Docetaxel in ovarian cancer: phase III perspectives and future development

Abstract

In the mid 1990s, the incorporation of paclitaxel into platinum-based therapy for ovarian cancer marked a significant advance in treatment. Future progress will probably involve reductions in toxicity, which may be achieved by combining the less neurotoxic agent docetaxel with carboplatin. In an international phase III study, 1,077 chemotherapy-naive patients with stage Ic-IV ovarian cancer were randomized to receive carboplatin targeted to an AUC of 5 plus either docetaxel 75 mg/m(2) or paclitaxel 75 mg/m(2) for six cycles. Patients treated with paclitaxel plus carboplatin experienced significantly greater neurotoxicity than those treated with docetaxel plus carboplatin. Docetaxel/carboplatin and paclitaxel/carboplatin produced similar rates of objective response (66% and 62%, respectively), and initial data on progression-free survival indicate that the two treatments appear very similar in efficacy. Thus, docetaxel may prove to be a valid alternative to paclitaxel as part of first-line therapy in ovarian cancer. Nevertheless, there remains considerable scope for improvements in treatment. There is the possibility of using existing drugs more effectively, perhaps by the use of sequential rather than concurrent regimens. This would allow the most active drugs to be used at full dose, increase tolerability, and avoid the possibility of negative drug interaction. The integration of molecularly targeted agents, such as those directed at epidermal growth factor receptors, into existing regimens is highly promising but will need to be explored in randomized trials of first-line therapy. Because the prime obstacle to successful treatment is the acquisition of drug resistance, understanding the underlying mechanisms is an important future priority. One candidate is mismatch repair deficiency; the interest here is that experimental resistance reversal is achievable with hypomethylating agents, raising the possibility of future clinical trials if the clinical relevance of this mechanism can be confirmed.