Shares in biotechnology giant CSL (ASX:CSL) have taken a dip after the company announced that its CSL112 drug candidate did not reach its primary phase three clinical trial endpoint.

The $143.36 billion market capitalisation company has been testing CSL112 (Apolipoprotein A-I [human]) against a placebo to reduce the risk of major adverse cardiovascular events (MACE) in patients following an acute myocardial infarction (AMI).

Having now received the top-line results from its phase three AEGIS-II trial, CSL says its product did not meet its primary efficacy endpoint of major adverse cardiovascular events reducing at 90 days.

As a result, CSL says it has no plans for a near-term regulatory filing.

The Lead Investigator for the AEGIS-II trial, C. Michael Gibson, says CSL will continue to analyse the findings and will share the full results in the coming months.

CSL notes that further analysis of the study is ongoing, and primary results will be presented at the American College of Cardiology Scientific Sessions — which is to be held on 6 April 2024.

CSL Executive Vice President and Head of Research and Development Bill Mezzanotte says there is still work to be done to analyse and understand the complete data, as well as determine any development path ahead for this asset.

“AEGIS-II is the most ambitious study in our company’s history and we are proud of the quality of the study we delivered and the enhanced capabilities we developed to do so.

We plan to apply these capabilities as well as our plasma protein platform to future unmet medical needs in cardiovascular and metabolic conditions as well as those in our other strategic therapeutic areas.”

“AEGIS-II is the most ambitious study in our company’s history, and we are proud of the quality of the study we delivered and the enhanced capabilities we developed to do so”

Shares in CSL were down 4.96% to $289.88 as of 2:10pm on 12 February.

CSL112 is an investigational cholesterol efflux enhancer, developed using a novel formulation of human plasma-derived apoA-I, the primary functional component of high-density lipoproteins. It is intended to improve cholesterol efflux capacity and prevent early recurrent cardiovascular events following AMI.

The AEGIS-II trial is a multicenter, double-blind, randomised, placebo-controlled, parallel-ground study.

Images: CSL Limited