04:01 AM EDT, 09/29/2025 (MT Newswires) -- Alnylam Pharmaceuticals ( ALNY ) said Sunday analyses of a phase 3 study of Amvuttra showed it was associated with a 42% reduction in adverse gastrointestinal events in patients with transthyretin amyloid cardiomyopathy compared with placebo.

The illness is caused by a build up of proteins in the heart, with patients often experiencing disease manifestations such as diarrhea, abdominal pain and discomfort, and constipation.

The lower rates of gastrointestinal problems were observed as early as three months into treatment and among both hereditary and wild-type patients, the company said.