The activity and tolerability of trabectedin has been widely studied in the second-line STS setting, but few studies evaluate it as first-line therapy for patients with comorbidities that preclude anthracycline-based chemotherapy. This study, TR1US, assessed the efficacy, tolerability, and pharmacokinetics of trabectedin in patients with STS in the latter group.
In this study, patients received trabectedin 1.3 to 1.5 mg/m2 as a 24-hour infusion every 3 weeks until progression or unacceptable toxicity. Response, progression-free survival (PFS), and overall survival (OS) were assessed per RECIST 1.1 and Kaplan-Meier, respectively.
From February 2014 to December 2015, 24 patients were enrolled. Their median age was 78 years (range, 64-89 years). STS histologies were leiomyosarcoma (46%), liposarcoma (33%), and others (21%). Two patients had previously received adjuvant anthracycline-based chemotherapy. A median of 4 cycles of trabectedin were delivered.
Among the 24 patients, 2 achieved partial response (8%), 13 stable disease (54%), 5 progressive disease (22%), and 4 were not evaluable (17%) for an overall disease control rate of 62%. After median follow-up of 14 months, median PFS was 4 months and median OS was 9 months.
Drug-related grade 3/4 adverse events were neutropenia (37%), fatigue (21%), and transaminitis (12%). Two serious events were deemed possibly related to trabectedin. No trabectedin-related deaths occurred.
Grosso F, et al. CTOS 2016. Abstract 2567652. P2. Poster 107.