Abstract: Provided are novel antibody drug conjugates (ADCs), and methods of using such ADCs to treat proliferative disorders.

Abstract: A compound with the formula I: wherein: R2 is of formula II: where A is a C5-7 aryl group, X is selected from the group comprising: NHNH2, CONHNH2, formula III, formula IV, and either: (i) Q1 is a single bond, and Q2 is selected from a single bond and —Z—(CH2)n—, where Z is selected from a single bond, O, S and NH and n is from 1 to 3; or (ii) Q1 is —CH?CH—, and Q2 is a single bond; R12 is a C5-10 aryl group, optionally substituted by one or more substituents selected from the group comprising: halo, nitro, cyano, ether, C1-7 alkyl, C3-7 heterocyclyl and bis-oxy-C1-3 alkylene; R6 and R9 are independently selected from H, R, OH, OR, SH, SR, NH2, NHR, NRR?, nitro, Me3Sn and halo; where R and R? are independently selected from optionally substituted C1-12 alkyl, C3-20 heterocyclyl and C5-20 aryl groups; R7 is selected from H, R, OH, OR, SH, SR, NH2, NHR, NHRR?, nitro, Me3Sn and halo; either: (a) R10 is H, and R11 is OH, ORA, where RA is C1-4 alkyl; (b) R10 and R11 form a nitrogen-carbon double bond between the n

Abstract: A compound which is selected from A: B: and C: and salts and solvates thereof, as well as conjugates thereof with cell binding agent.