A randomized phase III trial comparing trabectedin to best supportive care in patients with pre-treated soft tissue sarcoma: T-SAR, a French Sarcoma Group trial

Background: The French Sarcoma Group assessed the efficacy, safety, and quality of life (QoL) of trabectedin versus best supportive care (BSC) in patients with advanced soft tissue sarcoma (STS). Patients and methods: This randomized, multicenter, open-label, phase III study included adults with STS who progressed after 1-3 prior treatment lines. Patients were randomized (1: 1) to receive trabectedin 1.5 mg/m² every 3 weeks or BSC, stratified into L-STS (liposarcoma/leiomyosarcoma) and non-L-STS groups (other histotypes). Patients from the BSC arm were allowed to cross over to trabectedin at progression. The primary efficacy endpoint was progression-free survival (PFS) confirmed by blinded central review and analyzed in the intention-to-treat population. Results: Between 26 January 2015 and 5 November 2015, 103 heavily pre-treated patients (60.2% with L-STS) from 16 French centers were allocated to receive trabectedin (n = 52) or BSC (n = 51). Median PFS was 3.1 months [95% confidence interval (CI) 1.8-5.9 months] in the trabectedin arm versus 1.5 months (0.9-2.6 months) in the BSC arm (hazard ratio = 0.39, 95% CI 0.24-0.64, P < 0.001) with benefits observed across almost all analyzed subgroups, but particularly in patients with L-STS (5.1 versus 1.4 months, P = 0.0001). Seven patients (13.7%) in the trabectedin arm (all with L-STS) achieved a partial response, while no objective responses were observed in the BSC arm (P = 0.004). The most common grade 3/4 adverse events were neutropenia (44.2% of patients), leukopenia (34.6%), and transaminase increase (32.7%). Health-related 30-item core European Organization for the Research and Treatment of Cancer Quality-of-Life Questionnaire evidenced no statistical differences between the arms for any domain and at any time point. After progression, 91.8% of patients crossed over from BSC to trabectedin. Conclusion: Trabectedin demonstrates superior disease control to BSC without impairing QoL in patients with recurrent STS of multiple histologies, with greater impact in patients with L-STS.