Acesion Pharma, a biotech innovator in cardiac care, has enrolled the first patients in its Phase 2 clinical trial of AP31969, a potential new treatment for atrial fibrillation (AF), the most common heart rhythm disorder.
The randomized, double-blind, placebo-controlled, dose-finding study will recruit 200 patients across eight European countries, with results expected by Q1 2027.
The trial aims to measure AF burden—the percentage of time patients spend in arrhythmia—as its primary efficacy endpoint. Safety will be closely monitored, with a focus on ventricular proarrhythmia, a dangerous side effect that limits current antiarrhythmic drugs.
Participants will be fitted with implantable loop recorders, enabling continuous 24/7 heart rhythm monitoring for precise data collection.
AP31969 has already shown promise. In 2025, Acesion completed a Phase 1 trial in 92 healthy volunteers, assessing safety, pharmacokinetics, and QT interval effects—a key indicator of proarrhythmia risk. The drug demonstrated a favorable safety profile and suitability for chronic oral use, with no clinically significant effects on QTc.
Anders Gaarsdal Holst, Chief Executive Officer of Acesion, said: "Advancing our oral lead compound AP31969 into a Phase 2 clinical trial marks an important milestone for Acesion. With the use of implantable loop recorders in the trial, we can precisely estimate AF burden efficacy, as well as understand the risk of proarrhythmia.
"Being able to robustly understand both the efficacy and the key safety parameter within a therapy class is unusual in a phase 2 cardiovascular trial and, if successful, will greatly de-risk Phase 3 development and accelerate AP31969's path to becoming the preferred treatment option for the increasing number of patients suffering from AF."
