Table 4.

In vitro cytotoxicity of the conjugates.

Cell Line	IC50 (nM)
	(ZHER2:2891)2–ABD–MC-DM1	(ZHER2:2891)2–ABD–E3–MC-DM1	(ZHER2:2891)2–ABD–E6–MC-DM1	(ZHER2:2891)2–ABD–IAA	(ZTaq)2–ABD–MC-DM1
AU565	0.22	0.48	0.48	NM b	NM
	(0.16–0.26) a	(0.38–0.70)	(0.33–0.69)
SKBR-3	0.14	0.17	0.38	NM	NM
	(0.10–0.19)	(0.13–0.23)	(0.27–0.43)
SKOV-3	47.0	82.8	116	NM	350

^a Ranges in parenthesis correspond to 95% confidence interval; ^b Not measured.