Optimizing Management of Immune Tolerance Induction in Patients with Severe Haemophilia A and Inhibitors: Towards Evidence-based Approaches

Immune tolerance induction (ITI) is the only strategy proven to eradicate persistent inhibitors in severe haemophilia A patients. Thirty years experience has shown high success rates (60-80%) with heterogeneous dose regimens and has led to the identification of clinical features that define the patients' prognostic profile. Children with recently diagnosed inhibitors are the best candidates for ITI and adequate management may further contribute to improve the short- and long-term ITI outcome. In these patients inhibitor eradication represents a cost-effective option because it enables the restoration of FVIII prophylaxis and consequently prevents arthropathy development. Adults with long-standing inhibitors often show bad predictors of ITI outcome, however, ITI may be considered as a suitable and cost-effective approach in cases with frequent bleeds that are not satisfactorily controlled by by-passing treatment and/or when orthopaedic surgery is needed. Optimal ITI regimens should be established in these different settings and randomized trials are addressing these issues. This article reviews the available literature evidence and clinical implications with current recommendations on ITI management, and highlights the issues still unsolved.