PALO ALTO, Calif., Aug. 26, 2026

BridgeBio Pharma, Inc. has announced that the first participant has been dosed in ASCEND-ATTR, a Phase 3b/4 clinical study evaluating the long-term effects of acoramidis (Attruby) in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). The study is designed to further investigate whether long-term treatment with acoramidis can deliver sustained improvements in cardiac structure, heart function and amyloid burden, extending the clinical development program beyond the established goal of slowing disease progression. ASCEND-ATTR builds on findings from the Phase 3 ATTRibute-CM cardiac magnetic resonance (CMR) substudy, which previously indicated potential improvements in multiple measures of cardiac structure and function and showed evidence of amyloid regression in a subset of patients. BridgeBio is now advancing a dedicated prospective study to more closely characterize these potential long-term effects in a larger patient population.

ASCEND-ATTR to Evaluate Long-Term Cardiac Changes

ASCEND-ATTR is a single-arm, prospective, longitudinal, open-label Phase 3b/4 study expected to enroll approximately 150 participants with ATTR-CM. Participants will undergo annual cardiovascular magnetic resonance (CMR) and cardiac echocardiography assessments over a 36-month period, allowing investigators to evaluate changes in cardiac structure and function during continued acoramidis treatment. The study’s primary efficacy endpoint is responder status at Month 36 based on CMR assessment of improvement from baseline in left ventricular systolic function. Secondary assessments will examine additional CMR measures of cardiac function, structure and amyloid burden at Month 36, together with echocardiographic measurements, circulating biomarkers and imaging assessments at Months 12 and 24. By incorporating repeated cardiac imaging over three years, BridgeBio aims to generate a more detailed picture of how sustained TTR stabilization may affect the underlying cardiac manifestations of ATTR-CM.

BridgeBio Builds on ATTRibute-CM CMR Findings

The new study follows previously reported findings from the ATTRibute-CM CMR substudy, where treatment with acoramidis was associated with changes across several measures of cardiac structure and function through Month 30. These included mean improvements from baseline in left ventricular mass index (LVMi), left ventricular stroke volume index (LVSVi) and left ventricular ejection fraction (LVEF), alongside evidence of amyloid regression in a subset of patients. BridgeBio’s scientific rationale is that near-complete TTR stabilization of at least 90% may reduce the formation of new amyloid sufficiently to allow the body’s natural clearance mechanisms to outpace amyloid deposition. If sustained over time, this mechanism could potentially support cardiac remodeling and functional recovery, rather than simply slowing further deterioration. However, ASCEND-ATTR is intended to prospectively evaluate this hypothesis, and the company’s earlier observations should not be interpreted as proof that acoramidis reverses ATTR-CM.

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BridgeBio Advances Acoramidis in ATTR-CM

BridgeBio is positioning ASCEND-ATTR as an important next-stage study for acoramidis, an orally administered selective small-molecule transthyretin (TTR) stabilizer. Attruby is indicated for adults with cardiomyopathy associated with wild-type or variant transthyretin-mediated amyloidosis (ATTR-CM) to reduce cardiovascular death and cardiovascular-related hospitalization. The initiation of ASCEND-ATTR expands the clinical evidence program toward longer-term questions surrounding cardiac remodeling, structural damage and amyloid burden. Additional data from the ATTRibute-CM CMR substudy and its open-label extension, including comparisons with a natural-history cohort, are expected to be shared at the European Society of Cardiology (ESC) Congress 2026. With the first participant now dosed, BridgeBio will continue evaluating whether prolonged acoramidis treatment can produce measurable improvements in the heart beyond disease stabilization, potentially strengthening the understanding of long-term treatment effects in ATTR-CM.

Source: BridgeBio Pharma press relese