AstraZeneca PLC (LSE:AZN) shares opened lower on Wednesday after a late-stage trial of its experimental treatment for AL amyloidosis failed to meet its primary target in the overall patient group.
The CARES phase III study tested anselamimab, a drug designed to clear harmful protein deposits in organs.
While the trial did not achieve statistical significance in reducing deaths and cardiovascular hospitalisations across all participants, AZ said the drug showed a clear benefit in a prespecified subgroup of patients.
In that group, anselamimab led to “highly clinically meaningful” improvements in survival and fewer hospital admissions, the company said.
AL amyloidosis is a rare and life-threatening condition caused by the build-up of misfolded proteins, which can damage the heart, kidneys and other organs. Most patients are diagnosed late, often with limited treatment options.
AstraZeneca said the findings support further development of the drug for patients most likely to benefit.
The stock opened 1% lower at 10,376p.