The objectives of the study were to evaluate the efficacy, safety, and tolerability of valdecoxib 10 mg once daily (QD) or naproxen 500 mg twice daily (BID) versus placebo, and to assess the efficacy of valdecoxib 10 mg QD versus naproxen 500 mg BID, in treating the signs and symptoms of rheumatoid arthritis (RA) in a severe Rheumatoid Arthritis population.

Inclusion Criteria:

• A diagnosis of severe rheumatoid arthritis (RA) for at least 6 months
• The Rheumatoid Arthritis must have been treated with a stable regimen including a non-steroidal anti-inflammatory drug (NSAID), as well as methotrexate for at least 12 weeks -OR- an NSAID (for at least 12 weeks plus a tumor necrosis factor inhibitor (i.e., adalimumab [Humira®] for a minimum of 5 doses on a regular schedule, etanercept [Enbrel®] for 6 weeks, infliximab (Remicade®) for 3 doses and currently on a stable regimen of infusions not more than every 8 weeks)

Exclusion Criteria:

• A diagnosis of any other inflammatory arthritis or a secondary, noninflammatory type of arthritis (eg, osteoarthritis (OA) or fibromyalgia) that, in the investigator's opinion, was symptomatic enough to interfere with the evaluation of the effect of valdecoxib on the patient's primary diagnosis of Rheumatoid Arthritis were excluded from the study