Nipocalimab, which is being studied as a potential treatment for fetal and neonatal alloimmune thrombocytopenia (FNAIT), has shown promise in an early clinical trial, according to a recent review published in the journal Prenatal Diagnosis.
Nipocalimab is currently being tested as a potential treatment for both hemolytic disease of the fetus and newborn (HDFN) and FNAIT. HDFN and FNAIT are two rare but serious conditions that happen when a pregnant person’s immune system attacks their baby’s red blood cells or platelets. This can cause severe anemia, bleeding in the brain, pregnancy loss or serious illness in newborns.
The current standard treatment for both of these conditions is intravenous immune globulin (IVIG). IVIG contains antibodies from healthy donors that can block harmful antibodies from the mother, helping protect the baby. Research has shown that IVIG can delay the need for blood transfusions inside the womb and improve health outcomes for the baby.
IVIG treatment usually starts early in pregnancy and continues weekly, with doses tailored to the risk level. The most common side effects of IVIG are headaches, but these are generally manageable with medication.
A new drug, nipocalimab, has shown promise in an early clinical trial. It works by blocking a protein called the neonatal Fc receptor, which normally moves antibodies made by the mother’s immune system across the placenta to the baby. By preventing this transfer, nipocalimab can reduce the harmful antibodies reaching the baby’s blood and may be able to prevent both conditions if administered early enough in pregnancy.
Read more about FNAIT treatment and care
In the phase II UNITY trial for the treatment of early-onset HDFN, nipocalimab improved survival rates without increasing infection risk in pregnant women and their babies. The FREESIA-1 trial studying the drug’s ability to prevent or delay the onset of FNAIT is currently enrolling participants and is expected to be completed in 2029.
“The outcomes of a subsequent ongoing phase III clinical trial in HDFN and planned trials in FNAIT are awaited to prove the safety and efficacy in the treatment of these alloimmune diseases in pregnancy,” the authors of the review said.
