Abstract: The present invention relates to (i) conjugates comprising two DNA alkylating subunits linked by a moiety fitting to the minor groove of the DNA, (ii) to their preparation and (iii) to their use in cancer therapy. The alkylating subunits are especially cytotoxic under hypoxic conditions found in cancer cells. The compounds of the present invention and compositions thereof are useful in the treatment of cancer in a mammal, both alone or in a combination with other anti-cancer agents (e.g. checkpoint abrogators) and/or radiation. They may also be used as cytotoxic units for gene-directed enzyme-prodrug therapy (GDEPT) and antibody-directed enzyme-prodrug therapy (ADEPT). The present invention provides the compounds of Formula (I), Formula (II) and Formula (III): for treating cancer in a mammal.