Clinical use of HIV integrase inhibitors: a systematic review and meta-analysis

Current Challenges With Highly Active Antiretroviral Therapy and New Hope and Horizon With CRISPR-CAS9 Technology for HIV Treatment

Clustered regularly interspaced short palindromic repeats (CRISPR/Cas system) is now the predominant approach for genome editing. Compared to conventional genetic editing methods, CRISPR/Cas technology offers several advantages that were previously unavailable. Key benefits include the ability to simultaneously modify multiple locations, reduced costs, enhanced efficiency, and a more user-friendly design. By directing Cas-mediated DNA cleavage to specific genomic targets and utilizing intrinsic DNA repair processes, this system can produce site-specific gene modifications. This goal is achieved through an RNA-guided procedure. As the most effective gene editing method currently available, the CRISPR/Cas system has proven to be highly valuable in genomic research across a wide range of species since its discovery as a component of the adaptive immune system in bacteria. Its applicability extends to various organisms, making it increasingly prevalent in the medical field, where it shows great promise in investigating viral infections, cancer, and genetic disorders. Furthermore, it enhances our understanding of fundamental genetics. This article outlines the current antiretroviral therapy and its adverse effects but also CRISPR/Cas technology. This review article also discusses its mechanism of action and potential applications in the treatment of HIV/AIDS.

Brain N -acetyl-aspartyl-glutamate is associated with cognitive function in older virally suppressed people with HIV

OBJECTIVES

Cognitive impairment persists in virally suppressed people with HIV (VS-PWH) especially in higher order domains. One cortical circuit, linked to these domains, is regulated by N -acetyl-aspartyl glutamate (NAAG), the endogenous agonist of the metabotropic glutamate receptor 3. The enzyme glutamate carboxypeptidase II (GCPII) catabolizes NAAG and is upregulated in aging and disease. Inhibition of GCPII increases brain NAAG and improves learning and memory in rodent and primate models.

DESIGN

As higher order cognitive impairment is present in VS-PWH, and NAAG has not been investigated in earlier magnetic resonance spectroscopy studies (MRS), we investigated if brain NAAG levels measured by MRS were associated with cognitive function.

METHODS

We conducted a retrospective analysis of 7-Tesla MRS data from a previously published study on cognition in older VS-PWH. The original study did not separately quantify NAAG, therefore, work for this report focused on relationships between regional NAAG levels in frontal white matter (FWM), left hippocampus, left basal ganglia and domain-specific cognitive performance in 40 VS-PWH after adjusting for confounds. Participants were older than 50 years, negative for affective and neurologic disorders, and had no prior 3-month psychoactive-substance use.

RESULTS

Higher NAAG levels in FWM were associated with better attention/working memory. Higher left basal ganglia NAAG related to better verbal fluency. There was a positive relationship between hippocampal NAAG and executive function which lost significance after correction for confounds.

CONCLUSION

These data suggest brain NAAG serves as a biomarker of cognition in VS-PWH. Pharmacological modulation of brain NAAG warrants investigation as a therapeutic approach for cognitive deficits in VS-PWH.

Dolutegravir-induced acquired sideroblastic anemia in a HIV positive patient: A challenging hematologic complication

Dolutegravir, the most recent antiretroviral drug with high efficacy, good tolerability, infrequent drug-drug interactions, and a favorable safety profile has not been reported in current literature as a cause of acquired sideroblastic anemia. Here, we present a 35-year-old male patient who was diagnosed with acquired sideroblastic anemia to Dolutegravir therapy.

Four decades of continuing innovations in the development of antiretroviral therapy for HIV/AIDS: Progress to date and future challenges

The treatment of HIV-1 infection and AIDS represents one of the greatest challenges in medicine. While there is no cure for HIV/AIDS, truly remarkable progress has been made for treatment of HIV/AIDS patients today. The advent of combination antiretroviral therapy (cART) in the mid-1990s dramatically improved HIV-1 related morbidity, greatly prolonged life expectancy, and delayed progression of AIDS. Due to current antiretroviral therapy, the mortality rate for HIV infected patients is closely approaching the mortality rate for the general population. The long-term success of HIV-AIDS treatment requires continued enhancement of cART with further development of novel drugs that would exhibit fewer side effects, higher genetic barrier to the development of resistance, and longer action with durable virologic suppression. This editorial article provides a quick review of four decades of intense drug development research efforts targeting various viral enzymes and cellular host factors leading to the evolution of today's treatment of patients with HIV-1 infection and AIDS. It also touches on challenges of future treatment options.

Blood immune cells from people with HIV on antiviral regimens that contain tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF) have differential metabolic signatures

BACKGROUND

Mitochondria regulate immune and organ function. It is unknown whether higher intracellular drug levels observed in peripheral blood mononuclear cells (PBMCs) treated with tenofovir alafenamide (TAF) compared to tenofovir disoproxil fumarate (TDF) may alter mitochondrial function and energy production in immune cells in HIV(+) patients.

METHODS

Cellular bioenergetics were determined in PBMCs from HIV-1(-) participants exposed to TAF versus TDF in vitro, at a comparable concentration to a clinically relevant plasma exposure. A decrease in cellular oxygen consumption rate (OCR) at baseline (basal-OCR) and under cellular stress (max-OCR) may suggest mitochondrial dysfunction. We also assessed the in vivo impact of TAF vs TDF on OCR in PBMCs from 26 people with HIV (PWH) interchanged from TDF-based to TAF-based antiretroviral therapy (ART) over a 9-month period in the setting of an open label clinical trial. The Wilcoxon and Mann Whitney tests were used for comparison of continuous variables.

RESULTS

PBMCs from HIV-1(-) participants exposed in vitro to a concentration of 0.12-3.3 μM for TAF and TDF at 2 and 24 h, reduced basal and maximal OCR compared to vehicle control. Switch studies of antivirals (TAF vs TDF) within the same PWH showed that TAF-based ART was associated with reduced OCR compared to TDF-based ART in PBMCs. We observed that TAF-treated PBMCs selectively relied more on glucose/pyruvate supply rather than fatty acid to fuel their mitochondria.

CONCLUSIONS

Compared to TDF, TAF may alter bioenergetics in immune cells from PWH in vitro and in vivo. The clinical significance in terms of the differential impact caused by TAF versus TDF on mitochondrial function and energy production in immune cells, a regulator of immune function, requires further studied in HIV, preexposure prophylaxis and hepatitis B.

Prevalence of HIV-1 Natural Polymorphisms and Integrase-Resistance-Associated Mutations in African Children

Integrase inhibitors (INIs) are a potent option for HIV treatment. Limited data exist on INI resistance in West Africa, particularly in children living with HIV/AIDS. We determined the prevalence of integrase gene polymorphisms and the frequency of naturally occurring amino acid (aa) substitutions at positions associated with INI resistance. Dried blood spot (DBS) samples were obtained from one hundred and seven (107) HIV-1-infected children aged less than 15 years old in two West African countries, Benin and Mali. All children were naïve to INI treatment, 56 were naïve to anti-retroviral therapy (ART), and 51 had received ART. Genetic sequencing of HIV integrase was successful in 75 samples. The aa changes at integrase positions associated with INI resistance were examined according to the Stanford HIV Genotypic Resistance database. The median ages were 2.6 and 10 years for ART-naïve and -treated children, respectively. The most common subtypes observed were CRF02_AG (74.7%) followed by CRF06_cpx (20%). No major INI-resistance mutations at positions 66, 92, 121, 143, 147, 148, 155, and 263 were detected. The most prevalent INI accessory resistance mutations were: L74I/M (14/75, 18.6%) followed by E157Q (8/75, 10.6%), G163E/N/T/Q (5/75, 6.6%), Q95A/H/P (2/75, 2.6%), and T97A (4/75, 5.3%). Other substitutions observed were M50I/L/P, H51E/P/S/Q, I72V, T112V, V201I, and T206S. Polymorphisms at positions which may influence the genetic barrier and/or drive the selection of specific INI-resistance pathways were detected. However, no transmitted drug resistance (TDR) to INI was detected among samples of INI-naïve patients. These findings support the use of this treatment class for children with HIV-1, particularly in West Africa.

Association between integrase strand transfer inhibitor use with insulin resistance and incident diabetes mellitus in persons living with HIV: a systematic review and meta-analysis

Whether integrase strand transfer inhibitors (INSTIs) are associated with a higher risk of incident type 2 diabetes mellitus (DM) than other antiretroviral therapies (ART) needs to be established.MEDLINE, Embase, Web of Science, and ClinicalTrials.gov registries were searched for studies published between 1 January 2000 and 15 June 2022. Eligible studies reported incident DM or mean changes in insulin resistance measured by Homeostatic Model for Insulin Resistance (HOMA-IR) in patients on INSTIs compared with other ARTs. We performed random-effects meta-analyses to obtain pooled relative risks (RRs) with 95% CIs.A total of 16 studies were pooled: 13 studies meta-analyzed for incident diabetes with a patient population of 72 404 and 3 for changes in HOMA-IR. INSTI therapy was associated with a lower risk of incident diabetes in 13 studies (RR 0.80, 95% CI 0.67 to 0.96, I2=29%), of which 8 randomized controlled trials demonstrated a 22% reduced risk (RR 0.88, 95% CI 0.81 to 0.96, I2=0%). INSTIs had a lower risk compared with non-nucleoside reverse transcriptase inhibitors (RR 0.75, 95% CI 0.63 to 0.89, I2=0%) but similar to protease inhibitor-based therapy (RR 0.78, 95% CI 0.61 to 1.01, I2=27%). The risk was lower in studies with longer follow-up (RR 0.70, 95% CI 0.53 to 0.94, I2=24%) and among ART-naïve patients (RR 0.78, 95% CI 0.65 to 0.94, I2=3%) but increased in African populations (RR 2.99, 95% CI 2.53 to 3.54, I2=0%).In conclusion, exposure to INSTIs was not associated with increased risk of DM, except in the African population. Stratified analyses suggested reduced risk among ART-naïve patients and studies with longer follow-up.International Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42021273040.

Influence of UGT1A1 and SLC22A6 polymorphisms on the population pharmacokinetics and pharmacodynamics of raltegravir in HIV-infected adults: a NEAT001/ANRS143 sub-study

Using concentration-time data from the NEAT001/ARNS143 study (single sample at week 4 and 24), we determined raltegravir pharmacokinetic parameters using nonlinear mixed effects modelling (NONMEM v.7.3; 602 samples from 349 patients) and investigated the influence of demographics and SNPs (SLC22A6 and UGT1A1) on raltegravir pharmacokinetics and pharmacodynamics. Demographics and SNPs did not influence raltegravir pharmacokinetics and no significant pharmacokinetic/pharmacodynamic relationships were observed. At week 96, UGT1A1*28/*28 was associated with lower virological failure (p = 0.012), even after adjusting for baseline CD4 count (p = 0.048), but not when adjusted for baseline HIV-1 viral load (p = 0.082) or both (p = 0.089). This is the first study to our knowledge to assess the influence of SNPs on raltegravir pharmacodynamics. The lack of a pharmacokinetic/pharmacodynamic relationship is potentially an artefact of raltegravir's characteristic high inter and intra-patient variability and also suggesting single time point sampling schedules are inadequate to thoroughly assess the influence of SNPs on raltegravir pharmacokinetics.

Design, Synthesis, Docking Studies, and Biological Evaluation of Novel 2-Hydroxyacetophenone Derivatives as Anti-HIV-1 Agents

BACKGROUND

The persistence of HIV mutations and the existence of multidrug resistance have produced an opportunity for an array of innovative anti-HIV medicines with a variety of structures that target HIV key enzymes.

OBJECTIVE

The goal of this work was to find a new class of anti-HIV drugs founded on HIV integrase inhibitor pharmacophores.

METHODS

A novel class of 2-hydroxy acetophenone analogs featuring substituted benzamide or N-phenylthiourea groups was designed and synthesized based on the general pharmacophore of HIV-1 integrase inhibitors (INs).

RESULTS

Most of the synthesized analogs were found to be moderately active against the virus, with EC50 values ranging from 40 to 140 μM. Additionally, it was found that most of the compounds presented no considerable cytotoxicity (CC50 > 500 μΜ). The most potent compounds substituting with 4-fluorobenzamide (compound 7) and 4-methylbenzamide (compound 9) rings inhibited the HIV-1 replication by EC50 values of 40 and 45 μΜ, respectively. Docking studies using the crystallographic data available for PFV IN indicated that the Mg2+ coordination might be the possible mechanism of the anti-viral activity.

CONCLUSION

Our findings proved that the synthesized analogs may suggest a very good basis for the development of new anti-HIV-1 agents.

iDVIP: identification and characterization of viral integrase inhibitory peptides

Antiretroviral peptides are a kind of bioactive peptides that present inhibitory activity against retroviruses through various mechanisms. Among them, viral integrase inhibitory peptides (VINIPs) are a class of antiretroviral peptides that have the ability to block the action of integrase proteins, which is essential for retroviral replication. As the number of experimentally verified bioactive peptides has increased significantly, the lack of in silico machine learning approaches can effectively predict the peptides with the integrase inhibitory activity. Here, we have developed the first prediction model for identifying the novel VINIPs using the sequence characteristics, and the hybrid feature set was considered to improve the predictive ability. The performance was evaluated by 5-fold cross-validation based on the training dataset, and the result indicates the proposed model is capable of predicting the VINIPs, with a sensitivity of 85.82%, a specificity of 88.81%, an accuracy of 88.37%, a balanced accuracy of 87.32% and a Matthews correlation coefficient value of 0.64. Most importantly, the model also consistently provides effective performance in independent testing. To sum up, we propose the first computational approach for identifying and characterizing the VINIPs, which can be considered novel antiretroviral therapy agents. Ultimately, to facilitate further research and development, iDVIP, an automatic computational tool that predicts the VINIPs has been developed, which is now freely available at http://mer.hc.mmh.org.tw/iDVIP/.

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.

Development of Azaindole-Based Frameworks as Potential Antiviral Agents and Their Future Perspectives

The azaindole (AI) framework continues to play a significant role in the design of new antiviral agents. Modulating the position and isosteric replacement of the nitrogen atom of AI analogs notably influences the intrinsic physicochemical properties of lead compounds. The intra- and intermolecular interactions of AI derivatives with host receptors or viral proteins can also be fine tuned by carefully placing the nitrogen atom in the heterocyclic core. This wide-ranging perspective article focuses on AIs that have considerable utility in drug discovery programs against RNA viruses. The inhibition of influenza A, human immunodeficiency, respiratory syncytial, neurotropic alpha, dengue, ebola, and hepatitis C viruses by AI analogs is extensively reviewed to assess their plausible future potential in antiviral drug discovery. The binding interaction of AIs with the target protein is examined to derive a structural basis for designing new antiviral agents.

Machine learning-based predictive models for identifying high active compounds against HIV-1 integrase

HIV-integrase is an important drug target because it catalyzes chromosomal integration of proviral DNA towards establishing latent infection. Computer-aided drug design has immensely contributed to identifying and developing novel antiviral drugs. We have developed various machine learning-based predictive models for identifying high activity compounds against HIV-integrase. Multiclass models were built using support vector machine with reasonable accuracy on the test and evaluation sets. The developed models were evaluated by rigorous validation approaches and the best features were selected by Boruta method. As compared to the model developed from all descriptors set, a slight improvement was observed among the selected descriptors. Validated models were further used for virtual screening of potential compounds from ChemBridge library. Of the six high active compounds predicted from selected models, compounds 9103124, 6642917 and 9082952 showed the most reasonable binding-affinity and stable-interaction with HIV-integrase active-site residues Asp64, Glu152 and Asn155. This was in agreement with previous reports on the essentiality of these residues against a wide range of inhibitors. We therefore highlight the rigorosity of validated classification models for accurate prediction and ranking of high active lead drugs against HIV-integrase.

Weight Gain and Lipid Profile Changes in Koreans with Human Immunodeficiency Virus undergoing Integrase Strand Transfer Inhibitor-Based Regimens

Background

This study explored the relationship between integrase strand transfer inhibitor (INSTI)-based anti-retroviral agents and weight gain over time, and the risk factors for weight gain in Korean people living with human immunodeficiency virus (PLWH).

Materials and Methods

The study was conducted retrospectively in PLWHs 18 years of age or older who took one of three INSTI-based single-tablet regimens (STRs) (tenofovir disoproxil fumarate/emtricitabine/elvitegravir/cobicistat [TDF/F/EVG/c], tenofovir alafenamide/emtricitabine/elvitegravir/cobicistat [TAF/F/EVG/c], and abacavir/lamivudine/dolutegravir [ABC/3TC/DTG]) for more than 2 years at three university-affiliated hospitals in South Korea from May 2014 to December 2020. Analysis was performed in the treatment-naïve and treatment-experienced groups, respectively.

Results

Individual INSTI-based STRs were associated with weight gain at the 24-month follow up in both treatment-naïve (n = 179) and treatment-experienced (n = 290) groups. Body mass index (BMI) categories changed over time for TAF/F/EVG/c and ABC/3TC/DTG, with significant increases in the rates of overweight and obesity in treatment-naïve patients, whereas there was no change for TDF/F/EVG/c. TAF/F/EVG/c significantly increased total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) compared to other regimens over 24 months. In the treatment-naïve group, a baseline CD4⁺ T cell count <100 cells/mm³, human immunodeficiency virus (HIV) viral load (VL) ≥100,000 copies/mL, no physical exercise, and TAF/F/EVG/c (vs. TDF/F/EVF/c) were risk factors for ≥10% weight gain. In the treatment-experienced group, age <45 years, BMI <25 kg/m², and no physical exercise were risk factors for ≥5% weight gain.

Conclusion

INSTI-based STR continued to increase body weight at the 24-month follow up in treated and untreated Korean PLWH. Exercise, together with demographic-, HIV-, and anti-retroviral therapy-related factors, influenced weight gain. Therefore, when prescribing an INSTI-based STR, weight gain and metabolic changes should be closely monitored in PLWH with these risk factors.

Pharmacokinetic drug interactions of integrase strand transfer inhibitors

The integrase strand transfer inhibitor (INSTI)-containing regimens are currently considered as the first-line treatment of human immunodeficiency virus (HIV) infection. Although possessing a common mechanism of action to inhibit HIV integrase irreversibly to stop HIV replication cycle, the INSTIs, including raltegravir, elvitegravir, dolutegravir, and bictegravir, differ in pharmacokinetic characteristics. While raltegravir undergoes biotransformation by the UDP-glucuronosyltransferases (UGTs), elvitegravir is primarily metabolized by cytochrome P450 (CYP) 3A4 and co-formulated with cobicistat to increase its plasma exposure. The metabolism pathways of dolutegravir and bictegravir are similar, both including CYP3A and UGT1A1, and both agents are substrates to different drug transporters. Because of their differences in metabolism, INSTIs interact with other medications differently through CYP enzymes and transporters as inducers or inhibitors. These drug interactions may become an important consideration in the long-term clinical use because the life expectancy of people with HIV (PWH) approaches to that of the general population. Also, common geriatric challenges such as multimorbidity and polypharmacy have been increasingly recognized in PWH. This review provides a summary of pharmacokinetic interactions with INSTIs and future perspectives in implications of INSTI drug interactions.

A retrospective study of survival and risk factors for mortality among people living with HIV who received antiretroviral treatment in a resource-limited setting

BACKGROUND

The availability and accessibility of effective antiretroviral therapy (ART) for people living with HIV (PLWH) has substantially improved in the past two decades in resource-limited settings. Therefore, evaluation of survival is needed in the current setting.

METHOD

We retrospectively analyzed secondary data of the national AIDS program database from national health security region number 4 among PLWH who were ART-naive between January 2014 and December 2018. All PLWH were followed until December 2019 to evaluate their survival status and possible risk factors related to death.

RESULTS

A total of 42,229 PLWH were identified, of which 14,053 were ART-naive and thus enrolled in the study. Sixty-seven percent were male, the mean ± SD age was 35 ± 12 years, and the median (IQR) baseline CD4 count was 162 (44-353) cells/mm3. Regarding medical care benefits, 46% had a universal health coverage scheme, 34% had a national social security scheme, and 2% had a civil servants medical benefit scheme. A total of 2142 (15%) mortalities occurred during the total follow-up period of 28,254 patient-years. The mortality rate was 7.5 (95% CI 7.2-7.9) per 100 person-years. Survival rates at 1, 2, 3, 4 and 5 years after HIV registration were 88.2% (95% CI 87.6-88.7%), 85.3% (95% CI 84.6-85.9%), 82.9% (95% CI 81.9-83.4%), 81.3% (95% CI 80.5-82.0%) and 75.1% (95% CI 73.5-76.8%), respectively. The Cox proportional hazards model showed that all-cause mortality was associated with a history of ART switching (HR = 7.06, 95% CI 4.53-11.00), major opportunistic infections during ART (HR = 1.93, 95% CI 1.35-2.77), baseline CD4 count ≤ 200 vs. > 500 cells/mm3 (HR = 4.00, 95% CI 1.45-11.11), age ≥ 50 vs. < 30 years (HR = 1.77, 95% CI 1.12-2.78), and receiving nevirapine-based regimens(HR = 1.43, 95% CI 1.04-1.97).

CONCLUSIONS

This study demonstrated the substantial mortality rate over the consecutive 5 years of the follow-up period among PLWH who received ART in a resource-limited setting. Early case finding and prompt initiation of ART as well as continuous HIV care are a cornerstone to improve survival.

Integrase Inhibitor Prescribing Disparities in the DC and Johns Hopkins HIV Cohorts

Integrase inhibitors (INSTIs) are recommended by expert panels as initial therapy for people with HIV. Because there can be disparities in prescribing and uptake of novel and/or recommended therapies, this analysis assessed potential INSTI prescribing disparities using a combined data set from the Johns Hopkins HIV Clinical Cohort and the DC Cohort. We performed multivariable logistic regression to identify factors associated with ever being prescribed an INSTI. Disparities were noted, including clinic location, age, and being transgender. Identifying disparities may allow clinicians to focus their attention on these individuals and ensure that therapy decisions are grounded in valid clinical reasons.

The Use of Integrase Strand Transfer Inhibitors to Treat HIV in Pregnancy

For pregnant women with HIV, antiretroviral therapy (ART) plays a key role in prevention of perinatal transmission. Newer antiretroviral regimens now contain integrase strand transfer inhibitors, which have been found to rapidly suppress HIV viral load in nonpregnant women; however, there are limited data for use in pregnancy. Here, we present the case of a pregnant woman with well-controlled HIV on a well-tolerated prepregnancy regimen of bictegravir, emtricitabine, and tenofovir alafenamide. As there are limited safety data on bictegravir in pregnancy, this ART regimen was changed to a preferred regimen for pregnancy. In the second trimester, because of adverse effects from the new ART regimen and after a risk-benefit discussion, the patient restarted the original regimen. She was able to maintain viral suppression until giving birth.

Design, Synthesis, Molecular Modeling and Anti-HIV Assay of Novel Quinazolinone Incorporated Coumarin Derivatives

BACKGROUND

The emergence of drug-resistant viral strains has created the need for the development of novel anti-HIV agents with a diverse structure that targets key enzymes in the HIV lifecycle.

OBJECTIVE

Considering the pharmacophore of integrase inhibitors, one of the validated targets for anti-HIV therapy, we designed a quinazolinone incorporated coumarin scaffold to affect HIV.

METHODS

Coumarin is a beta enol ester and also a well-known drug scaffold. Designed structures were prepared using a one-pot three-component reaction from 3-amino-4-hydroxycoumarin, isatoic anhydride and benzaldehyde derivatives.

RESULTS

In vitro anti-HIV and cytotoxicity assay indicated that more than half of the compounds had EC50 values lower than 50 µM. Unsubstituted phenyl derivative showed the highest activity and selectivity with an EC50 value of 5 µM and a therapeutic index of 7. Compounds were docked into the integrase active site to investigate the probable mechanism of action. Accordingly, the hydroxyl moiety of coumarin along with the carbonyl of the quinazolinone ring could function as the metal chelating group. Quinazolinone and phenyl groups interact with side chains of IN residues, as well.

CONCLUSION

Here, a novel anti-HIV scaffold is represented for further modification and in-vivo studies.

Effectiveness of dolutegravir-based antiretroviral treatment for HIV-2 infection: retrospective observational study from Western India

BACKGROUND

Data on the use of dolutegravir for treatment of HIV-2 infection are limited.

OBJECTIVES

To assess the effectiveness of dolutegravir in people living with HIV-2 (PLHIV-2).

METHODS

A retrospective chart review was performed in two clinics in Western India. PLHIV-2 initiated on dolutegravir-based regimens were included. Response to treatment in both treatment-naive (TN) and treatment-experienced (TE; substitution and not in the context of failure) was assessed by CD4 counts and HIV-2 viral load (VL) in a proportion of individuals. The primary objective was to assess immunological effectiveness (absence of a drop in absolute CD4 counts by more than 30% of baseline). Change in absolute CD4 counts was assessed by fitting a mixed-effects model.

RESULTS

Sixty-two PLHIV-2 treated with dolutegravir were included. The immunological effectiveness rates (95% CI) were 91.9% (82.4%-96.5%), 92% (81.1%-96.8%) and 91.6% (64.6%-98.5%) amongst all, TE and TN individuals, respectively. Median change in absolute CD4 counts at 6, 12 and 18 months were +29 cells/mm3, +101 cells/mm3 and +72 cells/mm3, respectively. The virological effectiveness rates (HIV-2 VL <100 copies/mL) (95% CI) for all, TE and TN individuals were 88.8% (74.6%-95%), 89.6% (73.6%-96.4%) and 85.7% (48.6%-97.4%), respectively. Three clinical events were documented: spinal tuberculosis, relapsed non-Hodgkin's lymphoma and herpes simplex virus retinitis. One individual reported self-limiting somnolence.

CONCLUSIONS

Dolutegravir was well tolerated and associated with immunological, virological and clinical effectiveness in both TN and TE PLHIV-2 in a large cohort from Western India. Dolutegravir-based ART is an excellent option for treatment of individuals with HIV-2 infection.

Small Molecule HIV-1 Attachment Inhibitors: Discovery, Mode of Action and Structural Basis of Inhibition

Viral entry into host cells is a critical step in the viral life cycle. HIV-1 entry is mediated by the sole surface envelope glycoprotein Env and is initiated by the interaction between Env and the host receptor CD4. This interaction, referred to as the attachment step, has long been considered an attractive target for inhibitor discovery and development. Fostemsavir, recently approved by the FDA, represents the first-in-class drug in the attachment inhibitor class. This review focuses on the discovery of temsavir (the active compound of fostemsavir) and analogs, mechanistic studies that elucidated the mode of action, and structural studies that revealed atomic details of the interaction between HIV-1 Env and attachment inhibitors. Challenges associated with emerging resistance mutations to the attachment inhibitors and the development of next-generation attachment inhibitors are also highlighted.

Low Frequency of Integrase Inhibitor Resistance Mutations Among Therapy-Naïve HIV Patients in Southeast China

BACKGROUND

With the widespread use of integrase strand transfer inhibitors (INSTIs) in the clinical setting, transmission of INSTIs-resistance mutations may increase. Data regarding transmitted drug resistance mutations (TDRM) to INSTIs in Chinese HIV patients are limited. The aim of this study was to summarize the INSTIs TDRM, including the frequency of protease inhibitors (PIs) and reverse transcriptase (RT) inhibitors (RTIs) mutations in treatment-naïve patients in Southeast China.

METHODS

HIV-1 positive patients were retrospectively selected between April 2018 and October 2020 from the Mengchao Hepatobiliary Hospital of Fujian Medical University, the largest designated HIV/AIDS care hospital in Southeast China. Individuals who were antiretroviral therapy-naïve and received antiretroviral drug resistance testing at baseline were included. Clinical data including demographic data, CD4 counts, HIV-RNA loads, and drug resistance mutations were collected.

RESULTS

A total of 147 patients were enrolled. INSTIs TDRM was rare, with only one primary integrase mutation E138K observed in one sample and one secondary mutation E157Q detected in another sample. The overall prevalence of INSTIs TDRM was 1.36%. A substantial proportion of patients harbored common INSTIs-associated polymorphic variants. Two samples harbored the T215S, M184V and K70E mutations related to nucleoside RTIs (NRTIs). Twelve patients carried nonnucleoside RTIs (NNRTIs)-resistance mutations. Two individuals harbored PIs-resistance mutations: Q58E in one patient and M46I, I54V, V82A, L10F, and Q58E mutations in another patient. The total TDRM rate for RTIs and PIs was 10.20% (15/147), but only 0.68% (1/147) was according to the WHO recommendations on TDRM.

CONCLUSION

The rate of INSTIs TDRM was low among therapy-naïve HIV patients in Southeast China. INSTIs as a first-line regimen are suitable for untreated HIV-1 patients in Southeast China. But special attention must be still paid to INSTIs TDRM in clinical practice.

HIV-1 resistance patterns to integrase inhibitors in Chilean patients with virological failure on raltegravir-containing regimens

In this viewpoint we would like to describe our results in terms of resistance pattern in Chilean patients with virological failure (VF) on raltegravir (RAL)-containing-regimens and highlight the need for the concomitant availability of genotypic resistance testing to integrase strand transfer inhibitors (INSTIs) introduction in antiretroviral regimens, particularly in countries in South America. Indeed we found in our study the presence of two or more primary mutations in some of the participants which is associated with cross-resistance to all INSTIs. By using timely genotyping, we could optimally manage these patients, early after detection of VF.

Treatment outcomes of integrase inhibitors, boosted protease inhibitors and nonnucleoside reverse transcriptase inhibitors in antiretroviral-naïve persons starting treatment

OBJECTIVES

Although outcomes of antiretroviral therapy (ART) have been evaluated in randomized controlled trials, experiences from subpopulations defined by age, CD4 count or viral load (VL) in heterogeneous real-world settings are limited.

METHODS

The study design was an international multicohort collaboration. Logistic regression was used to compare virological and immunological outcomes at 12 ± 3 months after starting ART with an integrase strand transfer inhibitor (INSTI), contemporary nonnucleoside reverse transcriptase inhibitor (NNRTI) or boosted protease inhibitor (PI/b) with two nucleos(t)ides after 1 January 2012. The composite treatment outcome (cTO) defined success as VL < 200 HIV-1 RNA copies/mL with no regimen change and no AIDS/death events. Immunological success was defined as a CD4 count > 750 cells/μL or a 33% increase where the baseline CD4 count was ≥ 500 cells/μL. Poisson regression compared clinical failures (AIDS/death ≥ 14 days after starting ART). Interactions between ART class and age, CD4 count, and VL were determined for each endpoint.

RESULTS

Of 5198 ART-naïve persons in the International Cohort Consortium of Infectious Diseases (RESPOND), 45.4% started INSTIs, 26.0% PI/b and 28.7% NNRTIs; 880 (17.4%) were aged > 50 years, 2539 (49.4%) had CD4 counts < 350 cells/μL and 1891 (36.8%) had VL > 100 000 copies/mL. Differences in virological and immunological success and clinical failure among ART classes were similar across age groups (≤ 40, 40-50 and > 50 years), CD4 count categories (≤ 350 vs. > 350 cells/μL) and VL categories at ART initiation (≤ 100 000 vs. > 100 000 copies/mL), with all investigated interactions being nonsignificant (P > 0.05).

CONCLUSIONS

Differences among ART classes in virological, immunological and clinical outcomes in ART-naïve participants were consistent irrespective of age, immune suppression or VL at ART initiation. While confounding by indication cannot be excluded, this provides reassuring evidence that such subpopulations will equally benefit from contemporary ART.

Pharmacokinetics of HIV-Integrase Inhibitors During Pregnancy: Mechanisms, Clinical Implications and Knowledge Gaps

Prevention of mother-to-child transmission of HIV and optimal maternal treatment are the most important goals of antiretroviral therapy in pregnant women with HIV. These goals may be at risk due to possible reduced exposure during pregnancy caused by physiological changes. Limited information is available on the impact of these physiological changes. This is especially true for HIV-integrase inhibitors, a relatively new class of drugs, recommended first-line agents and hence used by a large proportion of HIV-infected patients. Therefore, the objective of this review is to provide a detailed overview of the pharmacokinetics of HIV-integrase inhibitors in pregnancy. Second, this review defines potential causes for the change in pharmacokinetics of HIV-integrase inhibitors during pregnancy. Despite increased clearance, for raltegravir 400 mg twice daily and dolutegravir 50 mg once daily, exposure during pregnancy seems adequate; however, for elvitegravir, the proposed minimal effective concentration is not reached during pregnancy. Lower exposure to these drugs may be caused by increased hormone levels and, subsequently, enhanced drug metabolism during pregnancy. The pharmacokinetics of bictegravir and cabotegravir, which are under development, have not yet been evaluated in pregnant women. New studies need to prospectively assess whether adequate exposure is reached in pregnant women using these new HIV-integrase inhibitors. To further optimize antiretroviral treatment in pregnant women, studies need to unravel the underlying mechanisms behind the changes in the pharmacokinetics of HIV-integrase inhibitors during pregnancy. More knowledge on altered pharmacokinetics during pregnancy and the underlying mechanisms contribute to the development of effective and safe antiretroviral therapy for HIV-infected pregnant women.

HIV-1 Integrase Diversity and Resistance-Associated Mutations and Polymorphisms Among Integrase Strand Transfer Inhibitor-Naive HIV-1 Patients from Cameroon

The World Health Organization (WHO) has put forth recommendations for the use of integrase (IN) strand transfer inhibitors (INSTIs) to be part of the first-line combination antiretroviral therapy regimen to treat HIV infections. The knowledge of pretreatment drug resistance against INSTIs is still scarce in resource-limited settings (RLS). We characterized the integrase gene to identify resistance-associated mutations (RAMs) in 56 INSTI-naive patient viral sequences from Cameroon. Study analysis used 37 sequences with fragment size ≥500 bp or of good quality .The majority of the sequences were identified as CRF02_AG 54.% (n = 20/37) and 45.9% (n = 17/37), other subtype viral sequences include (A, CRF36_cpx, F,G, and C). A total of 18.9% (n = 7/37) of the sequences had RAMs, with only 5.4% (n = 2/37) having major RAMs (Y143R/C/D/G and P145S), against INSTIs. Accessory RAMs were present in 8.1% (n = 3/37) of the sequences, of which one sequence contained solely E157Q, and another Q95K. One patient sequence had three accessory RAMs (G140E, E157Q, and G163R). We identified major RAMs to INSTIs, which might have a potential clinical impact to dolutegravir rollout in RLS, including Cameroon. This is the first study to describe RAMs among INSTI-naive people living with HIV-1 (PLHIV-1) infected with CRF02_AG and other subtypes in Cameroon.

Psychiatric Disorders after Switching to Dolutegravir: A Case Report of a 59-Year-Old Virosuppressed HIV-1 Positive Woman

We report a case of a woman who experienced psychiatric disorders after switching her antiretroviral therapy (c-ART) to dolutegravir (DTG). She is a 59-year-old HIV-1 positive woman with a recent story of cardiovascular disorders treated with beta-blockers, clopidogrel, and rosuvastatin. She underwent a c-ART switch from darunavir/cobicistat and maraviroc to emtricitabine/tenofovir alafenamide fumarate in association with dolutegravir due to drug-drug interactions. One week later, she started to show psychiatric symptoms that required admission to the psychiatric unit. These disorders resolved within a couple of days after DTG discontinuation to allow a regular discharge. With this case-report, we would like to analyse the possible correlation between integrase inhibitor and severe psychiatric disorders in order to confirm the evidences already published in literature.

Adherence to Antiretroviral Regimens in Australia: A Nationwide Cohort Study

The lifetime use of combination antiretroviral therapy (cART) highlights the need to understand patterns of and factors associated with adherence to cART. In this cohort study using a 10% random sample of dispensing claims data for eligible Australians, we identified 2042 people dispensed cART between January 2016 and December 2017 (mean age 48.0 ± 12.0 years old, 88.6% male, and 85.9% treatment experienced). We considered people to be adherent if the proportion of treatment coverage days was ≥80% in the 360 days after their first observed cART dispensing. We also used group-based trajectory modeling (GBTM) to examine different patterns of adherence for 360 days from first observed cART dispensing. Most commonly, people receiving cART were treated with two nucleoside/nucleotide reverse transcriptase inhibitors with an integrase strand transfer inhibitors (INSTI-46.6%). Overall, 1708 people [83.6% (95% confidential interval 82.0-85.3%)] remained adherent over 360 days. GBTM identified three distinct adherence patterns: nearly always adherent [67.8% (63.7-71.9%) of the cohort], moderate adherence [26.6% (23.0-30.1%)], and low adherence [5.6% (4.1-7.2%)]. People were more likely to belong to the "nearly always adherent" trajectory if they were older (per additional year of age), treated with an INSTI regimen, and on treatment for more than 6 months. Our study demonstrates that the 360-day adherence to cART is generally high, but approximately one-third maintain a moderate or low adherence pattern. The use of INSTI regimens and additional support of treatment adherence, especially among younger people and those initiating therapy, may further improve adherence.

Impact of an Antimicrobial Stewardship Team on Reducing Antiretroviral Medication Errors

Background: Numerous interventions have been used to reduce medication errors related to antiretroviral (ARV) therapy for hospitalized patients with HIV. Objective: This study assessed the impact of an antimicrobial stewardship (ASP) team intervention on reducing the rate of ARV therapy errors in patients admitted to an academic medical center. Methods: This observational, retrospective study included patients who received ARV therapy from June 2016 to December 2017. The primary outcome was evaluation of ASP team performance in detecting ARV medication errors in the inpatient setting. Errors were further categorized by type (interaction, dosing, regimen). The Mann-Whitney U test and χ² tests were utilized to analyze continuous and categorical data, respectively. Results: Medication errors occurred in 51% of patients in the preintervention group (n = 152) and 48% of patients in the postintervention group (n = 203; P = 0.43). The most frequent medication error type was drug interactions in both groups, involving integrase strand transfer inhibitors and polyvalent cations (64% vs 67%). There was a significant difference between preintervention and postintervention groups regarding number of errors detected (13 vs 106, P < 0.001), corrected (12 vs 86, P < 0.001), and persisting at discharge (106 vs 18, P < 0.001). Conclusion and Relevance: Review of ARV regimens by an ASP team significantly decreased medication errors. Drug interactions are the most common medication error found in HIV-positive patients admitted to our academic center.

Prevalence and clinical impact of minority resistant variants in patients failing an integrase inhibitor-based regimen by ultra-deep sequencing

Background

Integrase strand transfer inhibitors (INSTIs) are recommended by international guidelines as first-line therapy in antiretroviral-naive and -experienced HIV-1-infected patients.

Objectives

This study aimed at evaluating the prevalence at failure of INSTI-resistant variants and the impact of baseline minority resistant variants (MiRVs) on the virological response to an INSTI-based regimen.

Methods

Samples at failure of 134 patients failing a raltegravir-containing (n = 65), an elvitegravir-containing (n = 20) or a dolutegravir-containing (n = 49) regimen were sequenced by Sanger sequencing and ultra-deep sequencing (UDS). Baseline samples of patients with virological failure (VF) (n = 34) and of those with virological success (VS) (n = 31) under INSTI treatment were sequenced by UDS. Data were analysed using the SmartGene platform, and resistance was interpreted according to the ANRS algorithm version 27.

Results

At failure, the prevalence of at least one INSTI-resistant variant was 39.6% by Sanger sequencing and 57.5% by UDS, changing the interpretation of resistance in 17/134 (13%) patients. Among 53 patients harbouring at least one resistance mutation detected by both techniques, the most dominant INSTI resistance mutations were N155H (45%), Q148H/K/R (23%), T97A (19%) and Y143C (11%). There was no difference in prevalence of baseline MiRVs between patients with VF and those with VS. MiRVs found at baseline in patients with VF were not detected at failure either in majority or minority mutations.

Conclusions

UDS is more sensitive than Sanger sequencing at detecting INSTI MiRVs at treatment failure. The presence of MiRVs at failure could be important to the decision to switch to other INSTIs. However, there was no association between the presence of baseline MiRVs and the response to INSTI-based therapies in our study.

Dolutegravir based antiretroviral therapy compared to other combined antiretroviral regimens for the treatment of HIV-infected naive patients: A systematic review and meta-analysis

Background

Numerous randomized clinical trials (RCTs) were conducted to evaluate dolutegravir based triple antiretroviral therapy (ART) compared to other triple antiretroviral regimens in naïve patients, and a summary of the available evidence is required to shed more light on safety and effectiveness issues.

Methods

Systematic review and meta-analysis of RCTs comparing dolutegravir-containing ART to non-dolutegravir containing ART in HIV-infected naive patients. Primary outcomes: % of patients with viral load<50 copies/mL at 48 weeks, stratified according to baseline viral load levels (< or >100.000 copies/mL); overall rate of discontinuation and/or switching for any cause (virologic failure, clinical failure, adverse events). Measure of treatment effect: Risk Difference (RD) with 95% confidence intervals (CIs). The GRADE system was used to assess the certainty of the body of evidence,

Results

We included 7 RCTs (13 reports, 6407patients) comparing dolutegravir containing to non-dolutegravir containing ART, both in combination with 2 NRTIs. Controls were raltegravir or bictegravir (3 RCTs), boosted atazanavir or darunavir (2 RCTs) or efavirenz (2 RCTs). Rates of patients with VL <50 copies/ml were higher in dolutegravir recipients compared to controls at 48 weeks (RD, 0.05; 95% CIs, 0.03/0.08, p = 0.0002) and 96 weeks (RD, 0.06; 95% CIs, 0.03/0.10, p<0.0001); the average benefit of using dolutegravir was particularly evident at 48 weeks in the subgroup of patients with high baseline viral load (RD, 0.10; 95% CIs, 0.05/0.15; p< 0.0001; GRADE assessment: "high certainty of evidence"). Overall rate of discontinuation were lower in dolutegravir compared to controls (RD,-0.03, 95% CIs -0.05/-0.01; p = 0.007). No significant differences were observed in rates of discontinuation due to adverse events (RD, -0.02; 95% CIs, -0.05/0.00), virologic failure (RD, -0.01; 95% CIs, -0.02/0.01), and most common adverse events (GRADE assessment: from “very-low” to “moderate certainty of evidence”)

Conclusion

Starting treatment in naive patients with dolutegravir containing ART has an increased likelihood of achieving viral suppression in the comparison with non-dolutegravir containing ART. The average benefit is particularly evident in those with high baseline viral load.

Paediatric Integrase Inhibitor Use in a Real-Life Setting: A Single-Centre Cohort Experience 2009-2018

BACKGROUND AND OBJECTIVE

Integrase strand transfer inhibitors (INSTIs) have become the preferred first-line antiretroviral therapy in adults. There is paucity of published data on their use in children outside of clinical trials, particularly long-term safety and tolerability. This study aimed to describe INSTI use including the number of, and reasons for INSTI discontinuation.

METHODS

We conducted a retrospective cohort analysis by database and electronic record review of children aged under 18 years with perinatally acquired human immunodeficiency virus who started INSTI-based antiretroviral therapy between May 2009 and March 2018, in a single tertiary centre.

RESULTS

Fifty-six INSTI-based regimens were prescribed in 54 children, 64.9% from 2015 onwards. Twenty-one of 56 (37.5%) regimens commenced with raltegravir, 29 (51.8%) with dolutegravir and six (10.7%) with elvitegravir. The median age at the start of treatment was 15 years (interquartile range 13.5-16.4) with a median duration of INSTI-antiretroviral therapy of 1.65 years (range 0.01-8.8). Twenty-four children had a detectable viral load at the start INSTI therapy; 20 (83%) achieving viral suppression in a median of 26 days (interquartile range 19.5-34.5). There were 26 discontinuations of INSTI-based antiretroviral therapy after a median of 183 days; 9/26 because of adverse events. Four of nine adverse events were attributed to INSTI use, all in patients taking dolutegravir and the adverse events were neuropsychiatric and gastrointestinal in nature.

CONCLUSIONS

INSTI-based regimens were generally efficacious and well tolerated in this paediatric cohort, with 4/26 discontinuations due to INSTI-attributed adverse events. Further post-marketing surveillance of INSTI use in children is warranted.

Inhibition of Plasmodium falciparum cysteine protease falcipain-2 by a human cross-class inhibitor serpinB3: A mechanistic insight

Falcipain-2(FP2), a cysteine protease from Plasmodium falciparum, cleaves host erythrocyte hemoglobin and specific membrane skeleton components during the parasite life cycle. Therefore its inhibition has been considered as an attractive approach to combat the disease. SerpinB3 (SPB3) belongs to the ovalbumin-serpin family and is a potent cross-class inhibitor of cysteine cathepsins L, K, S and papain. This study explored the possibility of inhibition of FP2 by SPB3. It turned out that general proteolytic activities as well as specific hemoglobinolytic activity of FP2 have been inhibited by SPB3. Furthermore, studies have been designed to investigate and characterize the mechanism of inhibition in comparison with proteases Cathepsin L (CTSL) and papain. The Ki value of inhibition for FP2, measured against its specific substrate (VLK-pNA), is 338.11 nM and stoichiometry (I/E ratio) of inhibition is 1. These values are comparable to CTSL and papain. Analytical gel filtration profile and CD spectroscopy data confirm FP2-SPB3 complex formation. Our studies revealed that interaction of SPB3 with FP2 is non-covalent type like that of CTSL and papain but unlike other serine protease-inhibiting serpins. An in-silico docking and simulation study have been performed with FP2 as well as CTSL and results suggest different binding mode for FP2 and CTSL, though both the complexes are stable with significant contribution from electrostatic energy of interaction. We further showed a disease state mutant SPB3-Gly351Ala performed better anti-protease activity against FP2. This study, for the first time, has shown a serpin family inhibitor from human could efficiently inhibit activity of FP2.

Initial Antiretroviral Therapy in an Integrase Inhibitor Era: Can We Do Better?

With the second-generation integrase inhibitors (dolutegravir and bictegravir) extending the attributes of earlier integrase inhibitors, three-drug regimens containing integrase inhibitors plus two nucleos(t)ide reverse transcriptase inhibitors are now widely recommended for first-line (initial) treatment of human immunodeficiency virus-1 infection. Led by dolutegravir plus lamivudine, two-drug therapy is emerging as a way to reduce antiretroviral therapy cost and adverse effects without compromising treatment options should virologic failure occur. Initial two-drug therapy has limitations, including the relative incompatibility with the coemerging concept of same-day antiretroviral therapy initiation.

Assessment of antiretroviral third agent virologic durability after initiation of first antiretroviral regimen

Information on the virologic durability of modern antiretroviral regimens is important to clinicians. We aimed to describe virologic durability of first-line integrase strand transfer inhibitor (INSTI)-, nonnucleoside reverse transcriptase inhibitor (NNRTI)-, or protease inhibitor (PI)-based antiretroviral regimens. This was a retrospective study of antiretroviral-naïve patients that initiated first-line antiretroviral regimens with two nucleoside reverse transcriptase inhibitors and an INSTI, NNRTI, or PI between January 2006 and June 2016. The outcome was time to virologic failure, which was assessed by Kaplan-Meier survival analysis and Cox regression models. There were 780 patients (median age = 37 years [interquartile range (IQR) = 30-45], 93.3% male, 56.2% Caucasian, median HIV duration = 1.8 years [IQR = 0.4-5.4], baseline log₁₀ viral load [VL]=4.6 [IQR = 4.1-5.1], and baseline CD4+ cell count = 320 cells/µl [IQR = 217-440]). In total, 189/780 were on a third agent INSTI, 339/780 on a third agent NNRTI, and 252/780 on a third agent PI. Kaplan-Meier survival probability revealed longer time to virologic failure for INSTI, followed by NNRTI then PI (p < 0.001). Multivariable Cox regression revealed that being on an INSTI regimen (aHR = 0.27; 95%CI = 0.18-0.41) or NNRTI regimen (aHR = 0.64; 95%CI = 0.47-0.87) versus PI regimen, frequent VL testing (per year), (aHR = 0.64; 95%CI = 0.47-0.87), and duration of ART (aHR = 0.22; 95%CI = 0.17-0.30) (years) were inversely associated with time to virologic failure, and log₁₀ of baseline VL (aHR = 1.94; 95%CI = 1.58-2.39 per log₁₀) increased risk. Virologic failure was delayed and virologic durability prolonged for INSTI- compared to NNRTI- and PI-based regimens, supporting current antiretroviral therapy guidelines.

Pharmacokinetics of HIV-Integrase Inhibitors During Pregnancy: Mechanisms, Clinical Implications and Knowledge Gaps

Prevention of mother-to-child transmission of HIV and optimal maternal treatment are the most important goals of antiretroviral therapy in pregnant women with HIV. These goals may be at risk due to possible reduced exposure during pregnancy caused by physiological changes. Limited information is available on the impact of these physiological changes. This is especially true for HIV-integrase inhibitors, a relatively new class of drugs, recommended first-line agents and hence used by a large proportion of HIV-infected patients. Therefore, the objective of this review is to provide a detailed overview of the pharmacokinetics of HIV-integrase inhibitors in pregnancy. Second, this review defines potential causes for the change in pharmacokinetics of HIV-integrase inhibitors during pregnancy. Despite increased clearance, for raltegravir 400 mg twice daily and dolutegravir 50 mg once daily, exposure during pregnancy seems adequate; however, for elvitegravir, the proposed minimal effective concentration is not reached during pregnancy. Lower exposure to these drugs may be caused by increased hormone levels and, subsequently, enhanced drug metabolism during pregnancy. The pharmacokinetics of bictegravir and cabotegravir, which are under development, have not yet been evaluated in pregnant women. New studies need to prospectively assess whether adequate exposure is reached in pregnant women using these new HIV-integrase inhibitors. To further optimize antiretroviral treatment in pregnant women, studies need to unravel the underlying mechanisms behind the changes in the pharmacokinetics of HIV-integrase inhibitors during pregnancy. More knowledge on altered pharmacokinetics during pregnancy and the underlying mechanisms contribute to the development of effective and safe antiretroviral therapy for HIV-infected pregnant women.

Bictegravir in a fixed-dose tablet with emtricitabine and tenofovir alafenamide for the treatment of HIV infection: pharmacology and clinical implications

INTRODUCTION

Current antiretroviral therapy is more effective and simpler than in previous times due to the development of new drugs with improved pharmacokinetic and pharmacodynamic profiles and the advent of single pill regimens with low toxicity that facilitate long-term adherence. The recent approval of the novel potent integrase strand-transfer inhibitor bictegravir (BIC) co-formulated with emtricitabine (FTC) and tenofovir alafenamide (TAF) in a fixed daily dose pill, B/F/TAF, adds to the list of single-tablet regimens available to treat HIV infection. Areas covered: This review provides an overview of the pharmacological and clinical information obtained from MEDLINE/PubMed publications and the latest international conferences. Expert opinion: BIC is a potent antiretroviral with an improved resistance profile over previous integrase inhibitors. Its combination with the new tenofovir prodrug TAF and FTC creates an effective regimen B/F/TAF for treatment-naïve patients and for those switching from another successful combination. B/F/TAF's favorable pharmacokinetic profile, simple dose, low pill burden, and few drug-drug interactions or treatment-related adverse events, will make it one of the preferred regimens in the future.

Current and Future Therapeutic Strategies for Lentiviral Eradication from Macrophage Reservoirs

Macrophages, one of the most abundant populations of leukocytes in the body, function as the first line of defense against pathogen invaders. Human Immunodeficiency virus 1 (HIV-1) remains to date one of the most extensively studied viral infections. Naturally occurring lentiviruses in domestic and primate species serve as valuable models to investigate lentiviral pathogenesis and novel therapeutics. Better understanding of the role macrophages play in HIV pathogenesis will aid in the advancement towards a cure. Even with current efficacy of first- and second-line Antiretroviral Therapy (ART) guidelines and future efficacy of Long Acting Slow Effective Release-ART (LASER-ART); ART alone does not lead to a cure. The major challenge of HIV eradication is viral latency. Latency Reversal Agents (LRAs) show promise as a possible means to eradicate HIV-1 from the body. It has become evident that complete eradication will need to include combinations of various effective therapeutic strategies such as LASER-ART, LRAs, and gene editing. Review of the current literature indicates the most promising HIV eradication strategy appears to be LASER-ART in conjunction with viral and receptor gene modifications via the CRISPR/Cas9 system. Graphical abstract A multimodal approach to HIV treatment including gene editing, LASER-ART, and latency reversal agents may provide a means to achieve HIV eradication.

Impact of UGT1A1 polymorphisms on Raltegravir and its glucuronide plasma concentrations in a cohort of HIV-1 infected patients

The aim of this study was to evaluate the effect of UGT1A1 polymorphisms on Raltegravir (RAL) and its metabolite RAL-glucuronide trough plasma concentrations ([RAL]plasma and [RAL-glu]plasma) and on the metabolic ratio (MR): [RAL-glu]plasma/[RAL]plasma. UGT1A1 genotyping was performed on 96 patients. 44% (n = 42) were homozygous UGT1A1*1/*1 while 50% (n = 48) and 6% (n = 6) were UGT1A1*28 and UGT1A1*36 carriers, respectively. The median concentration and interquartile range (IQR) of [RAL]plasma were 88.5 ng/ml (41.0-236), 168 ng/ml (85.8-318) and 92.5 ng/ml (36.4-316) for UGT1A1*1/*1, UGT1A1*28 and UGT1A1*36 carriers, respectively. Only the difference between UGT1A1*1/*1 and *28 carriers was statistically significant (p = 0.022). The median MR (IQR) were 5.8 (3-10), 2.9 (1.6-5.3) and 3.2 (1.7-5.9) for UGT1A1*1/*1, UGT1A1*28 and UGT1A1*36 carriers, respectively. Only the difference between UGT1A1*1/*1 and *28 carriers was statistically significant (p = 0.004) with an allele-dependent effect: UGT1A1*28 homozygous having lower MR than heterozygous carriers who show lower MR compared to *1/*1. Except for the sensation of fatigue, this PK effect did not correlate with clinical adverse events or biological abnormalities. In Conclusion, we demonstrate that UGT1A1*28 polymorphism has a significant impact on RAL metabolism: UGT1A1*28 carriers being characterized by higher [RAL]plasma and lower MR.

Impact of the HIV-1 genetic background and HIV-1 population size on the evolution of raltegravir resistance

BACKGROUND

Emergence of resistance against integrase inhibitor raltegravir in human immunodeficiency virus type 1 (HIV-1) patients is generally associated with selection of one of three signature mutations: Y143C/R, Q148K/H/R or N155H, representing three distinct resistance pathways. The mechanisms that drive selection of a specific pathway are still poorly understood. We investigated the impact of the HIV-1 genetic background and population dynamics on the emergence of raltegravir resistance. Using deep sequencing we analyzed the integrase coding sequence (CDS) in longitudinal samples from five patients who initiated raltegravir plus optimized background therapy at viral loads > 5000 copies/ml. To investigate the role of the HIV-1 genetic background we created recombinant viruses containing the viral integrase coding region from pre-raltegravir samples from two patients in whom raltegravir resistance developed through different pathways. The in vitro selections performed with these recombinant viruses were designed to mimic natural population bottlenecks.

RESULTS

Deep sequencing analysis of the viral integrase CDS revealed that the virological response to raltegravir containing therapy inversely correlated with the relative amount of unique sequence variants that emerged suggesting diversifying selection during drug pressure. In 4/5 patients multiple signature mutations representing different resistance pathways were observed. Interestingly, the resistant population can consist of a single resistant variant that completely dominates the population but also of multiple variants from different resistance pathways that coexist in the viral population. We also found evidence for increased diversification after stronger bottlenecks. In vitro selections with low viral titers, mimicking population bottlenecks, revealed that both recombinant viruses and HXB2 reference virus were able to select mutations from different resistance pathways, although typically only one resistance pathway emerged in each individual culture.

CONCLUSIONS

The generation of a specific raltegravir resistant variant is not predisposed in the genetic background of the viral integrase CDS. Typically, in the early phases of therapy failure the sequence space is explored and multiple resistance pathways emerge and then compete for dominance which frequently results in a switch of the dominant population over time towards the fittest variant or even multiple variants of similar fitness that can coexist in the viral population.

Predicting poor adherence to antiretroviral therapy among treatment-naïve veterans infected with human immunodeficiency virus

Previous studies suggested that human immunodeficiency virus (HIV) infected patients at risk of poor adherence were not distinguishable only based on the baseline characteristics. This study is to identify patient characteristics that would be consistently associated with poor adherence across regimens and to understand the associations between initial and long-term adherence. HIV treatment-naïve patients initiated on protease inhibitors, nonnucleoside reverse transcriptase inhibitors, or integrase strand transfer inhibitors were identified from the Veteran Health Administration system. Initial adherence measured as initial coverage ratio (ICR) and long-term adherence measured as thereafter 1-year proportion days covered (PDC) of base agent and complete regimen were estimated for each patient. The patients most likely to exhibit poor adherence were African-American, with lower socioeconomic status, and healthier. The initial coverage ratio of base agent and complete regimen were highly correlated, but the correlations between ICR and thereafter 1-year PDC were low. However, including initial adherence as a predictor in predictive model would substantially increase predictive accuracy of future adherence.

Time from HIV infection to virological suppression: dramatic fall from 2007 to 2016

AIM

Time from HIV infection to virological suppression: dramatic fall from 2007 to 2016.

OBJECTIVES

We examined the time from HIV infection to virological suppression in MSM who were first diagnosed at Melbourne Sexual Health Centre between 2007 and 2016.

DESIGN

Retrospective cohort.

METHODS

Date of infection was imputed from the testing history or serological evidence of recent infection (negative or indeterminate western blot) or baseline CD4 cell count. Date of virological suppression was determined using clinical viral load data. We analysed predictors of diagnosis with serological evidence of recent infection (logistic regression) and time from diagnosis to suppression and from infection to suppression (Cox regression) using demographic, clinical, and behavioral covariates.

RESULTS

Between 2007 and 2016, the median time from HIV infection to diagnosis fell from 6.8 to 4.3 months (P = 0.001), from diagnosis to suppression fell from 22.7 to 3.2 months (P < 0.0001), and from infection to suppression fell from 49.0 to 9.6 months (P < 0.0001). Serological evidence of recent infection increased from 15.6 to 34.3% (P < 0.0001) of diagnoses. In the multivariate analyses, age, being recently arrived from a non-English speaking country, history of IDU, other sexually transmitted infections, and sexual risk were not associated with any of these measures.

CONCLUSION

The duration of infectiousness in MSM diagnosed with HIV infection at Melbourne Sexual Health Centre in Victoria has fallen dramatically between 2007 and 2016 and the proportion diagnosed with serological evidence of recent infection has increased. This effect is observed across all population subgroups and marks a positive milestone for the treatment as prevention paradigm.

Quantitative structure–activity relationships study of potent pyridinone scaffold derivatives as HIV-1 integrase inhibitors with therapeutic applications

Human immunodeficiency virus-1 (HIV-1) integrase appears to be a crucial target for developing new anti-HIV-1 therapeutic agents. Different quantitative structure–activity relationships (QSARs) algorithms have been used in order to develop efficient model(s) to predict the activity of new pyridinone derivatives against HIV-1 integrase. Multiple linear regression (MLR) and combined principal component analysis (PCA) with MLR have been applied to build QSAR models for a set of new pyridinone derivatives as potent anti-HIV-1 therapeutic agents. Four different approaches based on MLR method including; concrete-MLR, stepwise-MLR, concrete PCA–MLR and stepwise PCA–MLR were utilized for this aim. Twenty two different sets of descriptors containing 1613 descriptors were constructed for each optimized molecule. Comparison between predictability of the “concrete” and “stepwise” procedure in two different algorithms of MLR and PCA models indicated the advantage of the stepwise procedure over that of the simple concrete method. Although the PCA was employed for dimension reduction, using stepwise PCA–MLR model showed that the method has higher ability to predict the compounds’ activity. The stepwise PCA–MLR model showed highly validated statistical results both in fitting and prediction processes ([Formula: see text] and [Formula: see text]). Therefore, using stepwise PCA approach is suitable to remove ineffective descriptors, which results in remaining efficient descriptors for building good predictability stepwise PCA–MLR. The stepwise hybrid approach of PCA–MLR may be useful in derivation of highly predictive and interpretable QSAR models.

Potential of small-molecule fungal metabolites in antiviral chemotherapy

Various viral diseases, such as acquired immunodeficiency syndrome, influenza, and hepatitis, have emerged as leading causes of human death worldwide. Scientific endeavor since invention of DNA-dependent RNA polymerase of pox virus in 1967 resulted in better understanding of virus replication and development of various novel therapeutic strategies. Despite considerable advancement in every facet of drug discovery process, development of commercially viable, safe, and effective drugs for these viruses still remains a big challenge. Decades of intense research yielded a handful of natural and synthetic therapeutic options. But emergence of new viruses and drug-resistant viral strains had made new drug development process a never-ending battle. Small-molecule fungal metabolites due to their vast diversity, stereochemical complexity, and preapproved biocompatibility always remain an attractive source for new drug discovery. Though, exploration of therapeutic importance of fungal metabolites has started early with discovery of penicillin, recent prediction asserted that only a small percentage (5-10%) of fungal species have been identified and much less have been scientifically investigated. Therefore, exploration of new fungal metabolites, their bioassay, and subsequent mechanistic study bears huge importance in new drug discovery endeavors. Though no fungal metabolites so far approved for antiviral treatment, many of these exhibited high potential against various viral diseases. This review comprehensively discussed about antiviral activities of fungal metabolites of diverse origin against some important viral diseases. This also highlighted the mechanistic details of inhibition of viral replication along with structure-activity relationship of some common and important classes of fungal metabolites.

Current antiviral drugs and their analysis in biological materials - Part II: Antivirals against hepatitis and HIV viruses

This review is a Part II of the series aiming to provide comprehensive overview of currently used antiviral drugs and to show modern approaches to their analysis. While in the Part I antivirals against herpes viruses and antivirals against respiratory viruses were addressed, this part concerns antivirals against hepatitis viruses (B and C) and human immunodeficiency virus (HIV). Many novel antivirals against hepatitis C virus (HCV) and HIV have been introduced into the clinical practice over the last decade. The recent broadening portfolio of these groups of antivirals is reflected in increasing number of developed analytical methods required to meet the needs of clinical terrain. Part II summarizes the mechanisms of action of antivirals against hepatitis B virus (HBV), HCV, and HIV, their use in clinical practice, and analytical methods for individual classes. It also provides expert opinion on state of art in the field of bioanalysis of these drugs. Analytical methods reflect novelty of these chemical structures and use by far the most current approaches, such as simple and high-throughput sample preparation and fast separation, often by means of UHPLC-MS/MS. Proper method validation based on requirements of bioanalytical guidelines is an inherent part of the developed methods.

HIV-associated cellular senescence: A contributor to accelerated aging

Due to the advent of antiretroviral therapy HIV is no longer a terminal disease and the HIV infected patients are becoming increasingly older. While this is a major success, with increasing age comes an increased risk for disease. The age-related comorbidities that HIV infected patients experience suggest that they suffer from accelerated aging. One possible contributor to this accelerated aging is cellular senescence, an age-associated response that can occur prematurely in response to stress, and that is emerging as a contributor to disease and aging. HIV patients experience several stressors such as the virus itself, antiretroviral drugs and to a lesser extent, substance abuse that can induce cellular senescence. This review summarizes the current knowledge of senescence induction in response to these stressors and their relation to the comorbidities in HIV patients. Cellular senescence may be a possible therapeutic target for these comorbidities.

Targeting TNF and TNF Receptor Pathway in HIV-1 Infection: from Immune Activation to Viral Reservoirs

Several cellular functions such as apoptosis, cellular proliferation, inflammation, and immune regulation involve the tumor necrosis factor-α (TNF)/TNF receptor (TNFR) pathway. Human immunodeficiency virus 1 (HIV-1) interacts with the TNF/TNFR pathway. The activation of the TNF/TNFR pathway impacts HIV-1 replication, and the TNF/TNFR pathway is the target of HIV-1 proteins. A hallmark of HIV-1 infection is immune activation and inflammation with increased levels of TNF in the plasma and the tissues. Therefore, the control of the TNF/TNFR pathway by new therapeutic approaches could participate in the control of immune activation and impact both viral replication and viral persistence. In this review, we will describe the intricate interplay between HIV-1 proteins and TNF/TNFR signaling and how TNF/TNFR activation modulates HIV-1 replication and discuss new therapeutic approaches, especially anti-TNF therapy, that could control this pathway and ultimately favor the clearance of infected cells to cure HIV-infected patients.

Antiretroviral therapy in HIV-infected adolescents: clinical and pharmacologic challenges

INTRODUCTION

With the currently available combined antiretroviral therapy regimens, durable suppression of viral replication, preservation of immune function and normalizing life expectancy, are all becoming achievable goals. Teenagers and young adults living with HIV present unique clinical and pharmacologic challenges to optimizing antiretroviral treatment outcomes. Areas covered: In this expert review of the topic, we examine recent clinical trial data and draw on our program's 25 year experience working with both perinatally and behaviorally HIV infected adolescents. Expert commentary: In order to be effective, the antiretrovirals we provide must be combined with multidisciplinary interventions and ongoing socio-behavioral support to ensure treatment adherence and prevent the emergence of viral resistance.

Antiviral Activity of Bictegravir (GS-9883), a Novel Potent HIV-1 Integrase Strand Transfer Inhibitor with an Improved Resistance Profile

Bictegravir (BIC; GS-9883), a novel, potent, once-daily, unboosted inhibitor of HIV-1 integrase (IN), specifically targets IN strand transfer activity (50% inhibitory concentration [IC₅₀] of 7.5 ± 0.3 nM) and HIV-1 integration in cells. BIC exhibits potent and selective in vitro antiretroviral activity in both T-cell lines and primary human T lymphocytes, with 50% effective concentrations ranging from 1.5 to 2.4 nM and selectivity indices up to 8,700 relative to cytotoxicity. BIC exhibits synergistic in vitro antiviral effects in pairwise combinations with tenofovir alafenamide, emtricitabine, or darunavir and maintains potent antiviral activity against HIV-1 variants resistant to other classes of antiretrovirals. BIC displayed an in vitro resistance profile that was markedly improved compared to the integrase strand transfer inhibitors (INSTIs) raltegravir (RAL) and elvitegravir (EVG), and comparable to that of dolutegravir (DTG), against nine INSTI-resistant site-directed HIV-1 mutants. BIC displayed statistically improved antiviral activity relative to EVG, RAL, and DTG against a panel of 47 patient-derived HIV-1 isolates with high-level INSTI resistance; 13 of 47 tested isolates exhibited >2-fold lower resistance to BIC than DTG. In dose-escalation experiments conducted in vitro, BIC and DTG exhibited higher barriers to resistance than EVG, selecting for HIV-1 variants with reduced phenotypic susceptibility at days 71, 87, and 20, respectively. A recombinant virus with the BIC-selected M50I/R263K dual mutations in IN exhibited only 2.8-fold reduced susceptibility to BIC compared to wild-type virus. All BIC-selected variants exhibited low to intermediate levels of cross-resistance to RAL, DTG, and EVG (<8-fold) but remained susceptible to other classes of antiretrovirals. A high barrier to in vitro resistance emergence for both BIC and DTG was also observed in viral breakthrough studies in the presence of constant clinically relevant drug concentrations. The overall virologic profile of BIC supports its ongoing clinical investigation in combination with other antiretroviral agents for both treatment-naive and -experienced HIV-infected patients.