Forimtamig (RG-6324) is a bispecific antibody that targets GPRC5D and CD3 T cells. It features a 2 + 1 structure, comprising two high-affinity GPRC5D binding segments and one CD3-binding module. Forimtamig is engineered with a P329G LALA mutation in its Fc domain to prevent Fcγ receptor and C1q binding, while maintaining Fc receptor interaction. Its isotype control corresponds to human IgG1 kappa.