Phase III Study of CG100649 in Osteoarthritis Patients

6-week Efficacy Study The objective of this study is to prove the safety and non-inferiority of analgesic efficacy of CG100649 2 mg vs. celecoxib 200 mg, and analgesic superiority of CG100649 2 mg vs. placebo, when administered once a day in patients with osteoarthritis of the hip or knee over the 6 week Treatment period. The primary efficacy parameter is the difference from Baseline to Week 6 in the Western Ontario and McMaster Universities Index of Osteoarthritis (WOMAC)-Pain subscale. Extended Safety Study The objective of the Extended Safety Study is to collect a total of 24 weeks of safety data for CG100649 including the initial 6 weeks of safety data, and an additional 18 weeks of safety data for those subjects who agree on the consent form to continue into the Extended Safety Study. Subjects will be administered CG100649 2 mg only during 18 weeks of Extended Safety Study.