The MONARCH trial showed that subcutaneous sarilumab was superior to adalimumab monotherapy in reducing disease activity and improving physical function in active rheumatoid arthritis. Patients who completed the initial double-blind phase in MONARCH continued to the open-label extension and received sarilumab monotherapy. This analysis evaluated the sustainability of clinical responses and improvements in physical function achieved on MONARCH at week 24 with continued sarilumab monotherapy, and assessed disease activity, physical function, and safety in adult patients switching from adalimumab to sarilumab.
The sustainability of response was measured for the following clinical efficacy end points: Health Assessment Questionnaire Disability Index (HAQ-DI) ≥0.3 units of improvement, Simplified Disease Activity Index (SDAI) ≤3.3 (remission), Disease Activity Score 28–erythrocyte sedimentation rate (DAS28-ESR) <2.6 (remission), <3.2 (low disease activity [LDA]), DAS28–C-reactive protein <2.6 (remission), <3.2 (LDA), and 20%/50%/70% improvement in American College of Rheumatology improvement criteria (ACR20/ACR50/ACR70) responses.
Of the 321 patients who completed the MONARCH study, 320 entered the open-label extension; of these, 155 patients switched from adalimumab to sarilumab (switch group), and 165 remained on sarilumab (continuation group). At open-label extension entry, mean DAS28-ESR was 4.46 and 3.45 in the switch and continuation groups, respectively (P <.0001), and DAS28-ESR ≤3.2 was 16.1% and 47.9%, respectively (P <.0001); in comparison, DAS28-ESR was 6.8 in both treatment groups.
By week 24 of the open-label extension study, 49.7% and 58.8% of patients in the switch and continuation groups achieved LDA of DAS28-ESR ≤3.2, 40.0% and 42.4% achieved DAS28-ESR <2.6 remission; 12.3% and 18.8% achieved SDAI remission, respectively; 63.9% and 66.7% achieved improvement in HAQ-DI ≥0.3, respectively; and 14.8% and 22.4% achieved SDAI remission, respectively.
Treatment-emergent adverse events (TEAEs) in the switch and continuation groups were 63.9% and 57.9%, respectively; serious TEAEs were 9.0% and 1.2%, respectively; infections were 34.2% and 23.6%, respectively; and serious infections were 1.9% and 0%, respectively, with 1 death in the switch group (malignancy) and no deaths in the continuation group.
Source: Burmester GR, Fiore S, Hu CC, et al. Efficacy and safety of switching from adalimumab to sarilumab in an open-label extension of a phase 3 monotherapy trial in patients with active rheumatoid arthritis. Arthritis Rheumatol. 2017;69(suppl 10). Abstract 2482.