A Humanized Anti-CD22-Onconase Antibody-Drug Conjugate Mediates Highly Potent Destruction of Targeted Tumor Cells

Table 1

Binding affinity and ribonucleolytic activity of SPDP-based ADCs.

	OAR	Binding affinity	Ribonucleolytic activity
		(nM)	/ (10^3 M^−1s^−1)
ONC	—	NA	14.1 ± 0.8
huRFB4 IgG	—	0.27 ± 0.02	NA
SPDP-based 162 kDa ADC	1 : 1	0.39 ± 0.03	14.1 ± 0.8
SPDP-based 174 kDa ADC	2 : 1	0.47 ± 0.03	26.5 ± 2.4
SPDP-based 186 kDa ADC	3 : 1	0.62 ± 0.03	40.2 ± 3.3

Relative binding affinity () to CD22-positive Raji cells was calculated from equilibrium-binding curves as determined by flow cytometry performed in triplicate. Ribonucleolytic activity (/) was determined from at least three independent assays. Values are expressed as mean ± SE.
NA: not applicable.