Analgesic Efficacy and Safety of V116517 in Subjects With Moderate to Severe Chronic Pain Due to Osteoarthritis (OA) of the Knee

Key Inclusion Criteria: 1. Subjects with moderate pain due to OA of the knee as their primary pain condition. 2. Subjects with diagnostic criteria for primary pain condition (American college of Rheumatology \[ACR\] clinical and radiographic criteria): * At least 1 of the following in addition to knee pain: age \>50, stiffness \<30 min, crepitus on active motion, and * Kellgren-Lawrence (K-L) grade ≥ 2 radiographic evidence within the past 2 years. Key Exclusion Criteria: 1. Subjects with chronic pain conditions other than OA of the knee as their predominant pain condition, including gout, pseudo gout, psoriatic arthritis, active Lyme disease, rheumatoid arthritis or any other inflammatory arthritis, fibromyalgia, neuropathic pain conditions, bursitis, or acute injury or signs of active infection in the target pain area. 2. Subjects who cannot or will not agree to stop all concomitant analgesic medications, apart from specified protocol supplemental analgesic medications. 3. Subjects with history of seizures within the past 5 years. 4. Subjects who use opioids more than 4 days per week. 5. Pain-condition-specific exclusions: * Subjects who received local pain-control procedures, including intra- articular steroid injection in the study knee or intramuscular steroid injection at any site within 6 weeks of entering the study or hyaluronate injection in the study knee within 12 weeks of entering the study. 6. Subjects who have had arthroscopy on either knee or hip within 6 months of entering the study, or open surgery on either knee or hip within 12 months of entering the study. 7. Active-comparator-related exclusions: * Subjects who are allergic to or cannot tolerate naproxen or acetaminophen, including history of NSAID-induced asthma, or nasal polyps; * Subjects with history of bleeding disorders or history of documented gastrointestinal ulcer disease. Other protocol specific inclusion/exclusion criteria may apply.