The present application is directed to processes and intermediates for making 4-({2-[(aminosulfonyl)amino]ethyl}amino)-N-(3-bromo-4-fluorophenyl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide, which is an inhibitor of indoleamine 2,3-dioxygenase, useful in the treatment of cancer and other disorders.