Comparing anti-drug antibody signal-to-noise ratios to assess immunogenicity and interchangeability in adalimumab...

To support an interchangeability designation for Sandoz adalimumab biosimilar (GP2017), antidrug antibody (ADA) signal-to-noise (S/N) ratios were assessed in the GP2017 ADACCESS trial to directly assess potential changes in immunogenicity.

ADACCESS was a 51-week trial in patients with moderate-to-severe plaque psoriasis that included patients treated continuously with reference adalimumab (cH), and patients who experienced four switches between reference adalimumab and GP2017 (H2H). ADAs were measured every 6 weeks during the switching phase using an electrochemiluminescence assay. A non-parametric analysis was performed to estimate the 90% confidence interval (CI) of the median of difference in ADA S/N ratios between the cH and H2H treatment groups at week 41. If the 90% CI was within the margin of -0.16 to 0.16 (representing assay noise), this was considered a non-clinically meaningful difference in immunogenicity.

The 90% CIs of the median of difference in ADA S/N ratios between the two treatment groups were within the defined margin of -0.16 to 0.16 at week 41, and at all other time points. Efficacy and safety data were also similar between the treatment groups.

Analysis of ADA S/N ratios showed no increase in immunogenicity following up to four switches between reference adalimumab and GP2017.

NCT02016105.