Study to Assess Change in Disease Activity and Adverse Events of Oral Upadacitinib Compared to Subcutaneous Adalimumab in Adult Participants With Moderate to Severe Rheumatoid Arthritis

Inclusion Criteria:

• Diagnosis of Rheumatoid Arthritis (RA) for >= 3 months based on the 2010 AmericanCollege of Rheumatology/European Alliance of Associations for Rheumatology (ACR/EULAR) classification criteria for RA.

• Treated for >= 3 consecutive months prior to screening with 1 tumor necrosis factorinhibitor (TNFi) (only 1 of originator or biosimilar certolizumab pegol, etanercept,golimumab or infliximab) for RA, but continue to exhibit active RA, or had todiscontinue due to intolerability or toxicity, irrespective of treatment duration.Up to 15% of participants who were intolerant to 1 TNFi will be allowed to enroll.Prior administration of different biosimilar versions for the same originator TNFior switching between originator and biosimilar version of the same originator TNFiare acceptable. Cycling between biosimilars of different originator TNF inhibitorsis not acceptable.

• On oral or parenteral methotrexate (MTX) therapy >= 3 consecutive months and on astable prescription of 15 to 25 mg/week (or >= 10 mg/week in participants intolerantof MTX at doses >= 15 mg/week) for >= 4 weeks prior to the first dose of study drug.In addition, all participants should take a dietary supplement of folic acid orfolinic acid throughout the study participation.

• For a Chinese, Japanese, Korean, or Taiwanese participant, a stable dose of MTX >= 7.5 mg/week is acceptable.

• Additional local requirements for MTX may apply.

• Meets both of the following disease activity criteria:

• >= 6 swollen joint (based on 66 joint counts) and >= 6 tender joints (based on 68 joint counts) at screening and baseline;

• High-sensitivity C-reactive protein (hsCRP) >= 3 mg/L (central lab, upper limitof normal [ULN] 2.87 mg/L) at screening.

Exclusion Criteria:

• History of any arthritis with onset prior to age 17 years or current diagnosis ofinflammatory joint disease other than Rheumatoid Arthritis (RA).

• Prior exposure to any janus kinase (JAK) inhibitor.

• Prior exposure to adalimumab (original or biosimilar) or to any approved orinvestigational TNF inhibitor other than infliximab, etanercept, certolizumab pegoland golimumab.

• Prior exposure to an approved or investigational non-TNFi biologic disease modifyinganti-rheumatic drug (bDMARD) or targeted synthetic disease modifying antirheumaticdrug (tsDMARD).