Analytical and Functional Similarity Assessment of ABP 710, a Biosimilar to Infliximab Reference Product

Abstract

Purpose: ABP 710 has been developed as a biosimilar to infliximab reference product (RP). The objective of this study was to assess analytical similarity (structural and functional) between ABP 710 and infliximab RP licensed by the United States Food and Drug Administration (infliximab [US]) and the European Union (infliximab [EU]), using sensitive, state-of-the-art analytical methods capable of detecting minor differences in product quality attributes.

Methods: Comprehensive analytical characterization utilizing orthogonal techniques was performed with 14 to 28 unique lots of ABP 710 or infliximab RP, depending on the assay. Comparisons were used to investigate the primary structure related to amino acid sequence; post-translational modifications (PTMs) including glycans; higher order structure; particles and aggregates; primary biological properties mediated by target and receptor binding; product-related substances and impurities; and general properties.

Results: ABP 710 had the same amino acid sequence, primary structure, higher order structure, PTM profiles and biological activities as infliximab RP. The finished drug product had the same strength (protein content and concentration) as infliximab RP.

Conclusions: Based on the comprehensive analytical similarity assessment, ABP 710 was found to be highly analytically similar to infliximab RP for all biological activities relevant for clinical efficacy and safety.

Keywords: ABP 710; biological function; biosimilar; infliximab; physicochemical structure.

Fig. 1

Primary structure assessment of infliximab (EU), ABP 710, and infliximab (US) (a) Intact molecular mass. Identified peaks are reported in Table II; (b) Reduced tryptic peptide map; (c) HILIC glycan map.

Fig. 2

Higher order structural assessment of infliximab (EU), ABP 710, and infliximab (US). (a) Second derivative FTIR spectra; (b) NUV CD spectra; (c) DSC thermograms.

Fig. 3

Charge variant assessment of infliximab (EU), ABP 710, and infliximab (US) by CEX-HPLC. (a) Untreated; (b) carboxypeptidase B digested.

Fig. 4

Functional assessment of Fab-mediated activities for ABP 710, infliximab (US) and infliximab (EU). (a) Inhibition of sTNFα-induced apoptosis in U937 (potency); (b) binding to sTNFα by ELISA; (c) reverse signaling; (d) binding to mbTNFα on CHO MT-3 cells by imaging cytometry; Individual data points, the mean, and ± one standard deviation are shown.

Fig. 5

Functional assessment of Fc-mediated activities for ABP 710, infliximab (US) and infliximab (EU). (a) NK92 ADCC activity; (b) CDC activity; (c) ADCP activity; (d) binding to FcRn by AlphaScreen; Individual data points, the mean, and ± one standard deviation are shown.

Fig. 6

Similarity assessment of the specificity of ABP 710 and infliximab RP. (a) Binding of LTα using SPR; (b) inhibition of LTα-induced IL-8 release in HUVEC by ABP 710 and infliximab RP.

Fig. 7

Thermal stability and forced degradation of ABP 710 and infliximab RP. Fragmentation (LMW + MMW) results by rCE-SDS are shown for (a) accelerated thermal stability at 25°C; (b) stressed thermal stability at 40°C; and (c) reconstituted drug product at 40°C. Acidic charge variants results by CEX-HPLC are shown for (d) accelerated thermal stability at 25°C; (e) stressed thermal stability at 40°C; and (f) reconstituted drug product at 40°C.