BridgeBio presses challenge to Pfizer in ATTR-CM after data hint at survival edge

Indirect comparison suggests Attruby may outperform tafamidis on hospitalisations and survival, though analysts caution against over-reading cross-trial data

BridgeBio Pharma has presented late-stage data suggesting its transthyretin amyloidosis drug Attruby could gain an edge over Pfizer's tafamidis franchise in ATTR-CM, a closely watched rare heart-disease market.

The findings, while based on indirect comparisons rather than a head-to-head trial, could affect expectations for market share in a category that has become increasingly competitive.

In the Phase 3 ATTRibute-CM study, BridgeBio enrolled more than 630 patients with transthyretin amyloidosis cardiomyopathy, or ATTR-CM, and randomly assigned them to receive Attruby or placebo.

A separate analysis by researchers at Mater Misericordiae University Hospital in Ireland used anchored matching to compare Attruby indirectly with Pfizer's tafamidis products, sold as Vyndaqel and Vyndamax.

The analysis showed patients taking Attruby had a 34% lower rate of cardiovascular hospitalisations than those on tafamidis. All-cause mortality risk was 28% lower, although that result was not statistically significant.

Jefferies analysts forecast peak annual sales for Attruby of more than $3 billion, while cautioning that cross-trial comparisons remain a key limitation in judging differentiation from Pfizer's product.

BridgeBio also presented biomarker data showing Attruby increased serum transthyretin levels and reduced variability in the protein.

The commercial stakes are high. Pfizer's tafamidis franchise generated about $6.3 billion in worldwide sales in 2025, while Attruby posted $362.4 million in its first full year on the market.

Pfizer has also moved to defend its position. In April, the company said it had reached settlement agreements with Dexcel Pharma, Hikma Pharmaceuticals and Cipla that keep generic versions of Vyndamax out of the U.S. market until June 1, 2031, subject to other litigation.

Attruby is an oral transthyretin stabiliser designed to slow breakdown of the protein and limit the formation of amyloid deposits in patients with ATTR-CM. Tafamidis is also taken orally.