In a pooled analysis of the POWER 1, 2 and 3 (see Clinical experience subsection ART-experienced patients) and DUET 1 and 2 (TMC125-C206 and TMC125-C216) trials the amino acid substitutions identified that developed on PREZISTA co-administered with ritonavir (600/100 mg b.i.d.) in ≥ 20% of the isolates from subjects who experienced virologic failure by rebound were V32I, I54L and L89V.