The primary objective of this study is to evaluate the effectiveness of REGN475 compared to placebo in participants with pain due to osteoarthritis (OA) of the knee or hip and a history of inadequate joint pain relief or intolerance to current analgesic therapy.

Key Inclusion Criteria:

1. Body mass index ≤39
2. Clinical diagnosis of OA of the knee or hip
3. History of inadequate pain relief or intolerance to analgesics used for OA
4. Moderate to severe pain in the index joint
5. History of regular use of analgesic medications for OA pain
6. Willing to discontinue current non-steroidal anti-inflammatory drug (NSAID) and opioid pain medications

Key Exclusion Criteria:

1. Other diseases that may involve index knee or hip, including inflammatory joint diseases, crystalline disease (gout or pseudogout), endocrinopathies, metabolic joint disease, lupus erythematosus, rheumatoid arthritis, joint infections, neuropathic disorders, avascular necrosis, Paget's disease, renal osteodystrophy or tumors
2. History of osteonecrosis, destructive arthropathy (RPOA), hip dislocation, pathologic fractures, neuropathic joint arthropathy, knee dislocation or hip dislocation
3. Trauma to the index joint in the 30 days before screening
4. Active fibromyalgia, regional pain caused by lumbar or cervical compression with radiculopathy or other moderate to severe pain that may confound assessments or self-evaluation of the pain associated with OA
5. Prior to the start of the study has received a recommendation for, or is scheduled for joint replacement surgery to be performed during the study period
6. Presence of subchondral insufficiency fracture on screening films or MRI
7. Received an intra-articular injection of hyaluronic acid in the affected index joint within 90 days prior to the screening visit
8. Systemic (ie, oral or intramuscular) corticosteroids within 30 days prior to the screening visit. Intra-articular corticosteroids in the index joint within 12 weeks of the screening visit, or to any other joint within 30 days prior to the screening visit.
9. History of autonomic neuropathy, diabetic neuropathy, or presence of clinically relevant peripheral neuropathy at the time of screening
10. Women of childbearing potential who have a positive pregnancy test result, or who do not have their pregnancy test results at baseline
11. Pregnant or breastfeeding women