Paclitaxel and tamoxifen: An active regimen for patients with metastatic melanoma

In early trials of paclitaxel administered as a 24-hour infusion, an overall response rate of 16% was reported for patients with metastatic melanoma. Paclitaxel is a natural product-based agent and is thus subject to the problem of multidrug resistance (MDR). Tamoxifen is an agent that can abrogate MDR and potentially enhance the effect of paclitaxel. A Phase II trial of the combination was undertaken with previously treated patients.

Patients with metastatic cutaneous or mucosal melanoma who were previously treated with the Dartmouth chemotherapy regimen (dacarbazine, carmustine, cisplatin, and tamoxifen) were evaluated. Paclitaxel was administered at a dose of 225 mg/m(2) intravenously over 3 hours every 3 weeks. All patients also took tamoxifen 40 mg orally daily. Treatment continued until disease progression.

Twenty-one patients completed at least two cycles of paclitaxel and were evaluable for response. Five responses were observed, 1 complete response, and 4 partial responses, for an overall response rate of 24%. The combination was well tolerated. The most common nonhematologic side effects were myalgia and paresthesia. Hematologic toxicity was mild. No patients developed neutropenic fever.

This is the first report of a Phase II trial evaluating paclitaxel as a 3-hour infusion in melanoma patients. The 3-hour infusion is well tolerated and results in little myelosuppression and minimal neurotoxicity. The contribution of tamoxifen is difficult to evaluate because plasma levels were not measured. It is possible that a higher response rate might be observed with larger doses of tamoxifen. Further investigation of paclitaxel in the treatment of patients with metastatic melanoma is warranted.