Classes Of Antiretroviral Drugs Research Articles

Development, validation and clinical evaluation of a low cost in-house HIV-1 drug resistance genotyping assay for Indian patients.

Human Immunodeficiency Virus-1 (HIV-1) drug resistance genotyping assay is a part of clinical management of HIV-1 positive individuals under treatment with highly active antiretroviral therapy (HAART). Routine monitoring of drug resistance mutations in resource limited settings like India is not possible due to high cost of commercial drug resistance assays. In this study we developed an in-house, cost effective HIV-1 drug resistance genotyping assay for Indian patients and validated it against the US-FDA-approved ViroSeq HIV-1 drug resistance testing system. A reference panel of 20 clinical samples was used to develop and validate the assay against ViroSeq HIV-1 drug resistance testing system which was subsequently used to genotype a clinical panel of 225 samples. The Stanford HIV database was used to identify drug resistant mutations. The analytical sensitivity of the assay was 1000 HIV-1 RNA copies/ml of plasma sample while precision and reproducibility was 99.68±0.16% and 99.76±0.18% respectively. One hundred and one drug resistant mutations were detected by the in-house assay compared to 104 by ViroSeq system in the reference panel. The assay had 91.55% success rate in genotyping the clinical panel samples and was able to detect drug resistant mutations related to nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse-transcriptase inhibitor (NNRTI) as well as protease inhibitor (PI) classes of antiretroviral drugs. It was found to be around 71.9% more cost effective compared to ViroSeq genotyping system. This evaluation of the assay on the clinical panel demonstrates its potential for monitoring clinical HIV-1 drug resistance mutations and population-based surveillance in resource limited settings like India.

Contribution of human immunodeficiency virus type 1 minority variants to reduced drug susceptibility in patients on an integrase strand transfer inhibitor-based therapy.

The role of HIV-1 minority variants on transmission, pathogenesis, and virologic failure to antiretroviral regimens has been explored; however, most studies of low-level HIV-1 drug-resistant variants have focused in single target regions. Here we used a novel HIV-1 genotypic assay based on deep sequencing, DEEPGEN (Gibson et al 2014 Antimicrob Agents Chemother 58∶2167) to simultaneously analyze the presence of minority variants carrying mutations associated with reduced susceptibility to protease (PR), reverse transcriptase (RT), and integrase strand transfer integrase inhibitors (INSTIs), as well as HIV-1 coreceptor tropism. gag-p2/NCp7/p1/p6/pol-PR/RT/INT and env/C2V3 PCR products were obtained from twelve heavily treatment-experienced patients experiencing virologic failure while participating in a 48-week dose-ranging study of elvitegravir (GS-US-183-0105). Deep sequencing results were compared with (i) virological response to treatment, (ii) genotyping based on population sequencing, (iii) phenotyping data using PhenoSense and VIRALARTS, and (iv) HIV-1 coreceptor tropism based on the phenotypic test VERITROP. Most patients failed the antiretroviral regimen with numerous pre-existing mutations in the PR and RT, and additionally newly acquired INSTI-resistance mutations as determined by population sequencing (mean 9.4, 5.3, and 1.4 PI- RTI-, and INSTI-resistance mutations, respectively). Interestingly, since DEEPGEN allows the accurate detection of amino acid substitutions at frequencies as low as 1% of the population, a series of additional drug resistance mutations were detected by deep sequencing (mean 2.5, 1.5, and 0.9, respectively). The presence of these low-abundance HIV-1 variants was associated with drug susceptibility, replicative fitness, and coreceptor tropism determined using sensitive phenotypic assays, enhancing the overall burden of resistance to all four antiretroviral drug classes. Further longitudinal studies based on deep sequencing tests will help to clarify (i) the potential impact of minority HIV-1 drug resistant variants in response to antiretroviral therapy and (ii) the importance of the detection of HIV minority variants in the clinical practice.

Cytokine secretion from brain macrophages infected with human immunodeficiency virus in vitro and treated with raltegravir

BackgroundIntegrase inhibitors are a promising class of antiretroviral drugs to treat chronic human immunodeficiency virus (HIV) infection. During HIV infection, macrophages can extravasate from the blood to the brain, while producing chemotaxic proteins and cytokines, which have detrimental effects on central nervous system cells. The main goal of this study was to understand the effects of raltegravir (RAL) on human brain macrophage production of immune-mediators when infected with HIV, but did not compare with other antiretroviral agents.MethodsPro-inflammatory cytokines, IFN-γ, IL-10, IL-12-p70, IL-1, IL-8, TNF-α, and IL-6 were measured simultaneously in tissue culture supernatants from primary brain derived macrophages, microglia. We tested the effects of RAL on markers of astrocytosis and neurite integrity in primary human neuroglial cultures.ResultsRAL administered at 20 nM effectively suppressed HIV infection in microglia over 9 days. Only IL-8, IL-10, and TNF-α were above the detection limit in the majority of samples and RAL significantly suppressed the rate of cytokine production in HIV-infected microglia. During RAL-alone, the rate of IL-8 secretion was higher.ConclusionsRAL did not affect neurite area but inhibited astrocyte growth in the neuroglial cultures. Exploring the effects of RAL on pro-inflammatory molecule production in brain macrophages may contribute to designing ARV neuroprotective strategies in chronic HIV infection.

Nucleoside-Sparing Antiretroviral Regimens

Nucleoside reverse transcriptase inhibitors (NRTIs) were the first drugs approved for use as antiretroviral therapy in patients infected with HIV. Despite the introduction of other classes of antiretroviral drugs, they remain an important component of combination regimens as recommended by many treatment guidelines. They also continue to be used in prevention of disease from mother to child, postexposure prophylaxis, and more recently for preexposure prophylaxis. Unfortunately, the toxicities associated with this class of drugs can limit their use. Although NRTI-sparing regimens are not currently recommended for first-line therapy there is an increasing amount of data supporting their use in both treatment-naive and in treatment-experienced patients.

Safety and effectiveness of antiretroviral therapies for HIV-infected women and their infants and children: protocol for a systematic review and network meta-analysis.

BackgroundAntiretroviral therapy reduces mother-to-child transmission of human immunodeficiency virus (HIV) during pregnancy, delivery, and breastfeeding. However, these agents have been associated with preterm birth, anemia and low birth weight. We aim to evaluate the comparative safety and effectiveness of the use of antiretroviral drugs among HIV-infected women and the effects on their infants and children through a systematic review and network meta-analysis.Methods/DesignStudies examining the effects of six antiretroviral drug classes (nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors, integrase inhibitors, fusion inhibitors, co-receptor inhibitors) administered to HIV-infected pregnant women will be included. We will include randomized clinical trials (RCTs), quasi-RCTs, non-RCTs, controlled before-after, interrupted time series, cohort, registry, and case–control studies. No limitations will be imposed on publication status (that is, unpublished studies are eligible for inclusion), duration of follow-up, study conduct period, and language of dissemination. Comprehensive literature searches will be conducted in major electronic databases, including MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials. Gray literature will be identified through searching dissertation databases, trial protocol registries, and conference abstracts.Two team members will independently screen all citations, full-text articles, and abstract data; conflicts will be resolved through discussion. The risk of bias and methodological quality will be appraised using appropriate tools (for example, Cochrane Collaboration’s tool for assessing risk of bias, Newcastle-Ottawa Scale, and McMaster Quality Assessment Scale of Harms). If feasible and appropriate, we will conduct random effects meta-analysis. Network meta-analysis will be considered for outcomes with the greatest number of treatment comparisons available that fulfill network meta-analysis assumptions (for example, consistency of evidence between direct and indirect data, and low statistical heterogeneity between included studies).The primary effectiveness outcome is mother-to-child transmission of HIV, and the primary safety outcome is major congenital malformation (overall and specific types) among newborns of HIV-infected women. Secondary safety outcomes include stillbirths, infant/child death, preterm delivery, overall and specific minor congenital malformations, and small for gestational age infants.DiscussionOur systematic review will be of utility to healthcare providers, policy-makers, and HIV-positive women regarding the use of antiretroviral drugs.Trial registrationPROSPERO registry number: CRD42014009071.

"Old Dogs with New Tricks": exploiting alternative mechanisms of action and new drug design strategies for clinically validated HIV targets.

HIV-1 reverse transcriptase, protease and integrase have been recognized as clinically validated but still underexploited targets for antiretroviral treatment. Although a large number of inhibitors have been used in clinical trials, the rapid emergence of multiple drug-resistant strains requires the identification of not only novel classes of antiretroviral drugs that act via the unprecedented mechanism of action but also innovative drug discovery strategies towards these three important targets. This review summarizes and discusses current endeavours towards the discovery and development of novel inhibitors with alternative mechanisms of action, and also provides examples illustrating new methodologies in medicinal chemistry that contribute to the identification of novel antiretroviral agents.

Critical appraisal of elvitegravir in the treatment of HIV-1/AIDS.

Human immunodeficiency virus type 1 (HIV-1) integrase inhibitors belong to a novel class of antiretroviral drugs with high potency and better tolerability. Elvitegravir (EVG) is the second integrase inhibitor approved by the US Food and Drug Administration when administered in combination with a novel pharmacoenhancer, cobicistat (COBI), and two nucleoside/nucleotide reverse transcriptase inhibitors, emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF). This combination of drugs (EVG/COBI/FTC/TDF) developed and marketed by Gilead Sciences Inc. (Foster City, CA, USA) as STRIBILD®, is the first integrase inhibitor-based single-tablet regimen administered once-daily. In the USA, it has been approved for use in antiretroviral treatment-naïve HIV-1 patients with estimated creatinine clearance of >70 mL/min. The Department of Health and Human Services has approved EVG/COBI/FTC/TDF as one of preferred first-line regimens for HIV-1 treatment. In Europe, the European Medicines Agency has approved STRIBILD in treatment-naïve patients as well as in patients having no resistant mutation to any of the antiviral agents contained in STRIBILD. Its availability as a fixed-dose combination and once-daily dosage makes the adherence highly likely. However, it also discounts the possibility of dosage adjustment if needed.

Dolutegravir: clinical efficacy and role in HIV therapy.

The human immunodeficiency virus type-1 (HIV-1) integrase enzyme has recently emerged as a primary alternative target to block viral replication, and integrase strand transfer inhibitors (INSTIs) are now considered an alternative 'third agent' class of antiretroviral (ARV) drugs. Dolutegravir is the first next-generation INSTI showing some novel and intriguing characteristics: it has a favorable pharmacokinetic profile with a prolonged intracellular halflife, rendering feasible a once daily dosing without the need for pharmacokinetic boosting. Secondly, it is largely metabolized via uridine diphosphate glucuronosyltransferase-1A1 with a minor component of cytochrome P450 isoforms, thus allowing a low grade of drug-drug interactions, so that its metabolic profile consents co-administration with the majority of the other ARV drugs without dose adjustments. Lastly, but no less important, virological studies have clearly demonstrated that dolutegravir has a significant activity against HIV-1 isolates showing raltegravir and/or elvitegravir associated resistance mutations. The attributes of once daily administration and the potential to treat INSTI-resistant viruses make dolutegravir an interesting and promising new agent in the treatment of both naïve and experienced HIV-1 subjects. In this review, the main concerns on dolutegravir efficacy are focused through the analysis of the currently available data from clinical studies in naïve and experienced patients, evaluating its possible place within the anti-HIV-1 drug armamentarium. The development of newer once daily, single tablet coformulations improved drug adherence and maximized the success of ARV therapy. Pharmacokinetic studies and dose-ranging trials suggested that dolutegravir is a good candidate for a single tablet regimen in one or more new coformulated pills that will be available in the near future.

Under CMS proposed rule, MTM coverage would expand greatly

CMS hopes to require Medicare Part D plans to expand the pool of patients eligible for Part D medication therapy management (MTM), according to the new proposed rule published Friday in the Federal Register. The proposed new criteria for Part D MTM eligibility would include patients having two or more chronic conditions, with at least one being a core chronic disease; taking any two or more covered Part D drugs; and having a minimum annual drug spend of $620. “CMS clearly indicated that they believe MTM is a quality service, that pharmacists’ services are very beneficial and cost effective, and that they fully intend for MTM utilization to expand significantly. It’s possible that something like 50% of Medicare beneficiaries will now be eligible for MTM, and it may well be more than that,” said Jillanne Schulte, JD, APhA Director of Regulatory Affairs. The agency’s loosening of the eligibility criteria for Part D MTM is a “great opportunity for pharmacists to show what they can do.” “One of the really great things about [the proposed rule] is it’s a floor. So if a plan wants to go above and beyond what’s in the rule, it can,” Schulte added. “It can extend MTM to any number of people, in theory.” APhA’s detailed analysis of CMS’s proposed rule on “Contract Year 2015 Policy and Technical Changes to the Medicare Advantage and the Medicare Prescription Drug Benefit Programs” is under way. The Association plans to comment by the deadline of March 7, 2014. “A lot of the rule is applicable more to Part D sponsors,” in terms of both fraud and abuse, and general organizational and contracting requirements, explained Schulte. But “a lot of these big changes are going to trickle down to pharmacists.” CMS also proposed changes related to the six protected drug categories or classes of clinical concern. When Part D started, CMS implemented a policy that all Part D plans must include on their formularies “all or substantially all” Part D drugs in six drug classes: antineoplastics, anticonvulsants, anti- retrovirals, antipsychotics, antidepres- sants, and immunosuppressants; the Affordable Care Act later made this policy the law, but allowed CMS to specify criteria for identifying protected classes through rulemaking, according to the agency’s January 6 fact sheet on the proposed rule. MORE ONLINE■An expanded version of this article is available at www.pharmacist.com/under-cms-proposed-rule-mtm-coverage-would-expand-greatly.■The CEO Blog perspective is available at www.pharmacist.com/CEOBlog/cms-proposes-rule-expanding-access-part-d-mtm. ■An expanded version of this article is available at www.pharmacist.com/under-cms-proposed-rule-mtm-coverage-would-expand-greatly.■The CEO Blog perspective is available at www.pharmacist.com/CEOBlog/cms-proposes-rule-expanding-access-part-d-mtm. Under two criteria proposed by CMS, the antineoplastic, anticonvulsant, and antiretroviral drug classes would remain protected classes of drugs, but as of 2015, Part D formularies would no longer be required to include all anti- depressants and immunosuppressants. “Antipsychotics will remain protected at least through 2015 while CMS evaluates additional considerations and the need for any other formulary exceptions,” according to the CMS fact sheet. CMS has “basically said that this is a cost issue,” said Schulte. The proposed rule also contains two big changes related to mail service that may result in more Part D beneficiaries walking into their local pharmacy. First, CMS would require mail-service pharmacies to fill prescriptions within 3 or 5 days and would not permit mail-service pharmacies to waive cost sharing for a Part D plan unless cost sharing is waived for all plan enrollees. “I don’t think the response from most Part D plans is going to be to waive more copayments. I think they’re going to cut the co- payment waivers off,” Schulte said. Second, CMS stated that new prescriptions and 30-day prescriptions should not be available through mail service. “If Part D plans comply, it’s going to be better for patients because when they do get a new prescription, they will have to see their pharmacist,” Schulte said. In addition to more patient counseling options, pharmacies may also see more foot traffic in stores.

Performance of HIV-1 Drug Resistance Testing at Low-Level Viremia and Its Ability to Predict Future Virologic Outcomes and Viral Evolution in Treatment-Naive Individuals

Low-level viremia (LLV; human immunodeficiency virus [HIV-1] RNA 50-999 copies/mL) occurs frequently in patients receiving antiretroviral therapy (ART), but there are few or no data available demonstrating that HIV-1 drug resistance testing at a plasma viral load (pVL) <1000 copies/mL provides potentially clinically useful information. Here, we assess the ability to perform resistance testing by genotyping at LLV and whether it is predictive of future virologic outcomes in patients beginning ART. Resistance testing by genotyping at LLV was attempted on 4915 plasma samples from 2492 patients. A subset of previously ART-naive patients was analyzed who achieved undetectable pVL and subsequently rebounded with LLV (n = 212). A genotypic sensitivity score (GSS) was calculated based on therapy and resistance testing results by genotyping, and stratified according to number of active drugs. Eighty-eight percent of LLV resistance assays produced useable sequences, with higher success at higher pVL. Overall, 16 of 212 (8%) patients had pretherapy resistance. Thirty-eight of 196 (19%) patients without pretherapy resistance evolved resistance to 1 or more drug classes, primarily the nucleoside reverse transcriptase (14%) and/or nonnucleoside reverse transcriptase (9%) inhibitors. Patients with resistance at LLV (GSS <3) had a 2.1-fold higher risk of virologic failure (95% confidence interval, 1.2- to 3.7-fold) than those without resistance (P = .007). Progressively lower GSS scores at LLV were associated with a higher increase in pVL over time (P < .001). Acquisition of additional resistance mutations to a new class of antiretroviral drugs during LLV was not found in a subset of patients. Routine HIV-1 genotyping of LLV samples can be performed with a reasonably high success rate, and the results appear predictive of future virologic outcomes.

Discordance between genotypic resistance and pseudovirus phenotypic resistance in AIDS patients after long‐term antiretroviral therapy and virological failure

Sixteen original recombinant pseudoviruses were generated by cloning the reverse transcriptase and protease genes of human immunodeficiency virus (HIV)-1 from patients into a plasmid vector (pNL4-3-ΔE-EGFP). By site-directed mutagenesis two restriction endonuclease sites, ApaI and AgeI, were inserted into pNL4-3-ΔE-EGFP. Phenotypic susceptibility of recombinant pseudoviruses to five different classes of antiretroviral drugs was determined using a luciferase reporter assay system. The results were subjected to comparative analyses to detect genotype-phenotype associations. Among 16 strains tested, 12 strains had a discordant genotype-phenotype resistance pattern to at least one drug. In five strains resistance to two, in two strains to three, and in one strain resistance to four drugs was detected. HIV resistance genotyping could predict the phenotype for nevirapine and azidothymidine. For lamivudine, 2'-3'-didehydro-2'-3'dideoxythymidine and didanosine, phenotypic resistance testing was necessary. The study showed that in patients who experienced long-term highly active antiretroviral therapy and virological failure, there is some discordance between genotypic and phenotypic HIV drug resistance. To address the issue of limited resources in China, genotypic and phenotypic resistance testing should be done for different drugs in order to guide clinical therapy more effectively.

Metabolic syndrome, insulin resistance and the risk of cardiovascular disease in HIV patients undergoing antiretroviral therapy

We enrolled 103 patients, including 60 males (58.3%) and 43 females (41.7%). The mean age was 32.3±13.3 years (range: 13-65 years). The median Framingham score was 1.2% (IQR=5.8%). Most patients (81.63%) had a low CVR (below 10%) and 18.37% had Framingham score values above 10%. MS and IR prevalences were 16.9% and 61.2%, respectively. CVR in the general population is primarily dependent on age. This observation was valid for our group: the median age was 24 years in people with low CVR, compared with 50 years for those with Framingham score above 10% (p=0.000). None of the antiretroviral drug classes significantly influenced CVR.

Cognitive Decline in HIV/AIDS Linked to Lipid Disorder

Risk factors found in cerebrospinal fluid increase the likelihood that individuals with HIV disease will develop dementia or other neurocognitive disorders.

HIV-Associated Lipodystrophy: Impact of Antiretroviral Therapy

In the late 1990s, reports of unusual changes in body fat distribution named 'lipodystrophy' (LD) began to appear in HIV patients mitigating the enormous enthusiasm about improvement of survival and quality of life provided by the combinations of antiretroviral (ARV) drug classes, the so-called highly active antiretroviral therapy (HAART), which had just become available at that time. The objective of this paper is to critically review the literature on LD and to discuss the impact of newer ARV agents, namely atazanavir, darunavir and raltegravir, as well as strategies of the late HAART era, including single-tablet regimens and nucleoside-sparing regimens. Studies in which LD was measured by dual-energy x-ray absorptiometry or by abdominal computed tomography or magnetic resonance imaging scan only, were included. We were unable to identify studies depicting a negative impact of drugs or ARV regimens on limb fat loss. On the contrary, a few studies identified a negative impact of atazanavir/ritonavir or darunavir/ritonavir on trunk fat increase. It should be noted that this anthropometric measure is a poor instrument since it cannot distinguish between subcutaneous and visceral fat. We conclude that presumably the body fat changes currently observed in HIV-infected patients is the net result of competing phenomena: on one side the natural history of lipohypertrophy as a result of HIV and HAART impact, and on the other side the physiological body fat changes observed in the aging population.

Pharmacokinetic Study of Dual Therapy With Raltegravir 400 mg Twice Daily and Darunavir/Ritonavir 800/100 mg Once Daily in HIV-1–Infected Patients

Combinations of new classes of antiretroviral drugs are attractive options to avoid toxicity associated with nucleoside reverse transcriptase inhibitors (NRTIs) and to provide a full active regimen in patients with some degree of resistance to NRTIs. However, data on the pharmacokinetic (PK) profiles of these regimens are limited. We explore the plasma PK profile of raltegravir (RAL) at a dose of 400 mg twice a day plus darunavir/ritonavir (DRV/RTV) at a dose of 800/100 mg once a day in HIV-1-infected patients. This was a pilot, open-label, fixed-sequence, prospective, single-center single-arm PK study. The treating physician chose an NRTI-sparing regimen because of toxicity or resistance mutations to NRTIs, which included DRV/RTV 800/100 mg once daily plus RAL 400 mg twice daily. All patients were RAL and DRV naive and had no evidence of protease inhibitor mutations. After at least 15 days on therapy, patients were admitted for a 24-hour PK study. Laboratory tests to assess efficacy and safety were performed at all study visits. Fifteen patients were included. The geometric mean values for DRV were AUC0-24 68,730 ng·h·mL [95% confidence interval (CI): 58,970-86,480], Ctrough 1330 ng/mL (95% CI: 1110-1760; IC-50 for wild-type and resistant HIV-1 strains was 55 and 550 ng/mL, respectively), Cmax 7630 ng/mL (95% CI: 6740-9000), and t1/2 10.9 hours (95% CI: 9.20-13.99). Geometric mean values for RAL were AUC0-12 3050 ng·h·mL (95% CI: 2530-5180); Ctrough 40 ng/mL (95% CI: 30-80), Cmax 970 ng/mL (95% CI: 840-2270), t1/2 2.68 hours (95% CI: 1.97-4.40). No adverse effects including rash or laboratory test abnormalities were noted. At week 24, the HIV-1 viral load was below 37 copies/mL in all patients. Our data suggest that dual therapy with RAL 400 mg twice daily plus DRV/RTV 800/100 mg once daily had a favorable PK profile for both drugs and that short-term efficacy and tolerability of this combination were adequate.

Organic vapor sorption method of isostructural solvates and polymorph of tenofovir disoproxil fumarate

Tenofovir disoproxil fumarate (TDF) is a prodrug of tenofovir that belongs to a class of antiretroviral drugs, a nucleotide reverse transcriptase inhibitor. An acetonitrile solvate of TDF I, another new solvated form of TDF, was prepared and solid state characterization of its form was conducted using powder X-ray diffraction, FT-IR spectroscopy, and organic vapor sorption isotherm. During the characterization work, it was discovered that (1) TDF I can form solvates and polymorph with a wide variety of organic solvents as well as water and (2) to different extents, these solvates undergoes anisotropic lattice contraction/expansion during desolvation/solvation process suggesting the formation of isostructural solvates of TDF. Solvents used in this study include ethanol, isopropyl alcohol, acetonitrile, cyclohexane, toluene, and water. Four new solvates using ethanol, isopropyl alcohol, acetonitrile, and toluene vapor and one polymorph using water vapor were discovered. Their solid state characterizations were conducted using powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and Fourier transform infrared spectroscopy. A variety of isostructural solvates and a polymorph of TDF was produced by an organic vapor sorption method, showing varying physicochemical properties. This study demonstrates an alternative crystallization method to obtain isostructural solvates.

Dolutegravir versus raltegravir in antiretroviral-experienced, integrase-inhibitor-naive adults with HIV: week 48 results from the randomised, double-blind, non-inferiority SAILING study

Dolutegravir (GSK1349572), a once-daily HIV integrase inhibitor, has shown potent antiviral response and a favourable safety profile. We evaluated safety, efficacy, and emergent resistance in antiretroviral-experienced, integrase-inhibitor-naive adults with HIV-1 with at least two-class drug resistance. ING111762 (SAILING) is a 48 week, phase 3, randomised, double-blind, active-controlled, non-inferiority study that began in October, 2010. Eligible patients had two consecutive plasma HIV-1 RNA assessments of 400 copies per mL or higher (unless >1000 copies per mL at screening), resistance to two or more classes of antiretroviral drugs, and had one to two fully active drugs for background therapy. Participants were randomly assigned (1:1) to once-daily dolutegravir 50 mg or twice-daily raltegravir 400 mg, with investigator-selected background therapy. Matching placebo was given, and study sites were masked to treatment assignment. The primary endpoint was the proportion of patients with plasma HIV-1 RNA less than 50 copies per mL at week 48, evaluated in all participants randomly assigned to treatment groups who received at least one dose of study drug, excluding participants at one site with violations of good clinical practice. Non-inferiority was prespecified with a 12% margin; if non-inferiority was established, then superiority would be tested per a prespecified sequential testing procedure. A key prespecified secondary endpoint was the proportion of patients with treatment-emergent integrase-inhibitor resistance. The trial is registered at ClinicalTrials.gov, NCT01231516. Analysis included 715 patients (354 dolutegravir; 361 raltegravir). At week 48, 251 (71%) patients on dolutegravir had HIV-1 RNA less than 50 copies per mL versus 230 (64%) patients on raltegravir (adjusted difference 7·4%, 95% CI 0·7 to 14·2); superiority of dolutegravir versus raltegravir was then concluded (p=0·03). Significantly fewer patients had virological failure with treatment-emergent integrase-inhibitor resistance on dolutegravir (four vs 17 patients; adjusted difference -3·7%, 95% CI -6·1 to -1·2; p=0·003). Adverse event frequencies were similar across groups; the most commonly reported events for dolutegravir versus raltegravir were diarrhoea (71 [20%] vs 64 [18%] patients), upper respiratory tract infection (38 [11%] vs 29 [8%]), and headache (33 [9%] vs 31 [9%]). Safety events leading to discontinuation were infrequent in both groups (nine [3%] dolutegravir, 14 [4%] raltegravir). Once-daily dolutegravir, in combination with up to two other antiretroviral drugs, is well tolerated with greater virological effect compared with twice-daily raltegravir in this treatment-experienced patient group. ViiV Healthcare.

Abacavir-based triple nucleoside regimens for maintenance therapy in patients with HIV.

Regimen simplification can be defined as a change in established effective therapy to reduce pill burden and dosing frequency, to enhance tolerability, or to decrease specific food and fluid requirements. Many patients on suppressive antiretroviral therapy may be considered candidates for a simplification strategy and, among them, those who have achievedvirologic suppression. Several clinical trials have evaluated the efficacy of triple nucleoside combination as a simplification therapy in patients who achieved virologic suppression The aim of this review is to combine randomised, controlled trials to examine whether in patients with undetectable viraemia on a Protease inhibitor (PI) based regimen simplification treatment with abacavir (ABC)-based triple-nucleoside combinations has similar rates of efficacy and tolerability compared with a PI regimen or simplification with a NNRTIs (efavirenz-EFV- or nevirapine-NVP) containing regimen. Studies were included if they had at least two of the three interventions, including one 3NRTI arm. Electronic databases and conference proceedings were searched (1996-2012) with relevant search terms without limits to language. Randomised controlled trials (RCTs) only are included in this review. Patients population is represented by HIV-infected adult patients treated with a PI-containing regimen (PI or boosted PI), with undetectable viral load. Patients on a PI-containing regimen had three possibilities: continue the PI regimen or switch to a simplification maintenance regimen, including switch to a NNRTI (EFV or NVP) containing regimen, or switch to a triple-NRTI regimen (ABC-zidovudine-lamivudine) The primary outcomes were: proportion of patients discontinuing or switching antiretroviral therapy due to virologic failure or to adverse events; death (all cause) and AIDS defining illness; occurrence of myocardial infarction and cardiovascular disease. Secondary outcomes were: proportion of patients maintaining an undetectable viral load (e.g. HIV-RNA <50 or <400 copies/mm(3)); change in mean CD4+ cell count; occurrence of lipodystrophy. We applied Cochrane Collaboration tools to assess each individual study for risk for bias. We included eight RCT, for a total of 1,610 patients. All the studies included HIV-1 infected patients virologically suppressed after a successful treatment with PI containing ART. Articles included in the analysis were published between 2001 and 2010, and could be classified as low risk of bias trials in most of the domains considered. Overall, there was no significant difference between the participants on triple nucleoside combination and controls, either PI-based or NNRTI based in terms of overall failures, death and AIDS related events, and rates of patients with viral load below the detectability cut-off. For the outcomes discontinuation for adverse events and virologic failures, the RRs were not significant , albeit being not far from the alpha level of 0.05, thus suggesting a weak evidence of lower incidence of side effects and an higher incidence of virologic failure in the 3NRTI group compared to controls . Change in lipids and in CD4 cells from baselines were reported in 7 studies, but inconsistency in reporting these data did not allow quantitative analysis. However, all agreed that simplification with ABC had a favourable and significant impact on lipid metabolism compared to control group. An increase in CD4 cells count from baseline was evident in all analysed studies, without significant differences between ABC and controls in individual studies. The strategy of switching to triple nucleoside regimens shows weak evidence of lower incidence of side effects and a higher incidence of virologic failure in the 3NRTI group compared to controls. Simplification with 3NRTI holds the advantages of preserving other classes of antiretroviral drugs, to lower blood lipids, and to be cost effective and simple to administer.Thus, simplification with triple nucleoside regimens AZT + 3TC + ABC should be still considered for individuals who are unable to tolerate or have contraindications to NNRTI or PI based regimens. Additional data are needed on longer-term efficacy of triple NRTI regimens, particularly on the development of antiretroviral resistance. Though studies in the current review were conducted between 2001 and 2010, the largemajority of patients from studies analysed received oldPI regimens (e.g., indinavir, ritonavir, nelfinavir, saquinavir) not longer recommended by International Guidelines. Since current guidelines recommend new "lipid -friendly" PI, future studies should compare regimens containing these news PIs to triple NRTI regimens. More realistically, however, there are opportunities to examine these issues in existing cohorts.

Antiretroviral treatments in 2012: improvements and future prospects.

Chances of one-year survival to AIDS were only 41% in 1981. The availability of AZT in 1987 and mostly of the protease inhibitors in 1996 dramatically reduced the rate of deaths due to HIV. In 2013, six antiretroviral drug classes are available including more than 20 compounds. However, therapeutic progresses are still needed to improve tolerance and simplicity and also to evaluate new strategies, in particular for treatment simplification. In certain groups at risk, antiretroviral therapy as tool of prevention of transmission (Treatment as Prevention) now represents a treatment indication, beyond the individual benefit. In resource-limited countries, despite important progress obtained in access to antiretrovirals with a 30-fold increase since 2003 in the number of antiretroviral-treated patients, some issues prevent an optimised monitoring. Finally, cure is still an objective out of reach with current antiretroviral drugs that are limited to the inhibition of virus replication.

Explaining the Determinants of First Phase HIV Decay Dynamics through the Effects of Stage-dependent Drug Action

A recent investigation of the effect of different antiretroviral drug classes on first phase dynamics of HIV RNA plasma virus levels has indicated that drugs acting at stages closer to viral production, such as the integrase inhibitor raltegravir, can produce a steeper first phase decay slope that may not be due to drug efficacy. Moreover it was found that for most drug classes the first phase transitions from a faster (phase IA) to a slightly slower decay region (phase IB) before the start of the usual second phase. Neither of these effects has been explained to date. We use a mathematical model that incorporates the different stages of the HIV viral life cycle in CD4+ T cells: viral entry, reverse transcription, integration, and viral production, to investigate the intracellular HIV mechanisms responsible for these complex plasma virus decay dynamics. We find differences in the phase IA slope across drug classes arise from a higher death rate of cells when they enter the productively infected stage post-integration, with a half-life of approximately 8 hours in this stage, whereas cells in earlier stages of the infection cycle have half-lives similar to uninfected cells. This implies any immune clearance is predominantly limited to the productive infection stage. We also show that the slowing of phase IA to phase IB at day 2 to 4 of monotherapy, depending on drug class, is a result of new rounds of infection. The level at which this slowing occurs is a better indicator of drug efficacy than the slope of the initial decay.