Switching to SB5 Biosimilar from Reference Adalimumab in Patients with RA, Axial Spondyloarthritis, or Psoriatic Arthritis

Data from the ongoing PROPER study indicate switching from reference adalimumab to its biosimilar SB5 was not associated with any clinically meaningful difference in disease score from baseline in patients with rheumatoid arthritis (RA), axial spondyloarthritis, or psoriatic arthritis.

Published real-world data on switching from adalimumab reference to its biosimilar SB5 are limited. To evaluate candidate predictors of SB5 persistence among patients in the European Union who received SB5 across multiple indications, an ongoing observational study (PROPER) was initiated to evaluate persistence with SB5 following reference adalimumab treatment in patients with rheumatoid arthritis (RA), axial spondyloarthritis (AS), or psoriatic arthritis (PsA); the first interim analysis of this study on baseline characteristics, disease scores, and dose regimen up to 24 weeks post-initiation of SB5 was presented at the American College of Rheumatology Convergence 2020 meeting.

Eligible patients with a diagnosis of RA, AS, PsA, ulcerative colitis, or Crohn’s disease who switched to SB5 following a minimum of 16 weeks of treatment with reference adalimumab, at clinics in Belgium, Germany, Ireland, Italy, Spain, and the United Kingdom were enrolled in the study; 1200 patients are planned for enrollment. Data were collected retrospectively from clinic records for the 24 weeks prior to switch, and prospectively and/or retrospectively for 48 weeks following switch. The primary end points include baseline clinical characteristics, disease activity scores, and clinical management over time.

At data cutoff on May 1, 2020, 256 patients were included in the interim analysis; of these, 85 patients had a diagnosis of RA, 86 patients had AS, and 85 patients had PsA. In the RA population, the mean age was 59.9 years (standard deviation [SD], 12.8), mean duration of disease was 12.6 years (SD, 17.0), 22.2% had received biologic therapy prior to reference adalimumab, and 83.8% of patients had stable disease at baseline. In the AS population, the mean age was 52.7 years (SD, 13.5), mean duration of disease was 21.9 years (SD, 14.2), 13.3% had received biologic therapy prior to reference adalimumab, and 71.4% of patients had stable disease at baseline. In the PsA population, the mean age was 54.5 years (SD, 12.6), mean duration of disease was 12.2 years (SD, 10.3), 20.5% had received biologic therapy prior to reference adalimumab, and 80.5% of patients had stable disease at baseline.

By week 24 post-transition, no meaningful difference was observed from baseline in disease scores in the RA, AS, or PsA patient cohorts. In each cohort, ≥75% of patients transitioned to the same dose regimen of SB5 as received for reference adalimumab, and the majority of patients continued the same SB5 regimen through week 24.

These real-world data indicate that, consistent with previously reported data from controlled clinical studies, no clinically meaningful differences were seen in disease score from baseline in patients with RA, AS, or PsA who switched from reference adalimumab to its biosimilar SB5; data from additional patients enrolled and longer follow-up are awaited to further confirm these results.

Reference
Müller-Ladner U, et al. Arthritis Rheumatol. 2020;72(suppl 10):Abstract 805.