Der belv fundet 22 isolater med virologisk svigt og heraf havde ni patienter proteasemutationer, der var opstået som følge af behandling.
In the paediatric studies APV20003 and APV29005, 67 PI-experienced patients were treated with fosamprenavir / ritonavir and of 22 virological failure isolates genotyped, nine patients were found with treatment-emergent protease mutations.