A Study to Determine the Safety, Tolerability, Pharmacokinetics and Dynamic Effects of Different Doses of the Study Drug EMD 525797 in Prostate Cancer

Inclusion Criteria: * Provision of signed written informed consent * Age superior or equal to 18 years * Subjects with histological or cytologically proven prostate cancer with evidence of bone metastases on bone scans or CT / MRI after prior chemotherapy with e.g. taxane or mitoxantrone Patients should have undergone bilateral orchiectomy or should be on continuous androgen deprivation therapy with a gonadotropin releasing hormone agonist or antagonist and should have stopped any anti-androgen therapy for at least 4 weeks before inclusion in the study. Patients should be either on stable (i.e., since at least 3 months) ongoing therapy with a bisphosphonate or without any bisphosphonate therapy. Initiation of a bisphosphonate therapy within this time period prior the study or during the study is not allowed. Total serum testosterone should be less than 50 ng/dL or 1.7 nmol/L. * Evidence of progressive disease, defined by at least two PSA values above the individual nadir level with an increase of at least 10% each determined at a minimum interval of 2 weeks before screening examination. Presence of a measurable lesion is not required for study entry. Nodal (in lymph nodes superior or equal to 2cm) or visceral progression is sufficient for trial entry independent of PSA. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2 at study entry and an estimated life expectancy of at least 3 months. * Adequate hematological function, defined by white blood cell co…