Pharmaceutical composition having enhanced antitumor activity and/or reduced side effects, containing an antitumor agent and an hydroxlmic acid derivative

A method for reducing side effect(s) in a patient requiring a treatment for a tumor, comprising administering an effective amount of oxaliplatin and an effective non-toxic amount of a hydroximic acid derivative of the formula I,

• wherein R1,
• R1 is a hydrogen atom or a C1-5 alkyl group,
• R2 is a hydrogen atom, a C1-5 alkyl group, a C3-8 cycloalkyl group or a phenyl group optionally substituted by a hydroxy or a phenyl group, or
• R1 and R2 together with the nitrogen atom they are attached to form a 5 to 8 membered ring optionally containing one or more further nitrogen, oxygen or sulfur atom(s) and said ring is optionally condensed with another alicyclic or heterocyclic ring, furthermore the nitrogen and/or sulfur heteroatom(s) are optionally present in the form of an oxide or dioxide,
• R3 is a hydrogen atom, a phenyl group, a naphthyl group of a pyridyl group wherein said groups is optionally substituted by one or more halo atom(s) or C1-4 alkoxy groups(s)
• Y is a hydrogen atom, a hydroxy group, a C1-24 alkoxy group optionally substituted by an amino group, a C2-24 polyalkenyloxy group containing 1 to 6 double bond(s), a C1-25 alkanoyl group, a C3-9 alkenoyl R7 is a C2-30 polyalkenyl group containing 1 to 6 double bonds(s),
• X is a halo atom, an amino group, a C1-4alkoxy group or
• X forms with B an oxygen atom, or
• X and Y together with the carbon atom they are attached to and the —NR—O—CH2—group being between said carbon atoms form a ring of the formula (a):
• wherein
• Z is an oxygen atom or a nitrogen atom,
• R is a hydrogen atom or,
• R forms with B a chemical bond,
• A is a C1-4 alkylene group or a chemical bond or a group of the formula (b):
• wherein
• R4 is a hydrogen atom, a C1-5 alkyl group, a C3-8 cycloalkyl group or a phenyl group optionally substituted by a halo atom, a C1-4 alkoxy group or a C1-5 alkyl group,
• R5 is a hydrogen atom, a C1-4 alkyl group or a phenyl group,
• m has a value of 0, 1 or 2,
• n has a value of 0, 1 or 2, or a physiologically acceptable acid addition salt thereof to the patient, wherein said tumor is sensitive to said active substance;
• and the administration of the hydroximic acid derivative or a physiologically acceptable acid addition salt thereof reduces the neurotoxic and/or myelotoxic side effects caused by antitumor agents which are experienced by the patient requiring treatment for a tumor.