In a placebo-controlled, double-blind phase 3 trial (ATTR-ACT; ClinicalTrials.gov Identifier: NCT01994889) presented at the European Society of Cardiology Congress in Munich, Germany, and simultaneously published in the New England Journal of Medicine, treatment with tafamidis was associated with reduced all-cause mortality and cardiovascular-related hospitalizations in patients with transthyretin amyloid cardiomyopathy.
Additionally, tafamidis was associated with reductions in functional capacity decline and quality of life decline to a greater degree than that observed in patients treated with placebo.
Researchers enrolled patients with transthyretin amyloid cardiomyopathy (TTR mutation or wild-type transthyretin protein) that was clinically confirmed by identification of amyloid deposits on assessment of cardiac and noncardiac biopsy specimens (N=441). Participants were randomly assigned to either tafamidis, 80 mg or 20 mg (n=264), or matching placebo (n=177) for a total treatment period of 30 months.
The investigators evaluated all-cause mortality and the number of cardiovascular-related hospitalizations associated with treatment. Additionally, the researchers assessed the change from baseline to 30-month follow-up in the 6-minute walking test as well as in the Kansas City Cardiomyopathy Questionnaire-Overall Summary (KCCQ-OS) score.
Lower rates of all-cause mortality were observed in patients who received tafamidis vs those who received placebo (29.5% vs 42.9%, respectively; hazard ratio 0.70; 95% CI, 0.51-0.96; P <.001). In addition, rates of cardiovascular-related hospitalizations were also lower with tafamidis vs placebo (0.48 vs 0.70 hospitalizations per year, respectively; relative risk ratio 0.68; 95% CI, 0.56-0.81). At 30-month follow-up, a significantly lower rate of decline in the 6-minute walking test was associated with tafamidis compared with placebo (P <.001). Treatment with tafamidis was also associated with a significantly lower rate of decline in the KCCQ-OS score (P <.001).
Potential limitations of the analysis include the relatively short follow-up of 30 months and the assessment of only 2 tafamidis treatment doses.
Treatment with tafamidis was not associated with reduced hospitalizations in a subgroup of patients with transthyretin amyloid cardiomyopathy with New York Heart Association class III heart failure, possibly due to “longer survival during a more severe period of disease, underscoring the importance of early diagnosis and treatment of this fatal, progressive disease, which can be difficult to diagnose.”Disclosures: This study was funded by Pfizer.
Maurer MS, Schwartz JH, Gundapaneni B, et al; for the ATTR-ACT Study Investigators. Tafamidis treatment for patients with transthyretin amyloid cardiomyopathy [published online August 27, 2018]. N Engl J Med. doi:10.1056/NEJMoa1805689