ABSTRACT
Nowadays, antiretroviral therapy is recommended during pregnancy to prevent mother-to-child transmission of HIV. However, for many antiretroviral drugs, including maraviroc, a CCR5 antagonist, very little data exist regarding placental transfer. Besides, various factors may modulate this transfer, including efflux transporters belonging to the ATP-binding cassette (ABC) transporter superfamily. We investigated maraviroc placental transfer and the influence of ABC transporter expression on this transfer using the human cotyledon perfusion model. Term placentas were perfused ex vivo for 90 min with maraviroc (600 ng/ml) either in the maternal-to-fetal (n = 10 placentas) or fetal-to-maternal (n = 6 placentas) direction. Plasma concentrations were determined by ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). Fetal transfer rates (FTR) and clearance indexes (CLI) were calculated as ratios of fetal to maternal concentrations at steady state (mean values between 30 and 90 min) and ratios of FTR of maraviroc to that of antipyrine, respectively. ABC transporter gene expression levels were determined by quantitative reverse transcription (RT)-PCR and ABCB1 protein expression by Western blotting. For the maternal-to-fetal direction, the mean FTR and CLI were 8.0% ± 3.0 and 0.26 ± 0.07, respectively, whereas the mean CLI was 0.52 ± 0.23 for the fetal-to-maternal direction. We showed a significant inverse correlation between maraviroc CLI and ABCC2, ABCC10, and ABCC11 placental gene expression levels (P < 0.05). To conclude, we report a low maraviroc placental transfer probably involving ABC efflux transporters and thus in all likelihood associated with a limited fetal exposition. Nevertheless, these results would need to be supported by in vivo data obtained from paired maternal and cord blood samples.
Subject(s)
Cyclohexanes/metabolism , Gene Expression , HIV Fusion Inhibitors/metabolism , Models, Biological , Placenta/metabolism , Triazoles/metabolism , ATP Binding Cassette Transporter, Subfamily B , ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , ATP-Binding Cassette Transporters/genetics , ATP-Binding Cassette Transporters/metabolism , Chromatography, Liquid , Cyclohexanes/pharmacology , Diffusion Chambers, Culture , Female , Fetus , HIV Fusion Inhibitors/pharmacology , Humans , Kinetics , Maraviroc , Maternal-Fetal Exchange , Multidrug Resistance-Associated Protein 2 , Multidrug Resistance-Associated Proteins/genetics , Multidrug Resistance-Associated Proteins/metabolism , Organ Culture Techniques , Perfusion , Placenta/drug effects , Pregnancy , Tandem Mass Spectrometry , Triazoles/pharmacologyABSTRACT
BACKGROUND: Etravirine (ETR) is recommended as twice-daily dosing in pretreated patients. There are no data regarding the use of ETR once daily in HIV-experienced patients with prior resistance to first-generation non-nucleoside reverse transcripase inhibitors (NNRTIs). OBJECTIVES: To evaluate the capacity of once-daily ETR to maintain suppressed viremia over 48 weeks after switching from ETR twice daily in NNRTI-experienced patients. METHODS: In this pilot open-label study, patients with plasma viral load (pVL) <50 copies/mL on a stable ETR 200 mg bid regimen were enrolled to switch to ETR 400 mg qd and followed up over 48 weeks. The primary endpoint was the proportion of patients with pVL <50 copies/mL at week 24. Secondary endpoints included the rate of pVL< 50 copies/mL at week 48, ETR pharmacokinetic parameters, and tolerability and resistance profile. RESULTS: Twenty-four patients were included. They had extensive antiretroviral treatment for a median of 14 years (range, 1-19). All except for 2 had prior resistance to NNRTIs. Seven patients discontinued ETR once daily prior to week 48 for virological failure (3), protocol deviation (3), and side effects (1). At week 24, 95% of patients maintained pVL< 50 copies/mL (95% CI, 78.4-99.7) and 85% at week 48 (95%CI, 65.6-95.8). Two of the 3 patients with virological failure had ETR resistance mutations prior to initiation. The median ETR C(trough) level remained stable after switching from twice daily 515 ng/mL (340-758) to once daily 422 ng/mL (264-655). CONCLUSION: These results suggest that ETR is effective as a once-daily regimen in patients with prior NNRTI experience when HIV is sensitive to ETR. The stability of C(trough) concentrations on a once-daily regimen confirms the once-daily profile of the drug in experienced patients.
Subject(s)
HIV Infections/drug therapy , HIV-1/drug effects , Pyridazines/therapeutic use , Reverse Transcriptase Inhibitors/pharmacology , Drug Administration Schedule , Drug Resistance, Viral/genetics , Genotype , HIV Infections/virology , HIV-1/genetics , Humans , Nitriles , Pilot Projects , Pyridazines/administration & dosage , Pyrimidines , Reverse Transcriptase Inhibitors/administration & dosage , Reverse Transcriptase Inhibitors/therapeutic use , ViremiaABSTRACT
We studied the penetration of etravirine and HIV shedding in the genital tract among 12 HIV-1-infected women receiving an etravirine-containing regimen who had <40 copies/ml blood plasma (BP) HIV RNA. None of the cervicovaginal fluid (CVF) samples showed detectable HIV RNA. Median etravirine concentrations were 663 ng/ml in BP and 857 ng/ml in CVF, with a CVF/BP etravirine ratio of approximately 1.2. This good penetration of etravirine may contribute to the control of viral replication in the female genital tract.
