Study to Evaluate Adverse Events and Change in Disease Activity in Participants Between 18 to 75 Years of Age Treated With Subcutaneous (SC) Injections of ABBV-154 for Moderately to Severely Active Rheumatoid Arthritis (RA)

Participants were randomly assigned at a ratio of 1:1:1:1:1 to ABBV-154 at either 40 mg, 150 mg, 340 mg, subcutaneously (SC) EOW; 340 mg SC every 4 weeks (E4W); or placebo SC EOW. Randomization was stratified by baseline glucocorticoid (yes/no); number of prior failed biologic and/or targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) (1; 2 or more); and prior anti-TNF failure (yes/no) and if yes, further stratification by prior adalimumab use (yes/no). After 12 weeks, participants receiving placebo were re-randomized to receive ABBV-154 150 mg SC EOW or 340 mg SC EOW for the long-term extension (LTE) periods. At re-randomization, participants were stratified by baseline glucocorticoid use (yes/no) and prior adalimumab use (yes/no). Participants from the other dose groups were to continue with their respective dose and dosing regimen. The primary analysis was conducted after all ongoing participants completed Week 12 or withdrew from the study. A final analysis was to be conducted after all participants completed LTE period 2 and a safety follow-up visit or withdrew from the study. The study was terminated before any participants entered LTE Period 2.