At each dose level, 3 patients may be enrolled simultaneously. Escalation to the next higher dose will be allowed after patient 3 of a given dose level has received at least one full cycle of therapy if no dose limiting toxicity (DLT) occured at a given dose level. The decision to enter a next dose level will be made by the study team after reviewing all available toxicity data of the previous groups. A DLT is defined as any grade 4 toxicity, any grade 3 toxicity lasting more than one week or/and febrile neutropenia grade 3 (defined as neutrophils < 1.0 x 10e9/l and fever > 38.5 °C). Nausea, vomiting, anorexia, and alopecia (grade 2) will be excluded as dose limiting toxicities. Similarly, adverse events that are clearly related to the primary tumor, such as progression of disease will not be considered as DLTs. In addition, preexisting toxicities must be taken into account when defining and analyzing DLTs.