Second-line treatment of advanced measurable ovarian cancer with iproplatin: a Southwest Oncology Group study

105 patients with advanced ovarian cancer previously treated with cisplatin or carboplatin were entered into a study of iproplatin as second-line therapy. Patients were either clinically resistant to cisplatin or carboplatin, or had relapsed after complete response to these agents. Patients were treated intravenously at an initial dosage of 270 mg/m2 with dosage adjustments to 340, 200 or 135 based on observed toxicity. Of 101 eligible patients, 7 responses (3 complete, 4 partial; 12%) were observed in 60 patients resistant to cisplatin. 2 partial responses (11%) occurred in 18 patients resistant to carboplatin. 2 complete and 3 partial responses were observed in 19 patients (26%) previously treated with but not resistant to cisplatin. Response durations were 2-20 months. Toxicities of iproplatin included thrombocytopenia in 93% of patients, leukopenia in 76% of patients, anaemia in 68% of patients, and diarrhoea in 40% of patients. Thus iproplatin shares cross-resistance with cisplatin and carboplatin in the treatment of ovarian cancer and is not recommended as an effective second-line agent for platinum-resistant ovarian cancer.