Coramitug wins FDA fast track status for rare heart condition

The FDA has granted fast track designation to coramitug, which is in phase 3 development to treat patients with ATTR amyloidosis with cardiomyopathy (ATTR-CM). Fast track designation is intended to expedite the review of investigational drugs that treat serious conditions.

Transthyretin amyloid cardiomyopathy (ATTR-CM) 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 of ATTR-CM 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.

Coramitug is an investigational antibody designed to target and clear the non-native transthyretin aggregates associated with the disease and improve organ function and circulating non-native TTR to prevent further organ deposition. The therapy is an anti-fibril depleter because of its ability to remove existing amyloid deposits; it targets misfolded and aggregated forms of TTR.

No anti-fibril depleters have been approved by the FDA. Currently available therapies to treat ATTR-CM include TTR stabilizers, such as Attruby (acoramidis) and Vyndamax (tafamidis), and TTR silencers, such as Amvuttra (vutrisiran).

Coramitug was developed by the biotech company Prothena; Novo Nordisk acquired the rights to the therapy in 2021. In a phase 2 clinical trial conducted by Novo Nordisk, coramitug 60 mg/kg improved NT-proBNP from baseline, a validated marker of disease progression. Coramitug was associated with improved functional echocardiographic parameters and was well tolerated.

The phase 2 data were presented during a late-breaking session at the American Heart Association (AHA) Scientific Sessions in November 2025 and published in Circulation.

Novo Nordisk initiated phase 3 trials of coramitug (CLEOPATTRA) in October 2025. The trial will enroll approximately 1,280 patients with ATTR-CM with primary completion expected in 2029. The primary outcome is a composite outcome of cardiovascular deaths and recurrent cardiovascular events, such as hospital and heart failure visits.

Secondary outcomes include change in the six-minute walk test, number of occurrences of cardiovascular events, time to all-cause death and patient-reported outcomes from the Kansas City Cardiomyopathy Questionnaire, which measures the physical, social and emotional impact of heart failure on patients’ lives.