P127 Comparison of the Efficacy, Safety and Immunogenicity of a Proposed Biosimilar MSB11456 with Tocilizumab Reference Product in Moderate-to-Severe Rheumatoid Arthritis: Results of a Randomized Double-Blind Study
Authors: Zubrzycka-Sienkiewicz Anna , Misterska-Skora Maria , Socik-Pojawa Malgorzata , Klama Kamilla , Ullman Martin , Petit-Frere Corinne , Illes Andras , Baker Peter , Monnet Joëlle , Morais Jeremy , Brzezicki Jan 
Published: April 2024

Abstract

Background/Aims
Tocilizumab is an anti-interleukin-6 receptor monoclonal antibody indicated for treating rheumatoid arthritis (RA) and other inflammatory diseases. MSB11456 is a proposed biosimilar to US-licensed tocilizumab and EU-approved tocilizumab. It has already shown equivalent pharmacokinetic, pharmacodynamic safety, tolerability, and immunogenicity profiles to these products given subcutaneously (SC) as a single dose in healthy volunteers. This Phase III, multi-centre, randomised, double-blind, multiple fixed-dose, parallel group study compared efficacy, safety and immunogenicity of MSB11456 and EU-approved tocilizumab administered SC in moderate-to-severe RA patients.

Methods
Patients were randomised to 162mg MSB11456 or EU-approved tocilizumab for 24 weeks (W). At W24, patients receiving EU-approved tocilizumab were re-randomised to continue treatment or switch to MSB11456 for up to W52. Safety evaluations were conducted up to W63. A change from baseline in Disease Activity Score-28 Joint Count-ESR (DAS28-ESR) at W24 was analysed, as the primary efficacy endpoint, using analysis of covariance to determine the least squares mean (LSM) difference between MSB11456 and EU-approved tocilizumab; equivalence was considered if the 90% confidence interval (CI) was entirely within the FDA equivalence interval -0.6 to 0.5. Secondary endpoints were 20% improvement in ACR core set measures at W24 and DAS28-ESR at W12. Additional endpoints included ACR50/70, change in DAS28-CRP, Simplified and Clinical Disease Activity Indexes, evaluation of immunogenicity up to W55 and safety up to W63.

Results
Clinically relevant LSM decreases from baseline in DAS28-ESR were observed from W2 up to W24 with both treatments. The 90% CI for LSM difference in the change from baseline in DAS28-ESR between treatments was fully included within the predefined equivalence interval, which demonstrated therapeutic equivalence of MSB11456 and EU-approved tocilizumab (Table 1). Other efficacy endpoint analyses supported this conclusion. No discernible patterns in the nature or frequency of treatment-emergent adverse events (TEAEs) were identified to suggest a difference between drugs. Anti-drug antibodies incidence was similar among treatment arms. Switching from EU-approved tocilizumab to MSB11456 had no clinically relevant impact on efficacy or safety.

Conclusion
Equivalent efficacy, immunogenicity and safety profiles of MSB11456 and EU-approved tocilizumab were demonstrated in moderate-to-severe RA patients, confirming equivalence between MSB11456 and the EU-approved tocilizumab.

Disclosure
A. Zubrzycka-Sienkiewicz: None. M. Misterska-Skora: None. M. Socik-Pojawa: None. K. Klama: None. M. Ullman: Other; Employee of Fresenius Kabi SwissBioSim - Sponsor of the study. C. Petit-Frere: Other; Employee of Fresenius Kabi SwissBioSim - Sponsor of the study. A. Illes: Other; Employee of Fresenius Kabi SwissBioSim - Sponsor of the study. P. Baker: Other; Employee of Fresenius Kabi SwissBioSim - Sponsor of the study. J. Monnet: Other; Employee of Fresenius Kabi SwissBioSim - Sponsor of the study. J. Morais: Other; Employee of Fresenius Kabi SwissBioSim - Sponsor of the study. J. Brzezicki: None.