Ecteinascidin-743: a marine-derived compound in advanced, pretreated sarcoma patients--preliminary evidence of...

To report the activity of the chemotherapeutic agent ecteinascidin-743 (ET-743) in advanced pretreated sarcoma patients observed during a phase I study and a named-patient basis, compassionate use program.

Twenty-nine pretreated, advanced soft tissue sarcoma (STS) and bone sarcoma patients consecutively seen in our centers were included, 12 from a phase I trial and 17 from a compassionate use program cohort. Patients were treated every 3 weeks at either 1,200 microg/m(2) (six patients), 1,500 microg/m(2) (the recommended dose, 22 patients), or 1,800 microg/m(2) (the maximum-tolerated dose, one patient), given as a 24-hour infusion every 3 to 4 weeks.

Fifteen men and 14 women were treated. The median patient age was 46 years (range, 16 to 71 years), with a median World Health Organization performance status of 1 (range, 0 to 2). Twenty-five patients had STS, three had osteosarcoma, and one had Ewing's sarcoma, and all had progressive disease at accrual. Fifteen patients had bulky disease, and 14 had clinical resistance to anthracyclines. A total of 136 treatment cycles were administered (median per patient, five cycles; range, one to 12 cycles). Transient grade 3 and 4 transaminitis was reported in 24% and 5% of cycles, respectively, grade 3 to 4 neutropenia occurred in 32% of cycles, with concomitant sporadic grade 3 to 4 thrombocytopenia in 5.1% of cycles. Grade 2 to 3 asthenia occurred in 21% of cycles. There were two partial responses (PRs) in STS patients and two PRs in osteosarcoma patients. Two minor responses and 10 disease stabilizations were seen. Median duration of response was 10.5 months (range, 2.8 to 15 months), and mean duration of stabilization was 5.2 months.

ET-743 has activity in advanced, highly pretreated STS and osteosarcoma patients and warrants further trials to establish the extent of its activity in this setting.