Safety and efficacy of dolutegravir in treatment-experienced subjects with raltegravir-resistant HIV type 1 infection: 24-week results of the VIKING Study

Discovery of Dolutegravir Derivative against Liver Cancer via Inducing Autophagy and DNA Damage

We introduced a terminal alkyne into the core structure of dolutegravir, resulting in the synthesis of 34 novel dolutegravir-1,2,3-triazole compounds through click chemistry. These compounds exhibited remarkable inhibitory activities against two hepatocellular carcinoma cell lines, Huh7 and HepG2. Notably, compounds 5e and 5p demonstrated exceptional efficacy, particularly against Huh7 cells, with IC50 values of 2.64 and 5.42 μM. Additionally, both compounds induced apoptosis in Huh7 cells, suppressed tumor cell clone formation, and elevated reactive oxygen species (ROS) levels, further promoting tumor cell apoptosis. Furthermore, compounds 5e and 5p activated the LC3 signaling pathway, inducing autophagy, and triggered the γ-H2AX signaling pathway, resulting in DNA damage in tumor cells. Compound 5e exhibited low toxicity, highlighting its potential as a promising anti-tumor drug.

Relative Bioavailability of Dolutegravir (DTG) and Emtricitabine/Tenofovir Alafenamide Fumarate (F/TAF) Administered as Paediatric Tablet Formulations in Healthy Volunteers

BACKGROUND AND OBJECTIVE

Within the UNIVERSAL project (RIA2019PD-2882) we aim to develop a paediatric dolutegravir (DTG)/emtricitabine (FTC or F)/tenofovir alafenamide (TAF) fixed-dose combination. To inform dosing of this study, we undertook a relative bioavailability (RBA) study in healthy volunteers to investigate a potential pharmacokinetic effect when paediatric formulations of DTG and F/TAF are taken together.

METHODS

Participants received all of the following treatments as paediatric formulations in randomised order: a single dose of 180/22.5 mg F/TAF; a single dose of 30 mg DTG; a single dose of 180/22.5 mg F/TAF plus 30 mg DTG. Blood concentrations of DTG, FTC, TAF, and tenofovir (TFV) were measured over 48 h post-dose. If the 90% confidence intervals (CIs) of the geometric least squares mean (GLSM) ratios of area under the curve (AUC) and maximum concentration (Cmax) of each compound were within 0.70-1.43, we considered this as no clinically relevant PK interaction.

RESULTS

A total of 15 healthy volunteers were included. We did not observe a clinically relevant PK interaction between the paediatric DTG and F/TAF formulations for the compounds DTG, FTC, and TFV. For TAF, the lower boundaries of the 90% CIs of the GLSM ratios of the AUC0-∞ and Cmax fell outside our acceptance criteria of 0.70-1.43.

CONCLUSIONS

Although TAF AUC and Cmax 90% CIs fell outside the pre-defined criteria (0.62-1.11 and 0.65-1.01, respectively), no consistent effect on TAF PK was observed, likely due to high inter-subject variability. Moreover, there are several reasons to rely on TFV exposure as being more clinically relevant than TAF exposure. Therefore, we found no clinically relevant interactions in this study.

A preliminary study on plasma concentration, short-term efficacy, and safety profile of dolutegravir in Chinese people with HIV

BACKGROUND

This study examined the plasma concentration, clinical efficacy, and safety of dolutegravir (DTG) in Chinese people with HIV (PWH).

METHODS

In this observational study, HIV-positive individuals on DTG-based regimens for at least 6 months were included. Plasma DTG concentrations were measured 1 month after initiating treatment. Viral loads (VL) and CD4+ T cell counts were evaluated at baseline and after 1 and 6 months of therapy. High-performance liquid chromatography was used for measuring DTG concentrations, polymerase chain reaction for VL, and flow cytometry for CD4+ T cell counts. Safety assessments included monitoring liver enzymes, serum creatinine estimated glomerular filtration rate, and adverse reactions.

RESULTS

Eighty-two Chinese PWH were enrolled. Average VL decreased significantly from baseline by 3.1 log at 1 month and 3.5 log at 6 months. CD4+ T cell counts increased from 273 cells/mm3 at baseline to 378 cells/mm3 and 446 cells/mm3 after 1 and 6 months, respectively. Seventy-five percent achieved undetectable VLs (<20 copies/mL) by 6 months. Cmax and Cτ were 4.63 and 1.98 μg/mL, respectively. The safety profile was favorable with only 4.88% experiencing transient dizziness.

CONCLUSION

Preliminary findings suggest higher DTG plasma concentrations in Chinese PWH compared to Western populations, with promising short-term efficacy and safety.

Integrase inhibitors: current protagonists in antiretroviral therapy

Since HIV was identified as the etiological agent of AIDS, there have been significant advances in antiretroviral therapy (ART) that has reduced morbidity/mortality. Still, the viral genome's high mutation rate, suboptimal ART regimens, incomplete adherence to therapy and poor control of the viral load generate variants resistant to multiple drugs. Licensing over 30 anti-HIV drugs worldwide, including integrase inhibitors, has marked a milestone since they are potent and well-tolerated drugs. In addition, they favor a faster recovery of CD4+ T cells. They also increase the diversity profile of the gut microbiota and reduce inflammatory markers. All of these highlight the importance of including them in different ART regimens.

Expanded Multivariable Models to Assist Patient Selection for Long-Acting Cabotegravir + Rilpivirine Treatment: Clinical Utility of a Combination of Patient, Drug Concentration, and Viral Factors Associated With Virologic Failure

BACKGROUND

Previously reported post hoc multivariable analyses exploring predictors of confirmed virologic failure (CVF) with cabotegravir + rilpivirine long-acting (CAB + RPV LA) were expanded to include data beyond week 48, additional covariates, and additional participants.

METHODS

Pooled data from 1651 participants were used to explore dosing regimen (every 4 or every 8 weeks), demographic, viral, and pharmacokinetic covariates as potential predictors of CVF. Prior dosing regimen experience was accounted for using 2 populations. Two models were conducted in each population-baseline factor analyses exploring factors known at baseline and multivariable analyses exploring baseline factors plus postbaseline model-predicted CAB/RPV trough concentrations (4 and 44 weeks postinjection). Retained factors were evaluated to understand their contribution to CVF (alone or in combination).

RESULTS

Overall, 1.4% (n = 23/1651) of participants had CVF through 152 weeks. The presence of RPV resistance-associated mutations, human immunodeficiency virus-1 subtype A6/A1, and body mass index ≥30 kg/m2 were associated with an increased risk of CVF (P < .05 adjusted incidence rate ratio), with participants with ≥2 of these baseline factors having a higher risk of CVF. Lower model-predicted CAB/RPV troughs were additional factors retained for multivariable analyses.

CONCLUSIONS

The presence of ≥2 baseline factors (RPV resistance-associated mutations, A6/A1 subtype, and/or body mass index ≥30 kg/m2) was associated with increased CVF risk, consistent with prior analyses. Inclusion of initial model-predicted CAB/RPV trough concentrations (≤first quartile) did not improve the prediction of CVF beyond the presence of a combination of ≥2 baseline factors, reinforcing the clinical utility of the baseline factors in the appropriate use of CAB + RPV LA.

Pharmacokinetic Data of Dolutegravir in Second-line Treatment of Children With Human Immunodeficiency Virus: Results From the CHAPAS4 Trial

BACKGROUND

Dolutegravir (DTG), combined with a backbone of 2 nucleoside reverse transcriptase inhibitors, is currently the preferred first-line treatment for human immunodeficiency virus (HIV) in childhood. CHAPAS4 is an ongoing randomized controlled trial investigating second-line treatment options for children with HIV. We did a nested pharmacokinetic (PK) substudy within CHAPAS4 to evaluate the DTG exposure in children with HIV taking DTG with food as part of their second-line treatment.

METHODS

Additional consent was required for children on DTG enrolled in the CHAPAS4 trial to participate in this PK substudy. Children weighing 14-19.9 kg took 25 mg DTG as dispersible tablets and children ≥20 kg took 50 mg film-coated tablets. Steady-state 24-hour DTG plasma concentration-time PK profiling was done at t = 0 and 1, 2, 4, 6, 8, 12, and 24 hours after observed DTG intake with food. Reference adult PK data and pediatric data from the ODYSSEY trial were used primarily for comparison. The individual target trough concentration (Ctrough) was defined as 0.32 mg/L.

RESULTS

Thirty-nine children on DTG were included in this PK substudy. The geometric mean (GM) area under the concentration-time curve over the dosing interval (AUC0-24h) was 57.1 hours × mg/L (coefficient of variation [CV%], 38.4%), which was approximately 8% below the average AUC0-24h in children in the ODYSSEY trial with comparable dosages, but above the adult reference. The GM (CV%) Ctrough was 0.82 mg/L (63.8%), which was comparable to ODYSSEY and adult reference values.

CONCLUSIONS

This nested PK substudy shows that the exposure of DTG taken with food in children on second-line treatment is comparable with that of children in the ODYSSEY trial and adult references. Clinical Trials Registration.ISRCTN22964075.

Moving toward a contemporary classification of drug-induced kidney disease

Drug-induced kidney disease (DIKD) accounts for about one-fourth of all cases of acute kidney injury (AKI) in hospitalized patients, especially in critically ill setting. There is no standard definition or classification system of DIKD. To address this, a phenotype definition of DIKD using expert consensus was introduced in 2015. Recently, a novel framework for DIKD classification was proposed that incorporated functional change and tissue damage biomarkers. Medications were stratified into four categories, including "dysfunction without damage," "damage without dysfunction," "both dysfunction and damage," and "neither dysfunction nor damage" using this novel framework along with predominant mechanism(s) of nephrotoxicity for drugs and drug classes. Here, we briefly describe mechanisms and provide examples of drugs/drug classes related to the categories in the proposed framework. In addition, the possible movement of a patient's kidney disease between certain categories in specific conditions is considered. Finally, opportunities and barriers to adoption of this framework for DIKD classification in real clinical practice are discussed. This new classification system allows congruencies for DIKD with the proposed categorization of AKI, offering clarity as well as consistency for clinicians and researchers.

HIV drug resistance in the era of contemporary antiretroviral therapy: A clinical perspective

Contemporary antiretroviral therapy (ART) regimens have high barriers to the development of drug resistance. However, resistance to earlier antiretrovirals and uncommon cases of resistance to contemporary ART illustrate the continued need for good clinical management of HIV drug resistance. Here, we describe HIV drug-resistance mechanisms, the interaction of HIV drug-resistant mutations and the patterns of drug resistance to contemporary ART. We then provide guidance on the management of HIV drug resistance, including how to limit the development of resistance and manage virologic failure that is complicated by resistance. To complement this, links to resources and treatment guidelines are provided that can assist with the interpretation of HIV drug resistance test results and optimal ART selection in the clinic.

Treatment Emergent Dolutegravir Resistance Mutations in Individuals Naïve to HIV-1 Integrase Inhibitors: A Rapid Scoping Review

Background: Dolutegravir (DTG)-based antiretroviral therapy (ART) rarely leads to virological failure (VF) and drug resistance in integrase strand transfer inhibitor (INSTI)-naïve persons living with HIV (PLWH). As a result, limited data are available on INSTI-associated drug resistance mutations (DRMs) selected by DTG-containing ART regimens. Methods: We reviewed studies published through July 2023 to identify those reporting emergent major INSTI-associated DRMs in INSTI-naïve PLWH receiving DTG and those containing in vitro DTG susceptibility results using a standardized assay. Results: We identified 36 publications reporting 99 PLWH in whom major nonpolymorphic INSTI-associated DRMs developed on a DTG-containing regimen and 21 publications containing 269 in vitro DTG susceptibility results. DTG-selected DRMs clustered into four largely non-overlapping mutational pathways characterized by mutations at four signature positions: R263K, G118R, N155H, and Q148H/R/K. Eighty-two (82.8%) viruses contained just one signature DRM, including R263K (n = 40), G118R (n = 24), N155H (n = 9), and Q148H/R/K (n = 9). Nine (9.1%) contained ≥1 signature DRM, and eight (8.1%) contained just other DRMs. R263K and G118R were negatively associated with one another and with N155H and Q148H/K/R. R263K alone conferred a median 2.0-fold (IQR: 1.8-2.2) reduction in DTG susceptibility. G118R alone conferred a median 18.8-fold (IQR:14.2-23.4) reduction in DTG susceptibility. N155H alone conferred a median 1.4-fold (IQR: 1.2-1.6) reduction in DTG susceptibility. Q148H/R/K alone conferred a median 0.8-fold (IQR: 0.7-1.1) reduction in DTG susceptibility. Considerably higher levels of reduced susceptibility often occurred when signature DRMs occurred with additional INSTI-associated DRMs. Conclusions: Among INSTI-naïve PLWH with VF and treatment emergent INSTI-associated DRMs, most developed one of four signature DRMs, most commonly R263K or G118R. G118R was associated with a much greater reduction in DTG susceptibility than R263K.

Evaluation of Glomerular Filtration Rate Trends in People Living With HIV Corrected by the Baseline Glomerular Filtration Rate

BACKGROUND

Chronic kidney disease, for which estimated glomerular filtration rate (eGFR) trajectories are early markers, is frequent in people living with HIV.

SETTING

Identify eGFR trajectory patterns according to kidney function and assess associated factors over a 13-year follow-up period.

METHODS

We evaluated longitudinal changes and its associated factors in eGFR of 3366 participants according to kidney function with a 2-level, linear, mixed model.

RESULTS

Participants with initial kidney dysfunction experienced a slight eGFR increase, whereas others showed a slight decrease. A weak relationship was observed between baseline eGFR and its variation over time. Baseline eGFR was affected by age, CD4 + count, viral load, hypertension, hyperlipidemia, AIDS-defining illness and tenofovir (TDF) with integrase inhibitor (INSTI) or efavirenz. Significant factors for eGFR change included the following: in kidney dysfunction, CD4 + cell count of >350 cells per cubic millimeter and undetectable viral load increased eGFR, whereas TDF + protease inhibitor decreased eGFR; in mildly decreased kidney function, CD4 + cell count of >350 cells per cubic millimeter, AIDS-defining illness, and TDF + efavirenz increased eGFR, whereas age, hypertension, hyperlipidemia, and TDF + INSTI decreased eGFR; in normal kidney function, age, CD4 + cell count of > 350 cells per cubic millimeter, undetectable viral load, hypertension, hyperlipidemia, and TDF + INSTI decreased eGFR, whereas TDF + efavirenz increased eGFR (all P value for interaction < 0.05).

CONCLUSION

Our findings suggest that eGFR trajectories varied widely between individuals in people living with HIV. In the lower eGFR group, virus-related factors were more relevant, whereas traditional risk factors for renal dysfunction were more prominent in the highest eGFR group.

Current ARTs, Virologic Failure, and Implications for AIDS Management: A Systematic Review

Antiretroviral therapies (ARTs) have revolutionized the management of human immunodeficiency virus (HIV) infection, significantly improved patient outcomes, and reduced the mortality rate and incidence of acquired immunodeficiency syndrome (AIDS). However, despite the remarkable efficacy of ART, virologic failure remains a challenge in the long-term management of HIV-infected individuals. Virologic failure refers to the persistent detectable viral load in patients receiving ART, indicating an incomplete suppression of HIV replication. It can occur due to various factors, including poor medication adherence, drug resistance, suboptimal drug concentrations, drug interactions, and viral factors such as the emergence of drug-resistant strains. In recent years, extensive efforts have been made to understand and address virologic failure in order to optimize treatment outcomes. Strategies to prevent and manage virologic failure include improving treatment adherence through patient education, counselling, and supportive interventions. In addition, the regular monitoring of viral load and resistance testing enables the early detection of treatment failure and facilitates timely adjustments in ART regimens. Thus, the development of novel antiretroviral agents with improved potency, tolerability, and resistance profiles offers new options for patients experiencing virologic failure. However, new treatment options would also face virologic failure if not managed appropriately. A solution to virologic failure requires a comprehensive approach that combines individualized patient care, robust monitoring, and access to a range of antiretroviral drugs.

Design, synthesis and antitumour activity evaluation of novel dolutegravir derivatives

Based on the modification of the structure of dolutegravir, we introduced 1,2,3-triazole moieties with different substituted groups and obtained a lot of novel dolutegravir derivatives. The activity of A549 cells treated with the derivatives was examined, and most compounds showed good inhibitory effects. Among them, compounds 4b and 4g were the most effective, and inhibited the growth of A549 cells with IC50 values of 8.72 ± 0.11 μM and 12.97 ± 0.32 μM, respectively. In addition, compound 4g induced apoptosis and clonal suppression in A549 tumor cells. Compound 4g also activated the LC3 signaling pathway to induce autophagy in tumor cells, and activated the γ-H2AX signaling pathway to induce DNA damage in tumor cells.

Pharmacokinetics and pharmacodynamics of adult dolutegravir tablets in treatment-experienced children with HIV weighing at least 20 kg

OBJECTIVE

Limited pharmacokinetic/pharmacodynamic data are a barrier to the scale-up of dolutegravir-based antiretroviral therapy (ART) in children. We examined the pharmacokinetics/pharmacodynamics of the adult film-coated dolutegravir 50 mg tablets in children with HIV infection weighing at least 20 kg.

DESIGN

A prospective, observational, pharmacokinetic, and safety study.

METHODS

Treatment-experienced children with HIV weighing at least 20 kg and evidence of viral load suppression on ART were enrolled and switched to dolutegravir-based therapy. After at least 4 weeks and 7 months on dolutegravir-based therapy, blood samples were collected at 0, 1, 4, 8, 12, and 24-h postdose. Dolutegravir concentrations were measured using validated LCMS/MS and pharmacokinetic parameters calculated by noncompartmental analysis. Descriptive statistics were used to summarize pharmacokinetic parameters and comparisons with published reference values.

RESULTS

Of 25 participants, 92% were on efavirenz-based ART and 60.0% were men. Dolutegravir mean exposure, peak and trough concentrations at both pharmacokinetic visits were higher than the mean reference values in adults and children weighing 20 kg to less than 40 kg treated with 50 mg once daily, but were closer to the mean values in adults given 50 mg twice a day. Children weighing 20 kg to less than 40 kg had even higher dolutegravir exposures. The regimens were well tolerated with good virologic efficacy through week 48.

CONCLUSION

The higher dolutegravir exposure in our study population suggests that further studies and close monitoring should investigate the adverse effects of dolutegravir in more children and in the long term.

Fluorine in anti-HIV drugs approved by FDA from 1981 to 2023

Human immunodeficiency virus (HIV) is the etiological agent of acquired immunodeficiency syndrome (AIDS). Nowadays, FDA has approved over thirty antiretroviral drugs grouped in six categories. Interestingly, one-third of these drugs contain different number of fluorine atoms. The introduction of fluorine to obtain drug-like compounds is a well-accepted strategy in medicinal chemistry. In this review, we summarized 11 fluorine-containing anti-HIV drugs, focusing on their efficacy, resistance, safety, and specific roles of fluorine in the development of each drug. These examples may be of help for the discovery of new drug candidates bearing fluorine in their structures.

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

Introduction

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.

Methods

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.

Results

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.

Discussion

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.

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.

How to use COVID-19 antiviral drugs in patients with chronic kidney disease

Antiviral drugs such as Remdesivir (Veklury), Nirmatrelvir with Ritonavir (Paxlovid), Azvudine, and Molnupiravir (Lagevrio) can reduce the risk for severe and fatal Coronavirus Disease (COVID)-19. Although chronic kidney disease is a highly prevalent risk factor for severe and fatal COVID-19, most clinical trials with these drugs excluded patients with impaired kidney function. Advanced CKD is associated with a state of secondary immunodeficiency (SIDKD), which increases the susceptibility to severe COVID-19, COVID-19 complications, and the risk of hospitalization and mortality among COVID-19 patients. The risk to develop COVID-19 related acute kidney injury is higher in patients with precedent CKD. Selecting appropriate therapies for COVID-19 patients with impaired kidney function is a challenge for healthcare professionals. Here, we discuss the pharmacokinetics and pharmacodynamics of COVID-19-related antiviral drugs with a focus on their potential use and dosing in COVID-19 patients with different stages of CKD. Additionally, we describe the adverse effects and precautions to be taken into account when using these antivirals in COVID-19 patients with CKD. Lastly, we also discuss about the use of monoclonal antibodies in COVID-19 patients with kidney disease and related complications.

Genotypic Resistance Testing of HIV-1 DNA in Peripheral Blood Mononuclear Cells

HIV-1 DNA exists in nonintegrated linear and circular episomal forms and as integrated proviruses. In patients with plasma viremia, most peripheral blood mononuclear cell (PBMC) HIV-1 DNA consists of recently produced nonintegrated virus DNA while in patients with prolonged virological suppression (VS) on antiretroviral therapy (ART), most PBMC HIV-1 DNA consists of proviral DNA produced months to years earlier. Drug-resistance mutations (DRMs) in PBMCs are more likely to coexist with ancestral wild-type virus populations than they are in plasma, explaining why next-generation sequencing is particularly useful for the detection of PBMC-associated DRMs. In patients with ongoing high levels of active virus replication, the DRMs detected in PBMCs and in plasma are usually highly concordant. However, in patients with lower levels of virus replication, it may take several months for plasma virus DRMs to reach detectable levels in PBMCs. This time lag explains why, in patients with VS, PBMC genotypic resistance testing (GRT) is less sensitive than historical plasma virus GRT, if previous episodes of virological failure and emergent DRMs were either not prolonged or not associated with high levels of plasma viremia. Despite the increasing use of PBMC GRT in patients with VS, few studies have examined the predictive value of DRMs on the response to a simplified ART regimen. In this review, we summarize what is known about PBMC HIV-1 DNA dynamics, particularly in patients with suppressed plasma viremia, the methods used for PBMC HIV-1 GRT, and the scenarios in which PBMC GRT has been used clinically.

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.

A Korean Post-Marketing Surveillance Study of Dolutegravir Single-Agent Tablets in Patients with HIV-1

BACKGROUND

The integrase strand transfer inhibitor dolutegravir has been indicated in Korea since 2014 for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in combination with other antiretroviral agents. This regulatory post-marketing surveillance (PMS) study evaluated the real-life safety and effectiveness of dolutegravir in patients with HIV-1 in clinical practice in Korea.

MATERIALS AND METHODS

This open-label PMS study examined data from consecutive patients (aged ≥12 years) with HIV-1 infection receiving dolutegravir according to locally approved prescribing information; treatment-naïve and treatment-experienced patients were permitted. Data regarding patient demographics, medical history, clinical characteristics, medications (HIV-related and concomitant), and comorbidities were extracted from patient records over a 1-year treatment period. Outcomes included the safety of dolutegravir (primary endpoint) and real-life effectiveness according to the Physician Global Assessment (PGA) and the proportion of patients with plasma HIV-1 RNA count <50 copies/mL at 48 weeks.

RESULTS

Of 147 patients treated with dolutegravir at 18 centers in Korea (August 2014 - August 2020), 139 were eligible for the safety analyses and 75 for effectiveness analyses. Patients (mean age 47 years) were mostly male (92.8%) and received dolutegravir in combination with nucleoside reverse transcriptase inhibitor (70.5%) or protease inhibitors (21.6%). Adverse events (AEs) (n = 179 in total) were mostly mild in severity, with the most common being nasopharyngitis (5.0%), dyspepsia (5.0%), pruritus (4.3%), and rash (4.3%). Of 16 adverse drug reactions (ADRs), the most frequent were rash, diarrhea, headache, insomnia, and somnolence (1.4% each). Of 2 serious ADRs, only 1 (gastroenteritis) was unexpected, and both resolved. The risk of experiencing an AE while receiving dolutegravir appeared to be especially increased in patients receiving concomitant medications for other conditions. Dolutegravir effectively suppressed HIV-1 (93.3% of patients had plasma HIV-1 RNA <50 copies/mL), and 100% of patients showed symptom improvement based on physician global assessment.

CONCLUSION

Results of this PMS study showed that dolutegravir administered as highly active antiretroviral therapy was well tolerated and effective in patients with HIV-1 infection.

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.

High-level dolutegravir resistance can emerge rapidly from few variants and spread by recombination: implications for integrase strand transfer inhibitor salvage therapy

The integrase strand transfer inhibitor (INSTI) dolutegravir is commonly used in combination antiretroviral therapy regimens and retains strong potency even with primary resistance mutations to some other INSTIs. Acquisition of accessory mutations to primary mutations results in significant increases in dolutegravir resistance. Previously, we reported that addition of the secondary mutation T97A can result in rapid treatment failure in individuals with INSTI mutations at positions 140 and 148. Here, we conducted a detailed case study of one of these individuals and find that T97A-containing HIV emerged from a large replicating population from only a few (≤4) viral lineages. When combined with primary INSTI resistance mutations, T97A provides a strong selective advantage; the finding that T97A-containing variants spread by replication and recombination, and persisted for months after discontinuing dolutegravir, has important implications as dolutegravir is rolled out worldwide.

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

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

[HIV drug resistance: past and current trends]

HIV infection is incurable, but effective antiretroviral therapy (ART) makes it possible to achieve an undetectable viral load (VL), to preserve the function of the immune system and to prevent the patient's health. Due to the constant increase in the use of ART and the high variability of HIV, especially in patients receiving so-called suboptimal therapy for various reasons, the incidence of drug resistance (DR) is increasing. In turn, the presence of DR in an HIV-infected patient affects the effectiveness of therapy, which leads to a limited choice and an increase in the cost of treatment regimens, disease progression and, consequently, an increased risk of death, as well as transmission of infection to partners. The main problems of drug resistance, its types and causes, as well as factors associated with its development are considered. The main drug resistance mutations for each of the drug classes are described.

Drug-drug interactions of Integrase Strand Transfer Inhibitors among older people living with HIV: Interazioni farmacologiche degli inibitori delle integrase tra le persone anziane che vivono con HIV

The advancement of Human Immunodeficiency Virus (HIV) treatment improves the life expectancy of HIV-positive individuals. People living with HIV have more polypharmacy and drug-drug interactions than those without HIV. Integrase strand transfer inhibitors (INSTIs) are the newest class commonly used for HIV treatment. There are five INSTIs currently approved by the Food and Drug Administration, including raltegravir, elvitegravir, dolutegravir, bictegravir, and cabotegravir. INSTIs class contributes to better safety and efficacy profile, making them the preferred or recommended antiretroviral regimens in HIV treatment guidelines worldwide. Despite the shared mechanism of action, INSTIs differ in pharmacokinetics, contributing to different drug-drug interactions. This review summarized the potential drug interactions of INSTIs and the management of the drug interactions in clinical practice.

Dolutegravir dosing for children with HIV weighing less than 20 kg: pharmacokinetic and safety substudies nested in the open-label, multicentre, randomised, non-inferiority ODYSSEY trial

BACKGROUND

Dolutegravir-based antiretroviral therapy is a preferred first-line treatment for adults and children living with HIV; however, very little pharmacokinetic data for dolutegravir use are available in young children. We therefore aimed to evaluate dolutegravir dosing and safety in children weighing 3 kg to less than 20 kg by assessing pharmacokinetic parameters and safety data in children taking dolutegravir within the ODYSSEY trial.

METHODS

We did pharmacokinetic substudies nested within the open-label, multicentre, randomised, non-inferiority ODYSSEY trial. We enrolled children from seven research centres in South Africa, Uganda, and Zimbabwe. Children weighing 3 kg to less than 14 kg received 5 mg dispersible tablets of dolutegravir according to WHO weight bands: 5 mg for children weighing 3 kg to less than 6 kg and younger than 6 months, 10 mg for children weighing 3 kg to less than 6 kg and aged 6 months or older, 15 mg for children weighing 6 kg to less than 10 kg, and 20 mg for children weighing 10 kg to less than 14 kg. Children weighing 14 kg to less than 20 kg received a 25 mg film-coated tablet once per day early in the trial or 25 mg dispersible tablets (five 5 mg tablets once per day) later in the trial. A minimum of eight children per weight band or dose was targeted for 24 h pharmacokinetic profiling at steady state. The primary pharmacokinetic parameter was the trough concentration 24 h after observed dolutegravir intake (Ctrough). Pharmacokinetic targets were based on adult dolutegravir Ctrough and the 90% effective concentration (EC90; ie, 0·32 mg/L). Safety was evaluated in eligible children consenting to pharmacokinetic substudies.

FINDINGS

Between May 25, 2017, and Aug 15, 2019, we enrolled 72 children aged between 3 months and 11 years. 71 children were included in the safety population and 55 (76%) of 72 children contributed 65 evaluable pharmacokinetic profiles. Geometric mean Ctrough in children on dispersible tablets in weight bands between 3 kg and less than 20 kg ranged between 0·53-0·87 mg/L, comparable to the adult geometric mean Ctrough of 0·83 mg/L. Variability was high with coefficient of variation percentages ranging between 50% and 150% compared with 26% in adults. Ctrough below EC90 was observed in four (31%) of 13 children weighing 6 kg to less than 10 kg taking 15 mg dispersible tablets, and four (21%) of 19 weighing 14 kg to less than 20 kg taking 25 mg film-coated tablets. The lowest geometric mean Ctrough of 0·44 mg/L was observed in children weighing 14 kg to less than 20 kg on 25 mg film-coated tablets. Exposures were 1·7-2·0 times higher on 25 mg dispersible tablets versus 25 mg film-coated tablets. 19 (27%) of 71 children had 29 reportable grade 3 or higher adverse events (13 serious adverse events, including two deaths), none of which were related to dolutegravir.

INTERPRETATION

Weight-band dosing of paediatric dolutegravir dispersible tablets provides appropriate drug exposure in most children weighing 3 kg to less than 20 kg, with no safety signal. 25 mg film-coated tablets did not achieve pharmacokinetic parameters in children weighing 14 kg to less than 20 kg, which were comparable to adults, suggesting dosing with dispersible tablets is preferable or a higher film-coated tablet dose is required.

FUNDING

Paediatric European Network for Treatment of AIDS Foundation, ViiV Healthcare, and UK Medical Research Council.

Brief Report: Bictegravir/Emtricitabine/Tenofovir Alafenamide Efficacy in Participants With Preexisting Primary Integrase Inhibitor Resistance Through 48 Weeks of Phase 3 Clinical Trials

BACKGROUND

Preexisting drug resistance limits the utility of HIV antiretroviral therapy. Studies have demonstrated safety and efficacy of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF), including in patients with M184V/I substitutions.

SETTING

We investigated virologic outcomes through 48 weeks of B/F/TAF treatment in individuals with preexisting primary integrase strand transfer inhibitor resistance (INSTI-R).

METHODS

Preexisting INSTI-R was retrospectively evaluated from 7 B/F/TAF studies. INSTI-R was assessed by historical genotypes and/or baseline RNA or DNA sequencing. Viral loads were measured at all visits.

RESULTS

Preexisting primary INSTI-R substitutions were detected in 20 of the 1907 participants (1.0%). The 20 participants were predominantly male (75%), were Black (65%), had HIV-1 subtype B (85%), and had baseline median CD4 counts of 594 cells/mm3 and median age of 52 years. Most of the participants (n = 19) were virologically suppressed at baseline and had one primary INSTI-R substitution, E92G, Y143C/H, S147G, Q148H/K/R, N155S, or R263K, +/-secondary substitutions. All suppressed participants maintained virologic suppression throughout 48 weeks without any viral blips. One treatment-naive participant had virus with Q148H+G140S that was fully sensitive to bictegravir but only partially to dolutegravir (phenotype <2.5-fold change and >4-fold change, respectively). With a baseline viral load of 30,000 copies/mL, this participant was virologically suppressed by week 4 and maintained <50 copies/mL through week 48.

CONCLUSIONS

This small cohort with primary INSTI-R achieved and/or maintained virologic suppression through 48 weeks of B/F/TAF treatment. Consistent with the potent in vitro activity of bictegravir against most INSTI-R patterns, B/F/TAF may be a potential treatment option for patients with select preexisting INSTI-R, if confirmed by further studies.

Identification and Optimization of a Novel HIV-1 Integrase Inhibitor

Human immunodeficiency virus-1 (HIV-1) is the causative agent of acquired immunodeficiency syndrome (AIDS). HIV-1, like all retroviruses, stably integrates its vDNA copy into host chromatin, a process allowing for permanent infection. This essential step for HIV-1 replication is catalyzed by viral integrase (IN) and aided by cellular protein LEDGF/p75. In addition, IN is also crucial for proper virion maturation as it interacts with the viral RNA genome to ensure encapsulation of ribonucleoprotein complexes within the protective capsid core. These key functions make IN an attractive target for the development of inhibitors with various mechanisms of action. We conducted a high-throughput screen (HTS) of ∼370,000 compounds using a homogeneous time-resolved fluorescence-based assay capable of capturing diverse inhibitors targeting multifunctional IN. Our approach revealed chemical scaffolds containing diketo acid moieties similar to IN strand transfer inhibitors (INSTIs) as well as novel compounds distinct from all current IN inhibitors including INSTIs and allosteric integrase inhibitors (ALLINIs). Specifically, our HTS resulted in the discovery of compound 12, with a novel IN inhibitor scaffold amenable for chemical modification. Its more potent derivative 14e similarly inhibited catalytic activities of WT and mutant INs containing archetypical INSTI- and ALLINI-derived resistant substitutions. Further SAR-based optimization resulted in compound 22 with an antiviral EC₅₀ of ∼58 μM and a selectivity index of >8500. Thus, our studies identified a novel small-molecule scaffold for inhibiting HIV-1 IN, which provides a promising platform for future development of potent antiviral agents to complement current HIV-1 therapies.

An up-to-date evaluation of dolutegravir/abacavir/lamivudine for the treatment of HIV

INTRODUCTION

There are more than 30 agents available for the treatment of HIV with guidelines shifting toward integrase strand transfer inhibitors (INSTIs) as part of first line therapy. The fixed dose combination of dolutegravir (DTG), abacavir (ABC), and lamivudine (3TC) is a convenient, well tolerated, and highly effective option for treating HIV infection and remains a first line therapy across several prominent guidelines.

AREAS COVERED

In this drug evaluation, the authors provide a comprehensive overview of DTG/ABC/3TC for the treatment of HIV including the pharmacokinetics, pharmacodynamics, efficacy, safety, and tolerability. The authors also provide the reader with their expert perspectives on this particular treatment strategy.

EXPERT OPINION

While DTG/ABC/3TC remains a valuable HIV treatment option, newer combination regimens have entered the market. Bictegravir with tenofovir alafenamide and emtricitabine offers the benefit of same day initiation and efficacy in hepatitis B co-infection, while new two-drug regimens enhance the simplicity of HIV treatment. Continued study is required into the mechanisms and optimal management strategies for weight gain for many regimens, including DTG/ABC/3TC.

Antiviral Activity and Resistance Profile of the Novel HIV-1 Non-Catalytic Site Integrase Inhibitor, JTP-0157602

HIV-1 integrase (IN) is an essential enzyme for viral replication. Non-catalytic site integrase inhibitors (NCINIs) are allosteric HIV-1 IN inhibitors and a potential new class of antiretrovirals. In this report, we identified a novel NCINI, JTP-0157602, with an original scaffold. JTP-0157602 exhibited potent antiviral activity against HIV-1 and showed a serum-shifted EC₉₀ of 138 nM, which is comparable to the FDA-approved IN strand transfer inhibitors (INSTIs). This compound was fully potent against a wide range of recombinant viruses with IN polymorphisms, including amino acids 124/125, a hot spot of IN polymorphisms. In addition, JTP-0157602 retained potent antiviral activity against a broad panel of recombinant viruses with INSTI-related resistant mutations, including multiple substitutions that emerged in clinical studies of INSTIs. Resistance selection experiments of JTP-0157602 led to the emergence of A128T and T174I mutations, which are located at the lens epithelium-derived growth factor/p75 binding pocket of IN. JTP-0157602 inhibited HIV-1 replication mainly during the late-phase of the replication cycle, and HIV-1 virions produced by reactivation from HIV-1 latently-infected Jurkat cells in the presence of JTP-0157602 were non-infectious. These results suggest that JTP-0157602 and analog compounds can be used to treat HIV-1 infectious diseases. IMPORTANCE Non-catalytic site integrase inhibitors (NCINIs) are allosteric HIV-1 integrase (IN) inhibitors that bind to the lens epithelium-derived growth factor (LEDGF)/p75 binding pocket of IN. NCINIs are expected to be a new class of anti-HIV-1 agents. In this study, we present a novel NCINI, JTP-0157602, which has potent activity against a broad range of HIV-1 strains with IN polymorphisms. Furthermore, JTP-0157602 shows strong antiviral activity against IN strand transfer inhibitor-resistant mutations, suggesting JTP-0157602 and its analogs are potential agents to treat HIV-1 infections. Structural modeling indicated that JTP-0157602 binds to the LEDGF/p75 binding pocket of IN, and the results of in vitro resistance induction revealed the JTP-0157602-resistance mechanism of HIV-1. These data shed light on developing novel NCINIs, which exhibit potent activity against HIV-1 with broad IN polymorphisms and multi-drug resistant HIV-1 variants.

Integrase Inhibitor Resistance Mechanisms and Structural Characteristics in Antiretroviral Therapy-Experienced, Integrase Inhibitor-Naive Adults with HIV-1 Infection Treated with Dolutegravir plus Two Nucleoside Reverse Transcriptase Inhibitors in the DAWNING Study

At week 48 in the phase IIIb DAWNING study, the integrase strand transfer inhibitor (INSTI) dolutegravir plus 2 nucleoside reverse transcriptase inhibitors demonstrated superiority to ritonavir-boosted lopinavir in achieving virologic suppression in adults with HIV-1 who failed first-line therapy. Here, we report emergent HIV-1 drug resistance and mechanistic underpinnings among dolutegravir-treated adults in DAWNING. Population viral genotyping, phenotyping, and clonal analyses were performed on participants meeting confirmed virologic withdrawal (CVW) criteria on dolutegravir-containing regimens. Dolutegravir binding to and structural changes in HIV-1 integrase-DNA complexes with INSTI resistance-associated substitutions were evaluated. Of participants who received dolutegravir through week 48 plus an additional 110 weeks for this assessment, 6 met CVW criteria with treatment-emergent INSTI resistance-associated substitutions and 1 had R263R/K at baseline but not at CVW. All 7 achieved HIV-1 RNA levels of <400 copies/mL (5 achieved <50 copies/mL) before CVW. Treatment-emergent G118R was detected in 5 participants, occurring with ≥2 other integrase substitutions, including R263R/K, in 3 participants and without other integrase substitutions in 2 participants. G118R or R263K increased the rate of dolutegravir dissociation from integrase-DNA complexes versus wild-type but retained prolonged binding. Overall, among treatment-experienced adults who received dolutegravir in DAWNING, 6 of 314 participants developed treatment-emergent INSTI resistance-associated substitutions, with a change in in vitro dolutegravir resistance of >10-fold and reduced viral replication capacity versus baseline levels. This study demonstrates that the pathway to dolutegravir resistance is a challenging balance between HIV-1 phenotypic change and associated loss of viral fitness. (This study has been registered at ClinicalTrials.gov under identifier NCT02227238.).

HIV-1 drug resistance and genetic diversity in a cohort of people with HIV-1 in Nigeria

OBJECTIVE

This study was designed to provide information on the genetic diversity of HIV-1 and drug resistance mutations in Nigeria, as there is limited understanding of variants circulating in the country.

METHODS

We used an advanced next-generation sequencing platform, Primer ID, to: investigate the presence of high and low abundance drug resistance mutations; characterize preexisting Integrase Strand Transfer Inhibitor (INSTI) mutations in antiretroviral therapy (ART)-experienced but dolutegravir-naive individuals; detect recent HIV-1 infections and characterize subtype diversity from a cohort of people with HIV-1 (PWH).

RESULTS

HIV-1 subtype analysis revealed the predominance of CRF02_AG and subtype G in our study population. At detection sensitivity of 30% abundance, drug resistance mutations (DRMs) were identified in 3% of samples. At a sensitivity level of 10%, DRMs were identified in 27.3% of samples. We did not detect any major INSTI mutation associated with dolutegravir-resistance. Only one recent infection was detected in our study population.

CONCLUSION

Our study suggests that dolutegravir-containing antiretroviral regimens will be effective in Nigeria. Our study also further emphasizes the high genetic diversity of HIV-1 in Nigeria and that CRF02_AG and subtype G are the dominant circulating forms of HIV-1 in Nigeria. These two circulating forms of the virus are largely driving the epidemic in the country.

Adherence, Effectiveness and Safety of Dolutegravir Based Antiretroviral Regimens among HIV Infected Children and Adolescents in Tanzania

Objectives:This study aimed at assessing adherence, effectiveness, and safety of DTG-based HAART regimens among HIV-infected children and adolescents in Tanzania. Methods: This was a single-center prospective cohort study, conducted at the pediatric HIV Clinic in Mbeya, Tanzania. A binary logistic regression model was used to determine predictors of undetectable viral load at week 24. The results were significant when P-value was <0.05. Results: A total of 200 patients were enrolled with the majority (85.5%) being treatment experienced. High adherence levels (71%) were observed using the pharmacy refill method. At week 24, the overall proportion of patients with undetectable viral load was 70.2%. The predictors of undetectable viral load were age, World Health Organization (WHO) clinical stage, baseline VL and adherence to pharmacy refill. Conclusion: The majority of patients attained undetectable viral load 6 months after using DTG based regimen. DTG-based regimens were generally safe with few ADEs reported.

INSTIs and NNRTIs Potently Inhibit HIV-1 Polypurine Tract Mutants in a Single Round Infection Assay

Integrase strand transfer inhibitors (INSTIs) are a class of antiretroviral compounds that prevent the insertion of a DNA copy of the viral genome into the host genome by targeting the viral enzyme integrase (IN). Dolutegravir (DTG) is a leading INSTI that is given, usually in combination with nucleoside reverse transcriptase inhibitors (NRTIs), to treat HIV-1 infections. The emergence of resistance to DTG and other leading INSTIs is rare. However, there are recent reports suggesting that drug resistance mutations can occur at positions outside the integrase gene either in the HIV-1 polypurine tract (PPT) or in the envelope gene (env). Here, we used single round infectivity assays to measure the antiviral potencies of several FDA-approved INSTIs and non-nucleoside reverse transcriptase inhibitors (NNRTIs) against a panel of HIV-1 PPT mutants. We also tested several of our promising INSTIs and NNRTIs in these assays. No measurable loss in potency was observed for either INSTIs or NNRTIs against the HIV-1 PPT mutants. This suggests that HIV-1 PPT mutants are not able, by themselves, to confer resistance to INSTIs or NNRTIs.

Tenofovir alafenamide nephrotoxicity: a case report and literature review

Background

Tenofovir alafenamide (TAF), a novel prodrug of tenofovir (TFV), has become the preferred drug for the treatment of HIV-1 and chronic hepatitis B infection in clinical practice. Results from clinical trials showed that it had better renal and bone mineral outcomes compared to tenofovir disoproxil fumarate (TDF). However, as we have seen with TDF, side effects from the new medication can be more prevalent and recognized after extensive use in real world situations. Sporadic cases of acute kidney injury in patients using TAF have started to emerge.

Case presentation

We report a case of 49-year-old Thai, HIV treatment-experienced female with hypertension presented with worsening renal function after switching her antiretroviral regimen from TDF, emtricitabine (FTC), and lopinavir/ritonavir (LPV/r) to TAF, FTC and dolutegravir (DTG) for 3 months. Kidney biopsy showed distinctive picture of tenofovir nephrotoxicity with acute tubular injury and mitochondrial injury. The possible causes of acute kidney injury and nephrotoxicity from TAF for this patient were discussed. We have extensively reviewed all published case reports of TAF-associated nephrotoxicity and summarized the essential information in this article.

Conclusion

Although TAF has less nephrotoxicity compared with TDF; renal function should always be monitored after the initiation of both drugs. Future large cohort studies are required to identify the risk factors of TAF-associated nephrotoxicity and to design an effective preventive strategy.

Safety and Effectiveness Analysis of Dolutegravir in Patients with HIV-1: Interim Report of Post-Marketing Surveillance in Japan

Introduction

Dolutegravir (DTG), a novel HIV-integrase strand transfer inhibitor (INSTI), is usually used with multiple antiretrovirals (ARVs) for treatment of HIV. DTG is now approved as Tivicay tablets in over 120 countries and Triumeq combination tablets (DTG/abacavir [ABC]/lamivudine [3TC]) in over 90 countries. In Japan, these formulations have been marketed since 2014 and 2015. The post-marketing prospective surveillance has been conducted as part of the HIV-Related Drug (HRD) cooperative survey aimed to collect actual drug use information in all of these DTG-treated patients in accordance with conditions for initial approvals.

Methods

The survey has been conducted to evaluate long-term safety and effectiveness of DTG since 2014, for approximately 6 years. The safety was evaluated by incidence of adverse drug reactions (ADRs) and change in body weight. The effectiveness was evaluated by plasma HIV RNA copies/mL and peripheral CD4⁺ cell counts.

Results

Of 2292 patients in 30 Japanese sites, 565 (24.65%) reported ADRs. The most common ADR was blood creatinine increased (4.28%). Incidence of ADRs was statistically significantly higher in patients with severe symptoms (Centers for Disease Control and Prevention [CDC] categories B and C) than those with category A, and in patients with comorbidities than those without comorbidities. Whereas incidence of ADRs was statistically significantly lower in antiretroviral therapy (ART)-experienced patients than that in ART-naïve patients. Incidence of ADRs related to suicide or self-injurious behavior was statistically significantly higher in patients with comorbidities of psychiatric disorders than those without comorbidities. The body weight tended to increase over time and those changes and percentage changes from baseline were greater in ART-naïve patients compared with ART-experienced patients. HIV RNA copies/mL and CD4⁺ cell counts showed favorable shifts from baseline in both ART-naïve and ART-experienced patients.

Conclusion

The results of the survey identified no new safety and effectiveness risks in Japanese patients with HIV/AIDS treated with DTG.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01842-3.

Pharmacokinetics, Safety, and Tolerability of a Single Oral Dose of Abacavir/Dolutegravir/Lamivudine Combination Tablets in Healthy Japanese Study Participants

Pharmacokinetics, safety, and tolerability of abacavir 600 mg/dolutegravir 50 mg/lamivudine 300 mg were assessed in this phase 1, single‐arm, open‐label, single‐dose study in fasted healthy male (n = 4) and female (n = 8) participants of Japanese heritage. Participants received a single dose of abacavir 600 mg/dolutegravir 50 mg/lamivudine 300 mg after an 8‐hour fast, with safety assessments and blood samples for pharmacokinetic parameters collected through 72 hours after dosing. Geometric mean maximum plasma concentrations were 5.22 μg/mL (time to maximum concentration [t_max], 1.01 hours) for abacavir, 4.13 μg/mL (t_max, 3.50 hours) for dolutegravir, and 3.35 μg/mL (t_max, 2.98 hours) for lamivudine. Geometric mean area under the concentration‐time curve values were 18.20, 71.60, and 16.60 μg • h/mL for abacavir, dolutegravir, and lamivudine, respectively. No adverse events were reported, and no clinically significant findings were observed in laboratory values, physical examinations, or 12‐lead electrocardiographic parameters. Single‐tablet administration of abacavir 600 mg/dolutegravir 50 mg/lamivudine 300 mg was well tolerated in Japanese participants. Exposure to abacavir and lamivudine was comparable with that seen in previous studies. A modest increase in exposure to dolutegravir vs previous clinical studies was observed but is not expected to impact the clinical management of HIV‐1 or increase the risk for adverse events.

Primary resistance to integrase strand transfer inhibitors in Spain using ultrasensitive HIV-1 genotyping

BACKGROUND

Transmission of resistance mutations to integrase strand transfer inhibitors (INSTIs) in HIV-infected patients may compromise the efficacy of first-line antiretroviral regimens currently recommended worldwide. Continued surveillance of transmitted drug resistance (TDR) is thus warranted.

OBJECTIVES

We evaluated the rates and effects on virological outcomes of TDR in a 96 week prospective multicentre cohort study of ART-naive HIV-1-infected subjects initiating INSTI-based ART in Spain between April 2015 and December 2016.

METHODS

Pre-ART plasma samples were genotyped for integrase, protease and reverse transcriptase resistance using Sanger population sequencing or MiSeq™ using a ≥ 20% mutant sensitivity cut-off. Those present at 1%-19% of the virus population were considered to be low-frequency variants.

RESULTS

From a total of 214 available samples, 173 (80.8%), 210 (98.1%) and 214 (100.0%) were successfully amplified for integrase, reverse transcriptase and protease genes, respectively. Using a Sanger-like cut-off, the overall prevalence of any TDR, INSTI-, NRTI-, NNRTI- and protease inhibitor (PI)-associated mutations was 13.1%, 1.7%, 3.8%, 7.1% and 0.9%, respectively. Only three (1.7%) subjects had INSTI TDR (R263K, E138K and G163R), while minority variants with integrase TDR were detected in 9.6% of subjects. There were no virological failures during 96 weeks of follow-up in subjects harbouring TDR as majority variants.

CONCLUSIONS

Transmitted INSTI resistance remains rare in Spain and, to date, is not associated with virological failure to first-line INSTI-based regimens.

Impact of genotypic diversity on selection of subtype-specific drug resistance profiles during raltegravir-based therapy in individuals infected with B and BF recombinant HIV-1 strains

BACKGROUND

Current knowledge on HIV-1 resistance to integrase inhibitors (INIs) is based mostly on subtype B strains. This contrasts with the increasing use of INIs in low- and middle-income countries, where non-B subtypes predominate.

MATERIALS AND METHODS

HIV-1 drug resistance genotyping was performed in 30 HIV-1-infected individuals undergoing virological failure to raltegravir. Drug resistance mutations (DRMs) and HIV-1 subtype were characterized using Stanford HIVdb and phylogenetic analyses.

RESULTS

Of the 30 integrase (IN) sequences, 14 were characterized as subtype F (47%), 8 as subtype B (27%), 7 as BF recombinants (23%) and 1 as a putative CRF05_DF (3%). In 25 cases (83%), protease and reverse transcriptase (PR-RT) sequences from the same individuals confirmed the presence of different BF recombinants. Stanford HIVdb genotyping was concordant with phylogenetic inference in 70% of IN and 60% of PR-RT sequences. INI DRMs differed between B and F IN subtypes, with Q148K/R/H, G140S and E138K/A being more prevalent in subtype B (63% versus 0%, P = 0.0021; 50% versus 0%, P = 0.0096; and 50% versus 0%, P = 0.0096, respectively). These differences were independent of the time on raltegravir therapy or viral load at the time of genotyping. INI DRMs in subtype F IN genomes predicted a lower level of resistance to raltegravir and no cross-resistance to second-generation INIs.

CONCLUSIONS

Alternative resistance pathways to raltegravir develop in subtypes B and F IN genomes, with implications for clinical practice. Evaluating the role of HIV-1 subtype in development and persistence of mutations that confer resistance to INIs will be important to improve algorithms for resistance testing and optimize the use of INIs.

Using Climate-HIV to describe real-world clinical outcomes for people living with HIV taking dolutegravir-based regimens

Objectives:

The objective of this study was to describe the real-world use and effectiveness of dolutegravir-based regimens (DBRs) in routine clinical practice in the United Kingdom.

Methods:

Retrospective analysis was conducted using data from four National Health Service trusts using Climate-HIV, an electronic case record system. Eligible patients were aged ≥18 years with HIV-1 infection who were prescribed a DBR from December 2012 to March 2018. Outcome measurements were accessed at DBR initiation and at weeks 24, 48 and 96 and the last recorded visit up to the extraction date (last measurement). The primary endpoint was the proportion of patients with HIV-1 RNA <50 copies/mL at Week 48.

Results:

The study cohort included 934 patients; 337 (36%) were female, 414 (47%) were white and 717 (77%) were treatment experienced (TE). The Kaplan–Meier estimated probability of achieving HIV-1 RNA <50 copies/mL at 48 weeks was 96% for treatment-naive (TN) patients and 86% for TE patients. Median times to viral suppression (<50 copies/mL) were 49 and 57 days for TN and TE patients with detectable baseline viral load, respectively, according to Kaplan–Meier analysis. Median follow-up time was 377 days (interquartile range: 131–683). At last measurement, 87% (809/934) of patients remained on a DBR; among those patients, 681 (84%) had HIV-1 RNA <50 copies/mL.

Conclusions:

High levels of virologic suppression and low rates of discontinuation of DBRs were seen in a large, diverse, UK-based population with HIV-1 infection. These findings are broadly consistent with efficacy data from phase III studies.

HIV-1 Integrase Inhibitors with Modifications That Affect Their Potencies against Drug Resistant Integrase Mutants

Integrase strand transfer inhibitors (INSTIs) block the integration step of the retroviral lifecycle and are first-line drugs used for the treatment of HIV-1/AIDS. INSTIs have a polycyclic core with heteroatom triads, chelate the metal ions at the active site, and have a halobenzyl group that interacts with viral DNA attached to the core by a flexible linker. The most broadly effective INSTIs inhibit both wild-type (WT) integrase (IN) and a variety of well-known mutants. However, because there are mutations that reduce the potency of all of the available INSTIs, new and better compounds are needed. Models based on recent structures of HIV-1 and red-capped mangabey SIV INs suggest modifications in the INSTI structures that could enhance interactions with the 3′-terminal adenosine of the viral DNA, which could improve performance against INSTI resistant mutants. We designed and tested a series of INSTIs having modifications to their naphthyridine scaffold. One of the new compounds retained good potency against an expanded panel of HIV-1 IN mutants that we tested. Our results suggest the possibility of designing inhibitors that combine the best features of the existing compounds, which could provide additional efficacy against known HIV-1 IN mutants.

HIV-1 Integrase Inhibitors with Modifications That Affect Their Potencies against Drug Resistant Integrase Mutants

Integrase strand transfer inhibitors (INSTIs) block the integration step of the retroviral lifecycle and are first-line drugs used for the treatment of HIV-1/AIDS. INSTIs have a polycyclic core with heteroatom triads, chelate the metal ions at the active site, and have a halobenzyl group that interacts with viral DNA attached to the core by a flexible linker. The most broadly effective INSTIs inhibit both wild-type (WT) integrase (IN) and a variety of well-known mutants. However, because there are mutations that reduce the potency of all of the available INSTIs, new and better compounds are needed. Models based on recent structures of HIV-1 and red-capped mangabey SIV INs suggest modifications in the INSTI structures that could enhance interactions with the 3'-terminal adenosine of the viral DNA, which could improve performance against INSTI resistant mutants. We designed and tested a series of INSTIs having modifications to their naphthyridine scaffold. One of the new compounds retained good potency against an expanded panel of HIV-1 IN mutants that we tested. Our results suggest the possibility of designing inhibitors that combine the best features of the existing compounds, which could provide additional efficacy against known HIV-1 IN mutants.

Virologic failure after 48 weeks of raltegravir-based regimen in low HIV-1 incidence setting

Background

With the advent of next generation integrase strand transfer inhibitors, the rates of virologic failure in treated subjects are expected to decrease. In this study, we analyzed the mutation patterns leading to virologic failure before and after starting integrase strand transfer inhibitor-based regimen as first-line or salvage therapy.

Methods

Between 2016 and 2019, blood samples were received from 258 patients with HIV-1 infection. Plasma HIV-1 RNA concentrations, and pol gene sequences were determined at baseline, and 16–48 weeks of treatment with integrase strand transfer inhibitor-based regimen. Only patients who did not achieve viral suppression at 48 weeks of integrase strand transfer inhibitor-based treatment were eligible for the current study.

Results

Virologic failure was observed in seven patients on raltegravir-based regimen. All patients with virologic failure but one were infected with CRF01_AE virus subtype. Raltegravir based-regimen was offered as first-line therapy for four patients, and as salvage therapy for three patients. M184V mutation associated with high level resistance to lamivudine and emtricitabine was detected in six out of seven patients. Primary mutations (Y143C, N155H, T66I, G118R, E138K) conferring high level resistance to raltegravir were detected in only three patients. Pre-existing polymorphic integrase mutation (T97A) was detected in two patients. Furthermore, two patients reported low adherence to treatment.

Conclusions

Emergence of primary mutations in the integrase gene can account for virologic failure in less than half of patients on raltegravir-based regimen. Low adherence to treatment, pre-existing accessory mutations, and resistance to reverse transcriptase inhibitors may have some role in virologic outcome.

Mechanistic insights into antiretroviral drug-induced liver injury

All classes of antiretroviral therapy (ART) have been implicated to induce adverse drug reactions such drug-induced liver injury (DILI) and immune-mediated adverse reactions in Human Immunodeficiency Virus (HIV) infected individuals. Patients that develop adverse drug reactions tend to have prolonged stays in hospital and may require to change to alternative regimens if reactions persist upon rechallenge or if rechallenge is contraindicated due to severity of the adverse reaction. Diagnosis of DILI remains a huge obstacle that delays timely interventions, since it is still based largely on exclusion of other causes. There is an urgent need to develop robust diagnostic and predictive biomarkers that could be used alongside the available tools (biopsy, imaging, and serological tests for liver enzymes) to give a specific diagnosis of DILI. Crucial to this is also achieving consensus in the definition of DILI so that robust studies can be undertaken. Importantly, it is crucial that we gain deeper insights into the mechanism of DILI so that patients can receive appropriate management. In general, it has been demonstrated that the mechanism of ART-induced liver injury is driven by four main mechanisms: mitochondrial toxicity, metabolic host-mediated injury, immune reconstitution, and hypersensitivity reactions. The focus of this review is to discuss the type and phenotypes of DILI that are caused by the first line ART regimens. Furthermore, we will summarize recent studies that have elucidated the cellular and molecular mechanisms of DILI both in vivo and in vitro.

Interaction analysis of statistically enriched mutations identified in Cameroon recombinant subtype CRF02_AG that can influence the development of Dolutegravir drug resistance mutations

BACKGROUND

The Integrase (IN) strand transfer inhibitor (INSTI), Dolutegravir (DTG), has been given the green light to form part of first-line combination antiretroviral therapy (cART) by the World Health Organization (WHO). DTG containing regimens have shown a high genetic barrier against HIV-1 isolates carrying specific resistance mutations when compared with other class of regimens.

METHODS

We evaluated the HIV-1 CRF02_AG IN gene sequences from Cameroon for the presence of resistance-associated mutations (RAMs) against INSTIs and naturally occurring polymorphisms (NOPs), using study sequences (n = 20) and (n = 287) sequences data derived from HIV Los Alamos National Laboratory database. The possible impact of NOPs on protein structure caused by HIV-1 CRF02_AG variations was addressed within the context of a 3D model of the HIV-1 IN complex and interaction analysis was performed using PyMol to validate DTG binding to the Wild type and seven mutant structures.

RESULTS

We observed 12.8% (37/287) sequences to contain RAMs, with only 1.0% (3/287) of the sequences having major INSTI RAMs: T66A, Q148H, R263K and N155H. Of these,11.8% (34/287) of the sequences contained five different IN accessory mutations; namely Q95K, T97A, G149A, E157Q and D232N. NOPs occurred at a frequency of 66% on the central core domain (CCD) position, 44% on the C-terminal domain (CTD) position and 35% of the N-terminal domain (NTD) position. The interaction analysis revealed that DTG bound to DNA, 2MG ions and DDE motif residues for T66A, T97A, Q148H, N155H and R263K comparable to the WT structure. Except for accessory mutant structure E157Q, only one MG contact was made with DTG, while DTG had no MG ion contacts and no DDE motif residue contacts for structure D232N.

CONCLUSIONS

Our analysis indicated that all RAM's that resulted in a change in the number of interactions with encompassing residues does not affect DTG binding, while accessory mutations E157Q and D232N could affect DTG binding leading to possible DTG resistance. However, further experimental validation is required to validate the in silico findings of our study.

HIV-1 integrase strand transfer inhibitors: a review of current drugs, recent advances and drug resistance

Antiretroviral therapy has been imperative in controlling the human immunodeficiency virus (HIV) epidemic. Most low- and middle-income countries have used nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors extensively in the treatment of HIV. However, integrase strand transfer inhibitors (INSTIs) are becoming more common. Since their identification as a promising therapeutic drug, significant progress has been made that has led to the approval of five INSTIs by the US Food and Drug Administration (FDA), i.e. dolutegravir (DTG), raltegravir (RAL), elvitegravir (EVG), bictegravir (BIC) and cabotegravir (CAB). INSTIs have been shown to effectively halt HIV-1 replication and are commended for having a higher genetic barrier to resistance compared with NRTIs and NNRTIs. More interestingly, DTG has shown a higher genetic barrier to resistance compared with RAL and EVG, and CAB is being used as the first long-acting agent in HIV-1 treatment. Considering the increasing interest in INSTIs for HIV-1 treatment, we focus our review on the retroviral integrase, development of INSTIs and their mode of action. We also discuss each of the INSTI drugs, including potential drug resistance and known side effects.

Interactions of HIV and Antiretroviral Therapy With Neutrophils and Platelets

Neutrophils are important components of the innate immune system that mediate pathogen defense by multiple processes including phagocytosis, release of proteolytic enzymes, production of reactive oxygen species, and neutrophil extracellular trap formation. Abnormalities of neutrophil count and function have been described in the setting of HIV infection, with the majority of antiretroviral agents (ARVs), excluding zidovudine, having been reported to correct neutropenia. Questions still remain, however, about their impact on neutrophil function, particularly the possibility of persistent neutrophil activation, which could predispose people living with HIV to chronic inflammatory disorders, even in the presence of virally-suppressive treatment. In this context, the effects of protease inhibitors and integrase strand transfer inhibitors, in particular, on neutrophil function remain poorly understood and deserve further study. Besides mediating hemostatic functions, platelets are increasingly recognized as critical role players in the immune response against infection. In the setting of HIV, these cells have been found to harbor the virus, even in the presence of antiretroviral therapy (ART) potentially promoting viral dissemination. While HIV-infected individuals often present with thrombocytopenia, they have also been reported to have increased platelet activation, as measured by an upregulation of expression of CD62P (P-selectin), CD40 ligand, glycoprotein IV, and RANTES. Despite ART-mediated viral suppression, HIV-infected individuals reportedly have sustained platelet activation and dysfunction. This, in turn, contributes to persistent immune activation and an inflammatory vascular environment, seemingly involving neutrophil-platelet-endothelium interactions that increase the risk for development of comorbidities such as cardiovascular disease (CVD) that has become the leading cause of morbidity and mortality in HIV-infected individuals on treatment, clearly underscoring the importance of unraveling the possible etiologic roles of ARVs. In this context, abacavir and ritonavir-boosted lopinavir and darunavir have all been linked to an increased risk of CVD. This narrative review is therefore focused primarily on the role of neutrophils and platelets in HIV transmission and disease, as well as on the effect of HIV and the most common ARVs on the numbers and functions of these cells, including neutrophil-platelet-endothelial interactions.

Short Communication: Integrase Strand Transfer Inhibitors Drug Resistance Mutations in Puerto Rico HIV-Positive Individuals

The HIV-1 integrase viral protein is responsible for incorporating the viral DNA into the genomic DNA. The inhibition of viral integration into host cell DNA is part of recent therapeutic procedures. Combination therapy with protease and reverse transcriptase inhibitors has demonstrated good synergistic results in reducing viral replication. The purpose of this study is to assess the occurrence of integrase drug resistance mutations from the period comprising 2013 through 2018 in Puerto Rico (PR). We analyzed 131 nucleotide sequences available in our HIV genotyping database, and we performed drug resistance mutation analyses using the Stanford HIV Drug Resistance Database. Twenty-one sequences (16.03%) harbored major or resistance-associated mutations. We identified the Q148HKR, G140S, Y143R, N155H, S147G, and E138EA major drug resistance mutations and the D232DN, T97TA, E157Q, G163GART accessory mutations. We detected high-level drug resistance to Elvitegravir and Raltegravir (76.19% and 85.71%). Moreover, we identified sequences harboring drug resistance mutations that could provide resistance to Dolutegravir. The transmission of strains with integrase antiretroviral resistance has been previously documented in treatment naïve patients. Given the increase of patients treated with integrase inhibitors, surveillance of drug resistance mutations is an essential aspect of PR's clinical management of HIV infection.