(2-Methldisulfanylethyl) -amid of (2E, 10E, 12E, 16Z, 18E) -(R )-6-hydroxy-3, 5, 7, 9, 11,15, 17-heptamethyl-19-((2S, 3S)-3-methy(-6-oxo-3, 6-dihydro-2H-pyran-2-yl)-8-oxo-nonadeca-2,10,12,16, 18-pentaenoic acid

Abstract

This invention relates to a leptomycin derivative of formula (I): Wherein: • Ra and R a are H or a linear or branched C1-C20 alkyl; • R17 is alkyl optionally substituted by OR, CN, NRR, perfluoroalkyl; • R9 is alkyl optionally substituted by OR, CN, NRR, perfluoroalkyl; • X is -NR-; • Y is a linear or branched C1-C20 alkyl; • n is 0: • T represents a thiol protecting group such as Ac, R1 or SRI, wherein R1 represents H, methyl, a linear or branched C1 -C20 alkyl; having a moiety, such as a sulfide or a disulfide, thatcan conjugate to a cell binding agent as an antibody. The therapeutic use of such leptomycin derivative conjugates is also described: such conjugates being able to deliver cytotoxic leptomycin derivative to a specific cell population in a targeted fashion.