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Pfizer's rare heart disease drug succeeds in late-stage study

* Brokerage Suntrust estimates sales of $130 mln of drug in 2022

* Drug tafamidis meets main goal of late-stage study

* Shares of rivals Alnylam, Ionis Pharma down in regular trading (Adds analysts' comments, Alnylam and Ionis share price)

March 29 (Reuters) - Pfizer Inc's experimental drug to treat a rare and fatal disease linked to heart failure reduced deaths and need for hospitalizations 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 met the main goal of 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.

Brokerage SunTrust Robinson Humphrey said it expects tafamidis global sales of $130 million in 2022.

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.

However, Stifel analyst Stephen Wiley noted that the data could be a negative for Alnylam Pharmaceuticals and Ionis Pharma, whose shares were down in regular trading.

Alnylam and Ionis are developing drugs for the treatment of hereditary TTR amyloidosis, also caused by a buildup of transthyretin protein in the body.

Some investors could look at Pfizer's data as providing validation for both the companies' drugs, Wiley said, adding that he believed the data could potentially complicate product labeling for both the drugs.

Alnylam closed down 8.3 percent at $119.1, while Ionis closed at $44.08, down 4 percent. (Reporting by Anuron Kumar Mitra, Akankshita Mukhopadhyay and Manas Mishra in Bengaluru; Editing by Shounak Dasgupta)