CI-980 in Advanced Melanoma and Hormone Refractory Prostate Cancer

Introduction: CI-980 is a novel chemotherapeutic agent thatinhibits polymerization of tubulin. Preclinical studies haveindicated a high level activity of this agent against various tumorcell lines. Methods: 13 malignant melanoma patients who hadfailed prior chemotherapy and/or immunotherapy and 13 hormonerefractory prostate cancer patients, including 4 who had receivedprior chemotherapy, were treated in 2 separate NCI-supportedclinical trials. Subjects received a recommended phase II dose ofCI-980 of 4.5 mg/m2/day by continuous infusion for 72 hoursevery 3 weeks. Results: No activity was seen in either study.Toxicity was tolerable with neutropenia being the most common,significant toxicity. Among the melanoma patients, 15% and 31%developed grade 3 and grade 4 neutropenia, while 7% and 38% ofthe prostate patients developed grade 3 and grade 4 neutropenia,respectively. Conclusions: CI-980 at this dose and scheduleis ineffective against malignant melanoma and hormone refractoryprostate cancer.