- Maximum total number for planned enrollment: 117 - Dose-seeking cohorts of three to 6 patients until maximum tolerated dose (MTD)/dose limiting toxicity (DLT) reached (up to 24 patients) followed by a randomized phase II trial comparing the activity of the combination of bortezomib plus vandetanib with vandetanib alone (2:1 randomization 62 plus 31 equals 93 patients).