Tafamidis: A Novel Treatment for Transthyretin Amyloid Cardiomyopathy

Transthyretin (TTR) amyloid cardiomyopathy is a life-threatening condition in which amyloid fibrils accumulate in the heart, eventually leading to cardiac symptomatology and death. To date, treatment of this condition has been directed at symptom relief due to a lack of effective treatment options which target the cause of the disease. The discovery that amyloid deposition was a result of dissociation of the TTR protein structure allowed for the development of tafamidis, which acts by stabilizing the TTR tetramer. Due to the rare nature of the disease, there is limited clinical trial data with tafamidis, with the largest clinical trial enrolling only 441 patients. Nonetheless, that trial demonstrated tafamidis to reduce all-cause mortality as well as cardiovascular hospitalizations compared to placebo with a comparable adverse effect profile, although not all subgroups of patients received benefit. The United States Food and Drug Administration subsequently granted Fast Track review status to tafamidis, leading to its approval in May 2019. Important questions still remain, however, such as which patient groups will receive the most benefit with this drug, how the exceptionally high cost of the drug will be handled by third-party payers, and how the therapeutic role of tafamidis will evolve as competing or perhaps complementary medications complete their ongoing clinical trials and move into the marketplace.