The trial is conducted according to the optimal two-stage design of Simon with alpha 0.05 and beta 0.10, considering the following two hypotheses: first a response rate (RR) less than 10% is of no further interest; and second, an RR 30% is clinically meaningful. In the initial stage, 18 patients have to enter onto the study. If less than 3 responses (</=2 in 18) will be observed, the trial would be terminated. Otherwise, accrual will continue to a total of a maximum of 35 patients. At the end of the trial, if 6 or fewer responses will occur among the 35 patients (</= 6 in 35), it will be concluded that the regimen is not worthy of further investigations for that group of patients.