Pfizer deals extend patent life for a top-selling rare disease drug

An article from Pfizer deals extend patent life for a top-selling rare disease drug Settlements delaying the arrival of generic versions of tafamidis will protect billions in Pfizer revenue and have implications for others, including BridgeBio Pharma and Alnylam. Published April 28, 2026 Ben Fidler Lead Editor Share Copy link Email LinkedIn X/Twitter Facebook Print License Add us on Google Pfizer has reached settlements with a trio of drug manufacturers that’ll extend the patent protection for one of its best-selling medicines. In a short statement Tuesday, Pfizer said it has cut deals with Dexcel Pharma, Hikma Pharmaceuticals and Cipla.

All three companies are seeking to launch generic versions of tafamidis, the active ingredient in a blockbuster rare disease medicine Pfizer sells as Vyndamax. Pfizer sued all for patent infringement, aiming to delay their arrival. The agreements announced Monday ensure that tafamidis’ monopoly will hold until early next decade.

Pfizer had anticipated that tafamidis’ exclusivity might expire in 2028 and prepared investors for a “significant decline” in U.S. revenues over the next few years. The settlement, though, extends tafamidis’ patent life through June 1, 2031, pending the outcome of other litigation.

Drug sales in the U.S. should now “remain relatively stable” from 2028 through the middle of 2031, the company said. "We are very pleased by this outcome, both for patients and in recognition of the value of our innovative science and the strength of our patents," said Aamir Malik, Pfizer’s executive vice president and Chief U.S.

Commercial Officer, in Pfizer’s statement. Pfizer’s drug is the market-leading medicine for a form of the rare disease transthyretin amyloidosis that affects the heart. This cardiomyopathy transthyretin-mediated amyloidosis has proved to be a much bigger commercial opportunity than previously thought, making treatments that can slow its progression coveted and potentially lucrative products.

Pfizer got tafamidis from an acquisition of biotechnology company FoldRx in 2010. Many years later, Pfizer brought it to market in Europe and then the U.S. Tafamidis sales have since steadily climbed and, last year, totaled nearly $6.4 billion worldwide.

It’s now not only one of Pfizer’s important medications, but one of the world’s best-selling drugs overall. Starting in 2023, though, several generic companies began notifying Pfizer of plans to develop knock-off versions, challenging some or all of the patents covering tafamidis. Pfizer responded with lawsuits, setting the stage for the deals announced Tuesday.

“Pay for delay” agreements like these have long drawn scrutiny from federal regulators and industry critics as tools to impede price competition for branded medications. Vyndamax, for instance, has an annual list price in the U.S. of more than $250,000.

The tafamidis case has also been closely watched by Wall Street investors not only because of the implications of generic competition for Pfizer, but for others with cardiomyopathy transthyretin-mediated amyloidosis medicines either on the market or in development, too. BridgeBio Pharma has a pill called Attruby that works similarly to tafamidis and approached $363 million in sales last year. Alnylam Pharmaceuticals has a different kind of medicine, Amvuttra, that’s sold for two different forms of the disease.

AstraZeneca and Ionis Pharmaceuticals have another would-be competitor in late-stage testing. BridgeBio shares dipped about 5% in Tuesday trading, as some investors had been hopeful for settlements that might delay generic entry to 2032 or 2033, wrote Leerink Partners analyst Mani Foroohar. Still, Foroohar noted that the deals have effectively extended the runway for drugs like Attruby and tafamidis by multiple years, adding “several [billions] of topline revenue.” The effects on Alnylam and, down the road, Ionis, are more “modest.” The delay of a generic that’s used in initial care would help both companies, though it’d also be a “headwind” for drug combinations involving tafamidis, Foroohar added.

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