Efficacy and Safety of Increased Dose of TA-650(Infliximab) in Patients With Rheumatoid Arthritis

The ACR-N index of improvement is the minimum of the following: (1) the percent decrease from baseline in tender joint counts(TJC) or (2) the percent decrease from baseline in swollen joint counts(SJC) or (3) the median percent decrease from baseline for the following: a. Patient's assessment of pain (visual analog scale (VAS) 0-100, 100 worst pain); b. Patient's global assessment of disease activity (VAS 0-100); c. Physician's global assessment of disease activity (VAS 0-100); d. Physical function as measured by the Health Assessment Questionnaire(HAQ)(0-3); e. C-Reactive Protein(CRP) measurement. Higher numbers (maximum:100) indicate more improvement.

ACR 20 (50 or 70) response is a decrease of at least 20% (50% or 70%) in both TJC and SJC and in 3 to 5 assessments (patient's assessment of pain [VAS] with 0, no pain to 100, worst pain; patient's and physician's global assessment of disease activity VAS scales: overall disease activity [0, very well to 100, very poor and 0, no arthritis activity to 100, extremely active, respectively]; [HAQ]: 20-questions on life activities [0, no difficulty to 3, inability to perform a task]; [CRP])

The TJC was determined by examining 68 joints and identified the joints that were painful under pressure or to passive motion. The TJC was recorded on the joint assessment form at each visit, no tenderness = 0, tenderness = 1.

The SJC was determined by examination of 66 joints and identifying when swelling was present. The SJC was recorded on the joint assessment form at each visit, no swelling = 0, swelling =1.

The test for CRP is a laboratory measurement for evaluation of an acute phase reactant of inflammation. Normal range of CRP is 0 mg/dL to 0.3 mg/dL. A decrease in the level of CRP indicates reduction in inflammation and therefore improvement.

DAS28 is calculated using TJC, SJC erythrocyte sedimentation rate (ESR in mm/hour), and the Patient's Global Assessment of Disease Activity - Visual Analog Scale (VAS in mm) using the following formula: 0.56 x √(TJC) + 0.28 x √(SJC) + 0.70 x log (ESR) + 0.014 x Global Assessment of Arthritis where 28 joints are examined and a lower score indicates less disease activity. A negative change score indicates improvement. Total score range:0 to 9.4, higher score indicated more disease activity. DAS28 =<3.2 implied low disease activity, >3.2 to 5.1 implied moderate disease activity, >5.1 to 9.4 implied high disease activity and <2.6 implied remission.

HAQ: patient's assessment of ability to perform tasks in 8 categories of daily living activities: dress/groom; arise; eat; walk; reach; grip; hygiene; and common activities over past week. Each item scored on 4-point scale from 0 to 3: 0=no difficulty; 1=some difficulty; 2=much difficulty; 3=unable to do. Overall score was computed as the sum of domain scores and divided by the number of domains answered. Total possible score range 0-3 where 0 = least difficulty and 3 = extreme difficulty.

The mTSS is a measure of change in joint health. Digitized images of radiographs of hands and feet obtained at screening and Week 54 were scored in a blinded manner. Joints were scored for erosions on a scale of 0 (no damage) to 5 and joint space narrowing on a scale of 0 (no damage) to 4. Erosion scores and narrowing scores were added to obtain the mTSS (range = 0 [normal] to 390 [maximal disease]). An increase in mTSS from baseline represents disease progression and/or joint worsening, no change represents halting of disease progression, and a decrease represents improvement.

Serum level of infliximab was measured by enzyme-linked immunosorbent assay (ELISA), using a monoclonal antibody against infliximab. The lowest level of infliximab that could be reliably detected was 0.1 ug/ml.

ATI (antibody to Infliximab) was measured by a modification of an enzyme immunoassay.