Acesion Pharma has begun enrolling patients into a phase 2 clinical trial of AP31969, its novel oral SK ion channel inhibitor being developed for rhythm control in atrial fibrillation.
The company said the first participants have now entered the randomised, double‑blind, placebo‑controlled study, which will recruit 200 patients across eight European countries and is expected to complete in the first quarter of 2027.
The trial’s primary efficacy endpoint is atrial fibrillation burden, defined as the percentage of time a participant spends in atrial fibrillation. A key safety measure is the occurrence of ventricular proarrhythmia, a major limitation of existing antiarrhythmic drugs. To support continuous assessment, all participants will receive an implantable loop recorder enabling round‑the‑clock cardiac rhythm monitoring.
Acesion recently completed a phase 1 study of AP31969 in 92 healthy volunteers. That trial assessed single and multiple ascending doses, pharmacokinetics and effects on the QT interval, an established marker of proarrhythmia risk. According to the company, AP31969 showed a favourable safety profile and suitable pharmacokinetics for chronic oral dosing, and clinically relevant effects on QTc could be ruled out.
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.”
He added: “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.”
Acesion said AP31969 has the potential to become a first‑line therapy by addressing the proarrhythmia risks associated with current treatments, as the atrial fibrillation population in the US and EU is projected to reach 25 million by 2030.
