Immune tolerance induction in hemophilia patients with inhibitors: costly can be cheaper

The development of inhibitory antibodies to factor VIII (FVIII) occurs in a pproximately 30% to 40% of patients with severe hemophilia A. Management op tions for patients with inhibitor include eradicating it via immune toleran ce induction (ITI) or treating bleeding episodes with large quantities of h emostatic agents. ITI is costly, approaching $1 million for the average B-y ear-old, but if successful results in improved clinical outcomes. We constr ucted a decision analysis using the Markov process to model expected clinic al outcomes and costs over a lifetime for a typical 5-year-old hemophiliac with high inhibitor levels. Estimates of relevant variables were based on a thorough review of the medical literature, Outcomes modeled included total lifetime costs as well as life expectancy. The decision analytic model rev ealed that the ITI strategy was associated with an increase in projected li fe expectancy of 4.6 years. Total estimated lifetime costs for the ITI stra tegy were approximately $1.7 million less per patient. Sensitivity analyses over clinically and economically reasonable ranges did not change these fi ndings. The insight that ITI can achieve an improved clinical outcome while being cost-saving is not reflected in many current treatment regimens. Thi s example also illustrates that expensive therapy for patients with a chron ic disease may be cost effective when analyzed from a societal perspective over the patient's lifetime. This finding has important policy implications for medical decision makers at many levels and reinforces the need to unde rtake pharmacoeconomic analyses and choose therapies from a long-term, soci etal perspective. (C) 2000 by The American Society of Hematology.