Biosimilar SB5 Matches Originator in Safety, Efficacy for Inflammatory Diseases After Switching

Real-world evidence from Europe demonstrated that switching from Humira (reference adalimumab) to SB5 biosimilar was effective and safe for adults with inflammatory diseases, further supporting that SB5 can serve as a lower-cost alternative to the originator.

Immune mediated inflammatory diseases (IMIDs) range from rheumatoid arthritis (RA), axial spondyloarthritis (axSpA), psoriatic arthritis (PsA), Crohn disease (CD), and ulcerative colitis (UC). In August 2017, the European Medicines Agency approved SB5, also known as Imraldi, and it was accessible as prescribed in October 2018. Prior to the approval and launch, SB5 expressed equivalent efficacy with similar pharmacokinetic, safety, and immunogenicity to the reference adalimumab in phase 1 and 3 trials.

The study design of the non-interventional, single-cohort, real-world PROPER trial included specialists from Germany, Spain, Italy, the United Kingdom, Ireland, and Belgium. The cohort had a total of 955 participants with IMIDs who transitioned from the originator to SB5: 207 with RA, 127 with axSpA, 162 with PsA, 447 with CD, and 12 with UC. Participant clinical characteristics at baseline included sex, relevant medical history, age at SB5 initiation, disease duration, disease activity score and relevant concomitant therapy. Other characteristics were based on disease type, dose, regimen, and method of SB5 administration during the study. SAS version 9.4 or higher was used when conducting each statistical analysis.

Disease activity scores depended on the IMID associated with the participant. For patients with RA, calculations used Disease Activity Score in 28 joints using C-reactive protein and Funktionsfragebogen Hannover. Patients with axSpA utilized the bath ankylosing spondylitis disease activity index. Patients with PsA are measured with the Psoriatic Arthritis Response Criteria swollen joint count (of 66 joints) and tender joint count (of 68 joints). The Harvey-Bradshaw Index (HBI) can assist with determining severity in patients with CD while patients with UC use the Partial Mayo Score.

Out of the original 955, 932 completed follow-up and 722 received SB5 through week 48. Kaplin-Meier estimates of persistence on SB5 at week 48 were 0.86 (95% CI, 0.80-0.90) for RA, 0.80 (95% CI, 0.71-0.86) for axSpA, 0.81 (95% CI, 0.74-0.86) for PsA, and 0.72 (95% CI, 0.67-0.76) for the CD cohorts. Adverse reactions were the main reason participants discontinued SB5 (n = 79) due to reactions of the injection site (n = 66). Out of the participants who reported on 48 week follow-up, 722 (75.6%) were still taking SB5, with the most common dose beginning at baseline of 40 mg every 2 weeks.

Of the patients with RA, 59.2% were in remission at baseline, whereas 57.2% achieved remission in week 48. Patients with axSpA had 81% in remission at baseline and 93.7% at week 48. The HBI score in patients with CD was 84% at baseline and 85.1% at week 48. Remission was determined in 58.4% of patients with UC at baseline and in 83.3% at week 48. In the RA, axSpA, and CD cohorts, SB5 discontinuation had hazard ratios more prevalent in female participants prior to the 48 weeks (3.53, 2.38, 2.21, respectively). The slight changes from baseline initiation of SB5 among the variety of disease cohorts’ overtime did not represent any major differences.

After transitioning, mild adverse drug reactions (ADRs) and serious adverse events (SAEs) were evaluated in the study duration. In total, 232 patients experienced at least 1 mild ADR. However, none of the SAEs were fatal. Disease flares were also considered, and dose adjustments were required for patients enduring flare.

Study limitations were present in the data collection. The population disparities may have altered the findings due to the heterogeneity in healthcare systems. Regional and site effects failed to be accounted for in the analysis. The small proportion of candidate predictors did not allow consideration of all potential information.

The real-world use of SB5 as treatment for patients with IMIDs proved efficacy and tolerance when transitioning from the originator. However, the authors noted, “particular consideration should perhaps be given to female patients who are considering switching, since they appear to be more susceptible to discontinuation than their male counterparts”.

Reference

Müller-Ladner U, Dignass A, Gaffney K, et al. The PROPER study: A 48-week, pan-European, real-world study of biosimilar SB5 following transition from reference adalimumab in patients with immune-mediated inflammatory disease. BioDrugs. 2023;37(6):873-889. doi:10.1007/s40259-023-00616-3