Long-Term Survival With Tafamidis in Patients With Transthyretin Amyloid Cardiomyopathy

BACKGROUND: Tafamidis is approved in many countries for the treatment of transthyretin amyloid cardiomyopathy. This study reports data on the long-term efficacy of tafamidis from an ongoing long-term extension (LTE) to the pivotal ATTR-ACT (Tafamidis in Transthyretin Cardiomyopathy Clinical Trial). METHODS: Patients with transthyretin amyloid cardiomyopathy who completed ATTR-ACT could enroll in an LTE, continuing with the same tafamidis dose or, if previously treated with placebo, randomized (2:1) to tafamidis meglumine 80 or 20 mg. All patients in the LTE transitioned to tafamidis free acid 61 mg (bioequivalent to tafamidis meglumine 80 mg) following a protocol amendment. In this interim analysis, all-cause mortality was assessed in patients treated with tafamidis meglumine 80 mg in ATTR-ACT continuing in the LTE, compared with those receiving placebo in ATTR-ACT transitioning to tafamidis in the LTE. RESULTS: Median follow-up was 58.5 months in the continuous tafamidis group (n=176) and 57.1 months in the placebo to tafamidis group (n=177). There were 79 (44.9%) deaths with continuous tafamidis and 111 (62.7%) with placebo to tafamidis (hazard ratio, 0.59 [95% CI, 0.44-0.79]; P<0.001). Mortality was also reduced in the continuous tafamidis (versus placebo to tafamidis) subgroups of: variant transthyretin amyloidosis (0.57 [0.33-0.99]; P=0.05) and wild-type transthyretin amyloidosis (0.61 [0.43-0.87]; P=0.006); and baseline New York Heart Association class I and II (0.56 [0.38-0.82]; P=0.003) and class III (0.65 [0.41-1.01]; P=0.06). CONCLUSIONS: In the LTE, patients initially treated with tafamidis in ATTR-ACT had substantially better survival than those first treated with placebo, highlighting the importance of early diagnosis and treatment in transthyretin amyloid cardiomyopathy.

Automated summary

This study demonstrates the long-term efficacy of Tafamidis in the treatment of transthyretin amyloid cardiomyopathy, showing that patients who were initially treated with Tafamidis had significantly better survival rates than those who received placebo initially.