to 1-year prior to enrolment into D8450R00003 study observation period, irrespective of ATTR phenotype or genotype. For the comparative analyses, patients unexposed to eplontersen treatment and who initiated another ATTR treatment during D8450R00003 study observation period will be included

Exclusion criteria

Exclusion Criteria:

  1. Patients with exposure to eplontersen more than 1-year prior to enrolment into D8450R00003 study.
  2. Patients who participated in an interventional ATTR study in the 12-months prior to enrolment into D8450R00003 study.
05

Study design

Observational model
Cohort
Time perspective
Retrospective
Enrollment
320 participants (estimated)
Patient registry
No

Groups and cohorts

  • Eplontersen users

    D8450R00003 population of new and prior eplontersen users (including prior liver transplant and severe hepatic impairment subpopulations)

    Other: None ( observational study )

Interventions

  • OtherNone ( observational study )

    Not applicable this is observational study no intervention is planned.

06

What researchers measure

Primary outcomes

  1. Demographic and clinical characteristics of eplontersen users, including the prevalence of prior liver transplant and severe hepatic impairment

    1. Prevalence of liver transplant prior to eplontersen initiation (overall by reason for liver transplant), 2. Prevalence of severe hepatic impairment prior to eplontersen initiation These will be summarised as prevalence proportion and 95% CI. Secondary outcomes: Demographic characteristics (e.g. age, sex), general health factors (e.g. BMI), indication related characteristics (e.g. ATTR diagnoses dates and duration since first diagnosis, type, severity), prior and concomitant medications (as part of standard care of ATTR at eplontersen initiation), pre-existing and concurrent relevant morbidities will be described using descriptive statistics of counts, proportions and/or distribution characteristics (mean (SD), median (range)).

    Time frame: Quarter 2 2026- Quarter 1 2032

  2. Long term safety with patients who initiated eplonersen treatment

    Onset of new clinical events, abnormal laboratory values, serious adverse events will be analysed as follows: a) Counts and frequency of first events and total number of events, incidence rate and incidence risk of events per time periods (e.g., 0-6, 7-end of follow-up available at time of reporting). b) Cohort event monitoring analysis including a. Incidence densities per 6 months (in the first year) or 12-months (after one year) intervals will be estimated. b. Differences in incidence densities per 6 or 12months intervals c. Nelson-Aalen estimator of cumulative hazard rate function over time. c) For SAEs, qualitative case reports of clinical course and patients' characteristics and comorbidities will be provided. These outcomes are all relative to primary objective 2 of study and are all relative to the same outcome measure.

    Time frame: Quarter 2 2026- Quarter 1 2032

Secondary outcomes

  1. Eplontersen treatment use

    To describe eplontersen treatment use, including duration of treatment and reasons for discontinuation (overall, in patients with prior liver transplant, in patients with pre-existing severe hepatic impairment). These outcomes are all relative to secondary objective 1 of the study which is to describe "eplontersen treatment use".

    Time frame: Quarter 2 2026- Quarter 1 2032

  2. Long-term safety in patients who initiate eplontersen treatment by subgroups

    Same as primary objective 2, separately in i) patients with prior liver transplant and ii) patients with pre-existing severe hepatic impairment. These outcomes are relative to primary objective 2 of the study and to the same outcome measure, i.e. "long-term safety in patients who initiated eplontersen treatment". This is a long-term safety study without a prespecified adverse event of interest; therefore, all safety events are in scope, as defined in the protocol: all serious adverse events identified; other adverse events, including any new diagnosis reported as a co-morbidity, new sign or symptom, or new abnormal laboratory value within 115 days of last eplontersen dose. To support systematic and comprehensive listing of all AEs, clinical data in D8450R00003, in addition to serious adverse events, will be coded using MedDRA. Clinical data that cannot be mapped to MedDRA will also be considered.

    Time frame: Quarter 2 2026- Quarter 1 2032

07

Study locations

6 of 6 sites recruiting
  • Research Site
    Los Angeles, California 90095, United States
    Recruiting
  • Research Site
    Vancouver, British Columbia V6Z 1Y6, Canada
    Recruiting
  • Research Site
    Beijing, China
    Recruiting
  • Research Site
    Hanover, Germany
    Recruiting
  • Research Site
    Majadahonda, Spain
    Recruiting
  • Research Site
    Birmingham, United Kingdom
    Recruiting
08

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Started Sep 2026 (actual). Primary completion is estimated for Jan 2032, 64 months after the start.

How these figures are worked out, and which studies are left out of them.

Registered
May 19, 2026
First posted
Jun 17, 2026
StartActual
Sep 1, 2026
Primary completionEst.
Jan 29, 2032
CompletionEst.
Jan 29, 2032
Last update
Sep 14, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Sep 14, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT07654855
Lead sponsor
AstraZeneca
Collaborators
ICON Clinical Research
Responsible party
Sponsor
First posted
Jun 17, 2026
Start date
Sep 1, 2026
Primary completion
Jan 29, 2032 (estimated)
Completion
Jan 29, 2032 (estimated)
Last update
Sep 14, 2026

Study contacts

AstraZeneca Clinical Study Information Center
Contact
information.center@astrazeneca.com
1-877-240-9479

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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