BridgeBio's Attruby Shows Potential to Reverse Cardiac Damage in ATTR-CM at ESC Congress

BridgeBio Pharma (BBIO) presented long-term data at the ESC Congress 2026 showing its drug Attruby (acoramidis) is the first therapy to demonstrate potential reversal of cardiac structural disease in transthyretin amyloid cardiomyopathy (ATTR-CM), a progressive and fatal heart condition. The findings were simultaneously published in the European Journal of Heart Failure, and BridgeBio announced the data in an August 30 press release. BridgeBio shares closed at $76.59.

The 42-month cardiac magnetic resonance imaging (CMR) data from the Phase 3 ATTRibute-CM open-label extension showed that 54% of acoramidis-treated patients had clinically meaningful improvement in left ventricular systolic function at Month 30 versus 20% on placebo. At Month 42, 53% of patients receiving continuous acoramidis maintained that improvement, and 46% showed improvement in left ventricular mass index, indicating favorable structural remodeling of the heart. Both metrics were more than double the proportion observed in a natural history cohort.

This matters because the current standard of care, Pfizer’s tafamidis (Vyndamax), is positioned as slowing or stabilizing ATTR-CM. A credible reversal signal, where the heart actually gets better rather than just not getting worse, would reframe the treatment goal and give Attruby a genuine differentiation lever in a market projected to exceed $10 billion. Acoramidis is a near-complete transthyretin stabilizer, binding to at least 90% of TTR protein to prevent the amyloid fibril formation that damages heart tissue.

The signal comes with an important caveat: it is drawn from a completer analysis of patients who survived and stayed in the trial for 42 months. That introduces survivor bias. The open-label extension has no placebo control at that time point, and all-cause mortality in the continuous-acoramidis arm was approximately 30%. Those are not unusual numbers for ATTR-CM, but they temper the “reversal” framing. The most rigorously controlled signal in the dataset is the 65 additional days alive and out of hospital by Month 36 versus placebo, a finding that came from the randomized, placebo-controlled portion of the trial.

BridgeBio is not waiting for confirmation. It dosed the first patient in ASCEND-ATTR, a Phase 3b/4 study designed to determine whether long-term acoramidis treatment produces sustained improvement in cardiac structure, function, and amyloid burden. That trial will provide the randomized evidence the completer analysis cannot. Additional data is expected at the Heart Failure Society of America meeting in October.

What to watch next: the ASCEND-ATTR readout and whether the reversal narrative shifts prescribing behavior away from tafamidis in the near term. Attruby generated $222.4 million in US revenue in Q2 2026. For more on BridgeBio’s commercial trajectory, see our Attruby post-approval launch analysis.