TABLE 1 .

Total antibody (mAb) and catabolite concentrations in tissues of WSU-DLCL2 xenograft mice following a single 5-mg/kg i.v. dose of anti-CD22-cyclopropyl-disulfide-PBD-dimer, or anti-CD22-cyclobutyl-disulfide-PBD-dimer ADCs (n = 2)

Catabolites PBD-dimer and cyclopropyl-thiol and were not detected in tissues of mice dosed with vehicle. ND = not detected.

ADC	Time	PBD-dimer			Cyclopropyl-thiol			mAb
		Plasma	Liver	Tumor	Plasma	Liver	Tumor	Plasma	Liver	Tumor
	h	nM	nM	nM	nM	nM	nM	nM	nM	nM
Cyclobutyl-containing	24	0.43	0.26	1.03	NA	NA	NA	370	24.8	43.5
		0.55	0.55	2.09	NA	NA	NA	342	19.5	25.0
	96	<LLOQ	<LLOQ	1.93	NA	NA	NA	285	20.9	25.3
		<LLOQ	<LLOQ	2.05	NA	NA	NA	272	21.1	56.0
Cyclopropyl-containing	24	ND	ND	ND	0.74	1.42	7.58	294	28.4	59.4
		ND	ND	ND	0.57	0.63	6.76	216	18.6	27.4
	96	ND	ND	ND	<LLOQ	<LLOQ	4.33	349	23.4	23.5
		ND	<LLOQ	ND	0.30	0.34	4.69	331	16.6	16.6

NA, not applicable; LLOQ, lower limit of quantitation, 0.24 nM for both analytes in homogenates (nanomolar concentration in tumor and liver was estimated on the basis of an assumption of tissue density of 1 g/ml).