The purpose of this study is to evaluate the effectiveness of nipocalimab compared with
placebo in reducing the risk of severe fetal and neonatal alloimmune thrombocytopenia
(FNAIT).

A Study of Nipocalimab in Reducing the Risk of Fetal and Neonatal Alloimmune Thrombocytopenia (FNAIT)

Thrombocytopenia, Neonatal Alloimmune

Fetal Neonatal Alloimmune Thrombocytopenia (FNAIT)

Autoantibody diseases

Immune system conditions

Placebo

Nipocalimab

Double-blind, Randomized, Placebo-controlled Study Evaluating the Safety and Efficacy of Nipocalimab in Reducing the Risk of Fetal and Neonatal Alloimmune Thrombocytopenia (FNAIT) in At-risk Pregnancies

Outcome of fetus/neonate death or adjudicated severe bleeding up to the first week post
birth or platelet count <30*10^9/L will be reported.

Neonate/fetus With adjudicated bleeding will be reported.

Platelet count at birth in a neonate will be reported.

Fetus/neonate with outcome of death will be reported.

Platelet count at birth <10×10^9/L in a neonate will be reported.

Platelet count at birth <30×10^9/L in a neonate will be reported.

Platelet count at birth <50×10^9/L in a neonate will be reported.

Platelet count at birth <150×10^9/L in a neonate will be reported.

Nadir platelet count in a neonate will be reported.

Neonate(s) who require at least one platelet transfusion(s) will be reported.

Number of Platelet transfusion(s) per neonate will be reported.

Number of donor exposures for neonates who received platelet transfusion(s) will be
reported.

Neonate/Fetus With adjudicated severe bleeding will be reported.

Neonates with IVIG for the treatment of thrombocytopenia will be reported.

Maternal participants with a TEAE will be reported. An adverse event (AE) is any untoward
medical occurrence in a participant participating in a clinical study that does not
necessarily have a causal relationship with the intervention under study. TEAEs are
defined as AEs with onset or worsening on or after date of first dose of study treatment.

Maternal participants with SAE will be reported. An adverse event (AE) is any untoward
medical occurrence in a participant participating in a clinical study that does not
necessarily have a causal relationship with the intervention under study. SAE is any
untoward medical occurrence that at any dose that results in death, is life-threatening,
requires inpatient hospitalization/prolongation of existing hospitalization, results in
persistent or significant disability/incapacity, is a congenital anomaly/birth defect and
is medically important.

Maternal participants with an AESI will be reported. An adverse event (AE) is any
untoward medical occurrence in a participant participating in a clinical study that does
not necessarily have a causal relationship with the intervention under study. AESIs are
considered as infections that are severe, hypoalbuminemia, deep vein thrombosis and/or
pulmonary embolism, and clinically significant bleeding.

Maternal participants with TEAE leading to discontinuation of study intervention will be
reported.

Neonatal/infant participants with a TEAE will be reported. An adverse event (AE) is any
untoward medical occurrence in a participant participating in a clinical study that does
not necessarily have a causal relationship with the intervention under study. TEAEs are
defined as AEs with onset or worsening on or after date of first dose of study treatment.

Neonatal/infant participants with SAE will be reported. An adverse event (AE) is any
untoward medical occurrence in a participant participating in a clinical study that does
not necessarily have a causal relationship with the intervention under study. An SAE is
any untoward medical occurrence that at any dose that results in death, is
life-threatening, requires inpatient hospitalization or prolongation of existing
hospitalization, results in persistent or significant disability/incapacity, is a
congenital anomaly/birth defect and is medically Important.

Neonatal/infant participants with AESI will be reported. An adverse event (AE) is any
untoward medical occurrence in a participant participating in a clinical study that does
not necessarily have a causal relationship with the intervention under study. AESIs are
considered as: In infants- clinically significant mortalities in fetus/neonates due to
maternal infections, and hypogammaglobulinemia.

Fetus/Neonate with TEAE of Bleeding will be reported. An adverse event (AE) is any
untoward medical occurrence in a participant participating in a clinical study that does
not necessarily have a causal relationship with the intervention under study.
Treatment-emergent AEs are defined as AEs with onset or worsening on or after date of
first dose of study treatment.

Neonate with TEAE of Infection will be reported. An AE is any untoward medical occurrence
in a participant participating in a clinical study that does not necessarily have a
causal relationship with the intervention under study. Treatment-emergent AEs are defined
as AEs with onset or worsening on or after date of first dose of study treatment.

The Bayley Scales of Infant and Toddler Development include a set of individually
administered developmental scales designed to measure current developmental functioning
in infants and toddlers up to 42 months of age in the areas of cognition, language, motor
skills, social-emotional, and adaptive behavior, with age adjusted for prematurity. The
cognition, language, motor skills scales are directly administered to the infant, while
social-emotional, and adaptive behavior scales are caregiver questionnaires. The scores
are standardized using norm reference samples with representative demographics and age
adjusted for prematurity.

Maternal participants with antibodies to nipocalimab including neutralizing antibodies in
maternal serum during pregnancy and postpartum will be reported.

A Study of Nipocalimab in Reducing the Risk of Fetal and Neonatal Alloimmune Thrombocytopenia (FNAIT)

Trials at a glance

Trials at a glance

A Study of Nipocalimab in Reducing the Risk of Fetal and Neonatal Alloimmune Thrombocytopenia (FNAIT)

Outcome measures

Primary outcome measures

Secondary outcome measures