Safety and Efficacy of Tafamidis in Chinese Patients with Transthyretin Amyloid Cardiomyopathy.

Introduction: Tafamidis is approved in many countries for the treatment of patients with transthyretin amyloid cardiomyopathy (ATTR-CM). Approval is largely based on findings from an international phase 3 trial. This post-approval commitment study aimed to evaluate the safety and efficacy of tafamidis in patients with ATTR-CM in China.

Methods: A multicenter, single-arm study in Chinese patients with symptomatic ATTR-CM in China. All patients received once-daily, open-label tafamidis free acid 61 mg for 12 months. Safety reporting was ongoing with efficacy assessments at months 6 and 12, including 6-min walk test distance, New York Heart Association (NYHA) functional classification, National Amyloidosis Centre staging, N-terminal pro-B-type natriuretic peptide and troponin I concentrations, Kansas City Cardiomyopathy Questionnaire Overall Summary score, 5-level EQ-5D index score, EQ visual analog scale, and 12-item Short Form Survey.

Results: Patients (n = 53) were aged 60 (standard deviation [SD]: 12) years, 89% were male, and 94% had variant ATTR-CM (21% had A97S [p.A117S]). At baseline, most (81%) patients had NYHA class II symptoms (6% class I; 13% class III) and National Amyloidosis Centre stage I disease (74%; 21% stage II; 6% stage III). Median treatment exposure was 345 (range, 24‒418) days. Overall, 85% of patients reported treatment-emergent adverse events (TEAEs). The nature and incidence of TEAEs were consistent with the known safety profile of tafamidis. There were no serious or severe treatment-related TEAEs. At 6 and 12 months, there were minimal changes from baseline in all efficacy outcomes with tafamidis, and a high proportion of patients (≥ 44%) showed clinically relevant stability or improvement in each measure.

Conclusions: The safety of tafamidis in Chinese patients with ATTR-CM was consistent with that previously determined. Tafamidis treatment was associated with a stable disease profile over 12 months in a population of patients where most had variant ATTR-CM and mild heart failure symptoms.

Trial Registration: NCT04814186.