A new study examined the toxicity and efficacy of intravenous AEZS-108, a conjugate of a peptide targeting the luteinizing-hormone-releasing hormone (LHRH) receptor and doxorubicin, in patients with castration-resistant and taxane-resistant prostate cancer. The maximum tolerated dose was 210 mg/m2 and the dose-limiting adverse event was persistent neutropenia. Nine of 10 patients evaluable by RECIST achieved stable disease. Three patients had a PSA response and 10 patients had PSA stable disease.