PHASE-II EVALUATION OF DIDEMNIN-B IN HORMONALLY REFRACTORY METASTATICPROSTATE-CANCER - A SOUTHWEST-ONCOLOGY-GROUP STUDY

Didemnin B, a dipsipeptide isolated from the Caribbean tunicate Tridid emnum with antitumor and antiviral activity was evaluated in a phase I I trial in the treatment of metastatic, hormonally refractory adenocar cinoma of the prostate. Thirteen patients were treated with didemnin B at 3.5 mg/m(2) and 20 patients were treated at 6.3 mg/m(2) intravenou sly every 28 days. Response was assessed every 8 weeks. Of 32 evaluabl e patients there was one partial response for an overall response rate of 3% (95% confidence interval of 0.1-16%). The most common toxicitie s were nausea, vomiting, and diarrhea. Serious cardiac and pulmonary t oxicities were also noted. This drug does not appear to warrant furthe r evaluation in this disease as a single agent.