A Study to Evaluate ONO-4474 in Patients With Pain Due to Osteoarthritis of the Knee

Inclusion Criteria: * Symptomatic OA of the knee for ≥3 months diagnosed prior to screening as per American College of Rheumatology clinical criteria. * Radiographic evidence of tibiofemoral OA of index knee (Kellgren-Lawrence grade 2-3), as confirmed at screening. * Moderate to severe index knee pain due to OA requiring use of analgesic medication. * Willing to discontinue use of all analgesic medication (aside from rescue medication) during the study. Exclusion Criteria: * Presence of, or history of, 1. any inflammatory arthritis (e.g. gout, reactive arthritis, psoriatic arthritis, seronegative spondylarthropathy, septic arthritis, previous diagnosis of pseudogout in target joint with proven crystals on joint aspiration or elevated C-Reactive Protein (CRP) at time of knee arthritis flare), 2. RPOA, osteonecrosis, osteoporotic fracture or any other painful joint disease other than OA, 3. Secondary causes of OA; other rheumatologic or musculoskeletal conditions (e.g., rheumatoid arthritis, fibromyalgia, septic arthritis, congenital abnormality). * Orthopaedic surgery of a lower extremity or any major surgery within the previous 6 months prior to Visit 1 or has plans for surgical intervention during the study. * Symptomatic hip OA. * A history of partial or complete joint replacement surgery in the index knee at any time or anticipating knee surgery during the study period. * Significant knee injury or any knee surgery (including arthroscopy) in the index knee within 6 months prior to screening. * Uncontrolled diabetes.