Study boosts Pfizer’s heart drug

Finding could give U.S. drugmaker another potential blockbuster.

Pfizer’s pipeline may finally be delivering.

A new study shows that patients with a rare condition that can lead to heart failure lowered their risk of dying by 30 percent after being treated with Pfizer’s tafamidis. The finding could give the biggest U.S. drugmaker another potential blockbuster medicine and challenge a biotech startup marketing its own groundbreaking treatment for the same disease.

Pfizer estimates that as many as 500,000 patients worldwide have the disease known as transthyretin cardiomyopathy but that less than 1 percent have been diagnosed. Doctors also say the condition is more prevalent than what’s been reported. Pfizer said there are about 50 centers in the U.S. equipped with diagnostics to identify patients, which it expects to grow now that the data has been disclosed.

Tafamidis is expected to be the first of more than a dozen medicines the New York-based company has vowed to launch in the coming years that could generate more than $1 billion in annual sales. Some analysts project the drug will cross that threshold within five years, and possibly sooner if more patients with transthyretin cardiomyopathy are identified.

“It’s very, very exciting,” said Irina Sobol, director of the advanced heart failure fellowship program at Weill Cornell Medicine and New York-Presbyterian, who wasn’t involved in the trial. “I fully expect it would change the standard of care. It will make physicians be more excited, it will lead us all to look for patients with this disease because now there are clear paradigms for treatment.”

Pfizer shares, which have been trading near their highest level in more than 16 years, fell as much as 2.4 percent Monday after the company said on a conference call with analysts that it wouldn’t immediately pursue U.S. approval for the same indication that regulators recently granted to a treatment from Alnylam Pharmaceuticals Inc. Alnylam shares surged as much as 17 percent.

Transthyretin cardiomyopathy is a progressive, fatal disease caused by a protein that circulates naturally in the blood but becomes unstable and misfolds, building up in the heart and causing it to thicken and stiffen.

The data from the study was presented at the European Society of Cardiology’s annual conference in Munich and published Monday in the New England Journal of Medicine.