The tolerability and efficacy of four courses of paclitaxel and ifosfamide plus cisplatin every 3 weeks was evaluated in patients with residual or refractory ovarian cancer. Additionally, supportive haematological effects of recombinant human interleukin 3 (rhIL-3) and recombinant human granulocyte colony-stimulating factor (G-CSF) were studied. Paclitaxel starting dose was 135 mg m(-2) (day 1), with ifosfamide dose 1.2 g m(-2) day(-1) (days 2-4) and cisplatin dose 30 mg m(-2) day(-1) (days 2-4). All 16 patients received 5.0 microg kg(-1) day(-1) G-CSF (days 7-16) and, in addition, eight patients were randomized to receive 10 microg kg(-1) day(-1) rhIL-3 (days 5-9). Paclitaxel and ifosfamide doses were reduced when grade IV haematological toxicity occurred. In the absence of grade IV haematological toxicity and normal recovery of haematopoiesis, paclitaxel dose was escalated. Toxicity was evaluable in 56 courses, with haematological effects in 52. Despite antiemetic treatment, nausea and vomiting (> or = grade I) occurred in 50 courses. Five patients had persisting peripheral neuropathy. Renal and liver function were not affected. Grade IV neutropenia occurred in 12 out of 52 courses, with neutropenic fever in two patients, both of whom died from fatal septicaemia. Grade IV thrombocytopenia without bleeding was observed in 15 courses. Grade IV haematological toxicity was associated with hepatic metastases and concurrent increases in alkaline phosphatase (P <0.001) and gamma-glutamyltransferase (P=0.007). No relation was found between haematological toxicity and pharmacokinetic parameters of paclitaxel. Patients treated with rhIL-3 showed a tendency to a faster platelet recovery (not affecting platelet nadir), and the cisplatin dose intensity was higher (P=0.025). Six of the nine evaluable patients had a tumour response. The overall median progression-free survival was 7 months and the overall mean survival was 13 months. In conclusion, this potentially interesting combination as second-line treatment showed a low tolerability with unexpected mortality, while rhIL-3 administration tended to induce a more rapid platelet recovery.