A Study Comparing ABT-494 to Placebo and to Adalimumab in Subjects With Rheumatoid Arthritis Who Are on a Stable Dose of Methotrexate and Who Have an Inadequate Response to Methotrexate

Inclusion Criteria:

- Adult male or female, at least 18 years old.

- Diagnosis of RA for greater than or equal to 3 months.

- Subjects must have been on oral or parenteral methotrexate (MTX) therapy greater than
or equal to 3 months and on a stable prescription of greater than or equal to 15 to 25
mg/week (or greater than or equal to 10 mg/week in subjects intolerant of MTX at doses
greater than or equal to 12.5 mg/week) for greater than or equal to 4 weeks prior to
the first dose of study drug. In addition all subjects should take a dietary
supplement of folic acid or folinic acid throughout the study participation.

- Meets the following minimum disease activity criteria: greater than or equal to 6
swollen joints (based on 66 joint counts) and greater than or equal to 6 tender joints
(based on 68 joint counts) at Screening and Baseline Visits.

- At least one of the following at Screening: greater than or equal to 3 bone erosions
on x-ray OR greater than or equal to 1 bone erosion and a positive rheumatoid factor
OR greater than or equal to 1 bone erosion and a positive anti-cyclic citrullinated
peptide autoantibodies.

- Subjects with prior exposure to only one Biological disease-modifying anti-rheumatic
drugs (bDMARD) (except ADA) may be enrolled (up to 20% of total study population) if
they have documented evidence of intolerance to the bDMARD or limited exposure (less
than 3 months), but required washout periods need to be satisfied.

- Except for MTX, subject must have discontinued all conventional synthetic
disease-modifying anti-rheumatic drugs (csDMARDs).

Exclusion Criteria:

- Prior exposure to any Janus kinase (JAK) inhibitor (including but not limited to
tofacitinib, baricitinib, and filgotinib).

- Subjects who have been exposed to adalimumab or who are considered inadequate
responders to bDMARD therapy as determined by the Investigator.

- History of inflammatory joint disease other than RA. History of secondary Sjogren's
Syndrome is permitted.