N Engl J Med

Monoclonal antibody shows promise for hemolytic disease of the fetus and newborn

August 12, 2024

Compared with a historical benchmark, nipocalimab delayed or prevented fetal anemia or intrauterine transfusions in pregnancies at high risk for early-onset severe hemolytic disease of the fetus and newborn (HDFN).

• The open-label, single-arm, phase 2 UNITY trial assessed treatment with IV nipocalimab (30 or 45 mg/kg of body weight per week) administered from 14 to 35 weeks' gestation in pregnancies at high risk for recurrent early-onset severe HDFN. Primary endpoint was live birth at 32 weeks' gestation or later without intrauterine transfusions compared with a historical benchmark.
• The rate of live birth at 32 weeks' gestation or later without intrauterine transfusions was 54% (7 of 13 pregnancies). There were no cases of fetal hydrops; and 6 participants (46%) didn’t receive any antenatal or neonatal transfusions. Six fetuses received an intrauterine transfusion: five fetuses at 24 weeks' gestation or later and one fetus before fetal loss at 22 weeks and 5 days' gestation. Live birth occurred in 12 pregnancies. Median gestational age at delivery was 36 weeks and 4 days. Of the 12 live-born infants, 1 received one exchange transfusion and one simple transfusion and 5 received only simple transfusions. Maternal samples and cord blood demonstrated treatment-related decreases in the alloantibody titer and IgG level.

Source:

Moise Jr. KJ, et al; UNITY Study Group. (2024, August 7). N Engl J Med. Nipocalimab in Early-Onset Severe Hemolytic Disease of the Fetus and Newborn. https://pubmed.ncbi.nlm.nih.gov/39115062/