BHV-1300

BHV-1300 is a first-in-class, bispecific small molecule degrader engineered to rapidly and selectively deplete immunoglobulin G (IgG) antibodies from the circulation. It acts by targeting IgG1, IgG2, and IgG4 subclasses for lysosomal degradation in the liver while sparing IgG3 and other immunoglobulin classes (IgA, IgM), thus preserving key host immune defenses. The drug leverages Biohaven’s MoDE (Molecular Degrader of Extracellular protein) platform technology to achieve deep (>80%), rapid (within hours), tunable, and sustained reductions in total IgG after subcutaneous or intravenous administration. Unlike FcRn inhibitors or plasmapheresis approaches—which have limitations such as inability to co-administer with monoclonal antibody biologics—BHV-1300 can be safely combined with Fc-containing biologics without affecting their pharmacokinetics. Its primary indications under development are autoimmune diseases driven by pathogenic autoantibodies such as Graves’ disease and rheumatoid arthritis[1][5][6][7][8].