A new study has given hope to mothers with a negative blood type that they can safely deliver their babies without fear of fetal hemolysis or stillbirth. During pregnancy, mothers were given a revolutionary drug that has the potential to increase the survival chances of fetuses with a positive blood type for mothers with a negative blood type. This study represents a major step forward for mothers who suffer from severe early hemolysis in fetuses and newborns.
The University of Birmingham and the Women and Children’s NHS Foundation Trust in Birmingham conducted this global study, in which the drug “Nibocalimab” was given to treat pregnancies at risk of severe early hemolytic disease in the fetus and newborn, and its safety and effectiveness were evaluated.
Severe early hemolytic disease of the fetus and newborn
Blood is made up of red blood cells, white blood cells, and platelets in a fluid called plasma. A person’s blood type is determined by the antibodies and antigens in the blood.
Antibodies are proteins found in plasma. They are part of the body’s natural defenses, recognizing foreign substances, such as germs, and alerting the immune system, which destroys them.
Antigens are protein molecules found on the surface of red blood cells. There are 4 main blood types determined by the ABO system.
Sometimes red blood cells contain another antigen, a protein called the Rh antigen. If it is present, the blood type is Rh positive. If it is absent, the blood type is Rh negative.
Rhesus disease is a condition in which antibodies in a pregnant mother’s blood destroy her baby’s blood cells. It is also known as hemolytic disease of the fetus and newborn.
permanent test
Blood type testing is always done for pregnant women. This is because if the mother has Rh negative blood type and the baby has inherited Rh positive blood type from the father, it can cause complications if left untreated. Hemolytic disease does not harm the mother, but it can cause anemia in the baby and jaundice in the newborn.
Doctors use ultrasound-guided intrauterine blood transfusions to treat these critically ill unborn fetuses with a 98% success and survival rate. However, in 5% of pregnancies affected by severe early fetal and neonatal hemolysis, the mother may have very high levels of very strong autoantibodies. This can lead to the development of severe fetal anemia before 24 weeks.
In these rare cases, intrauterine blood transfusion is more challenging due to the small size of the fetal blood vessels and the immaturity of the fetal heart, which makes the fetus less able to tolerate blood transfusion. For this reason, the incidence of major complications leading to miscarriage is high, reaching 1 in 5 pregnancies.
hope to survive
The majority of pregnant women with severe early-onset fetal or neonatal hemolytic anemia who received nibocalimab had a live birth at or after 32 weeks of gestation, without the need for intrauterine blood transfusions throughout the pregnancy, according to results of a human trial published in the New England Journal of Medicine on August 7, sponsored by Johnson & Johnson.
The study showed that 54% of pregnant women who received nibocalimab delivered at or after 32 weeks of gestation without any intrauterine blood transfusions, while none had previously delivered after this period without a blood transfusion. Overall, the perinatal survival rate was 92%, whereas historically only 10% of pregnancies affected by severe early fetal and neonatal hemolysis have reached this point.
Of the 46% who required an intrauterine blood transfusion, the majority were after 24 weeks of gestation, and only one case was performed at 22 weeks, but it was complicated and ended in miscarriage.
“For mothers with severe early fetal and neonatal haemolytic anaemia, the outcomes of the condition and treatment can be devastating,” said lead researcher at the Birmingham site, Professor Mark Kilby, Honorary Professor of Fetal Medicine at the University of Birmingham and Honorary Consultant in Fetal Medicine at the Women and Children’s NHS Foundation Trust in Birmingham. “That’s why the search for treatments to reduce the effects of the mother’s immune response has been focused on this group of women.”
Mark Kilby added that the clinical study found that “nebocalimab is well tolerated and significantly increases the chance of survival of fetuses with severe early fetal and neonatal hemolysis, while reducing the need for intrauterine blood transfusion therapy.”
Revolutionary medicine
The promising results of this study prompted the FDA to grant Breakthrough Therapy Designation (BTD) to nebokalimab for the treatment of pregnant women with severe fetal or neonatal hemolytic anemia (SPHN) and is currently enrolling in a Phase 3 clinical trial for pregnant women at risk for SPHN at any stage of pregnancy, who have a history of SPHN in a previous pregnancy.
This revolutionary drug modifies the immune response that leads to the breakdown of fetal blood when it comes into contact with the pregnant mother’s blood.
“These are remarkable results,” Professor Kilby added, according to EurekAlert. “In this group of pregnant women with severe early fetal and neonatal haemolysis, medical treatment with nebocalimab significantly reduced the need for early fetal blood transfusion and improved survival of these fetuses, reducing the risk of miscarriage and stillbirth. Furthermore, and very importantly, nebocalimab appears to be well tolerated and safe for mother and fetus.”