Alnylam challenges Pfizer in ATTR market with FDA approval

Alnylam Pharmaceuticals (NASDAQ: ALNY) has secured U.S. regulatory approval to expand the use of its RNA interference (RNAi) therapy, Amvuttra (vutrisiran), for patients with transthyretin amyloidosis with cardiomyopathy (ATTR-CM). The decision by the FDA marks a critical step for the company, positioning Amvuttra as the first RNAi therapy available for both ATTR-CM and hereditary ATTR amyloidosis with polyneuropathy (hATTR-PN), following an earlier approval in 2022.

The ATTR-CM market, however, remains dominated by Pfizer (NYSE: PFE), whose Vyndaqel (tafamidis) family of transthyretin (TTR) stabilizers has led the segment since winning FDA approval in 2019. More recently, BridgeBio’s (NASDAQ: BBIO) Attruby (acoramidis) entered the space with U.S. approval in late 2024, intensifying competition.

Visible Alpha consensus estimates forecast $420 million in sales from Amvuttra’s new indication in 2025, contributing to an expected $1.5 billion in total sales from Alnylam’s ATTR franchise this year. By contrast, Pfizer’s Vyndaqel is projected to generate $6.2 billion, while BridgeBio’s Attruby is forecast to bring in $163 million.

Looking ahead, Pfizer’s Vyndaqel is expected to peak at $6.4 billion in 2026 before losing exclusivity in late 2025, setting the stage for potential market share shifts. Meanwhile, Amvuttra’s global sales are forecast to climb steadily, with peak annual revenue of $7.9 billion projected for 2035. The therapy’s success in hATTR-PN is expected to drive Alnylam’s broader expansion, with its share of the company’s total revenue forecast to rise from 43% in 2024 to 77% by 2035.