Finnish biotech major Aplagon has dosed the first patient in a mid-stage clinical trial testing a new treatment aimed at stopping severe artery disease that can lead to limb amputation.

 

The Phase 2a trial, known as HEALING, will evaluate the company’s experimental therapy APAC, a heparin proteoglycan mimetic designed to combine antiplatelet and anticoagulant effects to combat thrombo-inflammatory diseases.

 

The study targets patients with peripheral arterial occlusive disease (PAOD) that has progressed to chronic limb-threatening ischemia (CLTI), a severe condition caused by blocked arteries that restrict blood flow to the limbs. The disease carries a mortality rate of about 25% within the first year and frequently leads to amputation. Diabetes and smoking are the main risk factors.

 

The trial will enroll up to 42 patients in Finland across four cohorts, testing both single and repeated intravenous doses of APAC. Researchers will examine early signs of safety and effectiveness, including the drug’s impact on biomarkers linked to thrombo-inflammation.

 

Approval for the Phase 2a study came from Finnish Medicines Agency after an earlier international Phase 1 trial in 30 healthy volunteers found the therapy to be well tolerated and to produce dose-dependent, temporary antithrombotic effects.

 

An additional PET-imaging study using zirconium-89–labeled APAC in PAOD patients and healthy volunteers is expected to conclude in the first half of 2026.

 

Aki Prihti, CEO at Aplagon, said, “We’re delighted to have achieved this significant clinical milestone and dosed our first patient in our Phase 2a trial to treat PAOD/CLTI. These are common, serious, thrombo-inflammatory diseases with high morbidity. 

 

"Our innovative approach, using a heparin proteoglycan mimetic with targeting ability and retention on the vascular injury sites, has potential applications across a broad range of serious vascular diseases caused by thrombo-inflammation. Importantly, our APAC technology can be easily administered locally or intravenously in the hospital setting, supporting its uptake by vascular surgeons or angiologists.”

 

The trial is being conducted with researchers at Helsinki University Hospital and the University of Helsinki.

 

Maarit Venermo, professor of vascular surgery at the institutions, said, “The aim of this study is to improve the current treatment of PAOD/CLTI. APAC has been shown to prevent platelet aggregation and blood clotting. Previous studies have also shown that it reduces the inflammatory response in tissues damaged by oxygen deprivation during short follow-ups. 

 

"Through these actions, APAC enhances the medical treatment of lower limb arterial atherosclerosis, accelerate the healing of tissue damage caused by ischemia, and prevent restenosis after revascularization procedures, thereby reducing the need for reinterventions.”