Second-generation Integrase Strand Transfer Inhibitor Research Articles

Effect of ABCB1 most frequent polymorphisms on the accumulation of bictegravir in recombinant HEK293 cell lines

Bictegravir, a key second-generation integrase strand transfer inhibitor in the treatment of HIV, is subject to active efflux transport mediated by ABCB1 (P-glycoprotein). Several coding variants of ABCB1 have been described and associated with variable effects on substrate drugs pharmacokinetics. Here, we investigated the effect of the four most common coding ABCB1 single nucleotide polymorphisms (i.e., c.1199G > A, c.1236C > T, c.2677G > T and c.3435C > T) on the intracellular accumulation of bictegravir. Using a previously validated HEK293 recombinant cell line model, we found decreased bictegravir intracellular concentrations in cell lines overexpressing ABCB1 as compared to control cell lines, in line with the known role of ABCB1 in bictegravir transport. However, we were unable to demonstrate any significant difference in bictegravir intracellular accumulation when comparing HEK293 cells overexpressing the wild type (1236C-2677G-3435C, 1199G) or the variant (1236C-2677G-3435T, 1236T-2677T-3435T or 1199A) proteins. These findings suggest that the ABCB1 c.1199G > A and c.1236C > T-c.2677G > T-c.3435C > T variants have no or at least limited impact on the active transport of bictegravir by ABCB1.

Applying Next-Generation Sequencing to Track HIV-1 Drug Resistance Mutations Circulating in Portugal.

The global scale-up of antiretroviral treatment (ART) offers significant health benefits by suppressing HIV-1 replication and increasing CD4 cell counts. However, incomplete viral suppression poses a potential threat for the emergence of drug resistance mutations (DRMs), limiting ART options, and increasing HIV transmission. We investigated the patterns of transmitted drug resistance (TDR) and acquired drug resistance (ADR) among HIV-1 patients in Portugal. Data were obtained from 1050 HIV-1 patient samples submitted for HIV drug resistance (HIVDR) testing from January 2022 to June 2023. Evaluation of DRM affecting viral susceptibility to nucleoside/tide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), and integrase strand transfer inhibitors (INSTIs) was performed using an NGS technology, the Vela Diagnostics Sentosa SQ HIV-1 Genotyping Assay. About 71% of patients were ART naïve and 29% were experienced. Overall, 20% presented with any DRM. The prevalence of TDR and ADR was 12.6% and 41.1%, respectively. M184V, T215S, and M41L mutations for NRTI, K103N for NNRTI, and M46I/L for PIs were frequent in naïve and treated patients. E138K and R263K mutations against INSTIs were more frequent in naïve than treated patients. TDR and ADR to INSTIs were 0.3% and 7%, respectively. Patients aged 50 or over (OR: 1.81, p = 0.015), originating from Portuguese-speaking African countries (PALOPs) (OR: 1.55, p = 0.050), HIV-1 subtype G (OR: 1.78, p = 0.010), and with CD4 < 200 cells/mm3 (OR: 1.70, p = 0.043) were more likely to present with DRMs, while the males (OR: 0.63, p = 0.003) with a viral load between 4.1 to 5.0 Log10 (OR: 0.55, p = 0.003) or greater than 5.0 Log10 (OR: 0.52, p < 0.001), had lower chances of presenting with DRMs. We present the first evidence on TDR and ADR to INSTI regimens in followed up patients presenting for healthcare in Portugal. We observed low levels of TDR to INSTIs among ART-naïve and moderate levels in ART-exposed patients. Regimens containing PIs could be an alternative second line in patients with intermediate or high-level drug resistance, especially against second-generation INSTIs (dolutegravir, bictegravir, and cabotegravir).

Integrase strand transfer inhibitor resistance mediated by R263K plus E157Q in a patient with HIV infection treated with bictegravir/tenofovir alafenamide/emtricitabine: case report and review of the literature.

The in vivo selection of E157Q plus R263K has not been reported in patients treated with coformulated bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF). To the best of our knowledge, we hereby report the first case of high-grade INSTI resistance associated with the presence of these aminoacidic substitutions in a treatment-experienced HIV patient treated with BIC/FTC/TAF. Clinical case report and review of the literature. A heavily treatment-experienced patient was switched to BIC/FTC/TAF due to drug-drug interactions after being diagnosed with disseminated Mycobacterium avium-intracellulare disease. He had been treated before with raltegravir with poor adherence. No mutations in the integrase gene were detected 1 year after finishing treatment with raltegravir. Months after being switched to BIC/FTC/TAF, and again with poor adherence documented, virological failure (VF) was detected. The polymorphic substitution E157Q and the resistance mutation R263K in the integrase gene were detected, as well as M184V, among other mutations in the reverse transcriptase gene. The patient is currently being treated with dolutegravir q12h plus boosted darunavir along with directly observed treatment, and for the first time in 20 years, plasmatic viral load values are below 100 copies/mL. This case illustrates that the combination of E157Q and R263K plus M184V can be selected in vivo in a clinical scenario of poor adherence with BIC/FTC/TAF, although it is a very rare phenomenon. Previous VF with first-generation integrase strand transfer inhibitors (INSTIs) should be kept in mind when switching patients to second-generation INSTIs.

Trends of pre-treatment drug resistance in antiretroviral-naïve people with HIV-1 in the era of second-generation integrase strand-transfer inhibitors in Taiwan.

Monitoring the trends of pre-treatment drug resistance (PDR) and resistance-associated mutations (RAMs) among antiretroviral-naïve people with HIV (PWH) is important for the implementation of HIV treatment and control programmes. We analysed the trends of HIV-1 PDR after the introduction of second-generation integrase strand-transfer inhibitors (INSTIs) in 2016 in Taiwan, when single-tablet regimens of non-nucleoside reverse-transcriptase inhibitor (NNRTI-) and INSTI-based antiretroviral therapy became the preferred treatments. In this multicentre study, we included newly diagnosed, antiretroviral-naïve PWH who underwent tests for RAMs between 2016 and 2022. Pre-treatment genotypic resistance testing was performed, along with HIV-1 subtyping and determinations of plasma HIV RNA load and CD4 lymphocyte counts. RAMs were analysed using the Stanford University HIV Drug Resistance Database and only RAMs conferring at least low-level resistance were included. From 2016 to 2022, pre-treatment blood samples from 3001 newly diagnosed PWH, which constituted 24.3% of newly diagnosed PWH in Taiwan during the study period, were tested. Of the PWH with analysable gene sequences, the HIV-1 PDR prevalence to NNRTIs, nucleoside reverse-transcriptase inhibitors (NRTIs), first- and second-generation INSTIs and PIs was 10.0%, 2.1%, 2.5%, 0.6% and 0.4%, respectively. While the trends of PDR remained stable for NRTIs, INSTIs and PIs, there was a significantly increasing trend of PDR to NNRTIs from 6.0% in 2016% to 13.1% in 2022 (P = 0.001). After the introduction of second-generation INSTIs in Taiwan, the trends of HIV-1 PDR to NRTIs and INSTIs remained low. Furthermore, there was no significant decrease of the prevalence of PDR toward NNRTIs between 2016 and 2022.

N-Substituted Bicyclic Carbamoyl Pyridones: Integrase Strand Transfer Inhibitors that Potently Inhibit Drug-Resistant HIV-1 Integrase Mutants.

HIV-1 integrase (IN) is an important molecular target for the development of anti-AIDS drugs. A recently FDA-approved second-generation integrase strand transfer inhibitor (INSTI) cabotegravir (CAB, 2021) is being marketed for use in long-duration antiviral formulations. However, missed doses during extended therapy can potentially result in persistent low levels of CAB that could select for resistant mutant forms of IN, leading to virological failure. We report a series of N-substituted bicyclic carbamoyl pyridones (BiCAPs) that are simplified analogs of CAB. Several of these potently inhibit wild-type HIV-1 in single-round infection assays in cultured cells and retain high inhibitory potencies against a panel of viral constructs carrying resistant mutant forms of IN. Our lead compound, 7c, proved to be more potent than CAB against the therapeutically important resistant double mutants E138K/Q148K (>12-fold relative to CAB) and G140S/Q148R (>36-fold relative to CAB). A significant number of the BiCAPs also potently inhibit the drug-resistant IN mutant R263K, which has proven to be problematic for the FDA-approved second-generation INSTIs.

Portable Nanopore sequencing solution for next-generation HIV drug resistance testing

BackgroundTackling HIV drug resistance is one of major challenges for ending AIDS epidemic, but the elevated expense of cutting-edge genomics hampers the advancement of HIV genotype testing for clinical care. MethodsWe developed a HIV genotype testing pipeline that centers on a cost-efficient portable Nanopore sequencer. Accuracy verification was conducted through comparison with parallel data obtained via fixed-site Pacbio sequencing. Our complete pol-gene sequencing strategy coupled with portable high-throughput sequencing was applied to identify drug resistance mutations across 58 samples sourced from the ART-treated Los Angeles General Medical Center Rand Schrader Clinic (LARSC) cohort (7 samples from 7 individuals) and the ART-naïve Center for HIV/AIDS Vaccine Immunology (CHAVI) cohort (51 samples from 38 individuals). ResultsA total of 472 HIV consensus sequences, each tagged with a unique molecular identifier, were produced from over 1.4 million bases acquired through portable Nanopore sequencing, which matched those obtained independently via Pacbio sequencing. With this desirable accuracy, we first documented the linkage of multidrug cross-resistance mutations across Integrase Strand Transfer inhibitors (INSTIs) and Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) from an individual failing a second-generation INSTI regimen. By producing more than 500 full-length HIV pol gene sequences in a single portable sequencing run, we detected Protease Inhibitor (PI), Nucleoside Reverse Transcriptase Inhibitor (NRTI), NNRTI and INSTI resistance mutations. All drug resistance mutations identified through portable sequencing were cross-validated using fixed-site Pacbio sequencing. ConclusionsOur accurate and affordable HIV drug resistance testing solution is adaptable for both individual patient care and large-scale surveillance initiatives.

Characterization of Human Immunodeficiency Virus-1 Transmission Clusters and Transmitted Drug-Resistant Mutations in Croatia from 2019 to 2022.

Molecular epidemiology of HIV-1 infection is challenging due to the highly diverse HIV-genome. We investigated the genetic diversity and prevalence of transmitted drug resistance (TDR) followed by phylogenetic analysis in 270 HIV-1 infected, treatment-naïve individuals from Croatia in the period 2019-2022. The results of this research confirmed a high overall prevalence of TDR of 16.7%. Resistance to nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside RTIs (NNRTIs), and protease inhibitors (PIs) was found in 9.6%, 7.4%, and 1.5% of persons, respectively. No resistance to integrase strand-transfer inhibitors (INSTIs) was found. Phylogenetic analysis revealed that 173/229 sequences (75.5%) were part of transmission clusters, and the largest identified was T215S, consisting of 45 sequences. Forward transmission was confirmed in several clusters. We compared deep sequencing (DS) with Sanger sequencing (SS) on 60 randomly selected samples and identified additional surveillance drug resistance mutations (SDRMs) in 49 of them. Our data highlight the need for baseline resistance testing in treatment-naïve persons. Although no major INSTIs were found, monitoring of SDRMs to INSTIs should be continued due to the extensive use of first- and second-generation INSTIs.

1982. GLP-1 Receptor Agonists Promote Weight Loss Among People with HIV

Abstract Background Weight gain and associated metabolic complications are increasingly prevalent among people with HIV (PWH), especially those initiating second-generation integrase strand transfer inhibitors (INSTIs). Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are incretin-based therapies for diabetes that have been shown to result in substantial weight loss; however, studies of their efficacy in PWH are limited. We aimed to describe the prescribing practices and clinical outcomes of GLP-1 RA use among PWH. Methods We conducted a retrospective cohort study among PWH who were prescribed GLP-1 RAs at University of California, San Diego between 2/1/2021and 2/1/2023. Patients who were prescribed but never took GLP-1 RAs or those for whom weight data were not available after GLP-1 RA initiation were excluded. We collected baseline clinical data and calculated changes in weight, body mass index (BMI), and hemoglobin A1C (A1C) before and during receipt of GLP-1 RA. We conducted logistic regression to identify variables associated with more than 5% of total body weight loss. Results 227 patients met our inclusion criteria. Baseline characteristics are shown in Table 1. Ninety-nine patients (43%) were prescribed GLP-1 RAs for weight management alone without concurrent diabetes. Patients had received on average 15.2 months of GLP-1 RA therapy, with 92 (40.5%) achieving the maximum GLP-1 RA dose. On average, GLP-1 RA therapy resulted in a loss of 12 pounds, decrease in BMI by 1.8, and decrease in A1C by 0.5 among all patients and by 1.2 among patients with an A1C &amp;gt; 6.5 at baseline. In the multivariable analysis, higher baseline BMI [OR 1.07 (1.02-1.3)] and longer treatment duration of GLP-1 RA therapy [OR 1.04 (1.01-1.07)] were significantly more likely to be associated with &amp;gt;5% weight loss, whereas receipt of dulaglutide significantly decreased the likelihood of &amp;gt;5% weight loss compared to other GLP-1 RAs [OR 0.33 (0.17-0.66)]. Age, sex assigned at birth, race, ethnicity, ART regimen, baseline CD4 cell count, HIV viral load, and presence of diabetes were not predictive of weight change.Table 1.Baseline Patient Characteristics (N = 227)Table 2.Mean weight, BMI, and A1C before and during GLP-1 RA therapy for PWH Conclusion Use of GLP-1 RAs led to improvements in weight, BMI, and hemoglobin A1C among PWH and offers an additional strategy to address weight gain and related metabolic complications. Disclosures All Authors: No reported disclosures

1566. Determinants associated with weight gain among persons with HIV who switch to integrase strand transfer inhibitors (INSTI)

Abstract Background Weight gain associated with integrase strand transfer inhibitors (INSTI) has been well documented among patients with HIV. However, recent reports suggest that the observed weight gain among patients who switch to INSTIs may be associated in part with their pre-switch regimen. Methods We conducted retrospective analyses of a 50% sample of all treatment-experienced patients who switched to second-generation INSTI containing regimen (bictegravir/dolutegravir) at the Duke Adult Infectious Diseases Clinic (Durham, NC, USA) between 1 January 2014 and 31 December 2021. Covariates included sex at birth, age, race, ethnicity, pre-switch regimen, body mass index (BMI), CD4 count and HIV-1 viral load. All weights documented within 24 months from regimen switch were included. Outcomes of interest were percent change in weight and absolute weight change. Ordinary least squares was used to obtain average percent weight change from baseline, adjusted for covariates. Results Overall, 339 persons were included in the analyses. Cohort demographics were: median age 51.2 (interquartile range 44.4, 57.6), 73% male sex at birth, 56% Black, 4% Hispanic ethnicity. At regimen switch, median CD4 count was 671 (IQR 460-935), and 78% had a viral load &amp;lt; 200 copies/cc. Mean weight at regimen switch was 87.8 kg (standard deviation [SD] 22.1kg), and mean total weight change over 24 months post-switch was +1.3 kg (SD 7.1 kg). Overall, 28% of cohort members gained &amp;gt;5% of baseline body weight within 24 months of switch. Hispanic ethnicity (5.9% [95% CI 1.0, 10.7]) and BMI &amp;lt; 20 (3.7% [95% CI -0.3, 7.7]) were associated with post-switch weight gain. Only efavirenz-containing pre-switch regimens were significantly associated with weight gain over 24 months post-switch; EFV/FTC/TDF (3.1% [95% CI 0.2, 6.1]), all other EFV-containing regimens (6.3% [95% 0.1-12.4]). Conclusion Pre-switch regimens containing efavirenz were significantly associated with weight gain after switch to second-generation INSTI-based regimens, consistent with findings from non-US based cohorts. Disclosures Nwora Lance Okeke, MD MPH, Gilead Sciences: Advisor/Consultant

Effectiveness of second-generation integrase strand-transfer inhibitor-based regimens for antiretroviral-experienced people with HIV who had viral rebound.

Antiretroviral regimens containing a second-generation integrase strand-transfer inhibitor (INSTI) plus 2 nucleos(t)ide reverse-transcriptase inhibitors (NRTIs) are the recommended therapy for people with HIV (PWH) who are antiretroviral-naïve or on stable antiretroviral therapy (ART) with viral suppression. Real-world data on the virologic effectiveness of co-formulated bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) among PWH with virologic failure while receiving other ART remain sparse. We retrospectively reviewed the medical records of PWH who had viral rebound with plasma HIV RNA >1000 copies/mL and were switched to either dolutegravir combined with 2 NRTIs or BIC/FTC/TAF. The primary end point was re-achieving viral suppression within the first 48 weeks of switch. The association between NRTI-related resistance-associated mutations (RAMs) and virologic effectiveness was examined. Seventy-nine PWH with viral rebound while receiving other antiretroviral regimens were included. Within the first 48 weeks of switch, the overall probability of re-achieving viral suppression was 79.7% (82.5% [33/40] and 76.9% [30/39] for BIC/FTC/TAF and dolutegravir-based regimens, respectively, p=0.78). PWH with a higher CD4 lymphocyte count (adjusted odds ratio, per 100-cell/mm3 increase, 1.41; 95% confidence interval, 1.02-1.95) were more likely to re-achieve viral suppression. Among PWH switching to BIC/FTC/TAF who had pre-existing RAMs to NRTIs before switch, 14 of 15 (93.3%) successfully achieved viral suppression. Switching to BIC/FTC/TAF and dolutegravir-based regimens could re-achieve viral suppression in four-fifth of the PWH who experienced viral rebound during treatment with other antiretroviral regimens. Pre-existing NRTI-related RAMs did not have adverse impact on the effectiveness of dolutegravir combined with 2 NRTIs or BIC/FTC/TAF.

Effectiveness and safety of integrase strand transfer inhibitors in Spain: a prospective real-world study.

Second-generation integrase strand transfer inhibitors (INSTIs) are preferred treatment options worldwide, and dolutegravir (DTG) is the treatment of choice in resource-limited settings. Nevertheless, in some resource-limited settings, these drugs are not always available. An analysis of the experience with the use of INSTIs in unselected adults living with HIV may be of help to make therapeutic decisions when second-generation INSTIs are not available. This study aimed to evaluate the real-life effectiveness and safety of dolutegravir (DTG), elvitegravir/cobicistat (EVG/c), and raltegravir (RAL) in a large Spanish cohort of HIV-1-infected patients. Real-world study of adults living with HIV who initiated integrase INSTIs DTG, EVG/c, and RAL-based regimens in three settings (ART-naïve patients, ART-switching, and ART-salvage patients). The primary endpoint was the median time to treatment discontinuation after INSTI-based regimen initiation. Proportion of patients experiencing virological failure (VF) (defined as two consecutive viral loads (VL) ≥200 copies/mL at 24 weeks or as a single determination of VL ≥1,000 copies/mL while receiving DTG, EVG/c or RAL, and at least 3 months after INSTI initiation) and time to VF were also evaluated. Virological effectiveness of EVG/c- and RAL-based regimens was similar to that of DTG when given as first-line and salvage therapy. Treatment switching for reasons other than virological failure was more frequent in subjects receiving EVG/c and, in particular, RAL. Naïve patients with CD4+ nadir <100 cells/μL were more likely to develop VF, particularly if they initiated RAL or EVG/c. In the ART switching population, initiation of RAL and EVG/c was associated with both VF and INSTI discontinuation. There were no differences in the time to VF and INSTI discontinuation between DTG, EVG/c and RAL. Immunological parameters improved in the three groups and for the three drugs assessed. Safety and tolerability were consistent with expected safety profiles. Whereas second-generation INSTIs are preferred treatment options worldwide, and DTG is one of the treatment of choices in resource-limited settings, first-generation INSTIs may still provide high virological and immunological effectiveness when DTG is not available.

Incidence of cardiometabolic outcomes among people living with HIV-1 initiated on integrase strand transfer inhibitor versus non-integrase strand transfer inhibitor antiretroviral therapies: a retrospective analysis of insurance claims in the United States.

Integrase strand transfer inhibitor (INSTI)-containing antiretroviral therapy (ART) has been associated with weight gain, though there is limited information on associations between ART-related weight gain and cardiometabolic outcomes among people living with HIV-1 (PLWH). We, therefore, evaluated risks of incident cardiometabolic outcomes following INSTI versus non-INSTI-based ART initiation in the United States. We conducted a retrospective study using IBM MarketScan Research Databases (12 August 2012-31 January 2021). Treatment-naïve PLWH initiating ART (index date) on/after 12 August 2013 (approval date of the first second-generation INSTI, dolutegravir) were included and censored at regimen switch/discontinuation, end of insurance eligibility or end of data availability. We used inverse probability of treatment weights constructed with baseline (12 months pre-index) characteristics to account for differences between INSTI- and non-INSTI-initiating cohorts. Doubly robust hazard ratios (HRs) obtained from weighted multivariable Cox regression were used to compare time to incident cardiometabolic outcomes (congestive heart failure [CHF], coronary artery disease, myocardial infarction, stroke/transient ischemic attack, hypertension, type II diabetes, lipid disorders, lipodystrophy and metabolic syndrome) by INSTI-initiation status. Weighted INSTI (mean age = 39 years, 23% female, 70% commercially insured, 30% Medicaid insured) and non-INSTI (mean age = 39 years, 24% female, 71% commercially insured, 29% Medicaid insured) cohorts included 7059 and 7017 PLWH, respectively. The most common INSTI-containing regimens were elvitegravir-based (43.4%), dolutegravir-based (33.3%) and bictegravir-based (18.4%); the most common non-INSTI-containing regimens were darunavir-based (31.5%), rilpivirine-based (30.4%) and efavirenz-based (28.3%). Mean±standard deviation follow-up periods were 1.5±1.5 and 1.1±1.2 years in INSTI- and non-INSTI-initiating cohorts, respectively. INSTI initiators were at a clinically and significantly increased risk of experiencing incident CHF (HR = 2.12, 95% confidence interval [CI] = 1.08-4.05; p = 0.036), myocardial infarction (HR = 1.79, 95% CI = 1.03-5.65; p = 0.036) and lipid disorders (HR = 1.26, 95% CI = 1.04-1.58; p = 0.020); there was no evidence of an increased risk for other individual or composite outcomes. Over a short average follow-up period of <2 years, INSTI use among treatment-naïve PLWH was associated with an increased risk of several cardiometabolic outcomes, such as CHF, myocardial infarction and lipid disorders, compared to non-INSTI use. Further research accounting for additional potential confounders and with longer follow-up is warranted to more accurately and precisely quantify the impact of INSTI-containing ART on long-term cardiometabolic outcomes.

Synthetic Approaches to a Key Pyridone-carboxylic Acid Precursor Common to the HIV-1 Integrase Strand Transfer Inhibitors Dolutegravir, Bictegravir, and Cabotegravir.

Dolutegravir (DTG), Bictegravir (BIC), and Cabotegravir (CAB) are the second-generation integrase strand transfer inhibitors (INSTIs) that have been FDA-approved for the treatment of HIV-1 infection. Preparation of these INSTIs utilizes the common intermediate 1-(2,2-dimethoxyethyl)-5-methoxy-6-(methoxycarbonyl)-4-oxo-1,4-dihydropyridine-3-carboxylic acid (6). Presented herein is a literature and patent review of synthetic routes used to access the pharmaceutically important intermediate 6. The review highlights the ways in which small fine-tuned synthetic modifications have been used to achieve good yields and regioselectivity of ester hydrolysis.

RP-HPLC hyphenated with ESI -Q-TOF –MS for the detection of potential degradants in dolutegravir

Dolutegravir is an antiviral agent, a second-generation HIV integrase strand transfer inhibitor (INSTI). A precise liquid chromatography-tandem mass spectrometry method has been developed and validated for the detection of potential degradants in Dolutegravir. The goal of this study was to detect major and minor potential degradants that can develop during the various stages of the drug molecule, start from acquiring of raw material for the synthesis, manufacturing, formulation and storage of the final product. With this objective in mind preparative scale HPLC was used to detect possible oxidative degradants in Dolutegravir. The oxidative degradation sample was isolated using Prominence preparative high performance liquid chromatograph equipped with a reverse phase C18 Inertsil ODS (300mm×19mm ×7µ) column. Mobile phase was 0.1% trifluoro acetic acid in water (A) and acetonitrile (B) (50:50). Ethyl acetate was used for the extraction of aqueous layer and the same was distilled and the collected fractions were evaporated to dryness for LCMS studies. To detect the degradation products mass spectra of the drug was established by direct infusion of degradant into mass spectrometry systems. The LC-MS spectrum of Dolutegravir was recorded by Shimadzu LCMS spectrometer in the electron spray ionization mode. The outcome was intense protonated molecular ion peak at m/z 304.27 and 249.06 in the positive ionization mode, scan range 120–560 amu and the other possible degradant structures with m/z 320.32, m/z 207.18, m/z 185.17, m/z 385.41, m/z 155.14. The information obtained from degradation behaviour of dolutegravir by stress degradation studies, under peroxide oxidation and the degradation products formed were identified by HPLC, LCMS analytical techniques are useful information regarding manufacturing, formulation and storage of the drug.

No transmitted drug resistance to HIV integrase strand-transfer inhibitors after their scale-up in Estonia in 2017

In Eastern Europe HIV-1 transmitted drug resistance (TDR) data, especially in integrase (IN) region is limited. In Estonia INSTI (Integrase Strand Transfer Inhibitors) TDR has been studied only prior to the INSTI scale-up in late 2010s. Current study aimed to determine the levels of protease (PR), reverse transcriptase (RT) and IN surveillance drug resistance mutations (SDRMs) among newly diagnosed patients in Estonia in 2017. Study included 216 newly diagnosed HIV-1 individuals from January 1 until December 31, 2017 in Estonia. Demographic and clinical data were obtained from the Estonian Health Board, Estonian HIV Cohort Study (E-HIV) and clinical laboratories' databases. The PR-RT and IN regions were sequenced and analyzed for SDRMs and subtype determination. Seventy-one percent (151/213) of available HIV-positive samples were successfully sequenced. The overall level of TDR was 7.9% (12/151; 95% CI 4.4-13.8%); no dual or triple class resistance was detected. No major INSTI mutations were found. The distribution of SDRMs for NNRTI, NRTI and PI was 5.9% (9/151), 1.3% (2/151) and 0.7% (1/151), respectively. The predominant NNRTI mutation was K103N. CRF06_cpx was predominant variant (59%) in Estonian HIV-1 population followed by subtype A (9%) and subtype B (8%). Although no major INSTI mutations were found, close monitoring of INSTI SDRMs is needed considering the extensive use of the first and second-generation INSTIs. PR-RT TDR is slowly rising in Estonia indicating the need for continuous surveillance in the future. Low genetic barrier NNRTIs should be avoided in the treatment regimens.

New designs for HIV-1 integrase inhibitors: a patent review (2018-present)

Introduction Combination antiretroviral therapy (cART) has dramatically reduced morbidity and mortality of HIV-1-infected patients. Integrase strand transfer inhibitors (INSTIs) play an important role as a key drug in cART. The second-generation INSTIs are very potent, but due to the emergence of highly resistant viruses and the demand for more conveniently usable drugs, the development of “third-generation” INSTIs and mechanistically different inhibitors is actively being pursued. Areas covered This article reviews the patents (from 2018 to the present) for two classes of HIV-1 integrase inhibitors of INSTIs and integrase-LEDGF/p75 allosteric inhibitors (INLAIs). Expert opinion Since approval of the second-generation INSTI dolutegravir, the design of new INSTIs has been mostly focused on its scaffold, carbamoylpyridone (CAP). This CAP scaffold is used not only for HIV-1 INSTIs but also for drug discoveries targeting other viral enzymes. With the approval of cabotegravir as a regimen of long-acting injection in combination with rilpivirine, there is a growing need for longer-acting agents. INLAIs have been intensely studied by many groups, but have yet to reach the market. However, INLAIs have recently been reported to also function as a latency promoting agent (LPA), indicating further development possibilities.

Factors associated with HIV-1 resistance to integrase strand transfer inhibitors in Spain: Implications for dolutegravir-containing regimens.

Integrase strand transfer inhibitor (INSTI)-containing regimens in HIV-1-infected patients have experienced a global increase. Recently, WHO has emphasized the need to fast-track the transition to dolutegravir (DTG)-based antiretroviral (ARV) treatments. However, continued surveillance of INSTI resistance is recommended. In this study, clinical, epidemiological, and virological features associated with INSTI resistance diagnosed in Spain were analyzed. Samples collected between 2008 and 2021 from HIV-1-infected patients were analyzed in integrase, protease, and reverse transcriptase using Sanger population sequencing. ARV drug resistance was evaluated with the Stanford University HIVdb program. Among 2,696 patients, 174 (6.5%) had INSTI resistance, all of them to first-generation INSTIs, and 71 (2.6%) had also resistance to second-generation INSTIs. Of these, only 5 individuals were exposed to DTG as the only INSTI, in whom resistance development was associated with poor treatment adherence and/or resistance to other ARV classes. Of newly HIV-1-diagnosed individuals, 0.92% harbored INSTI-resistant viruses, with low prevalences maintained along time, and only one had low-level resistance to DTG. Persons who inject drugs, age over 39 years, resistance to other ARV classes, and longer time from diagnosis were associated with INSTI resistance (p < 0.001). Non-subtype B INSTI-resistant viruses lacked the Q148H + G140S resistance pathway and showed lower INSTI resistance levels than subtype B viruses. In conclusion, INSTI resistance is uncommon and associated with long-term infections, older age and additional resistance to other ARV drug classes, and is rare in newly diagnosed HIV-1 infections. Our results also support the preferential use of DTG-containing regimens in first-line treatments, although surveillance of INSTI resistance is encouraged.

Different Pathways Conferring Integrase Strand-Transfer Inhibitors Resistance.

Integrase Strand Transfer Inhibitors (INSTIs) are currently used as the most effective therapy in the treatment of human immunodeficiency virus (HIV) infections. Raltegravir (RAL) and Elvitegravir (EVG), the first generation of INSTIs used successfully in clinical treatment, are susceptible to the emergence of viral resistance and have a high rate of cross-resistance. To counteract these resistant mutants, second-generation INSTI drugs have been developed: Dolutegravir (DTG), Cabotegravir (CAB), and Bictegravir (BIC). However, HIV is also able to develop resistance mechanisms against the second-generation of INSTIs. This review describes the mode of action of INSTIs and then summarizes and evaluates some typical resistance mutations, such as substitution and insertion mutations. The role of unintegrated viral DNA is also discussed as a new pathway involved in conferring resistance to INSTIs. This allows us to have a more detailed understanding of HIV resistance to these inhibitors, which may contribute to the development of new INSTIs in the future.

Prevalence of neuropsychiatric adverse events and associated factors among adult patients on dolutegravir attending Mulago ISS clinic.

Dolutegravir (DTG) is a second-generation integrase strand transfer inhibitor that is recommended by the World Health Organization as the preferred first-line and second-line antiretroviral therapy (ART) in patients with HIV. In 2018, Uganda started using DTG-based regimens as the preferred first-line ART. However, concerns regarding the potential neurotoxicity of DTG have been increasing. Data on the occurrence of neuropsychiatric adverse events (NPAEs) and the associated factors among adult patients who are initiated on or switched to DTG-based first-line or second-line ART in Uganda are limited. This study aimed to determine the prevalence of NPAEs among adult patients on DTG and the factors associated with their occurrence. We conducted a cross-sectional study using questionnaires administered by a trained research assistant between 15 November 2021 and 15 December 2021. The study included patients aged ≥18 years with HIV who were either initiated on or switched to a DTG-based ART regimen between 1 January 2018 and 31 October 2021. Informed consent and data were collected from 892 participants attending Mulago ISS clinic, including data on age, sex, marital status, disclosure status, current regimen, duration on ART, concurrent illness, concurrent medications, year of switch to DTG, duration on DTG, whether the onset of NPAEs was immediate or delayed, history of alcohol use or smoking, level of education, report of NPAEs while on DTG, and history of NPAEs while on previous regimen. Data were entered into Epidata version 4.6.0.2 then exported to Stata version 14 for analysis. Of the 892 adults on DTG attending Mulago ISS clinic, 41.7% (95% confidence interval [CI] 38.5%-44.9%) experienced at least one NPAE. DTG duration in years (adjusted prevalence [aPR]=1.21, p=0.024), disclosure status (aPR=1.40, p=0.042), concurrent medications (aPR=1.31, p=0.026), year of switch to DTG, and concurrent illness were associated with an increased occurrence of NPAEs. The prevalence of NPAEs was higher than that reported by any clinical trial. About 9.1% of participants had experienced severe to life-threatening NPAEs that required intervention from a healthcare professional to improve tolerability. The high prevalence requires that clinicians screen for NPAEs at very visit and reassure patients to maximize the benefits of long-term ART.

Second-Generation Human Immunodeficiency Virus Integrase Inhibitors Induce Differentiation Dysregulation and Exert Toxic Effects in Human Embryonic Stem Cell and Mouse Models.

Each year, approximately 1.1 million children are exposed in utero to human immunodeficiency virus antiretrovirals, yet their safety is often not well characterized during pregnancy. The Tsepamo study reported a neural tube defect signal in infants exposed to the integrase strand transfer inhibitor (InSTI) dolutegravir from conception, suggesting that exposure during early fetal development may be detrimental. The effects of InSTIs on 2 human embryonic stem cell (hESC) lines were characterized with respect to markers of pluripotency, early differentiation, and cellular health. In addition, fetal resorptions after exposure to InSTIs from conception were analyzed in pregnant mice. At subtherapeutic concentrations, second-generation InSTIs bictegravir, cabotegravir, and dolutegravir decreased hESC counts and pluripotency and induced dysregulation of genes involved in early differentiation. At therapeutic concentrations, bictegravir induced substantial hESC death and fetal resorptions. It is notable that first-generation InSTI raltegravir did not induce any hESC toxicity or differentiation, at any concentration tested. Exposure to some InSTIs, even at subtherapeutic concentrations, can induce adverse effects in hESCs and pregnant mice. Given the increasingly prevalent use of second-generation InSTIs, including in women of reproductive age, it is imperative to further elucidate the effect of InSTIs on embryonic development, as well as their long-term safety after in utero exposure.