Share Abstract
Atazanavir and ritonavir pharmacokinetics with telaprevir-based HCV treatment (ANRSHC26)
Abstract Content:
Background: The ANRSHC26-TelapreVIH clinical trial enrolled HIV-HCV coinfected patients, non responders to Peg-interferon+ribavirin (PR) therapy. The objective was to estimate virological response rate when telaprevir was added to the standard bitherapy. Antiretroviral therapy was in most patients ritonavir boosted atazanavir with tenofovir/emtricitabine fixed dose combination. The pharmacokinetic (PK) parameters of atazanavir and ritonavir administered with PR bitherapy (at week 0) or after addition of telaprevir (at week 8), were estimated in a subgroup of patients.
Methods: Sixteen patients agreed to participate and 12 completed all samples for PK analysis. Atazanavir and ritonavir were assayed by a validated LC/MS/MS method. Pharmacokinetic parameters were estimated by non compartmental method. Geometric mean ratio (GMR) and 90% confidence interval (90%CI) were constructed for the ratio of each parameter for antiretroviral drug (ARV) combined to telaprevir+ PR / ARV +PR. Unless otherwise indicated, results are presented as median (IQR or range).
Results: Median (IQR) age and weight were 49 (38-61) years and 74 (53-90) kg respectively. Plasma HCV-RNA was 6.04 (5.46-7.30) log10 UI/mL. HIV-RNA was < 50cp/mL in 11 patients. Median CD4 were 452 (152-671) cells/µL. Median total bilirubin and unconjugated bilirubin were 41 (20-200) µmol/L and 33 (15-91) µmol/L respectively. Pharmacokinetic parameters as median (range) were:
[Pharmacokinetic parameters]
Unconjugated bilirubinemia increased by 1.21 fold when atazanavir was combined with telaprevir. A significant relationship between unconjugated bilirubinemia and atazanavir Cmin was observed (p=0.0015).
Conclusions: Atazanavir Cmin increased by 79% when coadministered with telaprevir in HCV-HIV coinfected patients despite a lower exposure to ritonavir. This drug-drug interaction was associated with a mild increase in bilirubin levels.
Methods: Sixteen patients agreed to participate and 12 completed all samples for PK analysis. Atazanavir and ritonavir were assayed by a validated LC/MS/MS method. Pharmacokinetic parameters were estimated by non compartmental method. Geometric mean ratio (GMR) and 90% confidence interval (90%CI) were constructed for the ratio of each parameter for antiretroviral drug (ARV) combined to telaprevir+ PR / ARV +PR. Unless otherwise indicated, results are presented as median (IQR or range).
Results: Median (IQR) age and weight were 49 (38-61) years and 74 (53-90) kg respectively. Plasma HCV-RNA was 6.04 (5.46-7.30) log10 UI/mL. HIV-RNA was < 50cp/mL in 11 patients. Median CD4 were 452 (152-671) cells/µL. Median total bilirubin and unconjugated bilirubin were 41 (20-200) µmol/L and 33 (15-91) µmol/L respectively. Pharmacokinetic parameters as median (range) were:
| ARV +PR | ARV+PR+Telaprevir | GMR (90%CI) | |
| Atazanavir | |||
| Cmax-ng/mL | 3169 (1176-4333) | 2779 (1331-4387) | 0.91 (0.73-1.13) |
| Cmin-ng/mL | 487 (137-2062) | 945 (289-1960) | 1.79 (1.30-2.47) |
| AUC-ng.h/mL | 32235 (13965-66420) | 33179 (20749-72531) | 1.14 (0.92-1.41) |
| Ritonavir | |||
| Cmax-ng/mL | 1115 (736-1934) | 857 (422-1135) | 0.70 (0.62-0.80) |
| Cmin-ng/mL | 48 (21-226) | 51 (17-106) | 0.80 (0.61-1.05) |
| AUC-ng.h/mL | 7979 (6001-18170) | 6100 (2731-10712) | 0.65 (0.56-0.76) |
Unconjugated bilirubinemia increased by 1.21 fold when atazanavir was combined with telaprevir. A significant relationship between unconjugated bilirubinemia and atazanavir Cmin was observed (p=0.0015).
Conclusions: Atazanavir Cmin increased by 79% when coadministered with telaprevir in HCV-HIV coinfected patients despite a lower exposure to ritonavir. This drug-drug interaction was associated with a mild increase in bilirubin levels.