enfuvirtide and efavirenz

We studied whether addition of enfuvirtide (ENF) to a background combination antiretroviral therapy (cART) would improve the CD4 cell count response at week 24 in naive patients with advanced HIV disease. ANRS 130 Apollo is a randomized study, conducted in naive HIV-1-infected patients, either asymptomatic with CD4 counts of <100/mm(3) or stage B/C disease with CD4 counts of <200/mm(3). Patients received tenofovir-emtricitabine with lopinavir-ritonavir (LPV/r) or efavirenz and were randomized to receive ENF for 24 weeks (ENF arm) or not (control arm). The primary endpoint was the proportion of patients with CD4 counts of ≥ 200/mm(3) at week 24. A total of 195 patients were randomized: 73% had stage C disease, 78% were male, the mean age was 44 years, the median CD4 count was 30/mm(3), and the median HIV-1 RNA load was 5.4 log(10) copies/ml. Eighty-one percent of patients received LPV/r. One patient was lost to follow-up, and eight discontinued the study (four in each arm). The proportions of patients with CD4 counts of ≥ 200/mm(3) at week 24 were 34% and 38% in the ENF and control arms, respectively (P = 0.53). The proportions of patients with HIV-1 RNA loads of <50 copies/ml were 74% and 58% at week 24 in the ENF and control arms, respectively (P < 0.02), and the proportion reached 79% in both arms at week 48. Twenty (20%) and 12 patients (13%) in the ENF and control arms, respectively, experienced at least one AIDS event during follow-up (P = 0.17). Although inducing a more rapid virological response, addition of ENF to a standard cART does not improve the immunological outcome in naive HIV-infected patients with severe immunosuppression.

Topics: Adenine; Adult; Alkynes; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Benzoxazines; CD4 Lymphocyte Count; CD4-Positive T-Lymphocytes; Cyclopropanes; Deoxycytidine; Drug Combinations; Emtricitabine; Enfuvirtide; Female; HIV Envelope Protein gp41; HIV Infections; HIV-1; Humans; Immune Tolerance; Lopinavir; Male; Organophosphonates; Peptide Fragments; Ritonavir; RNA, Viral; Tenofovir; Treatment Outcome; Viral Load

To assess if enfuvirtide (ENF) increases antiviral activity of a highly active four-drug antiretroviral (ARV) regimen containing lopinavir/ritonavir, efavirenz, lamivudine and tenofovir in ARV-naive, HIV-infected patients.. Pilot study in ARV-naive, HIV-infected patients with viral load (VL) >10,000 copies/ml and no documented resistance to any of the study drugs. Patients were randomized to receive ENF (ENF Group) or not (Control Group) in combination with lopinavir/ritonavir, efavirenz, lamivudine and tenofovir as a backbone. The primary endpoint was to assess differences in the HIV-1 RNA decay rate during the first phase of viral decay. VL and treatment adherence were measured at baseline, every 6 h during the first 3 days, and once daily from day 3 to 6. Individual HIV-1 RNA decay rates were obtained using a non-linear least squares regression model.. Eight subjects were included in each study group. Mean (SD) baseline VL was 4.98 (0.38) log10 copies/ml in the ENF Group and 5.10 (0.49) log10 copies/ml in the Control Group (P=0.607). Baseline CD4+ cell count was 463 (306) and 362 (225) cells/mm3 in the ENF and the Control Group, respectively (P=0.484). First phase HIV-1 RNA decay rate was 0.802 (0.127) d(-1) in the ENF Group and 0.624 (0.182) d(-1) in the Control Group (P=0.045). By day 6, VL was 3.55 (0.40) and 3.92 (0.36) log10 copies/ml in the ENF and the Control Group, respectively (P=0.079).. The addition of ENF increased the antiviral potency of a highly active four-drug ARV regimen by 28.5% in ARV-naive, HIV-infected patients. The clinical impact of this finding should be assessed.

Topics: Adenine; Alkynes; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Benzoxazines; Cyclopropanes; Drug Synergism; Drug Therapy, Combination; Enfuvirtide; HIV Envelope Protein gp41; HIV Fusion Inhibitors; HIV Infections; Humans; Lamivudine; Lopinavir; Organophosphonates; Oxazines; Patient Compliance; Peptide Fragments; Pyrimidinones; Reverse Transcriptase Inhibitors; Ritonavir; RNA, Viral; Tenofovir; Treatment Outcome

The availability of enfuvirtide enables assessment of whether human immunodeficiency virus (HIV) decay can be enhanced by targeting reverse transcriptase, protease, and fusion. We performed a 12-week study of 22 patients randomized to receive ritonavir-boosted saquinavir and efavirenz with (the 3-target arm) or without (the 2-target arm) enfuvirtide. We observed no difference in the mean+/-SD elimination-rate constant for overall decay (0.142+/-0.040 per day and 0.128 +/- 0.033 per day in the 2- and 3-target arms, respectively; P>.1) or for modeled first-phase decay rate (-0.62+/-0.34 per day and -0.51+/-0.16 per day; P>.1). Antiretroviral therapy that inhibits HIV reverse transcriptase and protease exerts potent antiviral effects that might not be augmented by the addition of an HIV fusion inhibitor.

Topics: Alkynes; Anti-HIV Agents; Benzoxazines; Cyclopropanes; Drug Therapy, Combination; Enfuvirtide; Female; HIV Envelope Protein gp41; HIV Infections; HIV-1; Humans; Male; Oxazines; Peptide Fragments; Ritonavir; Saquinavir; Viral Load

Enfuvirtide is a novel antiretroviral that blocks HIV-1 cell fusion and viral entry. This Phase II, controlled, open-label, randomized, multicentre dose-ranging trial explored the safety, antiviral activity and pharmacokinetics of enfuvirtide, administered by subcutaneous (s.c.) injection, in 71 HIV-1-infected, protease inhibitor-experienced, non-nucleoside reverse transcriptase inhibitor (NNRTI)-naive adults for 48 weeks. Study participants were randomized to receive enfuvirtide at a deliverable dose of 45, 67.5 or 90 mg twice daily; the 45 mg twice daily dose required 2 injections/day, while the higher doses required 4 injections/day. A background oral antiretroviral (ARV) regimen of abacavir (300 mg twice daily), amprenavir (1200 mg twice daily), ritonavir (200 mg twice daily) and efavirenz (600 mg once daily) was provided with enfuvirtide. A control group received the background ARV regimen alone. All potential participants underwent an HIV genotype at screen to ensure a homogenous population and to exclude patients with evidence of genotypic resistance to NNRTIs. Overall, the tolerability of the combination of abacavir, amprenavir, ritonavir, efavirenz and enfuvirtide was generally comparable to control through 48 weeks. No enfuvirtide dose-dependent adverse events (AEs) were observed across treatment groups. Injection site reactions (ISRs) occurred at least once in 68.5% of the enfuvirtide-treated population, and most ISRs were mild to moderate in severity, with no apparent dose relationship. Excluding ISRs, the most common treatment-emergent AEs were nausea, diarrhoea, dizziness and fatigue; with no clinically significant differences in the incidence of AEs observed between the control and enfuvirtide groups. Each treatment group benefited from ARV therapy, with a trend of increasing antiviral and immunological activity associated with increasing enfuvirtide dose. At 48 weeks, the median HIV-1 RNA change from baseline for the ITT population was -2.24 log10 copies/ml for the combined enfuvirtide groups compared with -1.87 log10 copies/ml for the control group. In addition, 54.9% of patients in the enfuvirtide group achieved HIV-1 RNA < or = 400 copies/ml versus 36.8% of patients in the control group. These results indicate that enfuvirtide has a favourable safety profile and is a promising new antiviral agent for HIV-infected patients who have been on previously failing ARV regimens.

Topics: Adult; Alkynes; Anti-HIV Agents; Benzoxazines; Carbamates; Cyclopropanes; Dideoxynucleosides; Drug Therapy, Combination; Enfuvirtide; Female; Furans; HIV Envelope Protein gp41; HIV Fusion Inhibitors; HIV Infections; HIV-1; Humans; Male; Middle Aged; Oxazines; Peptide Fragments; Reverse Transcriptase Inhibitors; Ritonavir; Sulfonamides; Treatment Outcome; Viral Load

Topics: Alkynes; Benzoxazines; Calibration; Chromatography, High Pressure Liquid; Chromatography, Reverse-Phase; Cyclopropanes; Enfuvirtide; Excipients; Indicators and Reagents; Limit of Detection; Lipids; Nanoparticles; Polymers; Reproducibility of Results

HIV entry inhibitors, such as maraviroc (MVC), prevent cell-free viruses from entering the cells. In clinical trials, patients who were treated with MVC often displayed viral loads that were above the limit of conventional viral load detection compared to efavirenz-based regimens. We hypothesize that viruses blocked by entry inhibitors may be redistributed to plasma, where they artificially increase viral load measurements compared to those with the use of antiretroviral drugs (ARVs) that act intracellularly. We infected PM-1 cells with CCR5-tropic HIV-1 BaL or CXCR4-tropic HIV-1 NL4-3 in the presence of inhibitory concentrations of efavirenz, raltegravir, enfuvirtide, maraviroc, and AMD3100, the latter three being entry inhibitors. Supernatant viral load, reverse transcriptase enzyme activity, and intracellular nucleic acid levels were measured at times up to 24 h postinfection. Infectivity of redistributed dual-tropic HIV-1 was assessed using TZM-bl cells. Extracellular viral load analysis revealed that entry inhibitor-treated cells had higher levels of virus in the supernatant than the cells treated with other ARVs at 8 h postinfection. By 24 h, the supernatant viral load was still higher for entry inhibitors than other ARVs. We observed a correlation between viral load and the step of entry inhibition. Dual-tropic virus infectivity was undiminished utilizing the CCR5 coreceptor following redistribution by CXCR4 entry inhibition. This in vitro model indicates that entry inhibitors exhibit a redistribution effect unseen with intracellular ARV drugs. Based on these results, the effectiveness of some entry inhibitors may be underestimated if plasma viral load is used as a sole indicator of clinical success.

Topics: Alkynes; Anti-HIV Agents; Benzoxazines; Benzylamines; Cell Line; Cyclams; Cyclohexanes; Cyclopropanes; DNA, Viral; Drug Resistance, Viral; Enfuvirtide; Heterocyclic Compounds; HIV Envelope Protein gp41; HIV Fusion Inhibitors; HIV Reverse Transcriptase; HIV-1; Humans; Maraviroc; Peptide Fragments; Pyrrolidinones; Raltegravir Potassium; Receptors, CCR5; Receptors, CXCR4; RNA, Viral; Triazoles; Viral Load; Virus Internalization

The new non-peptidic protease inhibitor tipranavir is used boosted with ritonavir in a 500/200 mg bid scheme. Multiple drug interactions are described for both drugs because of their different action in CYP450 3A4 and p-glycoprotein. In this retrospective analysis of 22 patients during therapy with tipranavir/ritonavir (TPV) 500 mg/200 mg bid, we found significantly decreased TPV-trough levels in combination with tenofovir (15.32+/-5.22 microg/ml) in comparison to TPV trough levels without tenofovir (20.21+/-14.87 microg/ml). Therapeutic drug monitoring of TPV is recommended.

Topics: Adenine; Alkynes; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Benzoxazines; Cyclopropanes; Drug Interactions; Drug Monitoring; Enfuvirtide; HIV Envelope Protein gp41; HIV Infections; Humans; Organophosphonates; Peptide Fragments; Pyridines; Pyrones; Retrospective Studies; Ritonavir; Sulfonamides; Tenofovir

Topics: Alkynes; Anti-HIV Agents; Benzoxazines; Cohort Studies; Cyclopropanes; Drug Information Services; Enfuvirtide; HIV Envelope Protein gp41; HIV Infections; Humans; Peptide Fragments

One likely mechanism of virological failure is poor antiretroviral drug diffusion in sites of viral replication such as the genital tract. We measured antiretroviral drug concentrations in blood and semen in 13 HIV-infected men failing treatment. Enfuvirtide did not cross the blood-testis barrier, whereas tenofovir accumulated in semen. Unlike indinavir, semen concentrations of lopinavir, amprenavir, saquinavir and efavirenz were ineffective. These are worrying findings, because suboptimal semen drug concentrations may enhance the risk of sexually transmitted drug-resistant HIV variants.

Topics: Adenine; Adult; Alkynes; Anti-HIV Agents; Benzoxazines; Blood-Testis Barrier; Cyclopropanes; Enfuvirtide; Genitalia, Male; HIV Envelope Protein gp41; HIV Fusion Inhibitors; HIV Infections; HIV Protease Inhibitors; HIV-1; Humans; Male; Middle Aged; Organophosphonates; Oxazines; Peptide Fragments; Tenofovir