Safety of Antithrombotic Heparin Proteoglycan Mimetic APAC in Peripheral Arterial Occlusive Disease and Chronic Limb-threatening Ischemia

The goal of this study is to learn if a new medicine (called antiplatelet and anticoagulant \[APAC\]) can help the body to prevent blood clots and whether APAC is safe and well tolerated in patients with blocked or narrowed arteries in their legs (peripheral arterial occlusive disease \[PAOD\]), and in patients with severely restricted poor blood flow to the legs that threatens limb health (chronic limb-threatening ischemia \[CTLI\]). The study also aims to find the best dose of the medicine. The study consists of two parts: Part A will include patients with PAOD and CTLI, Part B will only include patients with CTLI who are having a procedure to restore blood flow in their legs. Both parts will be subdivided into two subgroups (A1 and A2, B1 and B2) which will test different APAC doses and compare single dosing to weekly dosing for 4 weeks. APAC is injected into the blood. The possible treatment response will be compared either to a placebo (a look-alike substance that contains no drug), or to the current standard treatment. Patients will participate in the study for up to 90 or 180 days. During this time, patients will be regularly examined and asked to answer questions concerning their quality of life.