Phase II trial of carboplatin in soft-tissue sarcoma

As part of the Eastern Cooperative Oncology Group program for the assessment of new drugs in sarcomas, a Phase II trial of carboplatin was performed in patients who had received no more than one prior chemotherapy regimen. A total of 50 patients received either 400 mg/m2 or 320 mg/m2 depending on whether they had received prior radiotherapy. A response rate of 16% (95% confidence interval 6-32%) occurred in the 37 patients who had received doxorubicin as their only prior systemic therapy. Three of the six responses were complete and persisted for 7 to 34 months. In contrast none of the 13 patients who received carboplatin after initial progression on doxorubicin and subsequent progression on interferon alpha responded. The overall response rate was therefore 12% (95% confidence interval 5-24%). Toxicity was primarily hematologic, with 14 patients having Eastern Cooperative Oncology Group (ECOG) grade 3 toxicity and no grade 4 or 5 toxicities. In view of the number of complete responses, carboplatin should be studied further in untreated patients with advanced soft tissue sarcoma.