Purpose: Given the activity of prolonged oral etoposide in platinum and paclitaxel-resistant ovarian carcinoma, a phase I trial was conducted that combined increasing days of oral etoposide therapy with paclitaxel and carboplatin in chemotherapy-naive patients with ovarian peritoneal and tubal carcinoma to establish a maximum-tolerated dose (MTD) of this combination.
Patients and methods: Paclitaxel at 175 mg/m(2) given over 3 hours and carboplatin at an area under the curve of 5 were administered on day 1 followed by oral etoposide 50 mg/m(2)/d beginning on day 2. The number of days of etoposide therapy was escalated on the basis of toxicity. Toxicity end points included neutropenic sepsis, grade 4 thrombocytopenia, or grade 3 neutropenia or thrombocytopenia during etoposide administration. Cycles were repeated every 21 days for a maximum of six courses. Due to hematologic toxicity, the duration of the paclitaxel infusion was decreased to 1 hour for a second stage of accrual.
Results: Of 52 patients studied, 29 were in the first stage of accrual. Dose-limiting toxicity occurred with 8 days of oral etoposide, making the MTD six days of therapy. Twenty-three patients were entered into the second stage of accrual. Dose-limiting toxicity occurred at 12 days of oral etoposide, making the MTD 10 days of therapy. Three patients developed acute myeloid leukemia 16, 27, and 35 months after receiving a cumulative dose of 200 mg/m(2), 1,200 mg/m(2), and 2,400 mg/m(2), respectively.
Conclusion: One-hour paclitaxel, carboplatin, and oral etoposide at 50 mg/m(2)/d for 10 days is tolerable without supportive therapy. The leukemogenic potential is cause for concern and precludes its use in chemotherapy-naive ovarian carcinoma.