If after they have received 6 cycles of ZK-Epo and their doctor determines that the tumor is continuing to shrink, they will continue treatment with ZK-Epo. The number of treatments the patient receives after 6 cycles will depend upon when their doctor feels there has been maximum tumor response (tumor shrinkage). Two treatments will be given beyond what their doctor considers the point of maximum shrinkage. We estimate that they will spend anywhere from 1 1/2 months to 5 months taking part in this study.