Orphan drugs revisited: cost–effectiveness analysis of the addition of mifamurtide to the conventional treatment of osteosarcoma

Introduction: Mepact® (mifamurtide) is the first drug approved for the treatment of high-grade resectable non-metastatic osteosarcoma in patients aged 2–30 in the last 20 years. It follows a randomized clinical trial showing a statistically-significant and clinically-relevant decrease in the risk of death without compromising safety. Aim: This study assessed the cost–effectiveness and budget impact of mifamurtide. Methods: The economic evaluation was done on a hypothetical cohort of young patients under the age of 30 with high-grade, non-metastatic, resectable osteosarcoma. Standard chemotherapy without mifamurtide was used as comparator. A Markov model was adapted using Spanish costs and the results of the INT-0133 Phase III study. The analysis has been carried out from the perspective of the Spanish National Health Service, with a time horizon of up to 60 years in the base analysis. Results: The observed greater efficacy of mifamurtide in the trial translates into a gain of 3.03 (undiscounted) and 1.33 ...