Inclusion Criteria:

• Male or female outpatients and inpatients aged 2 to 16 years

• Diagnosis of idiopathic arthritis of childhood by ILAR criteria:

  • Age of onset less than 16 years
  • Arthritis in one or more joints defined as swelling, or - if no swelling is present - limitation in range of joint movement with joint pain or tenderness, which is not due to primary mechanical disorders
  • Duration of the disease > 6 weeks
  • Type of onset of disease during the first 6 months classified as polyarthritis (5 joints or more; rheumatoid factor positive or negative), oligoarthritis (4 joints or fewer) or systemic arthritis
• Oligoarthritic, extended oligoarthritic or polyarthritic current course of disease
• Active arthritis as defined above of at least 2 joints
• At least 2 other abnormal variables of any of the 5 remaining core set parameters. The physician and the parent ratings must be at least 10 mm on a 100 mm VAS scale and the CHAQ score more than 0.

• Patients requiring therapy with NSAIDs, i.e., the patient fits into one of the following categories:

  • New onset patient
  • Patient in remission, but experiencing a flare and now requiring an NSAID
  • Patient with insufficient therapeutic effect (ITE) or intolerability to another NSAID (other than Naproxen) and now must be changed
• Written informed permission given by the parent(s) or the subjects legally authorised representative in accordance with local legislation and ICH GCP
• Active assent given by the patient if the child is capable of understanding the given information (applies to children who have reached an intellectual age of 7 years or greater)

Exclusion Criteria:

• Patients with systemic course of JRA (intermittent fever with or without rash or other organ involvement) or with current systemic involvement
• All rheumatic diseases not covered by the inclusion criteria
• Any finding indicating that the patient has a clinically significant other disease than JRA at the time of enrollment
• Patients with abnormal, clinically relevant laboratory values not related to their JRA
• Pregnancy or breast feeding
• Women of childbearing potential not using adequate contraception precaution: attention should be drawn to reports that NSAIDs were reported to decrease the effectiveness of intrauterine devices (R95-0164)
• History of bleeding disorders, gastrointestinal bleeding or cerebrovascular bleeding
• Active peptic ulcer within the last 6 months
• Treatment with more than one SAARD/DMARD (slow-acting antirheumatic drug/disease-modifying antirheumatic drug) during the last 3 months prior to study entry
• Change in treatment with SAARDs/DMARDs during the last 3 months prior to study entry or intended change during the trial duration
• Change in treatment with corticosteroids during the last month prior to study entry or intended change during the trial duration with exception of local therapy for uveitis

• One of the following therapies during the last 3 months prior to study entry or their intended use during the trial treatment period

  • Systemic treatment (except for intra-articular injections) with corticosteroids at a dose higher than 10 mg/day or 0.2 mg/kg/day (prednisone equivalent), respectively (whichever is lower)
  • Treatment with hydroxychloroquine at a dose higher than 10 mg/kg/day
  • Treatment with cyclosporine at a dose higher than 5 mg/kg/day
  • Treatment with methotrexate at a dose higher than 15 mg/m2/week
  • Treatment with other cytotoxic agents, gold compounds, D-penicillamine, Enbrel (etanercept), biologic agents and experimentals
• Intra-articular injections of corticosteroids during the last month prior to study entry and intended injections during the first 4 weeks of the trial treatment period
• Concomitant administration of other NSAIDs (including topical forms for skin with exception of local therapy for uveitis) or analgesic agents except paracetamol or acetaminophen