Abatacept and tocilizumab tapering in rheumatoid arthritis patients: results of SONATA-a retrospective, exploratory cohort study.

Objectives: As data on disease-activity-guided dose optimization of abatacept and tocilizumab are scarce, we explored the feasibility, effectiveness and safety of dose optimization of these biological DMARDs in RA patients in daily practice.

Methods: RA patients who had been treated with abatacept or tocilizumab for ≥6 months, with DAS28 <3.2, were included. Four groups were identified: abatacept dose reduction (DR) and usual care (UC), and tocilizumab DR and UC. Successful DR and discontinuation entailed being on a lower dose than at baseline or having discontinued abatacept or tocilizumab, while maintaining disease activity score with ESR using 28 joint count (DAS28) <3.2. Proportions of patients with successful DR or discontinuation at 12 months were described. Maintenance of DR was investigated using Kaplan-Meier curves. Between-group differences in mean DAS28 and Health assessment questionnaire disability index (HAQ-DI) change (Δ) over 6 and 12 months were estimated.

Results: One hundred and nineteen patients were included. DR was attempted in 13 of 28 (46%; 95% CI: 28, 66%) abatacept and 64 of 91 (70%; 95% CI: 60, 79%) tocilizumab patients. At 12 months, 3 of 11 (27%; 95% CI: 6, 61%) abatacept and 20 of 48 (42%; 95% CI: 28, 57%) tocilizumab patients were successfully tapered. One of 11 (9%; 95% CI: 0, 41%) abatacept and 5 of 48 (10%; 95% CI: 3, 23%) tocilizumab patients were successfully discontinued. Mean ΔDAS28 and ΔHAQ-DI at months 6 and 12 were not significantly different between DR and UC. For tocilizumab, DAS28 was significantly higher in the DR compared with the UC group at 6 months. Adverse events were comparable between groups.

Conclusion: Abatacept and tocilizumab DR appears to be feasible and safe in clinical practice. No benefits in terms of fewer adverse events in the DR group were observed. Furthermore, DR was suboptimal, because all patients were eligible for DR, but in a substantial number of patients no DR was attempted.