Characteristics of Patients with Hereditary Transthyretin Amyloidosis and an Evaluation of the Safety of Tafamidis Meglumine in Japan: An Interim Analysis of an All-case Postmarketing Surveillance.

PURPOSE: An all-case, single-arm, observational, postmarketing surveillance is underway to assess the safety of tafamidis in patients with hereditary transthyretin (ATTRv) amyloidosis with peripheral polyneuropathy, also called transthyretin-type familial amyloid polyneuropathy, in Japan. Results from an interim analysis (data cutoff date, May 15, 2018) are presented in this preliminary report. METHODS: Patients were registered and treated with tafamidis meglumine 20 mg/d in routine clinical practice (observation period, 156 weeks). Data on patient demographic and clinical characteristics and adverse drug reactions (ADRs) were captured using case-report forms. FINDINGS: Of 219 patients included (mean age, 59.7 years; patients with age at disease onset ≥50 years, 61.2%; mean treatment duration, 95.5 weeks), 143 (65.3%) were male, 126 (57.5%) had a family history of ATTRv amyloidosis, and 149 (68.0%) originated from nonendemic areas. The most common ADRs were diarrhea (1.4%) and hematuria (0.9%). Six serious ADRs (pneumonia, bacteremia, malignant melanoma, pancreatic carcinoma, hematuria, and hereditary neuropathic amyloidosis [primary disease exacerbation]) were reported; no ADRs leading to death were recorded. IMPLICATIONS: This interim analysis successfully provided comprehensive, nationwide epidemiologic data from 219 Japanese patients with ATTRv amyloidosis. The safety profile of tafamidis was largely consistent with that obtained from previous research. No new safety concerns were identified to date. Data presented in this interim analysis are subject to change following completion of the study, and we will continue to assess the safety and effectiveness of tafamidis throughout the study. ClinicalTrials.gov identifier: NCT02146378.