Fosamprenavir/ritonavir in patients with viral hepatitis coinfection : an observational multicohort study

Objective: Safety and tolerability evaluation of adapted dose regimens containing fosamprenavir/ritonavir (FPV/r) in HIV-infected subjects with viral hepatitis co-infection. Methods: A retrospective multicohort analysis was conducted. Subjects from three European cohorts who started FPV/r or lopinavir/ritonavir (LPV/r) as a comparator contributed data to a centralized database. Subjects were divided into five groups by treatment regimen and level of hepatic impairment (aspartate aminotransferase [AST] platelet ratio index [APRI] score < or ≥2). Multivariable Cox regression analyses controlling for demographic factors, baseline CD4 count, FIB-4 score, use of antiretroviral therapy, and laboratory markers (bilirubin and platelet count) were performed to identify factors independently associated with risk of developing adverse events or safety events (eg, drug discontinuation, alanine aminotransferase (ALT) elevation, hepatic decompensation/death). Results: A total of 1096 patients contributed data to the study. Fosamprenavir/ritonavir (except in subjects with APRI ≥2 receiving standard dose) was associated with a higher two-year risk of drug discontinuation compared with LPV/r. Restricting the analysis to discontinuations due to adverse events (AEs), only subjects who received the reduced dose were more likely to discontinue ≥1 drug in the FPV/r regimen. There were no statistical differences in ALT elevation between groups. Incidence of hepatic decompensation events was similar among groups except for subjects who received non standard doses of FPV, though the number of events was small. Conclusions: Fosamprenavir/ritonavir discontinuation rate due to AEs or ALT elevation was similar across all European-approved FPV/r doses and to that of LPV/r subjects. Although liver tolerated antiretrovirals, such as integrase inhibitor and entry inhibitor, the use of FPV/r is acceptable in HIV infected patients with viral hepatitis.