A phase 3 clinical trial aiming to assess the safety and efficacy of nipocalimab, developed by Johnson & Johnson (J&J) in pregnancies at risk of fetal and neonatal alloimmune thrombocytopenia (FNAIT) is set to begin soon, according to a recently presented abstract at the American Society of Hematology Annual Meeting and Exposition.
The FREESIA-3 study will recruit pregnant individuals with confirmed immunization against HPA-a1 or HPA-5b antigens. Researchers will divide participants into two groups, one receiving nipocalimab for FNAIT prevention and the other receiving the current standard of care intravenous immunoglobulin (IVIG) with or without a steroid.
All participants will undergo careful obstetric monitoring during their pregnancies, with a bimonthly ultrasound examination to detect FNAIT complications early.
The main goal of the study is to compare the rate of fetal death or severe FNAIT complications, such as intracranial bleeding, between pregnancies that received nipocalimab and IVIG. Other study endpoints include platelet count at birth, neonatal bleeding during the first week of life, and need for platelet transfusions after birth.
About nipocalimab in FNAIT
Nipocalimab is an investigational monoclonal antibody that binds to the FC neonatal receptor, preventing it from recycling G immunoglobulin (IgG) and enabling transplacental antibody transfer. The objective of FNAIT is to reduce the number of material anti-HPA antibodies, thus reducing the risk of fetal platelet destruction. However, the drug is associated with a higher risk of infection.
The effectiveness and safety of nipocalimab in pregnancies at risk of FNAIT was previously demonstrated in Phase II studies. One study, including 14 pregnancies, revealed that nipocalimab led to live birth in 54% of cases, and 46% did not require transfusions before or after birth, statistics that represent a significant improvement to historical benchmarks.
“Nipocalimab showed proof-of concept efficacy in preventing or delaying fetal anemia with an acceptable safety profile in an open-label phase 2 study of hemolytic disease of the fetus and newborn,” the authors wrote.
