Clinical Trial to Examine the Pain Relief of PH-797804 Alone Or With Naproxen in Subjects With Osteoarthritis of the Knee

• PH-797804 (Drug): Tablet, 6 mg once daily for 2 weeks
• Placebo (Drug): Tablet, 0 mg once daily for 2 weeks
• Placebo (Drug): Tablet, 0 mg once daily for 2 weeks
• PH-797804 (Drug): Tablet, 6 mg once daily for 2 weeks
• Naproxen (Drug): Tablet, 500 mg twice daily for 2 weeks
• Naproxen + PH-797804 (Drug): Tablet, 500 mg twice daily for 2 weeks and Tablet, 6 mg once daily for 2 weeks
• Naproxen + PH-797804 (Drug): Tablet, 500 mg twice daily for 2 weeks and Tablet, 6 mg once daily for 2 weeks
• Naproxen (Drug): Tablet, 500 mg twice daily for 2 weeks

Primary outcomes

• Western Ontario & McMaster Osteoarthritis Index Pain Score [2 weeks]

Secondary outcomes

• Western Ontario & McMaster Osteoarthritis Index Stiffness Score [2 weeks]
• Western Ontario & McMaster Osteoarthritis Index Physical Function Score [2 weeks]
• Western Ontario & McMaster Osteoarthritis Index Total Score [2 weeks]
• Daily Pain Rating Scale [2 weeks]

Sex: All, ages: 18 Years to 75 Years

Inclusion Criteria:

* Male or female subjects between, and including, the ages of 18 and 75 years. Females must be of non-childbearing potential.
* Diagnosis of osteoarthritis of the knee based on American College of Rheumatology criteria with X-ray confirmation (a Kellgren-Lawrence X-ray grade of ≥2.

Exclusion Criteria:

* History of diseases other than osteoarthritis that may involve the index knee.
* Other severe pain that impairs the assessment of osteoarthritis of pain.
* Electrocardiogram abnormalities.
* History of gastrointestinal disorders.

• Pfizer CT.gov Call Center, Study director, Pfizer