Immunoglobulin G-degrading enzyme of Streptococcus pyogenes (IdeS) is an IgG specific endopeptidase which cleaves IgG molecules and efficiently neutralizes Fc-mediated activities. IdeS-mediated IgG degradation constitutes a novel therapeutic principle for the treatment of IgG-driven human diseases.~In addition to assessing the safety and tolerability of IdeS the study will also assess the efficacy of IdeS to significantly increase the ADAMTS13 activity and decrease the anti-ADAMTS13 antibody levels in patients diagnosed with asymptomatic antibody-mediated TTP with low ADAMTS13 activity.
The main purpose of this study is to evaluate safety and tolerability in patients diagnosed with asymptomatic antibody-mediated TTP with low ADAMTS13 activity after receiving single intravenous dose of IdeS.