Long-Term Durability of Acoramidis Efficacy in TransthyretinAmyloid CardiomyopathyOpen-Label Extension of the ATTRibute-CM Randomized Clinical Trial

IMPORTANCE Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive disorder
caused by destabilization of serum transthyretin (sTTR). Acoramidis, an approved therapy
that achieves near-complete (90%) sTTR stabilization, demonstrated clinical benefit
through month 30 in ATTRibute-CM, which was incremental through month 42 in the
open-label extension (OLE); however, the longer-term durability of outcomes has not been
reported.
OBJECTIVE To evaluate the long-term efficacy and safety of acoramidis through month 54.
DESIGN, SETTING, AND PARTICIPANTS This OLE of the ATTRibute-CM randomized clinical trial
is an international, multicenter, ongoing OLE study. Data accumulated between October 2021
and April 2025 through month 24 of the OLE (month 54) are reported. Participants (aged
18-90 years) who completed ATTRibute-CM and met the OLE eligibility criteria were invited
to enroll in the OLE. Data were analyzed from May 2025 through November 2025.
INTERVENTIONS All OLE participants received open-label oral acoramidis, 800 mg, twice
daily. Acoramidis recipients from ATTRibute-CM continued therapy (continuous acoramidis)
and placebo recipients switched to acoramidis (placebo to acoramidis).