Gamifant® (emapalumab) is a monoclonal antibody (mAb) that binds to and neutralises interferon gamma (IFNγ). In the US, Gamifant is approved for paediatric (newborn and older) and adult primary haemophagocytic lymphohistiocytosis (HLH) patients with refractory, recurrent or progressive disease, or intolerance to standard-of-care HLH therapy.