Groundbreaking Genetic Screening Test Has Helped Over 80,000 Pregnant Patients Determine Need for Anti-D Immune Globulin

MENLO PARK, Calif., April 17, 2024 /PRNewswire/ — BillionToOne, a molecular diagnostics company with a mission to create powerful and accurate tests that are accessible to all, has reached a milestone of testing over 80,000 patients for Rh incompatibility, which develops when a pregnant patient has Rh-negative blood and the baby has Rh-positive blood. In rare cases this incompatibility can lead to a serious issue in which the pregnant patient’s immune system will attack their baby’s red blood cells as foreign.

Currently, the protocol for managing this potential incompatibility for the 15% of pregnant patients who are Rh-negative is the administration of Anti-D Immune Globulin, an extremely effective intervention that significantly improved maternal and fetal care in the 20th century. However, the FDA recently announced that the most common brand of this medication, RhoGAM(R), is in shortage. While this treatment is necessary to prevent complications, it is only necessary if the baby’s blood is Rh-positive. As a result,  Anti-D Immune Globulin treatment is unnecessary for the 40% of pregnancies where the baby is Rh-negative.

“Healthcare providers and blood banks across the U.S. are facing a unique challenge because of the RhoGAM(R) shortage, and it’s important now that the healthcare industry works together to support the treatment of Rh sensitization and its implications. Utilizing cell-free DNA in maternal plasma, the UNITY Fetal RhD Non-Invasive Prenatal Test can determine fetal RhD status,” said Jennifer Hoskovec, MS, Certified Genetic Counselor and Senior Director of Medical Affairs at BillionToOne. “We are grateful to have the opportunity to support patients in avoiding unnecessary treatments during their pregnancies and to save the reduced supply of RhoGAM(R) for the pregnant people who truly need it to safely address and treat differing Rh status.”

The UNITY Fetal RhD NIPT offers a reliable and convenient alternative to traditional methods of determining fetal RhD status, such as paternal testing and invasive procedures like amniocentesis. The UNITY Fetal RhD NIPT accurately determines the RhD status of the fetus from maternal blood as early as 10 weeks gestation. Recent data published in Scientific Reports demonstrated that the test has diagnostic-level accuracy with >99.9% sensitivity and specificity, and 100% concordance with newborn outcomes, including for the detection of RhD Psi and RhD-CE, which had been a challenge in other assays.

A separate version of the assay has also been approved as a Clinical Trial Assay (CTA) by the FDA for use in a Phase III clinical trial in a global collaboration with Janssen Research & Development, LLC. In a separate study, this use case for alloimmunized pregnancies has also shown 100% accuracy with more than 500 newborn outcomes.

Currently, when the gestating parent is tested to be Rh negative, Anti-D Immune Globulin is administered to any pregnant person on any subsequent pregnancy at 28 weeks. In the event that Rh incompatibility goes untreated, the parent’s immune system sees the baby’s red blood cells as “foreign” and will try to eliminate them as invaders by making anti-Rh antibodies. These antibodies can cross the placenta and attack the fetus’s red blood cells, resulting in a variety of issues, including hemolytic disease of the fetus and newborn (HDFN), a condition in which the red blood cells of the fetus are destroyed by the mother’s antibodies – creating serious complications for the baby.

“The UNITY Fetal RhD NIPT is a reliable and convenient alternative to the traditional methods of determining fetal RhD status,” said Dr. Nicole Plenty, Maternal-Fetal Medicine Division Director at Wellstar Health System. “This test’s exceptional accuracy has enabled doctors to alleviate concerns and anxieties among expectant parents facing the uncertainty of RhD status in their pregnancies, particularly in the light of the national RhoGAM shortage. Due to confidence in the results of this test, physicians are able to dedicate resources like RhoGAM to patients who truly need them.”

About BillionToOne

Headquartered in Menlo Park, California, BillionToOne is a precision diagnostics company on a mission to make molecular diagnostics more accurate, efficient, and accessible for all. The company’s patented Quantitative Counting Technology™ (QCT™) molecular counting platform is the only multiplex technology that can accurately count DNA molecules at the single-molecule level.

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SOURCE BillionToOne