A Study Comparing Upadacitinib (ABT-494) Monotherapy to Methotrexate (MTX) Monotherapy in Adults With Rheumatoid Arthritis (RA) Who Have an Inadequate Response to MTX (SELECT-MONOTHERAPY)

The study includes a 35-day screening period; a 14-week randomized, double-blind, parallel-group, controlled treatment period (Period 1); a 246-week blinded extension period (Period 2); and a 30-day follow-up visit. Participants who met eligibility criteria were to be randomized in a 2:2:1:1 ratio to one of four treatment groups: * Group 1: upadacitinib 30 mg QD (Period 1) → upadacitinib 30 mg QD (Period 2) * Group 2: upadacitinib 15 mg QD (Period 1) → upadacitinib 15 mg QD (Period 2) * Group 3: MTX (Period 1) → upadacitinib 30 mg QD (Period 2) * Group 4: MTX (Period 1) → upadacitinib 15 mg QD (Period 2) Starting with implementation of Protocol Amendment 5, all participants in the extension period will receive open-label upadacitinib 15 mg QD, including those currently on upadacitinib 30 mg QD.