Evaluation of Tabalumab Using Auto-Injector or Prefilled Syringe in Participants With Rheumatoid Arthritis (RA)

Inclusion Criteria:

- Ambulatory males or females ≥18 years of age

- Diagnosis of adult-onset RA

- Active RA (at least 8/68 tender and at least 8/66 swollen joints)

- Screening C-reactive protein (CRP) >1.2 times the upper limit of normal (ULN) or a
screening erythrocyte sedimentation rate (ESR) >28 millimeters per hour (mm/hr)

- Documented history of, or current, positive rheumatoid factor (RF) and/or anti-cyclic
citrullinated peptide antibody (anti-CCP Ab) test

- Regular use of methotrexate (MTX) for at least 12 weeks and stable dose (10 to 25
mg/week) for at least 8 weeks prior to baseline

- American College of Rheumatology (ACR) functional class I, II, or III

- Able and willing to inject tabalumab by themselves (or have an assistant who will
inject tabalumab) and able and willing to complete all study procedures

- Able and willing to have blood drawn for pharmacokinetic (PK) sampling

Exclusion Criteria:

- Use of oral corticosteroids at average daily doses of >10 milligrams per day (mg/day)
of prednisone or its equivalent within 6 weeks prior to baseline

- Injection of any parenteral (including intraarticular) corticosteroid within 6 weeks
of baseline

- Have previously discontinued treatment with a biologic disease-modifying antirheumatic
drug (DMARD) or a novel drug that interrupts cytokine signaling [for example, Janus
kinase (JAK) inhibitors] due to insufficient efficacy

- Participants who had discontinued biologic DMARDS for reasons other than efficacy will
not be excluded but must have done so prior to baseline

- Participants who discontinued a JAK inhibitor for lack of efficacy

- Participants who discontinued a JAK inhibitor for reasons other than efficacy will not
be excluded, but must have done so prior to baseline for 21 days

- Previous severe reaction to any biologic therapy that, in the opinion of the
Investigator, would pose an unacceptable risk to the participant if participating in
the study

- Have had an inadequate response to treatment with 3 or more of the following DMARDs
prescribed alone or in combination at approved doses for a minimum of 90 days:
leflunomide, azathioprine, cyclosporine, and/or sulfasalazine

- Use of other DMARDs (for example, gold salts, cyclosporin, azathioprine, or any other
immunosuppressives) other than MTX, hydroxychloroquine, chloroquine, or sulfasalazine,
or the use of a JAK inhibitor in the 8 weeks prior to baseline