The purpose of the study was to assess the proportion of patients who achieve pain relief thresholds, the time needed to reach the thresholds, and the relationship between pain and inflammation among patients with rheumatoid arthritis (RA) and an inadequate response to methotrexate in RA-BEAM (NCT0170358). A randomized, double-blind trial was conducted, comparing baricitinib (N = 487), adalimumab (N = 330), and placebo (N = 488) plus methotrexate. Pain was evaluated by patient's assessment on a 0-100 mm visual analog scale (VAS). The following were assessed through a 24-week placebo-controlled period: the proportion of patients who achieved ≥30%, ≥50%, and ≥70% pain relief, the time to achieve these pain relief thresholds, remaining pain (VAS ≤ 10 mm, ≤20 mm, or ≤40 mm), and the relationship between inflammation markers and pain relief. Baricitinib-treated patients were more likely (p < 0.05) to achieve ≥30%, ≥50%, and ≥70% pain relief than placebo- and adalimumab-treated patients, as early as Week 1 vs. placebo and at Week 4 vs. adalimumab. A greater proportion of baricitinib-treated patients achieved ≤20 mm or ≤40 mm remaining pain vs. placebo- and adalimumab-treated patients. Baricitinib-treated patients tended to demonstrate consistent pain relief independent of levels of inflammation control. In RA patients with an inadequate response to methotrexate, baricitinib provided greater and more rapid pain relief than adalimumab and placebo. Analyses suggest the relationship between inflammation and pain may be different for baricitinib and adalimumab treatments.
Keywords: baricitinib; disease-modifying antirheumatic drugs; outcomes research; pain perception; patient perspective; rheumatoid arthritis.