Plasma Concentrations of Rosmarinic Acid in Patients on Antiretroviral Therapy: In Silico Exploration Based on Clinical Data.

Rosmarinic acid (RA) is a phenolic compound with antiviral properties, often encountered in dietary supplements and herbal drugs. Data on the pharmacokinetics of RA are lacking in cases of the chronic use of supplements containing this compound, and only limited data on the metabolism and distribution of RA are available. The aim of the study was to investigate the plasma levels of RA after 12 weeks of use and determine potential interactions of RA and selected antiretroviral drugs. Patients infected with human immunodeficiency virus took a supplement containing RA for 12 weeks, after which the RA concentrations in the plasma samples were analyzed. A detailed in silico analysis was conducted in order to elucidate the potential interactions between RA and the drugs efavirenz, darunavir and raltegravir. It was found that RA can be detected in patients' plasma samples, mainly in the form of sulphoglucuronide. The potential interactions are suggested on the level of liver metabolizing enzymes and efflux P-glycoprotein, with RA competing with antiretroviral drugs as a substrate in metabolism and distribution systems. The present study suggests that the simultaneous use of RA and antiretroviral therapy (containing efavirenz, darunavir or raltegravir) may affect the plasma levels of RA after prolonged supplementation.

PRESTIGIO RING: "A 59-year-old HIV-1 positive, highly treatment-experienced woman failing darunavir/ ritonavir plus raltegravir".

Management of heavily treatment experienced (HTE) people with HIV remains a challenge. Tailored antiretroviral therapy (ART) is needed in this fragile population who almost invariably harbor viral quasispecies with resistance-associated mutations (RAMs). The reference method for HIV genotypic resistance testing (GRT) has long been Sanger sequencing (SS), but next-generation sequencing (NGS), following recent progress in workflow and cost-effectiveness, is replacing SS because of higher sensitivity. From the PRESTIGIO Registry, we present a case of a 59-year-old HTE woman who failed darunavir/ritonavir plus raltegravir at low-viremia levels due mainly to high pill burden and poor adherence. NGS-GRT was performed on HIV-RNA at failure and the results were compared to all past SS-GRT data available (historical genotype). In this case, NGS-GRT did not detect any minority drug-resistant variants. After discussing several therapeutic options, the treatment was changed to dolutegravir 50 mg twice daily plus doravirine 100 mg once a day, based on clinical history, adherence issues, and pill burden, as well as the historical SS-GRT and the latest NGS-GRT results. At six months follow-up visit, the patient had HIV-RNA below 30 copies/ml and CD4+ T cell count increased from 673 cells/ mm3 to 688 cells/ mm3. Close follow-up of this patient is ongoing.

Spectrum of Activity of Raltegravir and Dolutegravir Against Novel Treatment-Associated Mutations in HIV-2 Integrase: A Phenotypic Analysis Using an Expanded Panel of Site-Directed Mutants.

BACKGROUND: Integrase inhibitors (INIs) are a key component of antiretroviral therapy for human immunodeficiency virus-1 (HIV-1) and HIV-2 infection. Although INI resistance pathways are well-defined for HIV-1, mutations that emerge in HIV-2 in response to INIs are incompletely characterized. METHODS: We performed systematic searches of GenBank and HIV-2 drug resistance literature to identify treatment-associated mutations for phenotypic evaluation. We then constructed a library of 95 mutants of HIV-2ROD9 that contained single or multiple amino acid changes in the integrase protein. Each variant was tested for susceptibility to raltegravir and dolutegravir using a single-cycle indicator cell assay. RESULTS: We observed extensive cross-resistance between raltegravir and dolutegravir in HIV-2ROD9. HIV-2-specific integrase mutations Q91R, E92A, A153G, and H157Q/S, which have not been previously characterized, significantly increased the half maximum effective concentration (EC50) for raltegravir when introduced into 1 or more mutational backgrounds; mutations E92A/Q, T97A, and G140A/S conferred similar enhancements of dolutegravir resistance. HIV-2ROD9 variants encoding G118R alone, or insertions of residues SREGK or SREGR at position 231, were resistant to both INIs. CONCLUSIONS: Our analysis demonstrates the contributions of novel INI-associated mutations to raltegravir and dolutegravir resistance in HIV-2. These findings should help to improve algorithms for genotypic drug resistance testing in HIV-2-infected individuals.

A clinical review of HIV integrase strand transfer inhibitors (INSTIs) for the prevention and treatment of HIV-1 infection.

Integrase strand transfer inhibitors (INSTIs) have improved the treatment of human immunodeficiency virus (HIV). There are currently four approved for use in treatment-naïve individuals living with HIV; these include first generation raltegravir, elvitegravir, and second generation dolutegravir and bictegravir. The most recent INSTI, cabotegravir, is approved for (1) treatment of HIV infection in adults to replace current antiretroviral therapy in individuals who maintain virologic suppression on a stable antiretroviral regimen without history of treatment failure and no known resistance to its components and (2) pre-exposure prophylaxis in individuals at risk of acquiring HIV-1 infection. Cabotegravir can be administered intramuscularly as a monthly or bi-monthly injection depending on the indication. This long-acting combination has been associated with treatment satisfaction in clinical studies and may be helpful for individuals who have difficulty taking daily oral medications. Worldwide, second generation INSTIs are preferred for treatment-naïve individuals. Advantages of these INSTIs include their high genetic barrier to resistance, limited drug-drug interactions, excellent rates of virologic suppression, and favorable tolerability. Few INSTI resistance-associated mutations have been reported in clinical trials involving dolutegravir, bictegravir and cabotegravir. Other advantages of specific INSTIs include their use in various populations such as infants and children, acute HIV infection, and individuals of childbearing potential. The most common adverse events observed in clinical studies involving INSTIs included diarrhea, nausea, insomnia, fatigue, and headache, with very low rates of treatment discontinuation versus comparator groups. The long-term clinical implications of weight gain associated with second generation INSTIs dolutegravir and bictegravir warrants further study. This review summarizes key clinical considerations of INSTIs in terms of clinical pharmacology, drug-drug interactions, resistance, and provides perspective on clinical decision-making. Additionally, we summarize major clinical trials evaluating the efficacy and safety of INSTIs in treatment-naïve patients living with HIV as well as individuals at risk of acquiring HIV infection.

Effectiveness of integrase strand transfer inhibitors in HIV-infected treatment-experienced individuals across Europe.

OBJECTIVES: To explore the effectiveness and durability of integrase strand transfer inhibitor (INSTI)-based regimens in pre-treated subjects. METHODS: Treatment-experienced individuals starting an INSTI-based regimen during 2012-2019 were selected from the INTEGRATE collaborative study. The time to virological failure [VF: one measurement of viral load (VL) ≥ 1000 copies/mL or two ≥ 50 copies/ml or one VL measurement ≥ 50 copies/mL followed by treatment change] and to INSTI discontinuation were evaluated. RESULTS: Of 13 560 treatments analysed, 4284 were from INSTI-naïve, non-viraemic (IN-NV) individuals, 1465 were from INSTI-naïve, viraemic (IN-V) individuals, 6016 were from INSTI-experienced, non-viraemic (IE-NV) individuals and 1795 were from INSTI-experienced, viraemic (IE-V) individuals. Major INSTI drug resistance mutations (DRMs) were previously detected in 4/519 (0.8%) IN-NV, 3/394 (0.8%) IN-V, 7/1510 (0.5%) IE-NV and 25/935 (2.7%) IE-V individuals. The 1-year estimated probabilities of VF were 3.1% [95% confidence interval (CI): 2.5-3.8] in IN-NV, 18.4% (95% CI: 15.8-21.2) in IN-V, 4.2% (95% CI: 3.6-4.9) in IE-NV and 23.9% (95% CI: 20.9-26.9) in IE-V subjects. The 1-year estimated probabilities of INSTI discontinuation were 12.1% (95% CI: 11.1-13.0) in IN-NV, 19.6% (95% CI: 17.5-21.6) in IN-V, 10.8% (95% CI: 10.0-11.6) in IE-NV and 21.7% (95% CI: 19.7-23.5) in IE-V subjects. CONCLUSIONS: Both VF and INSTI discontinuation occur at substantial rates in viraemic subjects. Detection of DRMs in a proportion of INSTI-experienced individuals makes INSTI resistance testing mandatory after failure.

Raltegravir 1200 mg once daily as maintenance therapy in virologically suppressed HIV-1 infected adults: QDISS open-label trial.

BACKGROUND: Raltegravir (RAL) has favorable tolerability and safety profile, with few and manageable drug interactions. The use of RAL 1200 mg once daily (qd) for first-line therapy is well established. We assessed efficacy and safety of RAL 1200 mg qd, as part of triple combined antiretroviral therapy (cART), for maintenance strategy. METHODS: The QDISS trial (NCT03195452) was a 48-week multicenter, single-arm, open-label study designed to evaluate the ability of 2 NRTIs + RAL 1200 mg qd to maintain virological suppression in HIV-1 infected subjects on a stable cART with 2 NRTIs and a third agent for at least 6 months. The primary endpoint was the proportion of participants with HIV-1 RNA < 50 copies/mL at week 24, by the FDA snapshot algorithm. RESULTS: Of 100 participants 91% maintained viral suppression (95% CI: 83.6-95.8) at week 24 and 89% (81.2-94.4) at week 48. At week 24, there was one virological failure, without emergence of resistance-associated mutation and 10 participants had discontinued, 4 because of adverse events (AEs). Over 48 weeks, 7 AEs of grade 3-4 were reported, one possibly study-drug related (spontaneous abortion). BMI remained stable regardless of previous therapy or baseline BMI category. Over 48 weeks, total cholesterol (p = 0.023) and LDL-cholesterol (p = 0.009) decreased, lifestyle and ease subscale significantly improved (p = 0.04). The quality of life and Patients Reported Outcomes (PROs) also improved at W12 (p = 0.007). CONCLUSION: RAL 1200 mg qd as part of a maintenance triple therapy showed a high efficacy in virologically suppressed HIV-1 infected subjects, with good safety profile and improved lipid profile and patient reported outcomes. TRIAL REGISTRATION: Clinical trials.gov NCT03195452 and EudraCT 2016-003702-13.

Transmitted drug resistance to NRTIs and risk of virological failure in naïve patients treated with integrase inhibitors.

OBJECTIVES: Nucleoside reverse transcriptase inhibitor (NRTI) transmitted drug resistance mutations (TDRMs) could increase the risk of virological failure (VF) of first-line integrase strand transfer inhibitor (InSTI)-based regimens. METHODS: Patients starting two NRTIs (lamivudine/emtricitabine plus abacavir/tenofovir) plus raltegravir or dolutegravir were selected from the EuResist cohort. The role of NRTI genotypic susceptibility score and of specific TDRMs in VF (i.e. two consecutive viral loads > 50 HIV-1 RNA copies/mL or a single viral load ≥ 200 copies/mL after 3 months from antiretroviral therapy start) was evaluated in the overall population and according to the InSTI employed. RESULTS: From 2008 to 2017, 1095 patients were eligible for the analysis (55.5% men, median age 39 years). In all, 207 VFs occurred over 1023 patient-years of follow-up. The genotypic susceptibility score (GSS) had no effect on the risk of VF in the overall population. However, the presence of M184V/I independently predicted VF of raltegravir- but not dolutegravir-based therapy when compared with a fully-active backbone [adjusted hazard ratio (aHR) = 3.09, P = 0.035], particularly when associated with other non-thymidine analogue mutations (aHR = 27.62, P = 0.004). Higher-zenith HIV-RNA and lower nadir CD4 counts independently predicted VF. CONCLUSIONS: NRTI backbone TDRMs increased the risk of VF with raltegravir-based but not dolutegravir-based regimens.

Integrase inhibitors versus efavirenz combination antiretroviral therapies for TB/HIV coinfection: a meta-analysis of randomized controlled trials.

BACKGROUND: Integrase inhibitors (INIs)-based antiretroviral therapies (ART) are more recommended than efavirenz (EFV)-based ART for people living with HIV/AIDS (PLWHA). Yet, the advantage of integrase inhibitors in treating TB/HIV coinfection is uncertain. Therefore, the objective of this systematic review is to evaluate the effects and safety of INIs- versus EFV-based ART in TB/HIV coinfection, and demonstrate the feasibility of the regimens. METHODS: Four electronic databases were systematically searched through September 2020. Fixed-effects models were used to calculate pooled effect size for all outcomes. The primary outcomes were virologic suppression and bacteriology suppression for INIs- versus EFV-based ART. Secondary outcomes included CD4+ cell counts change from baseline, adherence and safety. RESULTS: Three trials (including 672 TB/HIV patients) were eligible. ART combining INIs and EFV had similar effects for all outcomes, with none of the point estimates argued against the INIs-based ART on TB/HIV patients. Compared to EFV-based ART as the reference group, the RR was 0.94 (95% CI 0.85 to 1.05) for virologic suppression, 1.00 (95% CI 0.95 to 1.05) for bacteriology suppression, 0.98 (95% CI 0.95 to 1.01) for adherence. The mean difference in CD4+ cell counts increase between the two groups was 14.23 cells/µl (95% CI 0- 6.40 to 34.86). With regard to safety (adverse events, drug-related adverse events, discontinuation for drugs, grade 3-4 adverse events, IRIS (grade 3-4), and death), INIs-based regimen was broadly similar to EFV-based regimens. The analytical results in all sub-analyses of raltegravir- (RAL) and dolutegravir (DTG) -based ART were valid. CONCLUSION: This meta-analysis demonstrates similar efficacy and safety of INIs-based ART compared with EFV-based ART. This finding supports INIs-based ART as a first-line treatment in TB/HIV patients. The conclusions presented here still await further validation owing to insufficient data.

When special populations intersect with drug-drug interactions: Application of physiologically-based pharmacokinetic modeling in pregnant populations.

Pregnancy results in significant physiological changes that vary across trimesters and into the postpartum period, and may result in altered disposition of endogenous substances and drug pharmacokinetics. Pregnancy represents a unique special population where physiologically-based pharmacokinetic modeling (PBPK) is well suited to mechanistically explore pharmacokinetics and dosing paradigms without subjecting pregnant women or their fetuses to extensive clinical studies. A critical review of applications of pregnancy PBPK models (pPBPK) was conducted to understand its current status for prediction of drug exposure in pregnant populations and to identify areas of further expansion. Evaluation of existing pPBPK modeling efforts highlighted improved understanding of cytochrome P450 (CYP)-mediated changes during pregnancy and identified knowledge gaps for non-CYP enzymes and the physiological changes of the postpartum period. Examples of the application of pPBPK beyond simple dose regimen recommendations are limited, particularly for prediction of drug-drug interactions (DDI) or differences between genotypes for polymorphic drug metabolizing enzymes. A raltegravir pPBPK model implementing UGT1A1 induction during the second and third trimesters of pregnancy was developed in the current work and verified against clinical data. Subsequently, the model was used to explore UGT1A1-related DDI risk with atazanavir and rifampicin along with the effect of enzyme genotype on raltegravir apparent clearance. Simulations of pregnancy-related induction of UGT1A1 either exacerbated UGT1A1 induction by rifampicin or negated atazanavir UGT1A1 inhibition. This example illustrated the advantages of pPBPK modeling for mechanistic evaluation of complex interplays of pregnancy- and drug-related effects in support of model-informed approaches in drug development.

Identification of Influenza PAN Endonuclease Inhibitors via 3D-QSAR Modeling and Docking-Based Virtual Screening.

Structural and biochemical studies elucidate that PAN may contribute to the host protein shutdown observed during influenza A infection. Thus, inhibition of the endonuclease activity of viral RdRP is an attractive approach for novel antiviral therapy. In order to envisage structurally diverse novel compounds with better efficacy as PAN endonuclease inhibitors, a ligand-based-pharmacophore model was developed using 3D-QSAR pharmacophore generation (HypoGen algorithm) methodology in Discovery Studio. As the training set, 25 compounds were taken to generate a significant pharmacophore model. The selected pharmacophore Hypo1 was further validated by 12 compounds in the test set and was used as a query model for further screening of 1916 compounds containing 71 HIV-1 integrase inhibitors, 37 antibacterial inhibitors, 131 antiviral inhibitors and other 1677 approved drugs by the FDA. Then, six compounds (Hit01-Hit06) with estimated activity values less than 10 µM were subjected to ADMET study and toxicity assessment. Only one potential inhibitory 'hit' molecule (Hit01, raltegravir's derivative) was further scrutinized by molecular docking analysis on the active site of PAN endonuclease (PDB ID: 6E6W). Hit01 was utilized for designing novel potential PAN endonuclease inhibitors through lead optimization, and then compounds were screened by pharmacophore Hypo1 and docking studies. Six raltegravir's derivatives with significant estimated activity values and docking scores were obtained. Further, these results certainly do not confirm or indicate the seven compounds (Hit01, Hit07, Hit08, Hit09, Hit10, Hit11 and Hit12) have antiviral activity, and extensive wet-laboratory experimentation is needed to transmute these compounds into clinical drugs.

Effect of Pregnancy on Unbound Raltegravir Concentrations in the ANRS 160 RalFe Trial.

A population pharmacokinetic model was developed to explore the pharmacokinetics modification of unbound raltegravir during pregnancy. The RalFe ANRS160 study was a nonrandomized, open-label, multicenter trial enrolling HIV-infected pregnant women receiving a combined antiretroviral regimen containing 400 mg raltegravir twice daily. Biological samples were collected during the third trimester of pregnancy (between 30 and 37 weeks of gestational age) and at postpartum (4 to 6 weeks after delivery). A population pharmacokinetic model was developed with Monolix software. A total of 360 plasma samples were collected from 43 women during pregnancy and postpartum. The unbound raltegravir was described by a one-compartment model with a transit compartment with first-order absorption, evolving to bound raltegravir (by a linear binding to albumin) or metabolism to RAL-glucuronide or to a first-order elimination, with a circadian rhythm. During pregnancy, the absorption was decreased and delayed and the raltegravir elimination clearance and glucuronidation increased by 37%. Median total and unbound area under the curve from 0 to 12 h significantly decreased by 36% and 27% during pregnancy. Median total trough concentration (Ctrough) decreased significantly in the evening (28%); however, the median total Ctrough in the morning, unbound Ctrough in the morning, and unbound Ctrough in the evening showed a nonsignificant decrease of 16%, 1%, and 15%, respectively, during pregnancy compared to the postpartum period. This is the first study reporting the pharmacokinetics of unbound raltegravir during pregnancy. As unbound Ctrough did not significantly decrease during the third trimester, the pregnancy effect on raltegravir unbound concentrations was not considered clinically relevant. (This study has been registered at ClinicalTrials.gov under identifier NCT02099474.).

Efficacy of Three Antiretroviral Regimens Initiated during Pregnancy: Clinical Experience in Rio de Janeiro.

Few studies have compared the clinical efficacy and adverse events of combined antiretroviral therapy (cART) regimens in pregnant women seeking obstetrical care. The objective of this study was to compare the efficacy (virus load response), adverse events, and obstetrical and neonatal outcomes of three different regimens of cART in HIV-infected pregnant women initiating treatment in Rio de Janeiro, Brazil. This was a retrospective cohort study of cART-naive pregnant women who initiated either ritonavir-boosted protease inhibitors (atazanavir or lopinavir), efavirenz, or raltegravir plus a backbone regimen. From 2014 to 2018, 390 pregnant women were followed over time. At baseline, the median viral load (VL) for HIV was 4.1 log copies/ml. Among participants who received cART for 2 to 7 weeks, the VL decline was greater for raltegravir (2.24 log copies/ml) than for efavirenz or protease inhibitors (P < 0.001). Virologic suppression was achieved in 87% of women on raltegravir near delivery versus 73% on efavirenz and 70% on protease inhibitors (P = 0.011). Patients on raltegravir achieved virologic suppression faster than those on other regimens (P = 0.019). Overall, the HIV perinatal infection rate was 1.5%. This clinical study compared three potent and well-tolerated cART regimens and demonstrated that a higher proportion of participants on raltegravir achieved an undetectable HIV VL near delivery (P = 0.011) compared to the other arms. These findings suggest that raltegravir-containing regimens are optimal regimens for women with HIV initiating treatment late in pregnancy.

Weight gain in antiretroviral therapy-naive HIV-1-infected patients starting a regimen including an integrase strand transfer inhibitor or darunavir/ritonavir.

BACKGROUND: Weight gain after initiation of combination antiretroviral therapy (cART) is a possible side effect of all antiretroviral regimens, but it seems to be more evident in association with integrase strand transfer inhibitors (INSTIs). So, we aimed to evaluate weight change associated with an initial cART including one INSTI or darunavir-ritonavir (DRV/r). METHODS: A retrospective, observational, cohort study of antiretroviral therapy-naive adult HIV-positive patients starting an initial cART including raltegravir (RAL), dolutegravir (DTG), elvitegravir-cobicistat (EVG), or DRV/r. We compared changes in weight and body mass index (BMI) across the four groups during a 12-month follow-up. RESULTS: As a whole, 680 patients (470 males, mean age 42.1 years) were enrolled: 196 starting RAL, 174 DTG, 158 EVG/c, and 152 DRV/r. Baseline mean CD4 lymphocyte count was 455 cells/mm3 and 7.3% had an AIDS diagnosis. After 12 months, mean increase in body weight was 1.93 kg in the RAL group, 2.38 kg in the DTG group, 2.14 kg in the EVG group, and 1.85 in the DRV/r group. Mean increase in BMI was 0.71, 0.84, 0.77 and 0.63 kg/m2, respectively (p > 0.05 for each comparison). Therefore, no significant increases in weight and BMI were reported in each group, and no significant differences in weight and BMI changes were described across the four treatment groups. CONCLUSIONS: In our study, patients starting an initial cART including one INSTI or DRV/r after 12 months showed a small and comparable, but not significant, increase in body weight, whose long-term clinical consequences are unknown.

HIV-1 acquired drug resistance to integrase inhibitors in a cohort of antiretroviral therapy multi-experienced Mexican patients failing to raltegravir: a cross-sectional study.

BACKGROUND: In resource-limited settings, multi-experienced HIV infected patients are often prescribed raltegravir for salvage therapy. Patients failing raltegravir-containing regimens require other drugs including other integrase inhibitors. In this context, real-life data about the resistance and cross-resistance pathways between integrase inhibitors is limited. The aim of this study was to investigate integrase resistance pathways in a cohort of Mexican multi-experienced patients failing of a raltegravir-containing salvage regimen. METHODS: Twenty-five plasma samples from subjects failing antiretroviral regimens which included raltegravir were obtained from various healthcare centres from 2009 to 2017 in Mexico. Antiretroviral history and demographics were collected. Samples were processed for integrase resistance genotyping testing by sequencing. The viral sequences were analysed with the Stanford HIV drug resistance database algorithm. Data was analysed with SPSS Statistics software. RESULTS: We found a mean viral load of 4.17 log10 c/mL (SD 1.11) at the time of virologic failure. Forty-eight percent of the samples were raltegravir resistant. The Y143R/H/C substitutions were the most prevalent, followed by the N155H, and both Q148H/K and G140S/A in the same proportion. The Q148 + G140 combination was found in (12%) of the samples. Cross-resistance to elvitegravir was found in 83.3% and in 18.2% for both dolutegravir and bictegravir. Thirteen samples (52%) were susceptible to the four integrase strand-transfer inhibitors. CONCLUSIONS: Our findings suggest a high occurrence of resistance and cross-resistance to other integrase inhibitors among multi-experienced subjects failing raltegravir. We found a modestly lower proportion of cross-resistance to dolutegravir than data from clinical trials. Likely this drug could be used for salvage therapy. Explanations for the absence of mutations in half of the samples, other than reduced adherence, should be further investigated. Close surveillance is needed.

The HIV Integrase Inhibitor Raltegravir Inhibits Felid Alphaherpesvirus 1 Replication by Targeting both DNA Replication and Late Gene Expression.

Alphaherpesvirus-associated ocular infections in humans caused by human alphaherpesvirus 1 (HHV-1) remain challenging to treat due to the frequency of drug application required and the potential for the selection of drug-resistant viruses. Repurposing on-the-market drugs is a viable strategy to accelerate the pace of drug development. It has been reported that the human immunodeficiency virus (HIV) integrase inhibitor raltegravir inhibits HHV-1 replication by targeting the DNA polymerase accessory factor and limits terminase-mediated genome cleavage of human betaherpesvirus 5 (HHV-5). We have previously shown, both in vitro and in vivo, that raltegravir can also inhibit the replication of felid alphaherpesvirus 1 (FeHV-1), a common ocular pathogen of cats with a pathogenesis similar to that of HHV-1 ocular disease. In contrast to what was reported for HHV-1, we were unable to select for a raltegravir-resistant FeHV-1 strain in order to define any basis for drug action. A candidate-based approach to explore the mode of action of raltegravir against FeHV-1 showed that raltegravir did not impact FeHV-1 terminase function, as described for HHV-5. Instead, raltegravir inhibited DNA replication, similarly to HHV-1, but by targeting the initiation of viral DNA replication rather than elongation. In addition, we found that raltegravir specifically repressed late gene expression independently of DNA replication, and both activities are consistent with inhibition of ICP8. Taken together, these results suggest that raltegravir could be a valuable therapeutic agent against herpesviruses.IMPORTANCE The rise of drug-resistant herpesviruses is a longstanding concern, particularly among immunocompromised patients. Therefore, therapies targeting viral proteins other than the DNA polymerase that may be less likely to lead to drug-resistant viruses are urgently needed. Using FeHV-1, an alphaherpesvirus closely related to HHV-1 that similarly causes ocular herpes in its natural host, we found that the HIV integrase inhibitor raltegravir targets different stages of the virus life cycle beyond DNA replication and that it does so without developing drug resistance under the conditions tested. This shows that the drug could provide a viable strategy for the treatment of herpesvirus infections.

Dynamics of Simian Immunodeficiency Virus Two-Long-Terminal-Repeat Circles in the Presence and Absence of CD8+ Cells.

CD8+ cells play a key role in human immunodeficiency virus (HIV)/simian immunodeficiency virus (SIV) infection, but their specific mechanism(s) of action in controlling the virus is unclear. Two-long-terminal-repeat (2-LTR) circles are extrachromosomal products generated upon failed integration of HIV/SIV. To understand the specific effects of CD8+ cells on infected cells, we analyzed the dynamics of 2-LTR circles in SIVmac251-infected rhesus macaques (RMs) treated with an integrase inhibitor (INT). Twenty RMs underwent CD8+ cell depletion and received raltegravir (RAL) monotherapy or a combination of both. Blood, lymph nodes (LNs), and gut biopsy specimens were routinely sampled. Plasma viral loads (pVLs) and 2-LTR circles from peripheral blood mononuclear cells (PBMCs) and LN lymphocytes were measured with quantitative reverse transcription-PCR (qRT-PCR). In the CD8 depletion group, an ∼1-log increase in pVLs and a slow increase in PBMC 2-LTRs occurred following depletion. In the INT group, a strong decline in pVLs upon treatment initiation and no change in 2-LTR levels were observed. In the INT and CD8+ cell depletion group, an increase in pVLs following CD8 depletion similar to that in the CD8 depletion group was observed, with a modest decline following INT initiation, and 2-LTR circles significantly increased in PBMCs and LNs. Analyzing the 2-LTR data across all treatment groups with a mathematical model indicates that the data best support an effect of CD8+ cells in killing cells prior to viral integration. Sensitivity analyses of these results confirm that effect but also allow for additional effects, which the data do not discriminate well. Overall, we show that INT does not significantly increase the levels of 2-LTR circles. However, CD8+ cell depletion increases the 2-LTR levels, which are enhanced in the presence of an INT.IMPORTANCE CD8+ T cells play an essential role in controlling HIV and SIV infection, but the specific mechanisms involved remain poorly understood. Due to failed viral infection, HIV and SIV can form 2-LTR extrachromosomal circles that can be quantified. We present novel data on the dynamics of these 2-LTR forms in a SIV-infected macaque model under three different treatment conditions: depletion of CD8+ cells, administration of the integrase inhibitor in a monotherapy, which favors the formation of 2-LTR circles, and a combination of the two treatments. We used a new mathematical model to help interpret the data, and the results suggest that CD8+ cells exert a killing effect on infected cells prior to virus integration. These results provide new insights into the mechanisms of action of CD8+ cells in SIV infection. Confirmation of our results would be an important step in understanding immune control of HIV.

Discontinuation of dolutegravir, elvitegravir/cobicistat and raltegravir because of toxicity in a prospective cohort.

OBJECTIVES: The aim of the study was to assess the rates of discontinuation of integrase inhibitor regimens because of any neuropsychiatric adverse event (NPAE) and the factors associated with discontinuation. METHODS: A population-based, prospective, multicentre cohort study was carried out. Treatment-naïve subjects starting therapy with a regimen containing integrase inhibitors, or those switching to such a regimen, with plasma HIV-1 RNA < 50 HIV-1 RNA copies/mL in 14 hospitals in Catalonia or the Balearic Islands (Spain) were included in the study. Every discontinuation because of adverse events (AEs) was double-checked directly with treating physicians. Multivariable Cox models identified factors correlated with discontinuation. RESULTS: A total of 4165 subjects (37% treatment-naïve) started regimens containing dolutegravir (n = 1650; 91% with abacavir), raltegravir (n = 930) or elvitegravir/cobicistat (n = 1585). There were no significant differences among regimens in the rate of discontinuation because of any AE. Rates of discontinuation because of NPAEs were low but higher for dolutegravir/abacavir/lamivudine [2.1%; 2.9 (95% confidence interval (CI) 2.0, 4.2) discontinuations/100 patients/year] versus elvitegravir/cobicistat (0.5%; 0.8 (95% CI 0.3, 1.5) discontinuations/100 patients/year], with significant differences among centres for dolutegravir/abacavir/lamivudine and NPAEs (P = 0.003). We identified an association of female gender and lower CD4 count with increased risk of discontinuation because of any AE [Incidence ratio (IR) 2.3 (95% CI 1.4, 4.0) and 1.8 (95% CI 1.1, 2.8), respectively]. Female gender, age > 60 years and abacavir use were not associated with NPAE discontinuations. NPAEs were commonly grade 1-2, and had been present before and improved after drug withdrawal. CONCLUSIONS: In this large prospective cohort study, patients receiving dolutegravir, raltegravir or elvitegravir/cobicistat did not show significant differences in the rate of discontinuation because of any toxicity. The rate of discontinuations because of NPAEs was low, but was significantly higher for dolutegravir than for elvitegravir/cobicistat, with significant differences among centres, suggesting that greater predisposition to believe that a given adverse event is caused by a given drug of some treating physicians might play a role in the discordance seen between cohorts.

Low incidence of acute rejection within 6 months of kidney transplantation in HIV-infected recipients treated with raltegravir: the Agence Nationale de Recherche sur le Sida et les Hépatites Virales (ANRS) 153 TREVE trial.

OBJECTIVES: High rates of clinical acute rejection after kidney transplantation have been reported in people living with HIV (PLHIV), probably as a consequence of drug interactions. We therefore investigated the incidence of acute rejection within 6 months of transplantation in HIV-infected recipients treated with a protease-inhibitor-free raltegravir-based regimen. METHODS: The Agence Nationale de Recherche sur le Sida et les Hépatites Virales (ANRS) 153 TREVE (NCT01453192) study was a prospective multicentre single-arm trial in adult PLHIV awaiting kidney transplantation, with viral load < 50 HIV-1 RNA copies/mL, CD4 T-cell count > 200 cells/µL, and HIV-1 strains sensitive to raltegravir, aiming to demonstrate 6-month clinical acute rejection rates < 30%. Time to transplantation was compared with that for uninfected subjects matched for age, sex and registration date. RESULTS: In total, 61 participants were enrolled in the study, and 26 underwent kidney transplantation. Two participants experienced clinical acute rejection, corresponding to an estimated clinical acute rejection rate of 8% [95% confidence interval (CI) 2-24%] at 6 and 12 months post-transplantation. HIV infection remained under control in all but one participant, who temporarily stopped antiretroviral treatment. Median time to transplantation was longer in PLHIV than in controls (4.3 versus 2.8 years, respectively; P = 0.002) and was not influenced by blood group. CONCLUSIONS: Acute rejection rates were low after kidney transplantation in PLHIV treated with a raltegravir-based regimen. However, PLHIV have poorer access to transplantation than HIV-uninfected individuals after registration on the waiting list.

Antiviral activity of HIV-1 integrase strand-transfer inhibitors against mutants with integrase resistance-associated mutations and their frequency in treatment-naïve individuals.

The development of resistance to human immunodeficiency virus 1 (HIV-1) integrase strand-transfer inhibitors (INSTI) has been documented; however, knowledge of the impact of pre-existing integrase (IN) mutations on INSTI resistance (INSTI-R) is still evolving. The frequency of HIV-1 IN mutations in 2177 treatment-naïve subjects was investigated, along with the INSTI susceptibility of site-directed mutant viruses containing major and minor INSTI-R mutations. Total 6 of 39 minor INSTI-R mutations (M50I, S119P/G/T/R, and E157Q) were found in >1% of IN-treatment-naïve subjects with no impact on INSTI susceptibility. When each combined with major INSTI-R mutation, M50I, S119P, and E157Q led to decreased susceptibility to elvitegravir but remained sensitive to dolutegravir and bictegravir.

Alternative switching strategies based on regimens with a low genetic barrier: do clinicians have a choice nowadays?

Clinicians sometimes use switching strategies based on regimens such as RAL + ABC/3TC or RPV + ABC/3TC in order to resolve tolerability or safety issues associated with conventional recommended first-line strategies. Despite the low genetic barrier of these regimens, high safety and efficacy rates have been reported in retrospective studies.