When would you consider use of emapalumab for HLH/MAS?  

The FDA has approved emapalumab for familial HLH. For secondary HLH/MAS, I typically begin with anakinra (100 mg q 6 hrs for those 40 kg or more). If this is not enough and if CXCL9 (I send on day one to have the data available) is notably elevated, then consider adding emapalumab. Alternatively, a ...