BridgeBio heart drug redeems itself in phase 3 study

July 17, 2023

California-based BridgeBio has reported positive results at the 30-month mark of phase 3 study of its drug candidate, acoramidis, for the treatment of a rare heart disease — a departure from a disappointing 12-month readout.

The ATTRibute-CM trial was designed to study the efficacy and safety of acoramidis, an oral, highly potent small molecule designed to potently stabilize tetrameric transthyretin in patients with transthyretin amyloid cardiomyopathy (ATTR-CM) — a rare but potentially fatal disease of the heart muscle that can cause heart failure in older adults. 

But back in December 2021, BridgeBio revealed that the trial had failed to meet its endpoints at month 12 (part A) of the global study. In part A of the study, investigators compared patient's change from baseline numbers in a six-minute walk test. But at the 12-month mark, investigators found the change from baseline in the six-minute walk test was not improved in the acoramidis arm relative to the placebo arm.

At the time, CEO and founder Neil Kumar called the trial results "disappointing and baffling." The drugmaker attributed the failure to a surprisingly strong placebo response and insisted there was still potential for acoramidis to demonstrate benefit at the month 30 endpoint, which included all-cause mortality and cardiovascular hospitalizations. 

And it seems BridgeBio was correct: After 30 months, the drug met its primary endpoint, proving 1.8 times better than placebo when measured for preventing death, hospitalization and improvement in the six-minute walk test.

The drug also helped improve survival by 81% in patients on the treatment compared to 74% on the placebo, and reduced frequency of heart disease-related hospitalization by 50%.

BridgeBio intends to submit its NDA to the U.S. FDA before the end of 2023, with regulatory filings in additional markets to follow in 2024.