A randomized trial of carboplatin versus iproplatin in untreated advanced ovarian cancer.

Between August 1984 and October 1987, 120 patients with stage IC to IV epithelial ovarian cancer were randomly assigned to receive carboplatin (400 mg/m2) or iproplatin (300 mg/m2) every 4 weeks as initial treatment. Stratification was made according to International Federation of Gynecology and Obstetrics (FIGO) stage and according to size of residual disease after surgery. Response was evaluated after six courses when patients were restaged, with laparoscopy or laparotomy in clinical complete responders or those with no assessable disease. Treatment was then stopped in surgically proven complete responders. Patients with partial (PR) or minor response (MR) received a further six courses of their original drug at a reduced dose (carboplatin 300 mg/m2, iproplatin 225 mg/m2). Patients with stable (SD), progressive (PD), or recurrent disease were treated with cyclophosphamide (1 g/m2). The response rates were 63% (95% confidence interval [CI], 50% to 74%) for carboplatin and 38% (95% CI, 26% to 51%) for iproplatin. Fifteen patients were not assessable for response. The median survival was 114 weeks (95% CI, 82 to 233 weeks) for carboplatin patients and 68 weeks (95% CI, 48 to 82 weeks) for iproplatin patients (P = .008). The amount of residual disease after initial laparotomy was a prognostic factor for survival. Myelosuppression was the main toxicity and was greater with iproplatin. This study shows carboplatin to be more active than iproplatin in the treatment of ovarian cancer and less toxic. Few responses to cyclophosphamide occurred following either drug, implying resistance to the alkylating agent.