TABLE 2.

Known amino acid substitutions in RSV F associated with reduced susceptibility to presatovir or other RSV fusion inhibitors

Category	Substitutions
Presatovir resistance-associated substitutionsa	V127A, L138F, L138I, F140I, F140L, L141F, L141W, T323A, D338Y, S398L, K399I, K399N, T400I, T400A, T400V, I474T, D486N, E487D, F488L, F488S, F488Y, N517I
Fusion inhibitor resistance-associated substitutionsb	G143S, V144A, D392G, K394R, D401E, D486E, F488I, F488V, D489E, D489Y
Other substitutionsc	M396I, T397S

^aSubstitutions previously selected by presatovir treatment in a clinical study or in vitro and shown to reduce susceptibility to presatovir.

^bSubstitutions previously selected by or shown to reduce susceptibility to RSV fusion inhibitors other than presatovir in vitro (18, 20, 29, 31, 32). The effect of these substitutions on susceptibility to presatovir is unknown.

^cSubstitutions that developed during presatovir treatment in a clinical study for which presatovir susceptibility was unable to be characterized.