Phase II study of topotecan (NSC 609 699) in patients with recurrent or metastatic soft tissue sarcoma

Background: New drugs are needed for treatment of un-resectable or metastatic soft tissue sarcoma. Topotecan, a semisynthetic derivative of the alkaloid, camptothecin, exerts its cytotoxic effect through inhibition of topoisomerase I. Patients and methods: Thirty-two adult patients with locally advanced or metastatic soft tissue sarcoma entered this phase II study of topotecan, administered at 1.5 mg/m(2)/ day IV x 5 days every 3 weeks. AU had measurable disease and none had received previous chemotherapy. Results: There were 3 partial responses (10.3%; 95% CI 2.2-27.4%) in 29 evaluable patients. Grade 3 or 4 neutropenia occurred in 25 patients, and there was a 17% incidence of infection/neutropenic fever leading to one toxic death. Conclusions: Topotecan, in this dose and schedule, has low activity in adult soft tissue sarcoma.