Randomized multicenter phase III trial of trabectedin (T) versus doxorubicin-based chemotherapy as first-line therapy in patients with translocation-related sarcoma (TRS).

Abstract

TPS10101 Background: One third of sarcoma histotypes have specific chromosomal translocations which result in abnormal transcription factors, integral to the change to a malignant phenotype. T is the first of a new class of anti-tumor agents with a transcription-targeted mechanism of action. In vitro evidence exists of the ability of T to interfere with the aberrant transcription factor’s binding to DNA promoters in TRS. Patients with TRS, such as myxoid/round cell liposarcomas (MRCL) have benefited from long-lasting tumor control in response to T. Methods: A randomized, phase III study of T (1.5 mg/m2 in 24-h intravenous infusion every 3 weeks [q3wk]) vs doxorubicin 75 mg/m2 q3wk, or doxorubicin 60 mg/m2 with ifosfamide 6-9 g/m2 q3wk) as first line treatment in patients with advanced TRS. Primary aim: to determine the efficacy of T vs doxorubicin-based therapy by comparing progression-free survival (PFS) in each arm. Secondary aims: comparison of PFS rates at six months, response rate (RR), PFS and RR by histological type (MRCL vs other subtypes), overall survival, safety, exploratory response evaluation by Choi criteria and pharmacogenomic analyses. Patients with confirmed TRS of the following subtypes: MRCL, alveolar soft part sarcoma,angiomatoid fibrous histiocytoma, clear cell sarcoma, desmoplastic small round cell tumor, low grade endometrial stromal sarcoma, low grade fibromyxoid sarcoma,myxoid chondrosarcoma and synovial sarcoma, are stratified by performance status (PS 0 vs 1-2) and sarcoma subtype (MRCL vs other subtypes) and randomized (1:1 ratio) to T or doxorubicin ± ifosfamide. Confirmation of the translocation by fluorescence in situ hybridization is compulsory for inclusion in the primary efficacy analysis. An adaptive design was chosen to test the reduction in relative risk of progression or death with T, an interim analysis will be conducted with 45 PFS events from 80 evaluable patients. To date 117 patients have been enrolled from six countries and 29 centers. An independent data monitoring committee met on 15 November 2011 and concluded that the trial should continue as planned.