Modelling cost effectiveness of horse antithymocyte globulin for treating severe aplastic anaemia in Germany

Acquired severe aplastic anaemia (AA) is a serious condition caused by immune-triggered bone marrow failure. For patients not eligible for bone marrow transplantation, treatment of choice is immunosuppression by a combined treatment with antithymocyte globulin (ATG) and cyclosporine. The debate on treatment optimization in AA is focused on conflicting data regarding ATG preparations from horse (h-ATG) versus rabbit (r-ATG), recently favouring h-ATG. H-ATG has been withdrawn from the European market in 2007. Reimbursement for imported preparations from outside Europe is frequently denied in negotiations with statutory health insurance companies. This raises the question of whether h-ATG is cost effective and a sensible investment with regard to healthcare budgets as well as patient health. We modelled the cost effectiveness of r-ATG versus h-ATG based on a recent randomized trial and cost data provided by the hospital pharmacy of Jena University Hospital. We calculated the amount of life years gained and the average incremental costs per life year gained when comparing h-ATG and r-ATG. Our calculations revealed average incremental costs per life year gained of 11,033.80 for the examined patient population treated with h-ATG when compared to r-ATG. Assuming a cost effectiveness threshold of 25,000-35,000 per life year gained, our calculations demonstrate cost effectiveness of h-ATG as compared to r-ATG.