Results of a randomized phase II study of mitoxantrone versus mitoxantrone with cetuximab in metastatic castrate-resistant prostate cancer (CRPC) previously treated with docetaxel-based chemotherapy

4555 Background: Cetuximab (C), a chimeric monoclonal antibody with binding affinity to the epidermal growth factor receptor (EGFR), is active against androgen-independent prostate cell (AIPC) lines. No established therapy prolongs survival in CRPC patients (pts) who have received prior docetaxel (D). Mitoxantrone (M) is often used in this setting. In other cancers, C can restore sensitivity to chemotherapy. The combination of C+M was tested in D-treated CRPC pts. Methods: Pts with metastatic CRPC with evidence of progression (PSA or imaging) after D were eligible. PCWG2 guidelines for nonmeasurable disease applied. Treatment: Arm 1 (CM) C 250 mg/m2 (except 400 mg/m2 on Day 1 Cycle 1) Days 1, 8, & 15 and M 12 mg/m2 Day1; Arm 2 (M) 12 mg/m2 Day1; all pts took oral prednisone (P) 10 mg daily. Cycles were 21-days. Arm 2 pts could crossover to Arm 1 if progression was documented prior to Cycle 7 and were analyzed as Arm 2b. Radiological assessments of disease and PSA were done every 4 cycles. Results: 115 pts...