Comparing tocilizumab biosimilar BAT1806/BIIB800 with reference tocilizumab in patients with moderate-to-severe rheumatoid arthritis with an inadequate response to methotrexate: a phase 3, randomised, multicentre, double-blind, active-controlled clinical trial

Non-TNF biologics and their biosimilars in rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic inflammatory rheumatic disease that affects both the articular and extra-articular structures, leading to significant joint damage, disability and excess mortality. The treatment algorithm of RA has changed tremendously in the past 1-2 decades because of the emergence of novel biological therapies that target different mechanisms of action in addition to TNFα.

AREAS COVERED

This article summarizes the evidence and safety of the non-TNF biological DMARDs in the treatment of RA, including those that target B cells, T-cell co-stimulation, interleukin (IL)-6 and granulocyte-monocyte colony-stimulating factor (GM-CSF). The targeted synthetic DMARDs such as the Janus kinase inhibitors are not included. The availability of the less costly biosimilars has enabled more patients to receive biological therapy earlier in the course of the disease. The evidence for the non-TNF biosimilar compounds in RA is also reviewed.

EXPERT OPINION

There are unmet needs of developing novel therapeutic agents to enhance the response rate and provide more options for difficult-to-treat RA. These include the newer generation biologic and targeted synthetic DMARDs. A personalized treatment strategy in RA requires evaluation of the cellular, cytokine, genomic and transcriptomic profile that would predict treatment response to biologic or targeted DMARDs of different mechanisms of action.

Demonstration of Physicochemical and Functional Similarity of the Biosimilar BAT1806/BIIB800 to Reference Tocilizumab

BACKGROUND AND OBJECTIVE

Tocilizumab is an immunoglobulin G1 monoclonal antibody targeting the interleukin-6 receptor (IL-6R). BAT1806/BIIB800 (tocilizumab-bavi) has been developed as a biosimilar to the reference product tocilizumab (TCZ). The objective of this study was to demonstrate physicochemical and functional similarity between BAT1806/BIIB800 and TCZ in a comprehensive comparability exercise.

METHODS

A comprehensive panel of over 20 methods was used to generate datasets comparing critical and non-critical product quality attributes for 10 BAT1806/BIIB800 lots and 44 TCZ lots (16 sourced from China, 16 from the EU, and 12 from the US). Primary structure, higher-order structure, and physicochemical properties were assessed using liquid chromatography, mass spectrometry, various spectroscopy techniques/methods, capillary electrophoresis, and thermoanalytical techniques. Fragment antigen-binding (Fab)- and fragment crystallizable (Fc)-mediated biological properties were assessed using cell-based assays, immunoassays, flow cytometry, and kinetic binding assays.

RESULTS

BAT1806/BIIB800 and TCZ (irrespective of source) were shown to be similar in terms of structural and functional properties. No differences were observed in terms of the most critical quality attributes, that is, soluble-IL-6R binding and inhibition of IL-6-mediated cell proliferation. BAT1806/BIIB800 and TCZ demonstrated similarity in terms of Fab- and Fc-mediated binding and biological activity. Minor differences were observed in glycosylation (afucosylation and sialylation), glycation, aggregation, and charge variants, which were demonstrated to be not clinically relevant.

CONCLUSION

BAT1806/BIIB800 and TCZ were highly similar for all critical quality attributes. Where differences were observed in less critical quality attributes, additional analytical assessments and clinical study results determined these to be not clinically meaningful.