Pfizer’s Potential Blockbuster Heart Drug Gets Boost from Study

Pfizer Inc.’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. ...