Patupilone (epothilone B, EPO906) inhibits growth and metastasis of experimental prostate tumors in vivo

BACKGROUND. Microtubule agents appear promising for the treatment of prostate cancer. Patupilone (epothilone B), a highly potent non-taxane microtubule stabilizing agent, was evaluated in models of androgen-independent prostate cancer. METHODS. Patupilone was administered to athymic mice bearing human prostate cancer xenografts (subcutaneous DU 145 and PC-3M, orthotopic PC-3M). RESULTS. One 4 mg/kg patupilone administration produced transient regression of DU 145 tumors, while two weekly administrations of 2.5 mg/kg produced stable disease followed by protracted regression, however with more pronounced body weight loss. Taxol (R) (15 mg/kg every other day) weakly inhibited tumor growth, but with less body weight loss. Patupilone (5 mg/kg) produced protracted growth inhibition of subcutaneous PC-3M tumors, with transient body weight loss. In mice with orthotopic PC-3M tumors, 4 or 5 mg/kg/week patupilone impaired primary tumor growth, abrogated metastases and enhanced survival, with only transient body weight loss. CONCLUSIONS. These data suggest that patupilone holds promise for prostate cancer treatment.