A Phase 1 Clinical Trial to Assess the Safety and Pharmacokinetics of a Tenofovir Alafenamide/Elvitegravir Insert Administered Rectally for HIV Prevention

BACKGROUND

On-demand topical products could be an important tool for HIV prevention. We evaluated the safety, pharmacokinetics, and ex vivo pharmacodynamics of a tenofovir alafenamide/elvitegravir (TAF/EVG; 16 mg/20 mg) insert administered rectally.

METHODS

MTN-039 was a Phase 1, open-label, single-arm, 2-dose study. Blood, rectal fluid (RF), and rectal tissue (RT) were collected over 72 hours (hr) following rectal administration of one and two TAF/EVG inserts for each participant. ClinicalTrials.gov Identifier: NCT04047420.

RESULTS

TAF/EVG inserts were safe and well tolerated. EVG and tenofovir (TFV) were detected in blood plasma at low concentrations: median peak concentrations after 2 inserts were EVG 2.4 ng/mL and TFV 4.4 ng/mL. RT EVG peaked at 2-hr (median 2 inserts= 9 ng/mg) but declined to BLQ in the majority of samples at 24-hr, whereas TFV-DP remained high >2,000 fmol/million cells for 72-hr with 2 inserts. Compared to baseline, median cumulative log10 HIV p24 antigen of ex vivo rectal tissue HIV infection was reduced at each timepoint for both 1 and 2 inserts (p<0.065 and p<0.039, respectively).

DISCUSSION

Rectal administration of TAF/EVG inserts achieved high rectal tissue concentrations of EVG and TFV-DP with low systemic drug exposure and demonstrable ex vivo inhibition of HIV infection for 72 hours.

Extended post-exposure protection against vaginal SHIV infection with tenofovir alafenamide fumarate/elvitegravir inserts in macaques

Vaginal inserts that can be used on demand before or after sex may be a desirable HIV prevention option for women. We recently showed that inserts containing tenofovir alafenamide fumarate (TAF/20mg) and elvitegravir (EVG/16mg) were highly protective against repeated SHIV vaginal exposures when administered to macaques 4h before or after virus exposure (93% and 100%, respectively). Here, we show in the same macaque model that insert application 8h or 24h after exposure maintains high efficacy (94.4% and 77.2%, respectively). These data extend the protective window by TAF/EVG inserts and inform their clinical development for on-demand prophylaxis in women.

New onset type 2 diabetes mellitus risks with integrase strand transfer inhibitors-based regimens: A systematic review and meta-analysis

Objectives

The development of diabetes mellitus (DM) in patients taking integrase strand transfer inhibitors (INSTIs) has raised concerns. It's critical because, in most guidelines, INSTIs are the preferred third agent at first-line regimens. This study investigates the excess risk of developing DM among people living with HIV (PWH) on INSTIs-based regimens compared to those with other combination antiretroviral therapies (cART).

Methods

A search from PubMed, clinicaltrials.gov, Latin America and Caribbean health sciences literature, Cochrane, and google scholar to retrieve case-control and cohort studies were done. The literature search was performed for studies from January 2007 to January 2021. Data were extracted from studies and pooled as risk ratios (RR) with a 95% confidence interval (CI) using Stata 14 software. The protocol was registered in PROSPERO, ID: CRD42021230282.

Results

This review included ten studies, resulting in 62 400 participants. There was no significant difference in the incidence of DM between participants receiving INSTIs-based regimens versus other cARTs (RR 0.97, 95% CI: 0.92-1.03; participants = 50 958; studies = 4; I² = 86.8%, chi-square = 22.67). There is no statistically significant difference in DM among people treated with INSTIs-based regimens compared to those treated with boosted protease inhibitors (PIs)-based regimens (RR 0.97, 95% CI 0.92-1.03; participants = 49 840; studies = 3; I² = 89.3%, chi-square = 18.65). DM incidence was lower in INSTIs-based regimens than in those using non-nucleoside reverse transcriptase inhibitors (NNRTIs)-based regimens (RR 0.80, 95% CI 0.69-0.91; participants = 42 346; studies = 2; I² = 0%, chi-square = 0.18).

Conclusion

The present review shows a nonsignificant difference in the incidence of DM in patients receiving INSTIs-based regimens compared to other regimens. However, there was a lower incidence of DM in the INSTIs group compared to the NNRTIs-based and PIs compared to the NNRTIs-based. When the INSTIs drugs dolutegravir, raltegravir, and elvitegravir were compared, there was a lower incidence of DM in raltegravir compared with elvitegravir.

Single dose topical inserts containing tenofovir alafenamide fumarate and elvitegravir provide pre- and post-exposure protection against vaginal SHIV infection in macaques

BACKGROUND

Vaginal products for HIV prevention that can be used on-demand before or after sex may be a preferable option for women with low frequency or unplanned sexual activity or who prefer not to use daily or long-acting pre-exposure prophylaxis (PrEP). We performed dose ranging pharmacokinetics (PK) and efficacy studies of a vaginally applied insert containing tenofovir alafenamide fumarate (TAF) and elvitegravir (EVG) in macaques under PrEP or post-exposure prophylaxis (PEP) modalities.

METHODS

PK studies were performed in 3 groups of pigtailed macaques receiving inserts with different fixed-dose combinations of TAF and EVG (10/8, 20/16 and 40/24 mg). PrEP and PEP efficacy of a selected insert was investigated in a repeat exposure vaginal SHIV transmission model. Inserts were administered 4 h before (n = 6) or after (n = 6) repeated weekly SHIV exposures. Infection outcome was compared with macaques receiving placebo inserts (n = 12).

FINDINGS

Dose ranging studies showed rapid and sustained high drug concentrations in vaginal fluids and tissues across insert formulations with minimal dose proportionality. TAF/EVG (20/16 mg) inserts were selected for efficacy evaluation. Five of the 6 animals receiving these inserts 4 h before and 6/6 animals receiving inserts 4 h after SHIV exposure were protected after 13 challenges (p = 0.0088 and 0.0077 compared to placebo, respectively). The calculated PrEP and PEP efficacy was 91.0% (95% CI = 32.2%-98.8%) and 100% (95% CI = undefined), respectively.

INTERPRETATION

Inserts containing TAF/EVG provided high protection against vaginal SHIV infection when administered within a 4 h window before or after SHIV exposure. Our results support the clinical development of TAF/EVG inserts for on-demand PrEP and PEP in women.

FUNDING

Funded by CDC intramural funds, an interagency agreement between CDC and USAID (USAID/CDC IAA AID-GH-T-15-00002), and by the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) through the U.S. Agency for International Development (USAID) under a Cooperative Agreement (AID-OAA-A-14-00010) with CONRAD/Eastern Virginia Medical School.

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.

Comprehensive Review on Different Analytical Techniques for HIV 1- Integrase Inhibitors: Raltegravir, Dolutegravir, Elvitegravir and Bictegravir

The advent of HIV-Integrase inhibitors (IN) has marked a significant impact on the lives of HIV patients. Since the launch of the first anti retro-viral drug "Azidothymidine" to the recent advances of IN inhibitors, about 27.4 million people benefit by antiretroviral therapy (ART). The path had been challenging due to many crossroads, leading to the discovery of newer targets. One such recent ART target is Integrase. Use of Integrase inhibitors has surpassed the usage of all other ART owing to a strong barrier to resistance and have been reported to be the first-line therapy. Raltegravir, Elvitegravir, Dolutegravir and Bictegravir are US FDA approved IN inhibitors. The high usage of ART created an opportunity to study various analytical techniques for IN inhibitors. Hitherto, no review encompassing all IN inhibitors is presented. Herein, this review describes the analytical techniques employed for IN inhibitors estimation and quantification reported in the literature and official compendia. Literature suggests that most studies focus on LC-MS/MS and HPLC methods for drug estimation, and few reports suggest spectrophotometric, spectrofluorimetric and electrochemical methods. Furthermore, the review presents the techniques that describe the quantification of integrase drugs in various matrices. Although, antiretroviral drugs are extensively used but data suggests that limited studies have been conducted for determination of impurity profile and stability. This therefore, presents a scope to detect and validate impurities in order to meet ICH guidelines for their limits and further to improve the quality and safety of antiretroviral drugs.

Durability of rilpivirine-based versus integrase inhibitor-based regimens in a large cohort of naïve HIV-infected patients starting antiretroviral therapy

OBJECTIVES

Comparisons between rilpivirine (RPV) and integrase strand transfer inhibitors (INSTIs) in antiretroviral therapy (ART)-naïve HIV-infected individuals are currently lacking. This study aimed to compare, in an observational cohort setting, the durability of treatment with RPV-based and INSTI-based first-line regimens.

METHODS

Patients who started first-line ARTs based on RPV or INSTIs, with HIV-RNA < 100 000 copies/mL and CD4 cell count > 200 cells/μL were included. The primary endpoint was the cumulative probability of treatment failure (TF = virological failure [confirmed HIV-RNA > 50 copies/mL] or discontinuation of the anchor drug in the regimen), as assessed by the Kaplan-Meier method. A multivariable Cox regression was used to control for potential confounding.

RESULTS

Of the 1991 included patients, 986 started ART with an RPV-based regimen and 1005 with an INSTIs-based regimen. The median (IQR) follow-up was 20 (10, 35) months. The cumulative 2-year probability of TF with RPV (9.1% [95% 7.2, 11.1]) was lower than that observed in the INSTIs group (16.6% [13.8, 19.4], P = 0.0002) but not when compared with dolutegravir (DTG) alone. Starting ART with an INSTIs-based regimen vs. RPV was associated with a higher risk of TF after controlling for potential confounding factors (adjusted hazard ratio, AHR [95% CI]: 1.64 [1.28, 2.10]; P < 0.001). The results were similar when restricting the analysis to single-tablet regimens, although the probability of virological success was higher for INSTIs and DTG.

CONCLUSIONS

In ART-naïve patients with low viral loads and high CD4 counts, the risk of treatment failure was lower in those who started RPV-based vs. INSTIs-based regimens other than DTG-based ones.

Update on Adverse Effects of HIV Integrase Inhibitors

PURPOSE OF REVIEW

The goal of this paper is to provide an up-to-date review of adverse events related to the class of integrase strand transfer inhibitors (INSTIs), which became the class of choice in few years. We sought answers specifically to issues pertaining to neuropsychiatric adverse events, as well as weight gain, which were the two most important categories of adverse events raised in recent studies based on real-life experience. The primary focus of this paper is on adults with a brief summary on pregnant women and children/adolescents.

RECENT FINDINGS

Dolutegravir (DTG) bears the heaviest burden of neuropsychiatric side effects. Weight gain was reported with all INSTIs, although there are methodological caveats in the analyses and the findings need to be interpreted with caution.Moreover, due to recent findings on neural tube defects in infants exposed to dolutegravir during their peri-conception period, its use is not recommended for women of childbearing age without proper birth control method, while raltegravir remains the only drug which may be prescribed without caution. Given the importance of cognitive and metabolic co-morbidities in people living with HIV in regard to their quality of life, future research needs to focus on long-term effects of INSTIs in relation to these adverse events. Pharmacogenetics seems to be a promising tool. Safety during pregnancy is also another important issue to further clarify.

SUMMARY

INSTIs are a generally well-tolerated class of antiretrovirals (ARV), and has a higher antiviral potency compared to other classes of ARV.Clinicians and patients need however to be aware of some red flags when starting with and monitoring patients on INSTIs.All INSTIs can lead to mild increases in creatinine levels, usually without clinical significance, but caution is needed in patients with low eGFR (<30ml/min), when using other nephrotoxic drugs, such as as tenofovir disoproxil.Neuro-psychiatric (NP) effects are to be monitored with INSTIs, especially with DTG (though reports are at times contradictory); clinicians might want to avoid DTG for patients with history of severe NP symptoms, until clarity is provided.Weight gain was reported with all INSTIs, especially with DTG, with possible differential effects according to sex and ethnicity (female and non-white patients being at increased risk). This is worrying since patients from African descent are at higher risk of cardio-vascular events and increased body mass index (BMI) can cause further increase metabolic risk. There is possibly an additional effect of tenofovir alafenamide (TAF) on weight increase.Discrepancies between clinical trials - with low rates of adverse events - and reports from real-life settings might be due partly to under-representation of some groups of patients in clinical trials, and/or the short duration of follow-up, since some adverse effects may only occur after prolonged exposure.Preliminary data on safety of bictegravir (BIC), from clinical trials and non-trial settings, are very reassuring and seem to show lower rates of adverse events compared to DTG.Elvitegravir/cobicistat (EVG/cobi) need to be used with caution in patients with other co-morbidities given potential for polypharmacy, as it is the case for aging patients, because of the high potential of drug-drug interactions due to effects of the cobicistat booster.We are awaiting the release of cabotegravir (CAB), which could represent a good option for patients struggling with adherence, despite injection site reactions.Pharmacogenetics is a promising way to explore adverse effects occurrence in the INSTI class.

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.

Neuropsychiatric Adverse Events with Dolutegravir and Other Integrase Strand Transfer Inhibitors

Neuropsychiatric adverse events (NPAEs) observed with the integrase strand transfer inhibitor (INSTI) dolutegravir (DTG) are usually mild to moderate. The most prevalent symptoms are insomnia and sleep disorders, but the spectrum also includes dizziness, anxiety, depression, headache, paraesthesia, muscle-skeletal pain, poor concentration, and slow thinking. In recent cohort studies involving >6400 patients in different countries, discontinuation rates due to NPAEs were observed in around 3.5% (range, 1.4-7.2%) of subjects treated with DTG. These rates have been higher than those seen in randomized clinical trials and were also higher than with other INSTIs such as elvitegravir or raltegravir. Elderly, female patients and those who initiate abacavir simultaneously appear to be more vulnerable in some cohorts. It remains unclear if NPAEs are driven by an increased DTG exposure. With heightened awareness of health-care providers and patients, reports of NPAEs will probably increase in the future.

An evaluation of elvitegravir plus cobicistat plus tenofovir alafenamide plus emtricitabine as a single-tablet regimen for the treatment of HIV in children and adolescents

INTRODUCTION

Approximately 2.1 million of the estimated 36 million infected with HIV are children or adolescents. International guidelines for HIV-1 Infection suggest starting antiretrovirals (ARV) at the moment of diagnosis. Many factors limit the optimization of antiretroviral therapy in children and adolescents: lack of pediatric formulations, poor adherence, metabolic and pharmacokinetic changes associated withnormal child development and puberty. Areas covered: Three integrase inhibitors are approved by the US Food and Drug Administration and by European Medical Agency for children and adolescents with HIV-1 infection. Raltegravir is approved for children aged 4 weeks to 18 years, while dolutegravir and elvitegravir co-formulated with cobicistat, emtricitabine, and tenofovir alafenamide (E/C/FTC/TAF) are approved for children from 6 years of age. This article evaluates E/C/FTC/TAF as a treatment option. Expert opinion: E/C/FTC/TAF was well tolerated, and the antiretroviral activity and tolerability data of this combination support the use in children and adolescents. However, the studies regarding E/C/FTC/TAF in children and adolescents are scant. Consequently, additional studies investigating its safety and efficacy in children are paramount.

Injectable long-acting human immunodeficiency virus antiretroviral prodrugs with improved pharmacokinetic profiles

While highly active antiretroviral therapy (HAART) has significantly reduced mortality rates in patients with human immunodeficiency virus type 1 (HIV-1), its efficacy may be impeded by emergence of drug resistance caused by lack of patient adherence. A therapeutic strategy that requires infrequent drug administration as a result of sustained release of antiretroviral drugs would put less burden on the patient. Long-acting antiretroviral prodrugs for HIV therapy were synthesized through modification of the active drugs, emtricitabine (FTC) and elvitegravir (EVG), with docosahexaenoic acid (DHA) in one-step, one-pot, high-yielding reactions. The in vitro drug release profiles of these synthetic conjugates demonstrated sustained and controlled release of the active drug over a period of 3-4 weeks attributable to the hydrolysis of the chemical linker in conjunction with the hydrophilicity of the parent drug. Both conjugates exhibited superior antiviral activities in tissue culture models of HIV replication as compared to those of the free drugs, strengthening their role as potent prodrugs for HIV therapy. Pharmacokinetic analysis in CD1 mice further confirmed the long-acting aspect of these conjugates with released drug concentrations in plasma detected at their respective IC₉₀/IC₉₅ values over a period of 2 weeks and discernable amounts of active drug even at 6 weeks. Our findings suggest that the injectable small molecule conjugates could be used as long-acting controlled release of FTC and EVG in attempts to mitigate adherence-related HIV resistance.

Long-acting parenteral combination antiretroviral loaded nano-drug delivery system to treat chronic HIV-1 infection: A humanized mouse model study

Human immunodeficiency virus (HIV) patients are often diagnosed in the chronic stage of HIV/AIDS. Combination antiretroviral therapy (cART) has improved quality of life for HIV-infected patients. Present study describes a novel long-acting parenteral formulation of combination antiretroviral (cARV) loaded nano-drugs for treating chronic HIV-1 (cHIV) in a humanized-BLT (hu-BLT) mice model. The cARV (elvitegravir+tenofovir alafenamide+emtricitabine; EVG+TAF+FTC) drugs (mimicking marketed Genvoya^® one-pill for HIV-treatment) were encapsulated in poly (lactic-co-glycolic acid) nanoparticles (NPs). To establish cHIV, hu-BLT mice were intravaginally challenged with HIV-1 and maintained for 15 weeks. Plasma viral load (pVL) was monitored by RT-PCR to confirm cHIV. Baseline pVL (week 15) was comparable between treated (n = 10) and control (n = 5) mice groups. Subsequently, treatment hu-BLT mice received 3 subcutaneous doses of cARV NPs (417 mg/kg per dose; n = 10), biweekly, and a fourth/terminal dose a week later. Prior to each treatment and on sacrifice (week 24), pVL was determined. Within three subcutaneous doses of cARV NPs, a non-detectable pVL was established (week 19) and continued until week 22. After the establishment of a non-detectable pVL (week 19-22), 4 treated-mice were sacrificed for tissue drug concentration determination by LC-MS/MS analysis. A considerable amount of cARV was detected at the HIV-infection target and reservoir organs. Subsequently, pVL rebounded comparable to control group by week 24, (7 weeks post-terminal dosage). The present study demonstrated cARV NPs augments sustained ARV efficacy in the cHIV humanized-mouse model. Therefore, cARV NPs could be a novel delivery system to treat cHIV patients, by overcoming drawbacks of conventional cART.

Novel elvitegravir nanoformulation approach to suppress the viral load in HIV-infected macrophages

Purpose

Monocytes serve as sanctuary sites for HIV-1 from which virus is difficult to be eliminated. Therefore, an effective viral suppression in monocytes is critical for effective antiretroviral therapy (ART). This study focuses on a new strategy using nanoformulation to optimize the efficacy of ART drugs in HIV-infected monocytes.

Methods

Poly(lactic-co-glycolic acid) (PLGA)-based elvitegravir nanoparticles (PLGA-EVG) were prepared by nano-precipitation technique. The physicochemical properties of PLGA-EVG were characterized using transmission electron microscopy, dynamic light scattering, and Fourier-transform infrared spectroscopy. Cellular uptake study was performed by fluorescence microscopy and flow cytometry. All in vitro experiments were performed by using HIV-infected monocytic cell lines U1 and HIV-infected primary macrophages. Elvitegravir quantification was performed using LC-MS/MS. HIV viral replication was assessed by using p24 ELISA.

Results

We developed a PLGA-EVG nanoparticle formulation with particle size of ~ 47 nm from transmission electron microscopy and zeta potential of ~ 6.74 mV from dynamic light scattering. These nanoparticles demonstrated a time- and concentration-dependent uptakes in monocytes. PLGA-EVG formulation showed a ~ 2 times higher intracellular internalization of EVG than control group (EVG alone). PLGA-EVG nanoparticles also demonstrated superior viral suppression over control for a prolonged period of time.

Conclusions

PLGA-based EVG nanoformulation increased the intracellular uptake of EVG, as well as enhanced viral suppression in HIV-infected macrophages, suggesting its potential for improved HIV treatment in monocytic cells.

HIV treatment simplification to elvitegravir/cobicistat/emtricitabine/tenofovir disproxil fumarate (E/C/F/TDF) plus darunavir: a pharmacokinetic study

BACKGROUND

As a simplification strategy for treatment-experienced HIV-infected patients who have achieved virologic suppression on a multi-drug, multi-class antiretroviral regimen, the aim of this study was to evaluate the safety, efficacy, and pharmacokinetics of once-daily elvitegravir/cobicistat/emtricitabine/tenofovir disproxil fumarate (E/C/F/TDF) with darunavir.

METHODS

A single arm, open-label 48-week study was conducted of regimen simplification to E/C/F/TDF plus darunavir 800 mg daily from stable therapy including two nucleoside/nucleotide reverse transcriptase inhibitors, a ritonavir-boosted protease inhibitor, and an integrase inhibitor. Participants had plasma HIV viral load consistently < 200 copies/mL for ≥ 6 months, estimated glomerular filtration rate (eGFR) ≥ 60 mL/min, and no genotypic resistance to major components of the study regimen. Plasma viral load was measured at weeks 2 and 4, then every 4 weeks throughout the study. Safety laboratory assessments were conducted at baseline and at weeks 12, 24, 36, and 48. Antiretroviral drug concentrations were measured at baseline and once ≥ 2 weeks after the regimen change.

RESULTS

Ten HIV-infected adults (8 male and 2 female; median age 50.5 years) were enrolled. All maintained virologic suppression on the new regimen for 48 weeks. One subject experienced a decrease in eGFR from 62 mL/min at baseline to 52 mL/min at week 12; study medications were continued and his eGFR remained stable (50-59 mL/min) thereafter. No subjects discontinued study medications for renal function changes or other adverse events. Darunavir trough concentration were lower on the new regimen than on darunavir/ritonavir 800/100 mg (n = 5; p < 0.05).

CONCLUSIONS

Despite low darunavir trough concentrations, treatment simplification to a two-pill, once-daily regimen of E/C/F/TDF plus darunavir was safe and effective for 48 weeks among 10 selected treatment-experienced HIV-infected patients. Trial registration The study protocol was registered with ClinicalTrials.gov (NCT02199613) on July 22, 2014.

A Single-Center Retrospective Cohort Analysis of Maternal and Infant Outcomes in HIV-Infected Mothers Treated with Integrase Inhibitors During Pregnancy

Introduction

Integrase strand transfer inhibitors (INSTI) are currently being investigated for the treatment of HIV in pregnancy. The purpose of this study is to evaluate the differences in maternal and infant outcomes in HIV-positive mothers treated with INSTI-containing antiretroviral therapy (ART) during pregnancy compared to protease inhibitor (PI)-containing ART.

Methods

A retrospective, cohort study of INSTI- and PI-based ART used in pregnancy between 2007 and 2015 was performed. The primary objective was to evaluate the differences in viral load (VL) suppression prior to delivery. Secondary endpoints included time to and duration of VL suppression and safety parameters in both mothers and infants. For the primary analysis, the two arms were matched 1:2 INSTI to PI based on the presence or absence of viremia at the time of pregnancy determination. Additional analysis was performed on the entire matched and unmatched dataset.

Results

Twenty-one patients were matched (7 INSTI and 14 PI). There were no significant differences between groups with respect to the proportion of patients with VL suppression prior to delivery (71.4% INSTI vs. 92.9% PI, p = 0.247), and there were no significant differences in any of the secondary endpoints. Patients with documented adherence issues were statistically more likely to not be virologically suppressed prior to delivery (p = 0.002).

Conclusion

No differences in efficacy or safety were found between patients treated with INSTIs compared to PIs. This study supports the further investigation of the use of INSTIs during pregnancy to reduce HIV transmission.

Degradable bioadhesive nanoparticles for prolonged intravaginal delivery and retention of elvitegravir

New methods for long-lasting protection against sexually transmitted disease, such as the human immunodeficiency virus (HIV), are needed to help reduce the severity of STD epidemics, especially in developing countries. Intravaginal delivery of therapeutics has emerged as a promising strategy to provide women with local protection, but residence times of such agents are greatly reduced by the protective mucus layer, fluctuating hormone cycle, and complex anatomical structure of the reproductive tract. Polymeric nanoparticles (NPs) capable of encapsulating the desired cargo, penetrating through the mucosal surfaces, and delivering agents to the site of action have been explored. However, prolonged retention of polymer carriers and their enclosed materials may also be needed to ease adherence and confer longer-lasting protection against STDs. Here, we examined the fate of two poly (lactic acid)-hyperbranched polyglycerols (PLA-HPG) NP formulations - 1) nonadhesive PLA-HPG NPs (NNPs) and 2) surface-modified bioadhesive NPs (BNPs) - loaded with the antiretroviral elvitegravir (EVG) after intravaginal administration. BNP distribution was widespread throughout the reproductive tract, and retention was nearly 5 times higher than NNPs after 24 h. Moreover, BNPs were found to be highly associated with submucosal leukocytes and epithelial cell populations for up to 48 h after topical application, and EVG was retained significantly better in the vaginal lumen when delivered with BNPs as opposed to NNPs over a 24 h period. Our results suggest that bioadhesive PLA-HPG NPs can greatly improve and prolong intravaginal delivery of agents, which may hold potential in providing sustained protection over longer durations.

The inhibition process of HIV-1 integrase by diketoacids molecules: Understanding the factors governing the better efficiency of dolutegravir

The Human Immunodeficiency Virus-1 integrase is responsible for the covalent insertion of a newly synthesized double-stranded viral DNA into the host cells, and is an emerging target for antivirus drug design. Raltegravir (RAL) and elvitegravir (EVG) are the first two integrase strand transfer inhibitors used in therapy. However, treated patients eventually develop detrimental resistance mutations. By contrast, a recently approved drug, dolutegravir (DTG), presents a high barrier to resistance. This study aims to understand the increased efficiency of DTG upon focusing on its interaction properties with viral DNA. The results showed DTG to be involved in more extended interactions with viral DNA than EVG. Such interactions involve the halobenzene and scaffold of DTG and EVG and bases 5'G^-43', 3'A³5'and 3'C⁴5'.

HIV drug resistance against strand transfer integrase inhibitors

Integrase strand transfer inhibitors (INSTIs) are the newest class of antiretroviral drugs to be approved for treatment and act by inhibiting the essential HIV protein integrase from inserting the viral DNA genome into the host cell’s chromatin. Three drugs of this class are currently approved for use in HIV-positive individuals: raltegravir (RAL), elvitegravir (EVG), and dolutegravir (DTG), while cabotegravir (CAB) and bictegravir (BIC) are currently in clinical trials. RAL and EVG have been successful in clinical settings but have relatively low genetic barriers to resistance. Furthermore, they share a high degree of cross-resistance, which necessitated the development of so-called second-generation drugs of this class (DTG, CAB, and BIC) that could retain activity against these resistant variants. In vitro selection experiments have been instrumental to the clinical development of INSTIs, however they cannot completely recapitulate the situation in an HIV-positive individual. This review summarizes and compares all the currently available information as it pertains to both in vitro and in vivo selections with all five INSTIs, and the measured fold-changes in resistance of resistant variants in in vitro assays. While the selection of resistance substitutions in response to RAL and EVG bears high similarity in patients as compared to laboratory studies, there is less concurrence regarding the “second-generation” drugs of this class. This highlights the unpredictability of HIV resistance to these inhibitors, which is of concern as CAB and BIC proceed in their clinical development.

[Resistance profile and genetic barrier of dolutegravir]

The resistance profile of dolutegravir differs significantly from those of earlier integrase inhibitors (INI). Dolutegravir displays in vitro activity against mutant HIV-1 harboring any isolated resistance mutations selected during failures to raltegravir or elvitegravir (Y143C/H/, N155H, Q148H/K/R, E92G/Q, T66A/I/K, T97A, E138A/K, G140A/S). Its activity is only compromised by Q148X mutations combined with other mutations, particularly > 1 mutation. The drug has pharmacokinetic/pharmacodynamic properties (plasmatic t1/2 15.3 h, inhibitory quotient 19, dissociative t1/2 from the IN-DNA complex 71 h) that favor a high genetic barrier to resistance. In vitro the selection of HIV-1 resistance to dolutegravir is extremely difficult to achieve. The mutations eventually selected (R263K, H51Y and E138K) do not confer significant resistance, and induce a fitness cost that prevents HIV-1 from evading drug pressure. Suprisingly, HIV-1 is not able to compensate, leading the virus to a previously unnoticed evolutionary pathway with very low chances of developing resistance to INI or the backbone. No treatment-naïve patients starting dolutegravir therapy (+TDF/FTC o ABC/3TC) have selected resistance in IN or against the backbone. No INI- naïve patients with prior virologic failure selected phenotypic dolutegravir resistance. Only 4 out of 354 patients selected resistance mutations in IN, and rates of selection of mutations in IN or against the backbone were significantly lower than with raltegravir. In multitreated patients with widespread resistance including IN resistance, the high efficacy of dolutegravir was confirmed, irrespective of the previous pattern of IN mutations, provided that Q148X associated with other mutations was absent.

Drug resistant integrase mutants cause aberrant HIV integrations

Background

HIV-1 integrase is the target for three FDA-approved drugs, raltegravir, elvitegravir, and dolutegravir. All three drugs bind at the active site of integrase and block the strand transfer step of integration. We previously showed that sub-optimal doses of the anti-HIV drug raltegravir can cause aberrant HIV integrations that are accompanied by a variety of deletions, duplications, insertions and inversions of the adjacent host sequences.

Results

We show here that a second drug, elvitegravir, also causes similar aberrant integrations. More importantly, we show that at least two of the three clinically relevant drug resistant integrase mutants we tested, N155H and G140S/Q148H, which reduce the enzymatic activity of integrase, can cause the same sorts of aberrant integrations, even in the absence of drugs. In addition, these drug resistant mutants have an elevated IC₅₀ for anti-integrase drugs, and concentrations of the drugs that would be optimal against the WT virus are suboptimal for the mutants.

Conclusions

We previously showed that suboptimal doses of a drug that binds to the HIV enzyme integrase and blocks the integration of a DNA copy of the viral genome into host DNA can cause aberrant integrations that involve rearrangements of the host DNA. We show here that suboptimal doses of a second anti-integrase drug can cause similar aberrant integrations. We also show that drug-resistance mutations in HIV integrase can also cause aberrant integrations, even in the absence of an anti-integrase drug. HIV DNA integrations in the oncogenes BACH2 and MKL2 that do not involve rearrangements of the viral or host DNA can stimulate the proliferation of infected cells. Based on what is known about the association of DNA rearrangements and the activation of oncogenes in human tumors, it is possible that some of the deletions, duplications, insertions, and inversions of the host DNA that accompany aberrant HIV DNA integrations could increase the chances that HIV integrations could lead to the development of a tumor.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-016-0305-6) contains supplementary material, which is available to authorized users.

When food can make the difference: The case of elvitegravir-based co-formulation

Stribild should be administered under fed conditions to optimize drugs exposure. Here we assessed to what extent this advice is applied in the real life scenario by therapeutic drug monitoring in 75 HIV-infected patients given Stribild-based antiretroviral therapy. Fifty-three percent of our patients took Stribild at lunch/supper time, 23% in the morning with breakfast, and 24% middle in the morning or late in the evening. Twelve out of the 75 patients had unquantifiable elvitegravir concentrations, whereas in the remaining the levels were largely distributed. Wide inter-individual variability in the tenofovir, cobicistat and darunavir trough concentrations was also observed. In real life settings a significant proportion of patients took Stribild without food, namely in the mid-morning or late in the evening. This resulted in a wide inter-individual variability of antiretroviral drug trough concentrations. To avoid the risk for patients to experience suboptimal drug exposure, it is important that health professionals more convincingly advise their patients to take Stribild in fed conditions. On the other hand, the role of patient education and patient responsibility to correctly take the therapy should not be underestimated.

The development and application of a novel LC-MS/MS method for the measurement of Dolutegravir, Elvitegravir and Cobicistat in human plasma

Dolutegravir and Elvitegravir belongs to a class of integrase inhibitors which has recently been approved by the FDA for the treatment of HIV-infection. Elvitegravir and its co-administered booster drug, Cobicistat, has shown the potential to be a candidate for a one pill once a day regimen and is currently a component of many clinical trials. A sensitive LC-MS/MS method has been developed and validated for the simultaneous determination of these three drugs in human plasma. A liquid- liquid extraction was used as a sample preparation technique using 100μL of plasma. The method was validated from 10 to 4000ng/mL for Dolutegravir, Elvitegravir and Cobicistat. Chromatography was performed on XBridge C18 2.1mm×50mm column, using an 80:20 methanol/water mobile phase containing 0.1% formic acid on a gradient program. This method was successfully applied for ongoing clinical trials.

Impact of elvitegravir on human adipocytes: Alterations in differentiation, gene expression and release of adipokines and cytokines

Elvitegravir is a recently developed integrase inhibitor used for antiretroviral treatment of HIV infection. Secondary effects, including disturbances in lipid metabolism and, ultimately, in adipose tissue distribution and function, are common concerns associated with antiretroviral treatments. Here, we provide the first study of the effects of elvitegravir (in comparison with efavirenz, a non-nucleoside analog inhibitor of reverse transcriptase; and raltegravir, another integrase inhibitor) on human adipocyte differentiation, gene expression and secretion of adipokines and cytokines. Elvitegravir impaired adipogenesis and adipocyte metabolism in human SGBS adipocytes in a concentration-dependent manner (delaying acquisition of adipocyte morphology and reducing the expression of adipogenesis marker genes such as PPARγ, glucose transporter GLUT4, lipoprotein lipase, and the adipokines adiponectin and leptin). Compared with efavirenz, the effects of elvitegravir were similar but tended to occur at higher concentrations than those elicited by efavirenz, or were somewhat less intense than those caused by efavirenz at similar concentration. Elvitegravir tended to cause a more moderate induction of pro-inflammatory cytokines than efavirenz. Efavirenz induced a marked concentration-dependent increase in interleukin-8 expression and release whereas elvitregravir had little effect. Raltegravir had totally neutral actions of adipogenesis, adipocyte metabolism-related gene expression and release of adipokines and cytokines. In conclusion, elvitegravir alters adipocyte differentiation and function and promotes induction of pro-inflammatory cytokines similarly to efavirenz, but several effects were less intense. Further assessment of lipid metabolism and adipose tissue function in patients administered elvitegravir-based regimes is advisable considering that totally neutral effects of elvitegravir on lipid homeostasis cannot be anticipated from the current study in vitro.

Integrase Strand Transfer Inhibitors (INSTIs) Resistance Mutations in HIV-1 Infected Turkish Patients

OBJECTIVES

Integrase strand transfer inhibitor (INSTI) is a new class of antiretroviral (ARV) drugs designed to block the action of the integrase viral enzyme, which is responsible for insertation of the HIV-1 genome into the host DNA. The aim of this study was to evaluate for the first time INSTI resistance mutations in Turkish patients.

METHODS

This study was conducted in Turkey, between April 2013 and April 2015 using 169 HIV-1-infected patients (78 ARV naive patients and 91 ARV-experienced patients). Laboratory and clinical characteristics of ARV naive and ARV-experienced patients were as follows: gender (M/F): 71/7 and 80/11, median age: 38 and 38.4; median CD4(+) T-cell: 236 and 216 cells/mm(3), median HIV-1 RNA: 4.95+E5 and 1.08E+6 copies/ml. Population-based seqeunces of the reverse transcriptase, protease, and integrase domains of the HIV-1 pol gene were used to detect HIV-1 drug resistance mutations.

RESULT

INSTI resistance mutations were not found in recently diagnosed HIV-1-infected patients. However, ARV-experienced patients had major resistance mutations associated with raltegravir and elvitegravir; the following results were generated:F121Y, Y143R, Q148R and E157Q (6/91 - 6.6%).

CONCLUSIONS

The prevalence of INSTI resistant mutations in ART-experienced patients suggested that resistance testing must be incorporated as an integral part of HIV management with INSTI therapies.

Rapid regression of Kaposi's sarcoma of the hard palate under therapy with boosted elvitegravir-containing fixdose antiretroviral combination therapy

INTRODUCTION

Kaposi's sarcoma (KS) is a rare vascular tumor that may occur in a severe, rapidly progressive form, namely in HIV/AIDS patients. HIV-associated KS mainly affects the skin and mucous membranes.

CASE PRESENTATION

We report about an HIV-positive patient who presented with an exophytic growing tumor in the region of the hard palate and severe problems regarding his dental status. Histological examination revealed evidence of AIDS-related KS. Antiretroviral therapy initiation with elvitegravir/cobicistat/emtricitabine(FTC)/tenofovirdisoproxilfumarat (E/c/F/T-fix dose combination) resulted in rapid complete remission of the KS within 2 months.

CONCLUSION

In this case of a treatment-naive HIV-infected patient with coexisting KS, antiretroviral therapy with E/c/FTC/TDF was very well suited to achieve rapid complete remission of KS.

Elvitegravir for the treatment of HIV infection

Advances in antiretroviral treatment have transformed HIV-1 infection from a deadly disease to a chronic one. Novel antiretroviral drugs have been approved for clinical use. In order to achieve long-term suppression of viremia, patients have to commit and take these drugs, or others approved in the future, for the rest of their lives. However, the emergence of multidrug-resistant mutants, along with the side effects of them, often results in the failure of therapy, so better treatment options are needed. Elvitegravir is a potent HIV integrase inhibitor with antiviral activity against wild-type and drug-resistant strains of HIV. In addition, elvitegravir can also inhibit the replication of several retroviruses and lentiviruses. Elvitegravir undergoes extensive primary metabolism by hepatic and intestinal cytochrome P450 3A (CYP3A) and secondary metabolism by UDP-glucuronosyltransferase 1-1 and 1-3 (UGT1A1/3). Although boosting it with a strong CYP3A inhibitor such as ritonavir substantially increases its plasma exposure and prolongs its elimination half-life, other combinations or even monotherapy could also be considered. Ritonavir-boosted elvitegravir requires once-daily administration of a low dose. As a stand-alone agent, elvitegravir will require twice-daily dosing to achieve effective viral reductions.

Design of inhibitors of the HIV-1 integrase core domain using virtual screening

Acquired immunodeficiency syndrome (AIDS) is a disease of the human immune system caused by the human immunodeficiency virus (HIV). The integrase (IN) enzyme of HIV interacts with several cellular and viral proteins during the integration process. Thus, it represents an appropriate target for antiretroviral drugs (ARVs). We performed virtual screening of database compounds and designed analogues using Elvitegravir (EVG) as a standard compound. The 378 screened compounds were retrieved from ZINC, ChemSpider, PubChem, and ChemBank Chemical Databases based on chemical similarity and literature searches related to the structure of EVG. The Physiochemical properties, Bioactivity, Toxicity and Absorption, Distribution, Metabolism and Excretion of Molecules (ADME) of these compounds were predicted and docking Experiments were conducted using Molegro Virtual Docker software. The docking and ADME suggested very significant results in regard to EVG. The MolDock and Rerank scores were used to analyze the results. The compounds ZINC26507991 (-84.22), Analogue 9 (-68.49), ZINC20731658 (-66.79), ZINC00210363 (-43.44) showed better binding orientation with IN receptor model with respect to EVG (182.52). The ZINC26507991 has showed significant ADME result.

HIV integrase inhibitors: 20-year landmark and challenges

Since the discovery of HIV as the cause for AIDS 30 years ago, major progress has been made, including the discovery of drugs that now control the disease. Here, we review the integrase (IN) inhibitors from the discovery of the first compounds 20 years ago to the approval of two highly effective IN strand transfer inhibitors (INSTIs), raltegravir (Isentress) and elvitegravir (Stribild), and the promising clinical activity of dolutegravir. After summarizing the molecular mechanism of action of the INSTIs as interfacial inhibitors, we discuss the remaining challenges. Those include: overcoming resistance to clinical INSTIs, long-term safety of INSTIs, cost of therapy, place of the INSTIs in prophylactic treatments, and the development of new classes of inhibitors (the LEDGINs) targeting IN outside its catalytic site. We also discuss the role of chromatin and host DNA repair factor for the completion of integration.

Resistance to integrase inhibitors

Integrase (IN) is a clinically validated target for the treatment of human immunodeficiency virus infections and raltegravir exhibits remarkable clinical activity. The next most advanced IN inhibitor is elvitegravir. However, mutant viruses lead to treatment failure and mutations within the IN coding sequence appear to confer cross-resistance. The characterization of those mutations is critical for the development of second generation IN inhibitors to overcome resistance. This review focuses on IN resistance based on structural and biochemical data, and on the role of the IN flexible loop i.e., between residues G140-G149 in drug action and resistance.