Antibody-drug conjugate of the following formula (I): Ab- (LD) n (I) or pharmaceutically acceptable salt thereof, wherein Ab is an antibody to [target] or an antibody to antigen or a binding fragment [target] thereof or an antigen-binding fragment thereof； L is a linker of the following formula (III): ** (See formula) ** where L2 is (C4-C10) cycloalkyl -carbonyl, (C2-C6) alkyl, (C2-C6) alkylcarbonyl, W is an amino acid unit； w is an integer between 0 and 5； Y is PAB-carbonyl with PAB being ** (See formula) ** and is 0 or 1； the asterisk indicates the point of attachment to D； the wavy line indicates the point of attachment to Ab； D is a drug portion of the following formula (II): ** (See formula) ** in which: R1 is H or OH； R2 is a group: (C1-C6) alkyl, COOH, COO - (((C1-C6) alkyl) or thiazolyl； R3 is H or a (C1-C6) alkyl group； A is: - a group of the formula -Het-Alc- in which Alc is a (C1-C8) alkanediyl group and is linked to NR3, and Het is a heterocycle optionally substituted by a (C1-C6) alkyl group and containing at least one nitrogen atom , said nitrogen atom being linked to L, or - a group of the formula -Aa-Ab- in which Aa is linked to L and is O or NR9 with R9 being H or (C1-C6) alkyl and Ab is linked a NR3 and is: - a (C1-C8) alkanediyl group, - a group - (CH2CH2X1) a1 (CH2CH2X2) a2 (CH2CH2X3) a3 (CH2CH2X4) a4CH2CH2- with X1, X2, X3 and X4 each independently representing each other O or NR8； a1, a2, a3 and a4 each independently representing 0 or 1； and R8 representing H or a (C1-C6) alkyl group, - an aryl-alkanediyl group (C1-C8), or heterocycle- (C1-C8) alkanediyl, said group being optionally substituted by a (C1-C6) alkyl group, the portion being heterocyclyl or aryl linked to Aa and the (C1-C8) alkanediyl portion linked to NR3； the wavy line indicates the point of attachment to L； and n is 1 to 12.Conjugado anticuerpo-fármaco de la fórmula (I) siguiente: Ab-(L-D)n (I) o sal farmacéuticamente aceptable del mismo, en el que Ab es un anticuerpo de [diana]
