A Long-term Extension Study of Tocilizumab (Myeloma Receptor Antibody [MRA]) in Patients With Rheumatoid Arthritis

The American College of Rheumatology (ACR) established certain criteria to measure improvement in rheumatoid arthritis symptoms that include tender or swollen joint counts and five other criteria, including acute phase reactant, patient assessment, physician assessment, pain scale, and disability/functional questionnaire.

Clinical trials use the ACR Score, based on those criteria, as a standard for reporting different degrees of improvement in rheumatoid arthritis symptoms.

Scores on the ACR scale may be up to ACR100 because the number after "ACR" is the percent of improvement in tender or swollen joint counts as well as in three of the other five criteria. Clinical trials determine the percentage of participants who achieve that score - that percentage of improvement.

The disease activity score 28 (DAS28) is a combined index for measuring disease activity in rheumatic arthritis (RA) that includes swollen and tender joint counts, erythrocyte sedimentation rate (ESR), and general health (GH) status. The DAS28 scale ranges from 0 to 10, where lower scores represent less disease activity. Participants with DAS28 scores less than 2.6 were categorized as responders with remission and those with DAS 28 scores of 3.2 or less were categorized as responders with low disease activity (LDA). The percentage of participants classified as responders in each category was recorded over time.

Participants were classified as responders based on a European League Against Rheumatism (EULAR) response of Good or Moderate. Comparing the DAS28 from one patient on two different time points, it is possible to define improvement or response. The EULAR response criteria take into consideration both the first score and the change in score in order to classify them as good response, moderate response or no response. The percentage of participants who were classified as responders was recorded, as posted below.

Swollen joint count (SJC) includes an assessment of 66 joints, and tender joint count (TJC) include an assessment of 68 joints. Joint prosthesis, arthrodesis or fused joints were not considered. Joints were assessed and classified as swollen/not swollen, and tender/not tender, by pressure and joint manipulation on physical examination. Change from Baseline in the SJC and TJC were calculated at given time points, and a negative change indicates improvement.

A small proportion of participants in the all-exposure population reduced or stopped their oral corticosteroid use due to sustained efficacy (defined as at least a 50% improvement in both swollen joint count (SJC) and tender joint count (TJC).

The Stanford Health Assessment Questionnaire - Disability Index (HAQ-DI) is a questionnaire specific for rheumatoid arthritis with 8 component sets (domains): dressing/grooming, arising, eating, walking, hygiene, reach, grip, and common daily activities. Each domain has 2-3 questions (for a total of 20) that participants answer with categorical answers enumerated as a scale of 0-3, where 0=without any difficulty, 1=with some difficulty, 2=with much difficulty, and 3=unable to do.

To calculate the HAQ-DI the patient must have a domain score for at least 6 of the eight domains. The HAQ-DI is the sum of the domain scores, divided by the number of domains that have a score (in range 6-8). The resulting HAQ-DI scores are on a scale that ranges from 0 to 3, where 0=lowest level of difficulty and 3=highest level of difficulty. A negative change from baseline indicates improvement.

Patient's global assessment of disease activity is the patient's overall assessment of their disease activity during specified time periods on a 100 mm horizontal visual analogue scale (VAS). The left-hand extreme of the line was described as "no disease activity" (symptom-free and no arthritis symptoms) and the right-hand extreme as "maximum disease activity" (maximum arthritis disease activity). Change from baseline was calculated for given periods, and a negative change indicates improvement.

Physician's global assessment of disease activity is the treating physician's assessment of the patient's current disease activity on a 100 mm horizontal visual analogue scale (VAS). The extreme left end of the line was described as "no disease activity" (symptom-free and no arthritis symptoms) and the extreme right end as "maximum disease activity". Change from baseline was calculated for given periods, and a negative change indicates improvement.

The patient's assessment of the patient's current level of pain on a 100 mm horizontal VAS was recorded. The extreme left end of the line was described as "no pain" and the extreme right end as "unbearable pain". Change from baseline was calculated for given periods, and a negative change indicates improvement.

Quality of life is measured using the sub-scale for Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F). The assessment was originally developed for chronic illnesses and is now widely used for patients with rheumatoid arthritis.

FACIT-F is a 13-item questionnaire. Participants score each item on a 5-point scale: 0 (Not at all) to 4 (Very much), for a highest possible score of 52. The responses are transformed into a FACIT-F score, where a higher score reflects an improvement. The percentage of participants with at least a 5-point improvement from baseline in the Facit-F score is shown at categorical time points.

The SF-36 Health Survey is a standardized questionnaire consisting of 36 questions that measures patient-reported symptoms on 8 dimensions; it is used to assess health-related quality of life (HRQoL). The Physical Component Summary (PCS) score summarizes the subscales Physical Functioning, Role-Physical, Bodily Pain, and General Health. The Mental Component Summary (MCS) score summarizes the subscales Vitality, Social Functioning, Role-Emotional, and Mental Health. Each score was scaled from 0 to 100. A positive change score indicates better HRQoL. The percentage of participants with at least a 5-point improvement from baseline is presented for each subscale.