Abstract
Objective This study examined the effect of dose step-down in patients with rheumatoid arthritis (RA) who achieved sustained disease control with baricitinib 4 mg once daily for up to 96 weeks.
Methods Patients who completed a baricitinib phase III study could enter a long-term extension (LTE). In the LTE, patients who received baricitinib 4 mg for ≥ 15 months and maintained Clinical Disease Activity Index (CDAI) low disease activity (LDA) or remission (REM) were blindly randomized to continue with 4 mg or taper to 2 mg. If needed, 2-mg–treated patients could be rescued to 4 mg, and 4-mg–treated patients could be rescued by adding or increasing conventional synthetic disease-modifying antirheumatic drugs. Efficacy and safety were assessed through 96 weeks. Nonresponder imputation (NRI), considering rescued or discontinued patients as nonresponders, was used for CDAI response analyses.
Results At 96 weeks, most patients maintained LDA in both 2-mg and 4-mg arms, with a lower maintenance rate in the 2-mg than the 4-mg group (NRI 59.9% and 70.2%, respectively). Patients maintained REM in the 2-mg and 4-mg arms at 30.8% and 36.6%, respectively. Rescue rates were 14.7% for baricitinib 4 mg and 22.5% for 2 mg. Of 112 patients who lost LDA in the 2-mg arm and were rescued to 4 mg, 76.2% and 75.6% achieved LDA again at 12 and 24 weeks postrescue, respectively.
Conclusion In a randomized, blinded, phase III LTE study, maintenance of disease control following induction of sustained LDA/REM with baricitinib 4 mg was greater with continued 4 mg than after tapering to 2 mg. Nonetheless, 76% of patients tapered to 2 mg could maintain LDA/REM or recapture with return to 4 mg, if needed.
