Trabectedin for the treatment of advanced metastatic soft tissue sarcoma

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of trabectedin for the treatment of advanced metastatic soft tissue sarcoma, in accordance with the licensed indication, based on the evidence submission from the manufacturer to NICE as part of the single technology appraisal (STA) process. The outcomes stated in the manufacturer’s definition of the decision problem were overall survival (OS), progression-free survival (PFS), response rates, adverse effects of treatment, health-related quality of life, and cost per quality-adjusted life-year (QALY) gained. The clinical evidence was derived from one randomised controlled trial (RCT), in which the licensed dose of trabectedin was compared with a different dose of trabectedin, and three phase II studies. In the RCT, the median OS was 13.9 months for the licensed dose of trabectedin, which was not significantly different from that for the comparator dose of trabectedin, which was 11.8 months. From the phase II uncontrolled trials, median OS was reported as 9.2 or 12.8 months. The RCT reported significantly superior PFS for the licensed dose of trabectedin (median 3.3 months) over the comparator trabectedin dose (median 2.3 months). One phase II uncontrolled trial reported median PFS as 1.9 months in the licensed dose of trabectedin. The RCT reported PFS rates at 6 months were 35.5% for the licensed dose of trabectedin, and 27.5% for the comparator dose of trabectedin. From the phase II uncontrolled trials, PFS rates at 6 months were 24.4% or 29%. For the RCT, deaths attributed to trabectedin occurred in 3.1% of the licensed dose, and 2.3% of the comparator group. The most common severe adverse events were neutropenia, although with a low rate of febrile neutropenia, thrombocytopenia, and aspartate aminotransferase and alanine aminotransferase elevation, although these were reported to be non-cumulative and reversible. Following dialogue iterations with the ERG team, the manufacturer revised the model twice. However, despite revisions, errors/inconsistencies were found in the latest version of the model and were corrected by the ERG (only for the base case). In the latest manufacturer’s submission, the cost per QALY gained of trabectedin compared with best supportive care (BSC) was estimated to be £56,985 for the base case using effectiveness from the STS (Soft Tissue Sarcomas)-201 trial for trabectedin and a pool analysis of the European Organisation for Research and Treatment of Cancer data set for BSC. This analysis was constrained to patients with L–sarcomas only. When the joint uncertainty between parameters was considered, the cost-effectiveness acceptability curve showed that trabectedin has a very low probability of being cost-effective at a threshold of £30,000 per QALY gained compared with BSC for any scenario. The guidance has yet to be issued by NICE.