Major reduction of ultrasound-detected synovitis during subcutaneous tocilizumab treatment: results from a multicentre 24 week study of patients with rheumatoid arthritis

Objective: Few studies have investigated the efficacy of subcutaneous tocilizumab (TCZ-SC) on ultrasound-detected inflammation. This study aimed to explore the clinical efficacy of TCZ-SC treatment in rheumatoid arthritis (RA) patients and to evaluate the response by ultrasound compared to Composite Disease Activity Scores (CDAS). Method: This open-label, single-arm study enrolled RA patients with inadequate response to conventional synthetic disease-modifying anti-rheumatic drugs initiating TCZ-SC 162 mg once weekly for 24 weeks, with clinical assessments at baseline, 2, 4, 8, 12, 16, 20, and 24 weeks. Ultrasound examinations [semi-quantitative score (0-3) of 36 joints and four tendons] were performed at baseline, 4, 12, and 24 weeks. CDAS and American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) response, and sum scores of ultrasound grey scale/Doppler were calculated. Changes during follow-up were explored by the Mann-Whitney test and correlations by Spearman's rho. Results: In total, 133 patients (mean +/- sd age 55.9 +/- 12.0 years) were assessed clinically and 110 patients were also examined with ultrasound. All clinical and ultrasound scores decreased significantly after 4 weeks (p < 0.001). At 24 weeks there was EULAR good response in 87.7% and ACR 70% response in 47.4%. Ultrasound scores had no or low correlations with patient-reported outcomes. At 24 weeks, CDAS remission was achieved in 27.4-83.5% and a sum score Doppler of 0 was found in 53.3%. Conclusions: Clinical and ultrasound scores decreased rapidly. Ultrasound scores were not associated with patient-reported variables. Half of the patients reached ultrasound remission, while there were large discrepancies in the percentage of patients reaching remission based on different CDAS.

Automated summary

The study investigated the clinical efficacy of TCZ-SC treatment in RA patients and its ultrasound-detected inflammation response. Results showed significant decreases in clinical and ultrasound scores within a short period, with low correlations between ultrasound scores and patient-reported outcomes. Some patients achieved ultrasound remission, but there were discrepancies in remission rates based on different CDAS.