Clinically validated mutation scores for HIV-1 resistance to fosamprenavir/ritonavir

Results: In the 73 patients included, the median baseline HIV-1 RNA was 4.6 log10 copies/mL (range: 2.7–6.9) and the mean decrease at month 3 was 21.07+1.40 log10 copies/mL. Ninety per cent of the patients were infected by HIV-1 subtype B variants. Two fosamprenavir/ritonavir mutation scores were constructed: score A (L10F/I/V 1 L33F 1 M36I 1 I54L/M/V/A/T/S 1 I62V 1 V82A/F/C/G 1 I84V 1 L90M) was based only on mutations associated with a worse VR, whereas score B (L10FIV 1 L33F 1 M36I 1 I54L/M/ V/A/T/S 1 A71V 2 V77I 2 N88S 1 L90M) also took into account favourable mutations. Both scores were independent predictors of VR, however, co-administration of tenofovir was associated with a worse VR and the presence of the N88S protease mutation and co-administration of enfuvirtide with a better VR. Conclusions: These clinically validated mutation scores should be of interest for the clinical management of PI-experienced patients. The fosamprenavir/ritonavir score A was introduced in the 2006 ANRS algorithm along with isolated mutations I50V and V32I 1 I47V.