 ATN-224 is an orally active, small molecule that has been shown in cellular and animal models to be anti-angiogenic and to have activity against prostate cancer cell lines. ATN-224 has the potential to affect the progression of prostate cancer by mechanisms that include both antiangiogenic and antitumor pathways. ATN-224 may change the time to overt metastatic disease in patients with rising PSA as the only manifestation of disease after treatment with curative intent and delay the need for hormonal therapies. 