Emapalumab for the treatment of hemophagocytic lymphohistiocytosis.

Emapalumab-Igsz (Gamifant) is a human monoclonal antibody directed against interferon-γ (IFN-γ), and the first Food and Drug Administration (FDA)-approved therapy for primary hemophagocytic lymphohistiocytosis (HLH). HLH is a disorder characterized by hypercytokinemia in the setting of unbridled immune activation, and emapalumab represents the first therapeutic developed to address the underlying pathophysiology of HLH. Emapalumab is approved for treatment of primary HLH that is refractory, recurrent, progressing or intolerant to current HLH treatments in both adult and pediatric patients. FDA approval was based on the results of a phase II/III clinical trial evaluating the safety and efficacy of emapalumab in 34 pediatric patients with primary HLH, 27 of whom were refractory to current therapies. Additional studies of emapalumab are currently ongoing in adults and other pediatric populations. Here, we will review the pharmacology, safety and efficacy of emapalumab for the treatment of HLH.