This is a multicenter, randomized, phase II study of the safety and efficacy of two dose
levels of oral ATN-224 in patients with prostate cancer with a rising serum PSA in the
absence of detectable disease. Patients will be randomized (1:1) after confirmation of
eligibility requirements. The primary endpoint is to determine the proportion of patients who
do not have PSA progression for 24 weeks. PSA progression is defined as at least a 50%
increase in PSA and >5 ng/mL from baseline or post-treatment nadir if lower than baseline,
confirmed by another PSA at least 28 days later.