In Hemophilia, It Just Keeps Getting Better Comment

Long-term follow-up for novel therapies is essential to confirm initial safety and efficacy data, but how often does that long-term follow-up show better results than the initial studies? In this issue of Blood, a 2-year follow-up to the HAVEN trials by Callaghan et al(1) studying emicizumab for prophylaxis in severe hemophilia A with and without inhibitors has done just that.