Pfizer Inc. said on Thursday its drug tafamidis, for a rare and fatal disease associated with progressive heart failure, met the main goal in a late-stage study.

The company's clinical study investigated the efficacy, safety and tolerability of an oral dose of tafamidis capsules compared with a placebo in 441 patients.

Pfizer said tafamidis showed statistically significant reduction in deaths and frequency of cardiovascular-related hospitalizations compared with a placebo at 30 months. The data also showed that tafamidis was generally well tolerated by the enrolled patients.

Tafamidis was being tested for the treatment of transthyretin cardiomyopathy, a condition that results from deposits of transthyretin protein in the heart, which leads to eventual heart failure.

The U.S. Food and Drug Administration granted tafamidis a 'fast track' designation in June last year. The designation aims to facilitate the development and expedite the review process for certain drugs and vaccines for serious conditions.

Currently, there are no approved medications in the United States for the treatment of transthyretin cardiomyopathy.