Table 1.

IC50 of free SN‐38 and SN‐38 conjugated to monoclonal antibody (mAb) (immunoconjugate) for malignant lymphoma and pancreatic cancer cell lines (WST‐8 assay)

Malignant lymphoma cell lines	Free SN‐38	SN‐38 conjugated to mAb
		CD20	Collagen 4
		Ester vs carbamate	Ester vs carbamate
RL	>4.6 ± 3.7	>8.7 ± 2.9 vs 2.1 ± 1.0*	34 ± 17 vs 90 ± 30*
Pancreatic cancer cell lines	Free SN‐38	SN‐38 conjugated to mAb
		EpCAM	Collagen 4
		Ester vs carbamate	Ester vs carbamate
SUIT2	7.8 ± 3.6	24 ± 13 vs 15 ± 9	29 ± 15 vs 75 ± 22*

IC50 (50% cell survival) (nM), Mean ± standard deviation (n = 3), *P < 0.05.