Nipocalimab: A promising intervention for early-onset severe hemolytic disease of the fetus and newborn?: © Ramona Heimi - stock.adobe.com
- The UNITY phase 2 study focuses on evaluating the effectiveness and safety of nipocalimab, a neonatal Fc receptor blocker, in reducing the risk of fetal anemia, intrauterine transfusions (IUT), and adverse outcomes in high-risk pregnancies with Early-Onset Severe Hemolytic Disease of the Fetus and Newborn (EOS-HDFN).
- This open-label, single-arm study enrolled pregnant individuals with specific risk factors, such as a history of obstetric complications, high alloantibody titers, and a fetus with an incompatible blood type, and administered weekly doses of nipocalimab between 14 to 35 weeks of gestational age.
- Results show that 54% of participants achieved the primary efficacy endpoint, which is a live birth at or beyond 32 weeks GA without requiring IUT. The median gestational age at delivery was 37 1/7 weeks, indicating an improvement in expected outcomes.
- Out of the 13 pregnancies included in the analysis, 92.3% resulted in live births, with a median gestational age at delivery of 36 5/7 weeks. Importantly, none of these pregnancies developed fetal hydrops, a significant marker for EOS-HDFN.
- While there were no maternal or neonatal/infant deaths reported, the study did observe four serious adverse events (SAEs) possibly linked to nipocalimab, emphasizing the need for ongoing safety assessment in future research. Overall, the study suggests the potential of nipocalimab to positively impact the management of fetal anemia in high-risk pregnancies.
Nipocalimab (Janssen) may be for the antenatal and postnatal management of fetal anemia in pregnancies at high risk for early-onset severe hemolytic disease of the fetus and newborn (EOS-HDFN), according to data from the phase 2 UNITY study presented at the 2023 American Academy of Pediatrics National Conference & Exhibition.
This study primarily focused on the evaluation of the efficacy and safety of nipocalimab, a neonatal Fc receptor blocker, in reducing the risk of fetal anemia, intrauterine transfusions (IUT), and adverse outcomes in such high-risk pregnancies.
The trial was an open-label, single-arm study, which enrolled individuals with singleton pregnancies considered to be at high risk for EOS-HDFN based on several factors. The criteria for inclusion in this study included a prior obstetric history indicative of the condition, high alloantibody titers, and a fetus with an incompatible blood type. The intervention involved administering weekly doses of 30 or 45 mg/kg of intravenous nipocalimab between 14 to 35 weeks of gestational age (GA).
The primary endpoint was the proportion of participants who achieved a live birth at or beyond 32 weeks GA without necessitating an intrauterine transfusion. Additionally, secondary endpoints pertaining to antenatal and postnatal management were also monitored and reported.
During the study period, out of the 14 pregnancies enrolled, 1 was not included due to early elective abortion for unrelated reasons. Among the 13 pregnancies considered for analysis, 54% of participants successfully achieved the primary efficacy endpoint. The median GA at delivery for these pregnancies was 37 1/7 weeks, demonstrating a significant improvement in the expected outcome. Overall, 92.3% of the pregnancies resulted in live births, with a median GA at delivery of 36 5/7 weeks, indicating a favorable trend in high-risk pregnancies.
Only 1 pregnancy in the study experienced a fetal demise following complications arising from an intrauterine transfusion at 22 5/7 weeks GA. Notably, none of the 13 pregnancies developed fetal hydrops, which is a significant marker for EOS-HDFN. Among the 12 live births, 92% of the neonates received phototherapy, and 50% required at least 1 simple transfusion within the first 12 weeks of life. There were no maternal or neonatal/infant deaths reported during the study.
Additionally, there were 4 serious adverse events (SAEs) possibly related to nipocalimab, which occurred in 2 maternal participants. One neonate delivered at 29 weeks exhibited an SAE of neonatal respiratory distress. These SAEs emphasize the need for continued monitoring and evaluation of the safety aspects of nipocalimab in this context.
The results of the UNITY study may be promising for the antenatal and postnatal management of fetal anemia in pregnancies at high risk for EOS-HDFN, according to the study authors. The data demonstrates that nipocalimab may have a substantial impact in reducing the need for intrauterine transfusions and improving the gestational age at which live births occur. However, the authors note that the safety profile, particularly concerning serious adverse events, warrants further investigation.
Moise KJ, Ling LE, Oepkes D, et al. P2C310: Nipocalimab in Pregnancies at High Risk for Early-onset SevereHemolytic Disease of the Fetus and Newborn (EOS-HDFN). Poster. Presented at: 2023 American Academy of Pediatrics National Conference & Exhibition.