BACKGROUND:MK-0518 is a novel HIV-1 integrase strand transfer inhibitor with potent in vitro activity against HIV-1 (95% inhibitory concentration IC95 = 33 nM in 50% human serum) and good ...bioavailability in uninfected subjects. This study explored the antiretroviral activity and safety of MK-0518 versus placebo for 10 days as monotherapy in antiretroviral therapy-naive HIV-1-infected patients with plasma HIV-1 RNA levels of at least 5000 copies/mL and CD4 T-cell counts of at least 100 cells/mm.
METHODS:This was a multicenter, double-blind, randomized, placebo-controlled 2-part study, with the first part using MK-0518 in 1 of 4 doses (100, 200, 400, and 600 mg) versus placebo (randomized 1:1:1:1:1) given twice daily for 10 days of monotherapy. Patients were monitored for safety, pharmacokinetic parameters, and antiretroviral effect.
RESULTS:Thirty-five patients were enrolled (6-8 patients per treatment group) and completed 10 days of therapy; the mean baseline log10 HIV RNA level ranged from 4.5 to 5.0 copies/mL in each group. On day 10, the mean decrease from baseline in the log10 HIV RNA level was −0.2 copies/mL for the placebo group and −1.9, −2.0, −1.7 and −2.2 log10 copies/mL for the MK-0518 100-, 200-, 400-, and 600-mg treatment groups, respectively. All dose groups had superior antiretroviral activity compared with placebo (P < 0.001 for comparison of each dose with placebo). At least 50% of patients in each MK-0518 dose group achieved an HIV RNA level <400 copies/mL by day 10. Mean trough MK-0518 concentrations at each dose exceeded the IC95 of 33 nM. Study therapy was generally well tolerated. The most common adverse experiences were headache and dizziness; these were similar between active and control groups. There were no discontinuations because of adverse experiences and no serious adverse experiences.
CONCLUSIONS:MK-0518 showed potent antiretroviral activity as short-term monotherapy and was generally well tolerated at all doses. Based on these results, part 2 of the study, a dose-ranging 48-week trial of MK-0518 versus efavirenz in a combination regimen, has been initiated.
BACKGROUND:HIV treatment of neonates requires identifying appropriate antiretroviral dosing regimens. Our aims were to characterize raltegravir elimination kinetics in low birth weight (LBW) neonates ...after maternal dosing and to develop a pharmacokinetic model to predict raltegravir plasma concentrations for term and preterm neonates.
METHODS:Mothers living with HIV who received raltegravir during pregnancy and their LBW neonates participated in IMPAACT P1097 study. Up to 6 serial plasma samples were collected from each infant over the first 2 postnatal weeks to characterize raltegravir elimination. Safety laboratory evaluations were obtained, and infants were monitored for 6 weeks for signs of raltegravir toxicity. An integrated maternal–neonatal pharmacokinetic model was developed to predict neonatal raltegravir plasma concentrations.
RESULTS:Sixteen mothers and their 18 LBW neonates were enrolled. The median (range) raltegravir elimination half-life was 24.4 (10.1–83) hours (N = 17 neonates). No adverse events related to raltegravir in utero exposure were observed. Pharmacokinetic modeling revealed that raltegravir clearance in full-term LBW neonates was well described by allometric scaling but clearance in preterm LBW neonates was better described using slower clearance maturation kinetics. Simulations suggest receipt of the current dosing recommendations in a 34-week gestation neonate would result in plasma concentrations up to 2.5-fold higher than those observed in full-term LBW infants.
CONCLUSIONS:Modeling suggests that prematurity reduces raltegravir clearance and a modified raltegravir dosing regimen will be necessary to avoid elevated plasma raltegravir concentrations.
International Maternal Pediatric Adolescent AIDS Clinical Trials P1097 was a multicenter trial to determine washout pharmacokinetics and safety of in utero/intrapartum exposure to raltegravir in ...infants born to HIV-infected pregnant women receiving raltegravir-based antiretroviral therapy. Twenty-two mother–infant pairs were enrolled; evaluable pharmacokinetic data were available from 19 mother–infant pairs. Raltegravir readily crossed the placenta, with a median cord blood/maternal delivery plasma raltegravir concentration ratio of 1.48 (range, 0.32–4.33). Raltegravir elimination was highly variable and extremely prolonged in some infants; median t1/2 26.6 (range, 9.3–184) hours. Prolonged raltegravir elimination likely reflects low neonatal UGT1A1 enzyme activity and enterohepatic recirculation. Excessive raltegravir concentrations must be avoided in the neonate because raltegravir at high plasma concentrations may increase the risk of bilirubin neurotoxicity. Subtherapeutic concentrations, which could lead to inadequate viral suppression and development of raltegravir resistance, must also be avoided. Two ongoing International Maternal Pediatric Adolescent AIDS Clinical Trials studies are further investigating the pharmacology of raltegravir in neonates.
To determine the durability over 96 weeks of safety and efficacy of lopinavir/ritonavir (LPV/r) and raltegravir (RAL) which was demonstrated to have non-inferior efficacy relative to a regimen of ...LPV/r with nucleoside/nucleotide reverse transcriptase inhibitors (N(t)RTIs) (Control) in primary analysis at 48 weeks.
Open label, centrally randomised trial.
Recruitment was from 37 primary and secondary care sites from Africa, Asia, Australia, Europe and Latin America.
541 HIV-1 infected adults virologically failing first-line non-NRTI + 2N(t)RTI, with no previous exposure to protease inhibitors or integrase strand transfer inhibitors were analysed, 425 completed 96 weeks follow up on randomised therapy.
Randomisation was 1:1 to Control or RAL.
Differences between the proportion of participants with plasma HIV-1 RNA (VL) <200 copies/mL by intention to treat were compared with a non-inferiority margin of -12%. Differences in biochemical, haematological and metabolic changes were assessed using T-tests.
VL <200 copies/mL at 96 weeks was: RAL 80.4%, Control 76.0% (difference: 4.4 95%CI -2.6, 11.3) and met non-inferiority criteria. The RAL arm had a significantly higher mean change (difference Control-RAL; 95%CI) in haemoglobin (-2.9; -5.7, -1.1), total lymphocytes (-0.2; -0.3, -0.0), total cholesterol (-0.5; -0.8, -0.3), HDL cholesterol (-0.1; -0.1, -0.0) and LDL cholesterol (-0.3; -0.5, -0.2).
At 96 weeks, both RAL and Control maintained efficacy greater than 75% and continued to demonstrate similar safety profiles. These results support the use of a combination LPV/r and RAL regimen as an option following failure of 1st line NNRTI + 2N(t)RTIs.
ClinicalTrials.gov NCT00931463.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
WHO-recommended second-line antiretroviral therapy (ART) of a pharmacologically enhanced (boosted) protease inhibitor plus nucleoside or nucleotide reverse transcriptase inhibitors (NtRTIs) might be ...compromised by resistance. Results of the 96 week SECOND-LINE randomised trial showed that NtRTI-sparing ART with ritonavir-boosted lopinavir and raltegravir (raltegravir-group) provided non-inferior efficacy to ritonavir-boosted lopinavir and two or three NtRTIs (NtRTI-group) in participants with virological failure composed of a first-line regimen of a non-nucleoside reverse transcriptase inhibitor plus two NtRTIs. We report the relation of baseline virological resistance with virological failure and emergent resistance on study.
As part of the randomised open-label SECOND-LINE trial, second-line ART NtRTI selection was made by either genotype (local laboratory) or algorithm. Genotypic resistance for the entire cohort at baseline was assessed on stored samples at a central laboratory. Virological failure was defined as plasma viral load greater than 200 copies per mL. Baseline viral isolates were assigned genotypic sensitivity scores (GSSs) by use of the Stanford HIV Database version 6.3.1: a global GSS (gGSS), defined as the combined GSS for lamivudine or emtricitabine, abacavir, zidovudine, stavudine, didanosine, and tenofovir and a specific GSS (sGSS) defined as the GSS for the ART regimen initiated by a specific participant. Emergent resistance was reported on samples with a viral load greater than 500 copies per mL. We used multivariate logistic regression with backward elimination to assess predictors of virological failure and emergent resistance.
From April 19, 2010, to July 22, 2013, 271 patients were included in the NtRTI group and and 270 in the raltegravir group. In the NtRTI group 215 had available baseline sequence data, and 240 had viral load measurements at 96 weeks; in the raltegravir group 236 had baseline sequence data and 255 had viral load measurements at 96 weeks. Median (IQR) gGSS was 3.0 (1.3-4.3) in the NtRTI group and 3.0 (1.0-4.3) in the raltegravir group. The median sGSS in the NtRTI group was 1.0 (0.5-1.8). Multivariate analysis showed significant associations between virological failure and less than complete adherence at week 4 (odds ratio OR 2.18, 95%CI 1.07-4.47; p=0·03) and week 48 (2.49, 1.09-5.69; p=0.03), baseline plasma viral load greater than 100,000 copies per mL (3.43, 1.70-6.94; p=0.0006), baseline gGSS >4.25 (4.73, 1.94-11.6; p=0.0007), and being Hispanic (3.13, 1.21-8.13; p=0.02) or African (3.49, 1.68-7.28; p=0.0008) rather than Asian. We observed emergent major mutations in one (1%) of 129 participants for protease (both groups), eight (13%) of 64 for reverse transcriptase (NtRTI group) and 16 (20%) of 79 for integrase. Emergent resistance was associated with the raltegravir group (OR 2.47, 95% CI 1.02-5.99; p=0.05), baseline log10 viral load (1.83, 1.12-2.97; p=0.02), and absence of the Lys65Arg (K65R) or Lys70Glu (K70E) mutation at baseline (3.18, 1.12-9.02; p=0.03).
Poor adherence was a major determinant of virological failure in people on second-line ART. In settings with limited resources, investment in optimisation of adherence rather than implementation of drug resistance testing might be advisable.
University of New South Wales Australia, Merck, AbbVie, and the Foundation for AIDS Research.
Raltegravir readily crosses the placenta to the fetus with maternal use during pregnancy. After birth, neonatal raltegravir elimination is highly variable and often extremely prolonged, with some ...neonates demonstrating rising profiles after birth despite removal from the source of extrinsic raltegravir. To establish an appropriate dosing regimen, an integrated maternal–neonatal pharmacokinetics model was built to predict raltegravir plasma concentrations in neonates with in utero raltegravir exposure. Postnatal age and body weight were used as structural covariates. The model predicted rising or decreasing neonatal elimination profiles based on the time of maternal drug administration relative to time of birth and degree of in utero drug disposition into the central and peripheral compartments. Based on this model, it is recommended to delay the first oral dose of raltegravir until 1–2 days of age in those neonates born to mothers who received raltegravir during pregnancy, labor, and delivery.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Raltegravir is the first integrase strand transfer inhibitor approved for the treatment of HIV‐1 infection. As the first agent in this new class of antiretroviral therapies, raltegravir has ...demonstrated safety and efficacy in treatment‐naive as well as heavily pretreated HIV‐infected patients failing therapy with multidrug‐resistant virus. Raltegravir has a favorable drug interaction profile that permits both administration to a wide, demographically diverse patient population and coadministration with many other therapeutic agents, including antiretroviral agents and supportive medications, without restrictions or dose adjustment. Data through 96 weeks of follow‐up in three phase III studies, protocol 021 (STARTMRK) in treatment‐naive patients, and protocols 018 (BENCHMRK‐1) and 019 (BENCHMRK‐2) in treatment‐experienced patients, demonstrated the potent and durable antiretroviral and immunologic effects and the favorable long‐term safety profile of raltegravir in both treatment‐naive and treatment‐experienced patients. Raltegravir represents an important addition to the current armamentarium for the treatment of HIV infection.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
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