Reassuring results of a low rate of de novo inhibitors in PTPs who switched from pd-FVIII to rFVIII were shown in prospective premarketing studies carried out with these new products [45-50]. Subsequently, Luminespib purchase national product switches have provided important pieces of evidence. Two surveillance studies were carried out in Canada during the population switch from pd-FVIII to rFVIII and then from first to second generation rFVIII and neither of these studies showed an increase in inhibitor incidence [51, 52]. A retrospective

study performed in Ireland after a national tender with consequent en masse switch to a third generation full-length rFVIII did not detect changes in the rate of de novo inhibitor formation [53]. In the UK a national tender was floated in 2009–2010 and it required half of patients using rFVIII to change

rFVIII brands [54]. Inhibitor testing was performed in all patients prior to the switching date and 6-monthly thereafter. Overall 1217 patients with severe haemophilia A and no inhibitor history were analysed (535 switched and 682 did not). Almost all patients who switched changed to B-domainless rFVIII. The inhibitor incidence was not significantly different from that observed during the previous two decades [54]. All these studies indicate that switching is not associated with an increased risk of de novo inhibitor formation. However, due to the very low inhibitor incidence in PTPs, all studies were selleck compound underpowered. Meta-analyses of PTPs studies were also performed to gain further insight into the available evidence. This methodology was applied to compare the inhibitor risk in PTPs receiving full-length rFVIII with that of patients given B-domainless rFVIII [55]. Unexpectedly, a sevenfold to 10-fold higher inhibitor incidence was found MycoClean Mycoplasma Removal Kit in recipients of B-domainless FVIII [55]. These results were not confirmed in a subsequent systematic review

and meta-analysis adopting strict criteria for study selection [56]. In conclusion, prospective, controlled surveillance programmes on switching and not switching patients are still required to provide robust evidence concerning the inhibitor risk related to product switching. In this respect, inhibitor testing before and after the switch as well as testing of not switching patients is a crucial element to establish the correlation with the new treatment. The availability over time of newer therapeutic molecules and the variable market accessibility of different products often entail switching; in this light, patient information on evidences concerning potential risks and benefits associated with product switching is mandatory and should be part of our routine practice. Furthermore, physicians should discuss with patients and their caregivers the different therapeutic approaches and the available product options before the possible need for considering product switch.