Cilengitide in Treating Patients With Metastatic Prostate Cancer

PRIMARY OBJECTIVES: I. To evaluate the efficacy, as measured by the rates of clinical progression at six-months, of two dose levels of EMD121974 in patients with asymptomatic metastatic androgen-independent prostate cancer. SECONDARY OBJECTIVES: I. To evaluate the safety of the two dose levels of EMD121974 in patients with metastatic androgen-independent prostate cancer. II. To assess the objective response rate of two dose levels of EMD121974 in patients with metastatic androgen-independent prostate cancer and bidimensionally measurable disease. III. To assess the rate of 50% or greater decline in the level of Prostate Specific Antigen. TERTIARY OBJECTIVES: I. To determine the effects of integrin αvβ3 and αvβ5 inhibition on total circulating tumor cells and endothelial cells isolated from peripheral blood and bone marrow aspirates from patients with metastatic androgen-independent prostate cancer. II. To study the genotypic/phenotypic variances in circulating tumor cells in patients with metastatic androgen-independent prostate cancer before and after EMD121974 treatment. III. To develop a genetic profile by cDNA microarray analysis of circulating tumor cells isolated from patients with metastatic androgen-independent prostate cancer before and after integrin αvβ3 and αvβ5 inhibition. IV. Determine the effects of integrin αvβ3 and αvβ5 inhibition on systemic bone remodeling markers in patients with metastatic androgen-independent prostate cancer. OUTLINE: This is an open-label, randomized, multicenter study. Patients are stratified according to prior bisphosphonate use (yes vs no). Patients are randomized to 1 of 2 doses of cilengitide. ARM I: Patients receive lower dose cilengitide IV over 1 hour twice a week for 6 weeks. AMR II: Patients receive higher dose cilengitide IV over 1 hour twice a week for 6 weeks. In both arms, treatment repeats every 6 weeks for 2 courses in the absence of disease progression or unacceptable toxicity. After 2 courses, patients undergo response assessment. Patients achieving a complete response (CR) receive at least 3 additional courses beyond documentation of CR. Patients with partial response or stable disease continue treatment indefinitely in the absence of disease progression or unacceptable toxicity. Patients with a mixed response may continue treatment at the discretion of the investigator. Patients are followed for survival.