L9

L9 is a highly potent human monoclonal antibody (mAb) that targets the circumsporozoite protein (CSP) of the malaria parasite, *Plasmodium falciparum*. Developed by the Vaccine Research Center (VRC) at the National Institute of Allergy and Infectious Diseases (NIAID), L9 preferentially binds to the minor repeat region (specifically NVDP/NPNV motifs) of PfCSP and cross-reacts with the major repeat region (NANP). By binding to PfCSP on the surface of malaria-infective sporozoites, L9 neutralizes the parasite in the skin and blood, preventing it from invading hepatocytes in the liver. An engineered variant with a modified Fc domain, known as L9LS, incorporates leucine-to-serine (LS) mutations to extend its half-life, enabling long-acting protection against malaria via subcutaneous administration.

Other names

L9 antibodyL-9 antibodyL 9 antibodyanti-PfCSP monoclonal antibody L9mAb L9