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

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

• Treatment Sequence 1
  
  Interventions:
  

  • Drug: PH-797804
  • Drug: Placebo
• Treatment Sequence 2
  
  Interventions:
  

  • Drug: Placebo
  • Drug: PH-797804
• Treatment Sequence 3
  
  Interventions:
  

  • Drug: Naproxen
  • Drug: Naproxen + PH-797804
• Treatment Sequence 4
  
  Interventions:
  

  • Drug: Naproxen + PH-797804
  • Drug: Naproxen

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.