I wonder whether pharmacoeconomics is the right tool for payers or national markets. Some suggest that the hemophilia market is crowded, the products may be interchangeable, and with protein synthesis having its version of Moore's law, prices are being challenged, at least in the US.

An alternative is to negotiate a per-patient cap--e.g., stoploss--with the manufacturer, in exchange for access to the routine patients. This is a financial, not an economic approach. (I'm an actuary, so I tend to think of impact in terms of audited financial statements.) 

Best regards,

Bruce Pyenson, FSA, MAAA

My approach will be to search literature and check if there is enough data about the performance of therapeutical options than can be used for hemophilia patients with inhibitors. ITI is just one of the available options to treat inhibitors and you can build an economic model to compare costs and outcomes for each option.

may be the russian research can be interest for you

http://cyberleninka.ru/article/n/farmakoekonomicheskiy-analiz-vklyucheniya-v-shemy-lecheniya-ingibitornoy-formy-gemofilii-a-lekarstvennogo-sredstva-antiingibitornyy

http://www.pharmacoeconomics.ru/jour/article/view/44

Systemanic Reviews for your research you can find in Cochrane Library

http://onlinelibrary.wiley.com/cochranelibrary/search