Primary objective:

To assess the safety and tolerability of single ascending intravenous (i.v.) doses, a single subcutaneous (s.c.) dose of caplacizumab (Part I), and multiple s.c. doses of caplacizumab (Part II) in Japanese subjects.

Secondary objectives:

• To compare the pharmacokinetic (PK) and pharmacodynamic (PD) profiles (total vWF:Ag concentration levels [vWF:Ag], coagulation factor VIII [FVIII:C], and ristocetin cofactor activity [RICO]) after single i.v. or s.c. administration of caplacizumab in Japanese and White subjects.
• To evaluate the immunogenicity of caplacizumab (anti-drug antibodies [ADA]) in Japanese subjects.

Inclusion Criteria:

• BMI between ≥18 kg/m² and <30 kg/m² at time of screening
• Body weight between ≥45 kg and <100 kg
• Baseline vWF:Ag between ≥60% and <170% (0.6-1.7 IU/mL)

Exclusion Criteria:

• History of and/or any sign or symptom indicating current abnormal hemostasis or blood dyscrasia, including but not limited to thrombocytopenia, thrombocytopathy, thromboasthenia, hemophilia, von Willebrand's disease, vascular purpura, bleeding gums and/or frequent nose bleeding, easy/spontaneous bruises, meno- or metrorrhagia, history of gastrointestinal bleeding or excessive bleeding after minor injury such as shaving.
• Family history of congenital vascular malformation (e.g., Marfan's Syndrome) and/or bleeding disorder (e.g., hemophilia, von Willebrand's disease, Christmas disease)
• Any surgical intervention (including tooth extraction) or trauma within the 4 weeks preceding screening for the study or any planned surgical intervention during the participation in the study
• Treatment with vitamin K, direct oral anticoagulant (DOAC), warfarin, high dose heparin within 2 weeks before screening