Experience of the use of trabectedin (ET-743, Yondelis™) in 21 patients with pre-treated advanced sarcoma from a single centre

Aims: Trabectedin (ET-743, Yondelis (TM)) is a marine-derived alkaloid that has two actions. It binds in the minor groove of DNA resulting in a conformational change; thus potentially altering interactions with transcription factors and other DNA binding proteins and it also interacts with the transcription-coupled nucleotide excision repair machinery to induce lethal double-stranded DNA breaks. In recent phase 11 trials it has shown considerable activity in the treatment of sarcomas. Here the use of trabectedin in patients with advanced refractory sarcoma from a single institution is presented. Materials and methods: Twenty-one patients with advanced refractory sarcoma from a single UK centre were treated with trabectedin on a named patient compassionate basis programme. All patients had received prior treatment with an anthracycline, and 95% had received ifosfamide. Results: The patients received a median of four cycles of treatment. Objective partial responses were seen in three patients (14%) and a further eight patients (38%) achieved durable stable disease for a median duration of 4.5 months. The estimated 3- and 6-month progression-free survival was 58.8 and 17.6%, respectively. Six patients experienced early disease progression, and four patients died while on treatment. One death was due to treatment-related toxicity. Overall the drug was relatively well tolerated, with hepatic and haematological toxicities most commonly encountered. Both necessitated delays and/or dose reductions in a proportion of patients. Other significant toxicities were nausea, vomiting and asthenia. Conclusion: The disease responses and durable nature of disease stabilisation seen in a proportion of our patients support the continued investigational use of this drug in the treatment of advanced soft tissue sarcomas.