A Study of the Impact of Methotrexate (MTX) Discontinuation on the Efficacy of Subcutaneous (SC) Tocilizumab (TCZ) With MTX

Inclusion Criteria:

• Body weight

• Active moderate to severe rheumatoid arthritis (DAS28 >/=4.4) according to the revised 1987 ACR criteria at screening and baseline (prior to treatment on Day 1)

• Currently receiving oral MTX for at least 24 weeks and on a stable oral dose of atleast 15 mg/week for at least 6 weeks prior to treatment (Day 1), with the followingexception: a stable dose of at least 10 mg/week is allowed for participants with abody weight <50 kg or calculated glomerular filtration rate (or creatinine clearance) <60 milliliters per minute (mL/min)

• History of parenteral (SC or intramuscular [IM]) MTX is allowed, but not within 6weeks prior to treatment (Day 1). Participants must not have a documented, clinicallysignificant intolerance to oral MTX and must be receiving oral MTX at a dose of 15mg/week for at least 6 weeks prior to treatment (Day 1)

• Participants who have received one prior anti-tumor necrosis factor (TNF) must havediscontinued etanercept, infliximab, certolizumab, adalimumab, or golimumab for atleast 6 months prior to screening

• Oral corticosteroids must have been

• Participants receiving treatment on an outpatient basis

Exclusion Criteria:

• Documented medical history of significant intolerance to oral MTX >/=15 mg/week

• Participants receiving other (non-MTX) disease modifying anti-rheumatic drugs (DMARDs)within 8 weeks of screening

• Previous treatment with abatacept, rituximab, tofacitinib, or anakinra

• Treatment with parenteral corticosteroids within 4 weeks prior to treatment

• Previous treatment with cell-depleting therapies or alkylating agents

• Previous treatment with TCZ

• Major surgery (including joint surgery) within 8 weeks prior to screening or plannedmajor surgery during the study

• Rheumatic autoimmune disease other than rheumatoid arthritis

• Non-rheumatic active autoimmune diseases (for example, inflammatory bowel diseases,psoriasis, multiple sclerosis)

• Prior history of or current inflammatory joint disease other than rheumatoid arthritis

• Functional Class IV according to the revised (1987) ACR criteria for rheumatoidarthritis

• History of severe allergic or anaphylactic reactions to human, humanized, or murinemonoclonal antibodies

• Evidence of significant uncontrolled concomitant diseases; uncontrolled disease stateswhere flares are commonly treated with oral or parenteral corticosteroids

• Active current or history of recurrent infection, or any major episode of infectionrequiring hospitalization or treatment with intravenous antibiotics within 4 weeksprior to screening or oral antibiotics within 2 weeks prior to screening

• Active tuberculosis requiring treatment within the previous 3 years

• History of or currently active primary or secondary immunodeficiency

• Pregnant or breast-feeding women

• Positive for hepatitis B or hepatitis C infection

• For potential MRI substudy participants: the presence of any metal-containing deviceor object in the body