Pfizer Inc. said Tafamidis, an experimental treatment for a rare heart condition, met the main goal of a phase 3 trial.

The medicine for transthyretin cardiomyopathy, a condition that causes heart failure, reduced premature deaths and the frequency of heart-related hospitalizations compared to placebo after 30 months of treatment, the New York-based pharmaceutical company said.

Tafamidis was well tolerated by the patients with no new safety issues, Pfizer said.

Transthyretin cardiomyopathy occurs due to the collection and deposition of the transthyretin protein in the heart. These proteins then infiltrate the heart muscle, eventually causing heart failure, or the inability of the organ to adequately pump blood.

The average life expectancy for people with transthyretin cardiomyopathy is three to five years from diagnosis and only about 1% of people with the disease are diagnosed, according to Pfizer.

The company said there are no medicines specifically approved for treating transthyretin cardiomyopathy. Tafamidis was granted orphan drug designation for the rare disease in both the EU and U.S. in 2011, Pfizer said.

In June 2017, the U.S. Food and Drug Administration granted fast-track designation to the experimental drug for the same use.

Pfizer said that in March, Japan's Ministry of Health, Labour and Welfare granted tafamidis a Sakigake designation for the disease. A Sakigake designation can result in faster approval of drugs.