The invention relates to a therapy of cancer comprising co-administration to a person in need of such treatment and/or co-treatment of a person in need of such treatment with effective amounts of: (1) a compound 1 of formula (I), wherein the groups R.sup.a to R.sup.d have the meanings given in the claims and specification; and (2) at least a further chemotherapeutic agent 2; optionally in combination with radiotherapy, radio-immunotherapy and/or tumour resection by surgery, furthermore, the invention relates to corresponding medicaments and the preparation thereof.