Attruby reduces risk of death by 49% in rare heart condition in long-term study

In patients with cardiomyopathy, Attruby (acoramidis) was able to reduce the risk of mortality, according to the results of a long-term open label extension trial. At month 54, adults with transthyretin-mediated amyloidosis (ATTR-CM) saw a risk reduction of 44.7% in all-cause mortality and 49.3% in cardiovascular mortality. These data were presented at the American College of Cardiology (ACC) Annual Scientific Sessions & Expo and also published in JAMA Cardiology.

Transthyretin amyloid cardiomyopathy is a type of heart failure. It is a rare disease that leads to a buildup of the transthyretin (TTR) in the left ventricle, the heart’s main pumping chamber. Transthyretin is a protein that helps transport thyroxine, which regulates the metabolism and retinol in the body, but when it accumulates in the left ventricle, it thickens and stiffens the heart muscle. That thickening causes shortness of breath and heart failure. Other symptoms include swelling in the lower legs, chest congestion, increased heart rate and heart palpitations.

It is estimated that in the United States approximately 120,000 people have ATTR-CM. But the incidence and prevalence are increasing. A study published in January 2025 in the Journal of Cardiac Failure found that both incidence and prevalence increased, especially for older people, and more men were diagnosed with the disease than women.

“Despite dramatic therapeutic advances in the field, many patients with ATTR-CM still continue to suffer progressive heart failure and high mortality risk, and many have limited long-term treatment options,” Prem Soman, M.D., Ph.D., professor of Medicine at the University of Pittsburgh School of Medicine, said in a news release.

Developed by BridgeBio Pharma, Attruby was approved in November 2024. Attruby is an oral small molecule stabilizer of transthyretin, and it was designed to mimic the protective effects of TTR, which has been associated with reduced risk of vascular events. It has a wholesale acquisition cost of $19,790 for a month’s supply.

Overall, 389 participants were enrolled in the open-label extension of the ATTRibute-CM, including 263 who had received Attruby during the clinical portion of the trial and 126 who had received placebo. Patients who had received placebo were switched to Attruby during the open-label extension. The primary outcome was time to event for all-cause mortality, cardiovascular-related mortality, and first cardiovascular hospitalization.

At month 54, patients who had received continuous treatment with Attruby had a significant risk reduction of 44.7% in all-cause mortality and a 49.3% reduction in cardiovascular mortality. In patients who have previously received versus placebo, Attruby helps to lower NT-proBNP, which measures a protein released by the heart when under stress. Investigators also found that patients’ quality of life scores were maintained when taking Attruby.

No new safety concerns were seen in the open-label extension. During the open-label extension, treatment-related adverse events occurred. Overall, 10 patients experienced treatment-related adverse events leading to drug discontinuation; 191 patients experienced treatment adverse events leading to hospitalizations and 65 patients experienced a fatal outcome.

“The ATTRibute-CM long-term data show that early and continuous treatment with acoramidis can meaningfully change the trajectory of this disease, with sustained reductions in all-cause and cardiovascular mortality, cardiovascular hospitalization, continued mitigation of NT-proBNP progression, and a favorable long-term safety profile. These findings reinforce the importance of early diagnosis followed by prompt, durable treatment to deliver sustained clinical benefit for patients,” Soman said.