A Long-Term Safety Extension Study of WA19926 in Participants With Rheumatoid Arthritis

An AE was considered any unfavorable and unintended sign, symptom, or disease associated with the use of the study drug, whether or not considered related to the study drug. A SAE was any experience that: resulted in death, was life-threatening, required in-patient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect or was medically significant. Adverse Events of Special Interest for this study were: Serious and/or medically significant infections; myocardial infarction/Acute coronary syndrome; Gastrointestinal perforation; Malignancies; Anaphylaxis/hypersensitivity reactions; Demyelinating disorders; Stroke and Serious and/or medically significant bleeding and hepatic events.

The DAS28 (ESR) score is a measure of the participant's disease activity. It is calculated using the tender joint count (28 joints), swollen joint count (28 joints), erythrocyte sedimentation rate (ESR) and general health status. The DAS28-ESR scale ranges from 0 to 10, where higher scores represent higher disease activity. DAS28 <=3.2 implied low disease activity, DAS >3.2 to 5.1 implied moderate disease activity, DAS >5.1 implied high disease activity, and DAS28 <2.6 = clinical remission.

The SDAI was defined as the numerical sum of 5 outcome parameters: tender and swollen joint count (based on a 28-joint assessment), participant and physician global assessment of disease activity on a 100 millimeter (mm) Visual analogue scale (VAS) (VAS; 0 = no disease activity and 100 = worst disease activity) and level of C-reactive protein (CRP) (milligram per deciliter [mg/dl], normal < 1 mg/dl). SDAI total score = 0-86 where a higher score reflects worsening disease. SDAI <=3.3 indicates clinical remission, >3.4 to 11 = low disease activity, >11 to 26 = moderate disease activity, and >26 = high (or severe) disease activity.

Tender joint count was performed by a skilled assessor, evaluating 68 joints for tenderness.

Swollen joint count was performed by a skilled assessor, evaluating 66 joints for swelling.

RA flare was defined as any worsening of the participant's disease activity that in the opinion of the Investigator required treatment intensification beyond supportive therapy which included restarting of the study drug treatment. Time to RA flare was defined as the period of drug-free remission until documentation of RA flare. Drug-free remission was defined as clinical remission (based on DAS28-ESR < 2.6 and /or SDAI ≤ 3.3) for two consecutive assessment visits, followed by discontinuation of tocilizumab, at the Investigator's discretion, at the second assessment visit.

The participant global assessment of disease activity was measured using a 100 mm VAS ranging from 0=very good to 100=very bad.

A participant's overall assessment of pain on a VAS was assessed with a question concerning the amount of pain due to arthritis. Pain was assessed on a 100 mm VAS scale with a left-hand marker "no pain" (0 mm) or right-hand marker "extreme pain" (100 mm).

The Health Assessment Questionnaire Disability Index (HAQ-DI) is a participant-completed questionnaire specific for rheumatoid arthritis. It consists of 20 questions referring to 8 domains: dressing/grooming, arising, eating, walking, hygiene, reach, grip and common daily activities. Each item was 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 divided by the number of domains answered. Total possible scores range from 0 to 3, where 0=least difficulty, and 3=extreme difficulty.