UAB - Center for Clinical and Translational Science

Eligibility

Eligible Ages

Under 17 Years

Eligible Sex

All

Accepts Healthy Volunteers

No

Criteria

1. The participant has a documented diagnosis of severe VWD (baseline von Willebrand
factor ristocetin cofactor activity [VWF:RCo] <20 international units per deciliter
[IU/dL]) with a history of replacement therapy with VWF concentrate required to
control bleeding and a diagnosis of VWD type 1, type 2 (2A, 2B, 2M, 2N), or type 3.
Diagnosis is confirmed, as applicable, by genetic testing and/or by multimer
analysis, which may be documented in participant's history or at screening.

2. The participant is <18 years of age at the time of screening.

3. Prescreening treatment requirements:

1. The participant has been receiving OD therapy with VWF products for at least 12
months (for participants >=2 years of age) prior to screening, has experienced
at least 1 VWF-treated bleeding event during (excluding menorrhagia/heavy
menstrual bleeding [HMB], as applicable) in the last 12 months, and
prophylactic treatment is recommended by the investigator (Prior OD
participants); or

2. The participant has been receiving prophylactic treatment with pdVWF products
for at least 12 months prior to screening (for participants >=2 years of age)
and switching to prophylaxis with vonicog alfa (rVWF) is recommended by the
investigator (Switch participants).

3. For participants <2 years of age, the required duration for prior OD therapy
with VWF products or for prior prophylactic treatment with pdVWF products is at
least 6 months. Prior OD participants <2 years of age should have experienced
at least 1 VWF-treated bleeding event during the last 6 months based on medical
records and be recommended to receive prophylactic treatment by the
investigator.

4. For participants >=2 years of age, the participant has available records that
reliably evaluate type, frequency, severity, and treatment of BEs for at least 12
months preceding enrollment. For participants <2 years of age, the participant has
available records that reliably evaluate type, frequency, severity and treatment of
BEs for at least 6 months preceding enrollment.

5. If >=12 years old at the time of screening, the participant has a body mass index
(BMI) >=15 but <40 kilogram per square meter (kg/m^2). If >=2 to <12 years old at
the time of screening, the participant has a BMI of >=5th and <95th percentile (per
Centers for Disease Control and Prevention [CDC] clinical charts). For younger
participants who are <2 years old, the "weight-for-age" clinical charts (5th to 95th
percentile) provided by the CDC should be utilized to ensure the participant has a
body weight of >=5th and <95th percentile based on gender (for clinical charts
provided by CDC, refer to: https://www.cdc.gov/growthcharts/clinical_charts.htm).

6. Female participants of childbearing potential (that is, had onset of menses/reached
puberty) must have a negative blood/urine pregnancy test result at screening and
agree to employ highly effective birth control measures for the duration of their
participation in the study.

7. The participant has voluntarily provided assent (if appropriate) and the legally
authorized representative(s) has provided informed consent.

8. The participant and/or legally authorized representative is willing and able to
comply with the requirements of the protocol, which should also be confirmed based
on a prescreening evaluation held between the investigator and the sponsor to ensure
no eminent risk is present that could challenge the participant's compliance with
the study requirements.

Exclusion Criteria:

1. The participant has been diagnosed with pseudo VWD or another hereditary or acquired
coagulation disorder other than VWD (example, qualitative and quantitative platelet
disorders or elevated prothrombin time/international normalized ratio 1.4).

2. The participant has a history or presence of a VWF inhibitor at screening.

3. The participant has a history or presence of an factor VIII (FVIII) inhibitor with a
titer >=0.6 Bethesda units per milliliter (/mL).

4. The participant has a known hypersensitivity to any of the components of the study
drugs, such as mouse or hamster proteins.

5. The participant has a medical history of immunological disorders, excluding seasonal
allergic rhinitis/conjunctivitis, mild asthma, food allergies, or animal allergies.

6. The participant has a medical history of a thromboembolic event.

7. The participant is human immunodeficiency virus (HIV)-positive with an absolute
helper T cell (CD4) count <200 per cubic millimeter or microliter (/mm^3).

8. The participant has been diagnosed with significant liver disease per the
investigator's medical assessment of the participant's current condition or medical
history or as evidenced by, but not limited to, any of the following: serum alanine
aminotransferase (ALT) greater than 5 times the upper limit of normal (ULN),
hypoalbuminemia, portal vein hypertension (example, presence of otherwise
unexplained splenomegaly, history of esophageal varices), or liver cirrhosis
classified as Child-Pugh class B or C.

9. The participant has been diagnosed with renal disease, with a serum creatinine level
>=2.5 milligram per deciliter (mg/dL).

10. The participant has a platelet count <100,000/mL at screening (because participants
with type 2B VWD are considered eligible for this study, for participants with type
2B VWD, platelet count[s] at screening will be evaluated in consultation with the
sponsor, taking into consideration historical trends in platelet counts and the
investigator's medical assessment of the participants condition).

11. The participant has been treated with an immunomodulatory drug, excluding topical
treatment (example, ointments, nasal sprays), within 30 days prior to signing the
informed consent (or assent, if appropriate).

12. The participant is pregnant or lactating at the time of enrollment.

13. The participant has cervical or uterine conditions causing menorrhagia or
metrorrhagia (including infection, dysplasia).

14. The participant has participated in another clinical study involving another IP or
investigational device within 30 days prior to enrollment or is scheduled to
participate in another clinical study involving an IP or investigational device
during the course of this study.

15. The participant has not received OD or prophylactic treatment with a VWF product
prior to this study.

16. The participant has a progressive fatal disease and/or life expectancy of less than
15 months.

17. The participant is unable to complete screening procedures and/or comply with the
requirements of the protocol in the opinion of the investigator, based on the joint
prescreening evaluation held between the investigator and the sponsor.

18. The participant has a mental condition rendering him/her unable to understand the
nature, scope, and possible consequences of the study and/or evidence of an
uncooperative attitude.

19. The participant is member of the study team or in a dependent relationship with one
of the study team members, which includes close relatives (that is, children,
partner/spouse, siblings, and parents) as well as employees.