Phase II clinical trials of cisplatin-then-paclitaxel and paclitaxel-then-cisplatin in patients with previously untreated advanced epithelial ovarian cancer

Purpose: To examine the activity and safety of two sequentially scheduled chemotherapy regimens comprising four cycles of paclitaxel (pctx) 200 mg/m(2)/3 hours then four cycles of cisplatin (cisDDP) 100 mg/m(2), and vice versa, in patients with previously untreated advanced ovarian cancer. Patients and methods: Between January 1994 and February 1996, we recruited 30 patients to the pctx-then-cisDDP regimen and 29 to cisDDP-then-pctx, in parallel phase II trials. Results: Both regimens were predictably active with responses seen in 22 of 30 patients (OR 74%; CR 27%, PR 47%) treated with pctx-then-cisDDP, as against 13 of 21 patients (OR 62%; CR 38%, PR 24%) treated with cisDDP-then-pctx. The OR rate to four cycles of pctx (induction) was 43%, with 27% disease progression; the OR to four cycles of cisDDP (induction) was 57%, with 5% progression. However, progression rates across both induction and consolidation phases were 16% (pctx-then-cisDDP) and 29% (cisDDP-then-pctx). Both regimens were unacceptably neurotoxic, 11 patients suffering grade 3 sensory neurotoxicity (5 on pctx-then-cisDDP, 6 on cisDDP-then-pctx) and 20 having grade 3 deafness (9 on pctx-then-cisDDP, 11 on cisDDP-then-pctx). Conclusion: The activity of these sequential regimens justifies their further development using the less neurotoxic platinum analogue carboplatin, perhaps combining paclitaxel with other platinum non-cross resistant drugs.