The VIVID study is structured in a master protocol format comprised of multiple parts that evaluate intravenous (IV) and subcutaneous (SC) VGA039 in healthy volunteers and subjects with von Willebrand Disease (VWD) and other bleeding disorders.

This first-in-human study consists of 5 parts based on the subject population. Part 1 is a randomized, double-blind, placebo-controlled, single-ascending dose (SAD) evaluation of IV or SC VGA039 or placebo in up to 8 cohorts in healthy volunteers. Part 2 is an open-label, SAD of SC or IV VGA039 in up to 8 cohorts in subjects diagnosed with VWD. All participants will be enrolled, treated, and followed up for 15 weeks (IV SAD) or 8 weeks(SC SAD). Part 3 is an open-label, Phase 1b study of SC multiple doses (MD) of VGA039 in up to 4 cohorts. Part 4 is an open-label, Phase 2 study of SC single, surgical prophylaxis (SP) doses of VGA039 administered prior to a minor surgical procedure in subjects diagnosed with VWD in up to 2 cohorts. Part 5 is an open-label extension (OLE) study of SC MD of VGA039 in eligible subjects diagnosed with VWD who have previously participated in a VGA039 interventional trial.

Key Inclusion Criteria (All Subjects)

• Subjects, 18 to 60 years of age, inclusive for Parts 1 and 2
• Subjects, 12 to 60 years of age, inclusive for Parts 3 and 5
• No clinically significant laboratory, ECG, or vital signs results.

Additional Key Inclusion Criteria (for Subjects in Part 1 Only) • Body mass index of 18-32 kg/m2

Additional Key Inclusion Criteria (for Subjects in Part 2 Only)

• Subjects with VWD who are symptomatic, defined as having a history of bleeding or bruising.
• Hemoglobin level ≥ 8 g/dL and platelet count ≥ 150 × 109/L at Screening.

Exclusion Key Criteria (All Subjects)

• Use of hormonal contraceptives within 56 days prior to administration of the study drug.
• Subjects with detection of FV Leiden or Prothrombin G20210A mutation, protein C or S deficiency, antithrombin deficiency, or antiphospholipid antibody syndrome at Screening.
• Subjects with other known pro-thrombotic disorders or abnormal findings in any prior laboratory thrombophilia evaluation.
• History of arterial or venous thrombosis, including superficial thrombophlebitis, or embolism.
• Evidence of renal, hepatic, central nervous system, respiratory, cardiovascular disease, cerebrovascular disease, peripheral vascular disease, or metabolic dysfunction.

Additional Key Exclusion Criterion (Subjects in Part 1 Only)

• Baseline FVIII activity > 150 IU/dL.

Additional Key Exclusion Criteria (Subjects in Parts 2, 3, 4 and 5 Only)

• Baseline FVIII activity > 50 IU/dL.
• Any acute, clinically significant bleeding event requiring surgical or procedural intervention within 7 days prior to receiving study drug.