Plonmarlimab, a novel anti-GM-CSF blocking antibody, ameliorates disease progression in the pre-clinical model of macrophage activation syndrome.

Objectives: We aimed to characterize and investigate the safety and efficacy of Plonmarlimab, a novel anti-granulocyte-macrophage colony-stimulating factor (anti-GM-CSF) neutralizing antibody, on the treatment of macrophage activation syndrome (MAS), a life-threatening systemic inflammatory disease, in pre-clinical models.

Methods: The binding affinity was evaluated using Biacore. The neutralizing activity was measured through the blockade of ligand-receptor interaction, inhibition of STAT5 phosphorylation and suppression of TF-1 cell proliferation.