PRIMARY OBJECTIVES:~I. Determine the effect of cilengitide on changes in serum VEGFR2, a pharmacodynamic biomarker of sunitinib malate effects on endothelial function, during the withdrawal phase of a course of sunitinib malate in patients with advanced solid tumors or glioblastoma multiforme.~SECONDARY OBJECTIVES:~I. Determine the effect of cilengitide exposure on changes in VEGFR2 over the 14-day interval from the end of sunitinib malate administration to the end of course 1 in these patients.~II. Test the safety and efficacy of this regimen in these patients. III. Develop serum collagen c-telopeptide crosslinks (CTx) as a pharmacodynamic marker for cilengitide.~OUTLINE:~COURSE I: Patients receive oral sunitinib malate on days 1-14 (weeks 1-2). Patients are then randomized to 1 of 2 treatment arms.~ARM I: Patients receive cilengitide IV over 1 hour twice in weeks 3 and 4.~ARM II: Patients do not receive treatment in weeks 3 and 4.~COURSE II: Patients in both arms then receive oral sunitinib malate on days 1-14 and cilengitide IV over 1 hour twice in weeks 3 and 4. Treatment repeats every 4 weeks in the absence of disease progression or unacceptable toxicity.~After completion of study therapy, patients are followed up periodically.
This clinical trial is studying how well giving cilengitide together with sunitinib malate works in treating patients with advanced solid tumors or glioblastoma multiforme. Cilengitide and sunitinib malate may stop the growth of tumor cells by blocking blood flow to the tumor. Giving cilengitide together with sunitinib malate may kill more tumor cells. Studying samples of blood in the laboratory from patients receiving cilengitide and sunitinib malate may help doctors understand the effect of these drugs on biomarkers.