A Trial of Caplacizumab in Japanese Patients With Acquired Thrombotic Thrombocytopenic Purpura (aTTP)

Inclusion criteria : * Japanese participant must be 18 years or older at the time of signing the informed consent. * Participants who have a clinical diagnosis of aTTP (initial or recurrent), which includes thrombocytopenia (defined as platelet count \<100,000/µL), microangiopathic hemolytic anemia as evidenced by red blood cell fragmentation (eg, presence of schistocytes), and increased levels of LDH * Participants who require initiation of daily PE treatment and have received a maximum of 1 PE treatment prior to enrollment in the study * Contraceptive use by men or women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies * Capable of giving signed informed consent Exclusion criteria: * Platelet count ≥100,000/µL, * Serum creatinine level \> 2.3mg/dL in case platelet count is \> 30,000µL * Known other causes of thrombocytopenia * Congenital TTP * Clinically significant active bleeding or high risk of bleeding * Malignant arterial hypertension * Known chronic treatment with anticoagulant treatment that cannot be stopped * Participants who were previously enrolled in a clinical study with caplacizumab and received caplacizumab or for whom the assigned treatment arm is unknown * Participants currently or less than 28 days prior to enrollment in this study, enrolled in a clinical study with another investigational drug or device * Clinical condition other than that associated with TTP, with life expec…