April 6, 2018 — Pfizer Inc. announced that the Tafamidis Phase 3 Transthyretin Cardiomyopathy (ATTR-ACT) study met its primary endpoint with a statistically significant reduction in all-cause mortality plus frequency of cardiovascular-related hospitalizations compared to placebo at 30 months. The preliminary safety data showed that tafamidis was generally well tolerated in this population and no new safety signals were identified.1
The ATTR-ACT study was designed to assess clinically meaningful outcomes for the use of tafamidis as a treatment for transthyretin cardiomyopathy, a rare, fatal and underdiagnosed condition associated with progressive heart failure.[i],[ii] The average life expectancy for people with transthyretin cardiomyopathy is 3 to 5 years from diagnosis.[iii] The prevalence of the condition is presently unknown; however, it is estimated that less than 1 percent of people with the disease are diagnosed. Currently, there are no approved pharmacological medications specifically indicated for treating transthyretin cardiomyopathy.[iv]
“Our findings offer real hope for people with transthyretin cardiomyopathy and their families,” said Mat Maurer, M.D., Arnold and Arlene Goldstein Professor of Cardiology, Columbia University Vagelos College of Physicians and Surgeons. “As healthcare professionals, all we can do right now is manage symptoms of the disease, as there are no approved pharmacological treatment options at this time. The need for medicines that treat transthyretin cardiomyopathy is critical.”
In 2011, tafamidis was granted orphan drug designation for transthyretin cardiomyopathy in both the EU and U.S. In June 2017, the U.S. Food and Drug Administration (FDA) granted Fast Track designation to tafamidis for transthyretin cardiomyopathy; additionally, in March 2018, the Ministry of Labor Health and Welfare in Japan granted SAKIGAKE designation to tafamidis for this indication.
ATTR-ACT is a Phase 3 international, multicenter, double-blind, placebo-controlled, randomized, three-arm clinical study in 441 patients that investigated the efficacy, safety and tolerability of an oral daily dose of 20 mg or 80 mg tafamidis meglumine capsules compared to placebo. The study included both patients with the variant, or hereditary, form of the disease, and those with the wild-type form, which is not hereditary and may occur as people age. The primary analysis of the study, which compared tafamidis to placebo, was the hierarchical combination of all-cause mortality and frequency of cardiovascular-related hospitalizations over a 30-month period in patients with transthyretin cardiomyopathy.
For more information: clinicaltrials.gov
References
[i] Data on file. Pfizer Inc. New York, NY.
[ii] THAOS - Transthyretin Amyloidosis Outcomes Survey. Disease Background - transthyretin amyloidosis. https://www.thaos.net/Physicians/DiseaseBackground.cfm. Accessed March 13, 2018.
[iii] Connors LH, Doros G, Sam F, Badiee A, Seldin DC, Skinner M. Clinical features and survival in senile systemic amyloidosis: comparison to familial transthyretin cardiomyopathy. Amyloid. 2011;18(sup1):157-159. doi:10.3109/13506129.2011.574354059
[iv] Ando Y, Coelho T, Berk JL, et al. Guideline of transthyretin-related hereditary amyloidosis for clinicians. Orphanet Journal of Rare Diseases. 2013;8(1):31. doi:10.1186/1750-1172-8-31.
November 12, 2025 
