Serial cardiac magnetic resonance imaging (CMR) data from the Phase III ATTRibute-CM trial and its open-label extension (OLE) now show that acoramidis (Attruby) may do more than slow transthyretin amyloid cardiomyopathy (ATTR-CM) — in a meaningful proportion of patients, it appears to reverse it. Presented at the European Society of Cardiology Congress 2026 and simultaneously published in the European Journal of Heart Failure, the findings add a structural remodeling dimension to the mortality and hospitalization benefits already established for the drug.
Acoramidis binds the thyroxine-binding sites of the transthyretin (TTR) tetramer, achieving near-complete (≥90%) stabilization and preventing the protein from dissociating into amyloidogenic monomers. BridgeBio Pharma (Nasdaq: BBIO) markets it as Attruby in the US, where it received FDA approval in November 2024, and as Beyonttra in the EU and several other markets.
The CMR substudy evaluated two analytical approaches. In a completer analysis, 54% of acoramidis-treated patients demonstrated clinically meaningful improvement from baseline in left ventricular (LV) systolic function at Month 30, versus 20% of placebo-treated patients; 53% of continuous-acoramidis patients maintained that improvement at Month 42. A more conservative analysis — accounting for patients who did not complete imaging — found improvement in 34% of acoramidis patients versus 9% of placebo patients at Month 30, and 30% at Month 42. For structural context, 46% of continuously treated patients showed improvement from baseline in LV mass index at Month 42, indicating favorable myocardial remodeling. An independent natural history cohort showed only 26% of patients improved in LV systolic function by Month 24, approximately half the rate observed with acoramidis in the completer analysis.
A separate post-hoc analysis introduced a patient-centered composite measure — days lost to death and/or cardiovascular-related hospitalization (DLDCVH) — integrating mortality, hospitalizations, and length of stay. Acoramidis reduced estimated mean DLDCVH to 7.5% versus 11.7% with placebo through Month 30. The absolute benefit grew over time: 38 additional days alive and out of hospital over 30 months, 65 days (observed) over 36 months, and modelled estimates of up to 94 days over the same period. These are post-hoc findings and should be interpreted accordingly.
OLE data in 56 variant ATTR-CM patients — 35 carrying the p.Val142Ile variant, which disproportionately affects individuals of Western African ancestry — extended survival findings to Month 54. All-cause mortality was 30.4% with continuous acoramidis versus 66.7% in the placebo-to-acoramidis arm in the p.Val142Ile subgroup, and 24.3% versus 57.9% across the overall variant population. These figures are consistent with the 44.7% all-cause mortality reduction and 49.3% cardiovascular mortality reduction reported across the full ATTRibute-CM OLE population at Month 54 in March 2026. Serum TTR levels and NT-proBNP attenuation were sustained through Month 54 in both variant subgroups, with no new safety signals.