BillionToOne recently announced that it will allow its UNITY fetal antigen test to be used to test patients included in Johnson & Johnson’s (J&J’s) AZALEA phase 3 clinical trial testing the safety and efficacy of nipocalimab, an antineonatal Fc receptor (FcRn) blocking antibody, in hemolytic disease of the fetus and newborn (HDFN).
What is HDFN?
Hemolytic disease of the fetus and newborn (HDFN) is an immune-mediated red blood cell (RBC) disorder that occurs when a baby’s RBCs break down quickly, which is called hemolysis. HDFN is caused by a mismatch between a mother’s and her baby’s blood type (A, B, AB, or O) or Rhesus (Rh) factor (Rh-positive or Rh-negative) during pregnancy. Numerous antibodies to RBC antigens can be linked to HDFN, such as those from the ABO and Rh blood group systems.
UNITY is a noninvasive test used to assess the need for Rh immunoglobulin (RHIG) administration in pregnant Rh-negative patients by detecting the presence of specific antigens capable of triggering antibody production and HDFN in a subsequent pregnancy.
Earlier this year, BillionToOne published clinical validation data for the UNITY Fetal Antigen Laboratory Developed Test (LDT). The validation study demonstrated the LDT’s accuracy in determining antigen status, achieving >99.9% concordance and sensitivity and specificity of >99.9% (95% CI: 99-100%). The UNITY Fetal Antigen LDT results were 100% concordant with neonatal antigen genotype/serology for 23 RhD-negative pregnant individuals and 93 antigen evaluations in 30 alloimmunized pregnancies.
The assay will function as a screening tool to determine the eligibility of pregnant individuals participating in the trial across the United States, the European Union and select countries worldwide.
Learn more about HDFN therapies
This news comes after J&J announced promising results from the AZALEA phase 2 trial. J&J reported that within two weeks of initiating nipocalimab, patients achieved full FcRn occupancy, together with a substantial decrease in maternal IgG levels and alloantibody titers. Additionally, FcRn occupancy in each patient was lost two to three weeks after the final dose, causing an increase in IgG and alloantibody titers.
The U.S. Food and Drug Administration (FDA) granted an Investigational Device Exemption (IDE) for the UNITY Fetal Antigen CTA in April 2023, thus supporting the launch of the phase 3 AZALEA study of nipocalimab in HDFN in the U.S.
Oguzhan Atay, PhD, CEO of BillionToOne, stated his team is “extremely proud” to play a role in the trial.
“The ability to detect fetal antigens as early as 10 weeks is only made possible due to our expertise in fetal DNA quantification. The UNITY Fetal Antigen CTA is just one of the many applications of our QCT technology’s capabilities,” he added.
