Patent ID: 8759496

Claim:
An immunoconjugate having a structural formula selected from the group consisting of MAb-CL2A-SN-38, MAb-CL6-SN-38, MAb-CL7-SN-38, MAb-CLX-SN-38 and MAb-CLY-SN-38, with a structure represented by: where R is hydrogen or C1 to C10 alkyl group and AA is selected from any one of the following L-amino acids: alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine, where R and R′ can be independently hydrogen or methyl; and when R═R′=methyl, referred to as MAb-CL2E-SN-38.