ADAMTS13 and thrombotic thrombocytopenic purpura: The efficacy and safety profile were assessed in a recent phase 3, open-label, cross-over trial, which showed that no patients developed acute TTP or neutralizing antibodies when administered at 40 IU per kilo body weight, with raised ADAMTS13 activity (101%) after treatment with recombinant ADAMTS13, compared to standard treatment (19%) [78].