Early access to tafamidis for patients with transthyretin amyloid cardiomyopathy

Abstract

[Abstract] Background: Tafamidis is a standard of care treatment for patients with transthyretin amyloid cardiomyopathy (ATTR-CM). While evidence was being assessed by regulatory authorities, a new, independent, and inclusive cohort of the phase 3 long-term extension study offered early access to tafamidis.

Objectives: The purpose of this study was to present safety, mortality, and hospitalization findings for patients who received early access tafamidis.

Methods: Patients with ATTR-CM and who had not taken part in the phase 3 study were able to receive tafamidis free acid 61 mg (the dose later approved) for up to 60 months or until commercial availability in their region. Enrollment criteria were minimal.

Results: Among the 1,476 patients initiating tafamidis in the study between 2018 and 2023, mean (SD) age at enrollment was 76.5 (7.8) years, 88.8% were male, 85.6% had wild-type ATTR-CM, and 52.9% had NYHA functional class II symptoms (I: 14.9%, III: 30.8%, IV: 1.3%). Median exposure and follow-up were 12 (range: 0-55) and 19 (95% CI: 18.4-20.7) months, respectively. Overall, 7.6% of patients reported treatment-related adverse events, with 0.6% considered serious and 0.6% leading to study discontinuation. No new safety signals were identified. In Kaplan-Meier analyses, all-cause and cardiovascular (CV)-related mortality occurred in 23.4% and 13.8% of patients over the study period. Furthermore, 43.3% and 26.5% of patients had all-cause and CV-related hospitalizations. The total annual CV-related hospitalization rate was 0.26.

Conclusions: In an inclusive patient cohort receiving early access to tafamidis, safety findings were consistent with those reported from other trials and real-world studies. (Long-term Safety of Tafamidis in Subjects With Transthyretin Cardiomyopathy; NCT02791230).