3-​Azabicyclo[3.1.0]​hexane-​2-​carboxamide, N-​[3-​amino-​1-​(cyclobutylmethyl)​-​2,​3-​dioxopropyl]​-​3-​[(2S)​-​2-​[[[[1,​1-​di(methyl-​d3)​ethyl-​2,​2,​2-​d3]​amino]​carbonyl]​amino]​-​3,​3-​dimethyl-​1-​oxobutyl]​-​6,​6-​dimethyl-​, (1R,​2S,​5S)​-