Subcutaneous Tocilizumab Leads to Major Reduction of Synovitis in RA Patients

In patients with rheumatoid arthritis (RA), subcutaneous tocilizumab treatment is associated with a major reduction of ultrasound-detected synovitis, according to a multicenter 24-week study. The results of this study were published in the Scandinavian Journal of Rheumatology.

Studies have shown that the safety and efficacy of subcutaneous tocilizumab treatment are comparable to those of intravenous tocilizumab when disease activity was assessed using Composite Disease Activity Scores (CDAS), such as Disease Activity Score based on 28-joint count, Clinical Disease Activity Index, and Simplified Disease Activity Index. However, limited data are available on ultrasound-detected synovitis during treatment with subcutaneous tocilizumab.

The objective of the current study was to examine the clinical efficacy of subcutaneous tocilizumab treatment in patients with RA and to determine the response by ultrasound, compared with CDAS.

The multicenter, open-label, single-arm study was part of the TOZURA trial and included adults with biologic-naive active RA, who had an inadequate response or intolerance to conventional synthetic disease-modifying antirheumatic drugs. All patients initiated treatment with subcutaneous tocilizumab 162 mg once weekly for 24 weeks, administered as monotherapy or in combination with a conventional synthetic disease-modifying antirheumatic drug. Clinical assessments were completed at baseline and at 2, 4, 8, 12, 16, 20, and 24 weeks.

The study sample enrolled 133 patients (mean age, 55.9 years; 81.2% women) who received at least 1 dose of subcutaneous tocilizumab. Of these, 40 patients received subcutaneous tocilizumab as monotherapy, and 84 had concomitant conventional synthetic disease-modifying antirheumatic drugs.

All patients were assessed clinically, and a subgroup of 110 patients was followed with ultrasound assessments.

At 4 weeks, all CDAS and ultrasound scores decreased significantly from baseline (P <.001), and erythrocyte sedimentation rate and C-reactive protein level were normalized.

At 24 weeks, almost half of patients (47.4%) met American College of Rheumatology criteria of 70% improvement in RA activity measures, and 87.7% had European League Against Rheumatism good response.

There were large discrepancies between the percentages of patients achieving CDAS remission at 24 weeks, ranging from27.4% according to American College of Rheumatology/European League Against Rheumatism Boolean, to 83.5% according to Disease Activity Score based on 28-joint count-erythrocyte sedimentation rate. More than half of the patients (53.3%) had achieved the most stringent definition of Doppler remission with a sum score of 0, while 78.9% of the patients had reached a sum score Doppler ≤3.

There were no or low correlations between the different patient-reported outcome measures and the ultrasound scores.

The open-label design is an important limitation of the current study, it was noted.

“This is the first large longitudinal study to explore ultrasound-detected inflammation during TCZ-SC (tocilizumab subcutaneous) treatment, and we found that more than half of the patients reached the most stringent definition of ultrasound remission,” wrote the researchers.

Disclosure: This research was supported by Hoffmann la Roche. Please see the original reference for a full list of authors’ disclosures. 

Reference

Hammer HB, Hansen I, Järvinen P, et al. Major reduction of ultrasound-detected synovitis during subcutaneous tocilizumab treatment: results from a multicentre 24 week study of patients with rheumatoid arthritis. Scand J Rheumatol. Published online January 19, 2021. doi:10.1080/03009742.2020.1845394