Disproportionate articular pain is a frequent phenomenon in rheumatoid arthritis and responds to treatment with sarilumab

Objectives In some patients with RA, joint pain is more severe than expected based on the amount of joint swelling [referred to as disproportionate articular pain (DP)]. We assessed DP prevalence and the effects of sarilumab, an IL-6 inhibitor, on DP. Methods Data from RA patients treated with placebo or 200 mg sarilumab in the phase 3 randomized controlled trials (RCTs) MOBILITY and TARGET, adalimumab 40 mg or sarilumab 200 mg in the phase 3 RCT MONARCH and sarilumab 200 mg in open-label extensions (OLEs) were used. DP was defined as an excess tender 28-joint count (TJC28) over swollen 28-joint count (SJC28) of ≥7 (TJC28 − SJC28 ≥ 7). Treatment response and disease activity were determined for patients with and without DP. Results Of 1531 sarilumab 200 mg patients from RCTs, 353 (23%) had baseline DP. On average, patients with DP had higher 28-joint DAS using CRP (DAS28-CRP) and pain scores than patients without DP, whereas CRP levels were similar. After 12 and 24 weeks, patients with baseline DP treated with sarilumab were more likely to be DP-free than those treated with placebo or adalimumab. In RCTs, more sarilumab-treated patients achieved low disease activity vs comparators, regardless of baseline DP status. In OLEs, patients were more likely to lose rather than gain DP status. Conclusion About one-quarter of patients with RA experienced DP, which responded well to sarilumab. These data support the concept that other mechanisms (potentially mediated via IL-6) in addition to inflammation may contribute to DP in RA.