ARGX-119 is a novel humanized agonistic monoclonal antibody specifically targeting muscle-specific kinase (MuSK). It is utilized in the research of neuromuscular diseases. For an isotype control of ARGX-119, refer to HumanIgG1lambda1, Isotype Control.

ARGX-119 binds with high affinity to the Frizzled-like domain of MuSK in humans, non-human primates, rats, and mice, without off-target interactions, making it suitable for clinical development. Within its Fc region, ARGX-119 includes the L234A and L235A mutations to reduce potential immune activation effects. Its mechanism of action activates MuSK without interfering with its natural ligand, neuro Agrin, and it promotes acetylcholine receptor clustering in a dose-dependent manner, thereby stabilizing neuromuscular function [1].

In a mouse model of congenital myasthenia (CM) caused by DOK7, ARGX-119 (20 mg/kg) effectively restores neuromuscular function in a dose-dependent manner, reducing muscle weakness and fatigue. This treatment prevents early postnatal death and reverses disease recurrence in adult Dok7 CM mice [1].