Rallybio Corp. has announced the approval of its clinical trial applications (CTAs) for a Phase 2 clinical trial of RLYB212 in pregnant women at higher risk for HPA-1a alloimmunization and fetal and neonatal alloimmune thrombocytopenia (FNAIT). The approvals, granted by the European Medicines Agency (EMA) and the United Kingdom’s Medicines and Healthcare products Regulatory Agency (MHRA), pave the way for Rallybio to initiate screening of participants in the fourth quarter of 2024.
Trial Design and Objectives
The single-arm Phase 2 dose confirmation trial (2024-512651-20/NCT06435845) will be conducted across multiple European sites, including Belgium, the Netherlands, Norway, Sweden, and the UK. The trial aims to evaluate the pharmacokinetics (PK) and safety of RLYB212, a monoclonal anti-HPA-1a antibody, in eight pregnant women at higher risk for HPA-1a alloimmunization and FNAIT. Secondary objectives include assessing pregnancy and neonatal/infant outcomes, and the occurrence of emergent HPA-1a alloimmunization. RLYB212 will be administered subcutaneously every 4 weeks, starting at gestational week 16 and continuing through parturition.
Addressing Unmet Needs in FNAIT Prevention
FNAIT is a rare, potentially life-threatening disease that can cause uncontrolled bleeding in fetuses and newborns. It arises from an immune incompatibility between a mother and her fetus, specifically involving the human platelet antigen 1 (HPA-1). Individuals lacking the HPA-1a antigen can develop antibodies against it upon exposure, leading to alloimmunization during pregnancy if the fetus is HPA-1a positive. These maternal antibodies can cross the placenta, destroying fetal platelets and resulting in thrombocytopenia, potentially leading to miscarriage, stillbirth, or severe neurological disabilities in surviving infants. Currently, there is no approved therapy for the prevention or prenatal treatment of FNAIT.
Leadership Perspective
"Securing these CTA approvals from European health authorities to advance RLYB212 into a Phase 2 trial is a significant achievement," said Stephen Uden, M.D., Chief Executive Officer of Rallybio. "These approvals are a testament to the dedication and innovation of our team and our partners as we advance this first ever program to prevent maternal alloimmunization and FNAIT. We are activating clinical sites and expect to initiate screening this quarter, which will mark another important step toward achieving our mission to prevent FNAIT and its potentially devastating consequences."
Steven Ryder, M.D., Chief Medical Officer at Rallybio, added, "These approvals recognize Rallybio’s commitment to safely and effectively progress a novel prophylactic approach for preventing alloimmunization in pregnant women at higher FNAIT risk. We are proud to be leaders in bringing much needed innovation to this area of women’s health, which has gone unaddressed for far too long."
