Reducing Adverse Vascular Outcomes With Factor XI Inhibition in Adult Participants With Peripheral Artery Disease

Key Inclusion Criteria: 1. Successful LER distal to the external iliac artery for ischemia due to atherosclerotic disease within 10 days prior to randomization as described in the protocol 2. At least 1 of the following enrichment factors for major thrombotic vascular events: 1. Bypass with prosthetic graft 2. Endovascular treatment with stenting 3. Target lesion length \>15 cm 4. History of LER or amputation for PAD prior to qualifying LER 5. Type 2 diabetes mellitus requiring pharmacologic treatment 6. Comorbid symptomatic coronary artery disease as described in the protocol 7. Chronic kidney disease as described in the protocol 8. Age ≥75 years Key Exclusion Criteria: 1. Has any active clinical condition requiring chronic therapeutic anticoagulation after the index revascularization including known triple positive antiphospholipid syndrome 2. Has known bleeding diathesis, platelet count \<50,000/mm\^3 or history of non-traumatic intracerebral hemorrhage, known cerebral amyloid angiopathy, or known unrepaired cerebrovascular malformations 3. Has recent coronary revascularization as described in the protocol 4. For Cohort 2 only: Has estimated Glomerular Filtration Rate (eGFR) \<15 mL/min/1.73m\^2 within 14 days prior to randomization or on dialysis or expected to be started on dialysis within the next 12 weeks starting from randomization 5. Has any other condition or therapy which would make the participant unsuitable for this study or not allow participation for the full planned study period 6. Has allergy, hypersensitivity, or other contraindication to REGN7508, REGN9933, or rivaroxaban (Cohort 2 only) or their excipients Note: Other Protocol Defined Inclusion/ Exclusion Criteria Apply