This is a prospective, non-interventional, Long-term, multinational cohort safety study of patients with Hereditary Transthyretin Amyloidosis with Polyneuropathy (hATTR-PN). The overarching goal of this study is to further characterize the long-term safety of TEGSEDI (inotersen) in patients with hATTR-PN under real-world conditions.

Study Rationale:

hATTR-PN is an inherited, progressive, fatal disease caused by misfolded transthyretin (TTR) proteins that accumulate as amyloid fibrils predominantly in the peripheral nerves, heart, gastrointestinal tract, and other organs. hATTR-PN is a rare disease and there are no large epidemiological studies that reliably provide an indication of its prevalence. The worldwide distribution is unequal, with higher rates in Portugal, Japan, Northern Sweden, and the US. Current estimates suggest there may be 10,000 afflicted patients worldwide.

TEGSEDI (inotersen) is an antisense oligonucleotide inhibitor of human TTR protein synthesis. In Europe and Canada, TEGSEDI is indicated for the treatment of Stage 1 or Stage 2 polyneuropathy in adult patients with hereditary transthyretin amyloidosis (hATTR). In the US, TEGSEDI is indicated for treatment of the polyneuropathy of hereditary TTR-mediated amyloidosis in adults. Efficacy has been demonstrated in patients with hATTR-PN, as reflected by a slowing or reversal of disease progression.

Research Question:

The overarching goal of this study is to further characterize the long-term safety of TEGSEDI in patients with hATTR-PN under real-world conditions.

Population:

Patients in Europe, US, and Canada will be enrolled from centers that manage patients with hATTR-PN. Physicians participating in the study will be instructed to invite all patients who meet study eligibility criteria to enroll until the enrollment period is closed.

Inclusion Criteria:

1. Either:

   1. TEGSEDI Exposed Cohort: Patients diagnosed with hATTR-PN who have taken any dose of TEGSEDI within 25 weeks prior to enrollment
   2. TEGSEDI Unexposed Cohort: Patients diagnosed with hATTR-PN who have not taken any dose of TEGSEDI within 25 weeks prior to enrollment and are eligible for TEGSEDI treatment per applicable product label. Patients may take other drugs to treat hATTR-PN.

2. Clinically managed in Canada, Europe, or the US

3. Have provided appropriate written informed consent

Exclusion Criteria:

• None

The TEGSEDI-exposed cohort will consist of patients diagnosed with hATTR-PN who are receiving TEGSEDI. Data from the TEGSEDI-exposed cohort will be compared to data collected prospectively from a TEGSEDI-unexposed cohort which will consist of patients diagnosed with hATTR-PN who have not taken any dose of TEGSEDI within 25 weeks prior to enrollment and are eligible for TEGSEDI treatment per applicable product label.

Patients in Europe, US, and Canada will be enrolled from centers that manage patients with hATTR-PN.