Application of a Plug-and-Play Immunogenicity Assay in Cynomolgus Monkey Serum for ADCs at Early Stages of Drug Development

Table 5

Summary of immunogenicity data for cynomolgus monkey Studies 1 and 2 with the biotin-DIG ELISA and the plug-and-play assay. Samples from cynomolgus monkey studies with two ADCs and their corresponding mAbs were analyzed in the plug-and-play assay. The number of animals that developed anti-drug antibodies after exposure to the above molecules and the immunogenicity incidence obtained with this assay were compared to those previously obtained in the biotherapeutic-specific biotin-DIG ELISA. In Study 1, the plug-and-play assay detected the same positive responses as the biotin-DIG ELISA plus three additional animals with ADA positive responses. In Study 2, all the monkeys had positive responses with the biotin-DIG ELISA and the plug-and-play assay.

Study	Molecule	Positive of total		Immunogenicity incidence
		Biotin-DIG	Plug-and-play	Biotin-DIG	Plug-and-play
1	mAb A	1 of 4	2 of 4	25%	50%
1	ADC A	1 of 4	3 of 4	25%	75%
2	mAb B	3 of 3	3 of 3	100%	100%
2	ADC B	6 of 6	6 of 6	100%	100%

ADAs = anti-drug antibodies; ADC = antibody-drug conjugate; mAb = monoclonal antibody.