RLYB212

RLYB212 is a recombinant human monoclonal antibody developed by Rallybio Corporation for the prevention of fetal and neonatal alloimmune thrombocytopenia (FNAIT). The drug is designed to be administered subcutaneously and targets the HPA-1a isoform of integrin β3, a platelet antigen. Its mechanism of action involves selectively binding to HPA-1a and rapidly eliminating HPA-1a positive fetal platelets from a pregnant woman's circulation, thereby preventing maternal HPA-1a alloimmunization and reducing the risk of FNAIT in the fetus. In April 2025, Rallybio announced the discontinuation of the RLYB212 program following disappointing pharmacokinetic results from a Phase 2 trial in pregnant women at higher risk for HPA-1a alloimmunization.

Other names

anti-HPA-1a antibodyanti-HPA1a antibodyanti-HPA 1a antibodyAnti-(integrin beta-3) human monoclonal antibody