A Research Study to Compare a Medicine Called Semaglutide Against Placebo in People With Peripheral Arterial Disease and Type 2 Diabetes

This study is done to see if semaglutide has an effect on walking ability compared with placebo (dummy medicine) in people with peripheral arterial disease (PAD) and type 2 diabetes. Participants will either get semaglutide or placebo ("dummy") medicine - which treatment participants get is decided by chance. Semaglutide is a medicine for type 2 diabetes that can be prescribed by doctors in some countries. Participants will get the study medicine (semaglutide or placebo) in a pre-filled pen for injection. Participants must inject it once a week into the stomach area, thigh, or upper arm, at any time of the day. The study will last for about 59 weeks. Participants will have 8 clinic visits and 1 phone call with the study doctor. At some clinic visits, participants will have blood tests. At some visits participants will also do a treadmill test to measure how far they can walk. Women cannot take part if pregnant, breast-feeding or planning to become pregnant during the study period.

Inclusion Criteria: * Male or female, age above or equal to 18 years at the time of signing informed consent. For Japan: Male or female, age above or equal to 20 years at time of signing informed consent * Diagnosed with type 2 diabetes mellitus at least 180 days prior to the day of screening. * Symptomatic PAD with intermittent claudication corresponding to Fontaine stage IIa (Rutherford classification grade I, category 1 and 2) meeting all of the following: 1. Stable symptoms of PAD with intermittent claudication in Fontaine stage IIa (able to walk without stopping more than 200 m/656 feet/2 blocks) for at least 90 days prior to the day of screening based on patient interview. 2. Screening flat treadmill test (3.2 km/h (2 mph)): Pain-free walking distance of at least 200 meters/656 feet. 3. Screening constant load treadmill test with fixed inclination of 12% and a fixed speed of 3.2 km/h (2 mph): Walking distance equal to or less than 600 meters/1968 feet. 4. Ankle-brachial-index (ABI) equal to or below 0.90 or toe-brachial index (TBI) equal to or below 0.7 (the leg with lowest index is chosen in case of bilateral disease). Exclusion Criteria: * Current or previous treatment with any GLP-1 receptor agonist (GLP-1-RA) within 90 days prior to the day of screening. * Walking ability limited by conditions other than PAD (e.g. aortic aneurism, dysregulated arrhythmia or hypertension, angina pectoris, heart failure, chronic obstructive or restrictive pulmonary disease, Parkinson's disease, severe peripheral neuropathy, amputations, wheel chair or walker dependency, osteoarthritis, morbid obesity, severe varicose veins, etc.). * Planned orthopaedic surgery in the legs, or other major surgery known on the day of screening (surgery affecting walking ability). * Vascular revascularisation procedure of any kind 180 days prior to the day of screening. * Planned arterial revascularisation known on the day of screening. * Myocardial infarction, stroke, hospitalisation for unstable angina pectoris or transient ischemic attack within 180 days prior to the day of screening. * Heart failure presently classified as being in New York Heart Association (NYHA) class III-IV.