BridgeBio lifts the hood on phase 3 acoramidis data, including mortality figures

BridgeBio is diving deeper into phase 3 acoramidis data in patients with transthyretin amyloid cardiomyopathy (ATTR-CM), underscoring the treatment’s ability to reduce cardiovascular-related deaths.

The additional results, released Sunday at the European Society of Cardiology, show that acoramidis was associated with a relative risk reduction of 30% in cardiovascular-related deaths compared to placebo. Nearly 15% of participants in the treatment group had a CV-related death, compared to 21.3% of patients in the placebo group.

BridgeBio reports that 79% of deaths in the study were “cardiovascular (CV) in nature.” The overall relative risk reduction in all-cause mortality was 25% among patients given acoramidis compared to placebo, according to a presentation for investors that followed the data. 

It’s a noteworthy delineation of the mortality data after all-cause mortality was the one cog in the company’s top-line hierarchy of endpoints that did not have a statistically significant improvement. In a release, the company did not say whether the relative reduction in cardiovascular-related mortality was statistically significant. 

The Bay Area biotech also elaborated on previously reported hospitalization data, finding that the average annual hospitalization rate for patients on acoramidis was 0.29, close to the annual hospitalization rate for U.S. Medicare patients generally. The mean annual hospitalization rate for Pfizer’s Vyndaqel was 1.00. 

Slightly more was disclosed about how acoramidis-treated patients fared on a six-minute walk test, with 40% of acoramidis patients reporting an improvement at month 30 compared to 22% for patients on placebo. The company did not say, however, what the average test results were among the two groups. 

The data reaffirm BridgeBio’s initial confidence after the data were first unveiled in July. The company still expects to submit an approval application to the FDA before the end of the year, with more submissions to additional markets set for 2024. BridgeBio also expects to launch a primary prevention study next year. 

The company could enter the market about a year after Alnylam’s Onpattro, with the FDA slated to decide on expanding that drug’s label to include ATTR-CM in early October. Onpattro is already approved to treat ATTR polyneuropathy.