The antibody anselamimab, which AstraZeneca picked up in its 2021 purchase of Caelum Biosciences, failed to improve survival and reduce hospitalizations, but the company sees promise in data from an unspecified patient subgroup.
AstraZeneca’s amyloidosis treatment missed its primary endpoint in two late-stage trials, the company announced Wednesday. Nevertheless, the AstraZeneca said there was an effect in a prespecified subgroup.
Anselamimab, an antibody that targets amyloid deposits with the hope of eliminating them, is being tested by the pharma’s rare disease division, Alexion, in two separate global Phase III trials, together called Cardiac Amyloid Reaching for Extended Survival (CARES).
The studies enrolled 406 patients in two different stages of light chain amyloidosis, a rare disease where abnormal antibody proteins accumulate in and damage organs, particularly the heart and kidneys. The studies’ primary endpoint was a combination of time to all-cause mortality and frequency of cardiovascular hospitalizations. While across the trials, anselamimab didn’t clear that bar, for a “prespecified patient subgroup,” AstraZeneca said that there was a “clinically meaningful improvement.” The company did not specify what that patient subgroup was.
The drug was well tolerated, the company added, with most adverse events “balanced” between the treatment and the placebo arms.
AstraZeneca acquired anselamimab in 2021 when it purchased Caelum Biosciences from its owner, Fortress Biotech, for an option exercise price of about $150 million plus $350 million in potential payments to Caelum stockholders upon certain regulatory and commercial milestones.
Anselamimab has been granted fast track and orphan drug designation by the FDA for treating amyloidosis, as well as orphan drug tracks in the European Union and Japan.
AstraZeneca said it is performing a fuller data analysis of the trial and will present the results at an upcoming medical meeting.
The anselamimab readout comes in a news-packed month for AstraZeneca. Earlier this week, baxdrostat, the pharma’s treatment for uncontrolled or treatment-resistant hypertension, pushed blood pressure down in patients enrolled in a Phase III trial. Like with anselamimab, AstraZeneca acquired baxdrostat through deal-making, in its 2023 purchase of CinCor Pharma.
In early July, Alexion got access to a suite of new AAV vectors from the Japanese biotech JCR Pharmaceuticals to support its gene therapy program.
