OBJECTIVES: To compare the cost-effectiveness and cost-utility of a new orphan drug trabectedin, Yondelis, against various end-stage treatments (EST) following the failure with two chemotherapy agents (anthracycline and ifosfamide) that are approved for the first line treatment of mSTS in Finland. METHODS: An Excel-based Markov model with trabectedin and no trabectedin arms is used in the evaluation. Analyses are performed from a societal lifetime perspective (production losses and VAT excluded) using a probabilistic (second-order Monte Carlo) approach. The cost-effectiveness is evaluated on the basis of cost-effectiveness acceptability frontier, incremental cost per life-year gained (LYG) and quality-adjusted life-years (QALY) gained. Included resources are drugs, mSTS treatments, adverse event treatments and travelling. In the base case analysis, 33% of patients are assumed to receive EST (67% etoposide, 33% dacarbazine). The effectiveness of drugs is based on the indirect comparison of EORTC Soft Tissue and Bone Sarcoma Group (Nielsen 2000; van Oosterom 2002) and ET743-STS-201 trial results. Finnish resources and costs from year 2006 are taken, and both costs and outcomes are discounted with 5% per annum. RESULTS: Trabectedin is associated with incremental 1.14 LYGs, €37,875 additional costs and €33,099 cost per LYG compared to EST. With the willingness to pay of €50,000 per LYG, trabectedin has over 98% probability of being cost-effective. When the quality of remaining life time is taken into account using assumptions, the incremental cost per QALY range between €38,801-€46,425. The results are robust according to multiple sensitivity analyses (including also comparisons against other ESTs: etoposide or dacarbazine monotherapy; doxorubicin, ifosfamide, mesna and dacarbazine (IADIC); ifosfamide, mesna, etoposide, fenobarbital and growth hormone (IE); and ifosfamide, mesna, etoposide and methotrexate (IMVP-a6)). CONCLUSIONS: Trabectedin is a valuable addition for the treatment of mSTS. The cost-effectiveness of trabectedin is comparable or even superior to many other cancer drugs for non-orphan conditions.