Tafamidis: A First-in-Class Transthyretin Stabilizer for Transthyretin Amyloid Cardiomyopathy

Objective: To review the pharmacology, efficacy, and safety of the selective transthyretin inhibitor tafamidis for transthyretin amyloid cardiomyopathy (ATTR-CM). Data Sources: A PubMed (1966 to October 2019) and ClinicalTrials. gov search was conducted using the keywords tafamidis, Fx-1006A, Vyndaqel, and Vyndamax. Additional articles were identified from references. Study Selection and Data Extraction: We included English-language clinical studies evaluating the pharmacology, efficacy, or safety of tafamidis in humans for ATTR-CM. Data Synthesis: Tafamidis binds to the thyroxine-binding sites of the transthyretin tetramer and inhibits its dissociation into monomers, which is the rate-limiting step in the amyloidogenic process. Treatment with tafamidis was significantly associated with a significant reduction in mortality, lowered cardiovascular-related hospitalizations, less functional decline, and improved transthyretin stabilization compared with placebo. Additionally, tafamidis was found to have fewer adverse events, with no difference found compared with placebo. Relevance to Patient Care and Clinical Practice: Historically, symptomatic management for ATTR-CM was the only option, and the treatment of the underlying disease was limited to liver or heart transplantation. Tafamidis is the first medication approved for the treatment of ATTR-CM and the only medication that showed a reduction in all-cause mortality and cardiovascular-related hospitalizations in patients with amyloidosis. However, the role of tafamidis in patients with the New York Heart Association class III/IV heart failure or mutated transthyretin remains unclear. Conclusion: Tafamidis is an effective and safe oral medication for the treatment of the cardiomyopathy of transthyretin-mediated amyloidosis in adults to reduce cardiovascular mortality and cardiovascular-related hospitalization.