Docetaxel and herceptin: foundation for future strategies

Randomized controlled studies have demonstrated that both docetaxel and Herceptin are capable of increasing survival in patients with metastatic breast cancer. The two agents show synergy in vitro, and their use in combination is not likely to be associated with the problem of enhanced cardiotoxicity. In two trials of Herceptin plus docetaxel in patients with advanced breast cancer, preliminary data are available for 35 patients. These early results show that the combination is well-tolerated. No symptomatic cardiotoxicity has occurred. The preliminary response rates (RR) in these first- and second-line patients are 44% in one study and 63% in the other. In the subgroups of patients who were HER-2 3+ overexpressers, the RRs are currently 55% and 73%. In an attempt to maximize the efficacy of Herceptin, its use has also been studied in combination with docetaxel and a platinum salt, producing a preliminary RR of 78% in patients positive for HER-2 on the fluorescence in situ hybridization assay. These data are sufficiently promising to justify a study of the role of Herceptin in combination with adjuvant chemotherapy regimens containing docetaxel or docetaxel plus a platinum. The combination of Herceptin with adjuvant therapy containing docetaxel and a platinum may provide a helpful alternative to the potentially cardiotoxic Herceptin/anthracycline-containing regimens currently under investigation.