Efficacy, safety, and tolerability of dolutegravir-based ART regimen in Durban, South Africa: a cohort study

BACKGROUND

Dolutegravir is an integrase strand transfer inhibitor that has been recommended for use in first-line antiretroviral regimens by the World Health Organisation and is currently being rolled out globally. There has been safety concerns with dolutegravir which has caused concern about its use in the general population. Dolutegravir first-line regimens have been used in South Africa since early 2020. Therefore, the aim of the present study was to assess the efficacy, safety, and tolerability of first-line dolutegravir-based antiretrovirals amongst adults living with HIV in Durban, South Africa.

METHODS

This was a mixed-methods study, which comprised a cross-sectional survey and longitudinal retrospective follow-up of medical records. The study was conducted between October 2020 and January 2022. Data were described using descriptive and summary statistics. Bivariate logistic regression was applied to socio-demographic and clinical variables and crude odds ratios with a 95% confidence interval was calculated. Pearson chi-square tests, paired sample T-tests, and cross-tabulations were performed on selected variables.

RESULTS

A total of 461 participants were enrolled in the study. There was a significant change in immunological outcomes (p < 0.001) after dolutegravir initiation. Furthermore, an assessment of laboratory parameters showed that there was a significant decrease in cholesterol (p < 0.001) and increase in creatinine (p < 0.001) levels. Increased weight was shown by 60.7% of the participants but was not associated with age, gender, CD4 counts, and previous antiretroviral usage. The study found that 43.6% of the participants experienced at least one side-effect. A total of 21.6% and 23.2% of the participants experienced neuropsychiatric and central nervous system side-effects, respectively. In the bivariate analyses, only gender was shown to be associated with side-effects, and only 1.7% of the participants discontinued the study due to side-effects.

CONCLUSION

Our results suggest that dolutegravir is effective, safe, and well tolerated in the study population.

Incidence of low-level viremia and its impact on virologic failure among people living with HIV who started an integrase strand transfer inhibitors: a longitudinal cohort study

BACKGROUND

Low-level viremia (LLV) has been identified as a potential precursor to virologic failure (VF), yet its clinical implications, particularly within the context of Integrase Strand Transfer Inhibitors (INSTIs)-based regimens, remain insufficiently explored. The study aimed to investigate the relationship between LLV and VF within ART-naïve patients on INSTIs-based regimens in China.

METHODS

A longitudinal cohort study was conducted with ART-naïve patients aged ≥ 18 years at Beijing Ditan Hospital, under the Chinese National Free Antiretroviral Treatment Program (NFATP). The LLV was defined as a viral load (VL) ranging from 50 to 199 copies/mL after six months of ART initiation, and VF as a VL ≥ 200 copies/mL. Sensitive analyses were also performed, defining LLV as 50-999 copies/mL and VF as exceeding 1000 copies/mL. Multivariate logistic regression, Kaplan-Meier (KM) curve, and Generalized Estimating Equation (GEE) models were used to evaluate the risk factors associated with LLV and VF events.

RESULTS

The study involved 830 ART-naïve patients, comprising 600 in the INSTIs group and 230 in the protease inhibitors (PIs) group. LLV events were observed in 10.4% of patients on PIs-based regimens and and 3.2% on INSTIs-based regimens (P < 0.001). INSTIs-based regimens demonstrated a protective effect against LLV events (aHR = 0.27, 95% CI 0.137-0.532). VF events occurred in 10.9% of patients on PIs-based regimens and 2.0% on INSTIs-based regimens, respectively (P < 0.001). The occurrence of LLV events significantly increased the risk of VF by 123.5% (95% CI 7.5%-364.4%), while the integrase inhibitors were associated with a 76.9% (95% CI 59.1%-86.9%) reduction in VF risk.

CONCLUSION

Our findings indicate that INSTIs-based regimens are critical protective factors against LLV and subsequent VF. These results underscore the importance of HIV viral load monitoring to ensuring effective treatment outcomes, highlighting the necessity for prompt and precise monitoring to refine HIV treatment methodologies.

Effect of tenofovir alafenamide in combination with and without integrase inhibitors on weight gain, diabetes, and hypertensive disorders of pregnancy

OBJECTIVES

We sought to determine if tenofovir alafenamide (TAF) was associated with excessive weight gain, diabetes (DM), and hypertensive disorders of pregnancy (HDP) in persons with HIV.

STUDY DESIGN

This is a retrospective cohort study of pregnant persons with HIV prescribed antiretroviral therapy (ART) during the period of 01/01/2009 to 12/31/2020.

MAIN OUTCOMES MEASURES

χ2 tests were used to compare the proportion of persons with excessive weight gain, DM, and HDP according to ART regimens. Excess total gestational weight gain was calculated using BMI and Institute of Medicine recommendations for weight gain in pregnancy. HDP included gestational hypertension and preeclampsia. Logistic regression models were used to determine predictors of excessive weight gain, DM, and HDP.

RESULTS

We identified 189 pregnant persons prescribed ART with (30) and without TAF (159). The percentage of persons with excessive gestational weight gain was not significantly different in persons prescribed TAF (32 %) and other ART (17 %), p = 0.2. Persons prescribed TAF were more likely to have HDP (30 %) compared to other ART (9 %), p = 0.001. In the adjusted analysis, DM [aOR 6.2 (95 % CI 1.2-32.7)] and TAF exposure [aOR 3.2 (95 % CI 1.0-8.9)] were significantly associated with HDP.

CONCLUSION

Despite similar gestational weight gain, persons with HIV prescribed TAF were more likely to have HDP. Further understanding of the metabolic and cardiovascular impact of ART recommended for use during pregnancy is needed.

Advances in long-acting slow effective release antiretroviral therapies for treatment and prevention of HIV infection

Adherence to daily oral antiretroviral therapy (ART) is a barrier to both treatment and prevention of human immunodeficiency virus (HIV) infection. To overcome limitations of life-long daily regimen adherence, long-acting (LA) injectable antiretroviral (ARV) drugs, nanoformulations, implants, vaginal rings, microarray patches, and ultra-long-acting (ULA) prodrugs are now available or in development. These medicines enable persons who are or at risk for HIV infection to be treated with simplified ART regimens. First-generation LA cabotegravir, rilpivirine, and lenacapavir injectables and a dapivirine vaginal ring are now in use. However, each remains limited by existing dosing intervals, ease of administration, or difficulties in finding drug partners. ULA ART regimens provide an answer, but to date, such next-generation formulations remain in development. Establishing the niche will require affirmation of extended dosing, improved access, reduced injection volumes, improved pharmacokinetic profiles, selections of combination treatments, and synchronization of healthcare support. Based on such needs, this review highlights recent pharmacological advances and a future treatment perspective. While first-generation LA ARTs are available for HIV care, they remain far from ideal in meeting patient needs. ULA medicines, now in advanced preclinical development, may close gaps toward broader usage and treatment options.

The impact of integrase inhibitors on steatosis and fibrosis biomarkers in persons with HIV naïve to antiretroviral therapy

BACKGROUND

Non-alcoholic Fatty Liver Disease (NAFLD) has a high prevalence among persons with HIV infection. Since Integrase Strand Transfer Inhibitors (INSTIs) are used worldwide and have been associated with weight gain, we must determine their effect in the development of NAFLD and Non-alcoholic Steatohepatitis (NASH) in these patients. The aim of this study was to explore the impact of INSTIs on variation of liver steatosis and fibrosis in the ART-naïve person with HIV, using Hepatic Steatosis Index (HSI), Fibrosis-4 Index (FIB-4), BARD score and NAFLD Fibrosis Score (NFS).

METHODS

We performed a monocentric, retrospective cohort study in ART-naïve persons with HIV that initiated INSTI based regimens between December 2019 and January 2022. Data was collected at baseline, 6 and 12 months after initiation. Demographic, clinical and laboratory characteristics, hepatic steatosis, and fibrosis scores were compared between baseline and last visit at 12 months. Linear regression models were performed to analyse the associations between analytical data at baseline and hepatic scores variation during the 12 months of treatment. Models were performed unadjusted and adjusted for age and sex.

RESULTS

99 patients were included in our study. 82% were male and median age was 36 years. We observed a significant increase in body mass index (BMI), HDL, platelet count, albumin, and creatinine and a significant decrease in AST levels. HSI showed no statistically significant differences during follow-up (p = 0.114). We observed a significant decrease in FIB-4 (p = 0.007) and NFS (p = 0.002). BARD score showed a significant increase (p = 0.006). The linear regression model demonstrated a significant negative association between baseline HIV RNA and FIB-4 change (β= -0.08, 95% CI [-0.16 to -0.00], p = 0.045), suggesting that higher HIV RNA loads at baseline were associated with a greater decrease in FIB-4.

CONCLUSION

INSTIs seem to have no impact on hepatic steatosis, even though they were associated with a significant increase in BMI. This might be explained by the direct effect of a dolutegravir-containing regimen and/or by the "return-to-health effect" observed with ART initiation. Furthermore, INSTIs were associated with a reduction in risk of liver fibrosis in ART-naïve persons with HIV, possibly due to their effect on viral suppression.

Identification of integrase inhibitor-related drug resistance mutations in newly diagnosed ART-naïve HIV patients

BACKGROUND

In China, the recommended treatment regimens for HIV-infected individuals were tenofovir in combination with lamivudine or emtricitabine as NRTIs, efavirenz or rilpivirine as NNRTIs, lopinavir/ritonavir as protease inhibitors, and raltegravir or dolutegravir as INSTIs. The development of drug resistance increases the risk of viral rebound, opportunistic infections, and ultimately treatment failure such that the early detection of resistance is ideal. This study was developed to explore primary drug resistance characteristics and genotypic distributions in newly diagnosed antiretroviral therapy (ART)-naïve HIV-1 patients in Nanjing with the goal of establishing a basis for their individualized treatment in the clinic.

METHODS

Samples of serum were collected from newly diagnosed ART-naïve HIV patients from the Second Hospital of Nanjing between May 2021 and May 2022. The HIV-1 integrase (IN), protease (PR), and reverse transcriptase (RT) gene coding sequences were amplified from these samples, sequenced, and assessed for drug resistance-related mutations.

RESULTS

Major integrase resistance-related mutations were detected in 4/360 amplified samples, with 5 other patient samples exhibiting accessory resistance mutations. The overall prevalence of PR and RT inhibitor-related transmitted drug resistance mutations (TDRMs) in this patient population was 16.99% (61/359). The most common mutations were non-nucleoside reverse transcriptase inhibitor-related mutations (51/359; 14.21%), followed by those associated with nucleoside reverse transcriptase inhibitors (7/359; 1.95%) and protease inhibitors (7/359; 1.95%). Dual-resistant strains were also observed in a subset of patients.

CONCLUSIONS

In summary, this study is the first to have surveyed the prevalence of integrase inhibitor resistance-related mutations and other drug resistance-related mutations among newly diagnosed ART-naïve HIV-positive patients in Nanjing, China. These results highlight the need for further molecular surveillance-based monitoring of the HIV epidemic in Nanjing.

Change in body weight and risk of hypertension after switching from efavirenz to dolutegravir in adults living with HIV: evidence from routine care in Johannesburg, South Africa

BACKGROUND

The integrase strand transfer inhibitor (INSTI) dolutegravir is recommended in World Health Organization guidelines, but is associated with weight gain. We evaluated weight change in patients switching from efavirenz to dolutegravir in first-line antiretroviral therapy (ART) in Johannesburg, South Africa.

METHODS

We conducted a prospective cohort study of adults (≥16 years) of black African ancestry with HIV who initiated ART between January 2010-December 2020. Patients were propensity score-matched 1:1 (unexposed i.e. remaining on efavirenz: exposed i.e. switched from efavirenz to dolutegravir) on sex, age, months on ART, first ART regimen, haemoglobin, body mass index (BMI), blood pressure, viral load and CD4 count. We used linear regression to assess the effect of switching from efavirenz to dolutegravir on weight change and hypertension 12 months after exposure.

FINDINGS

We matched 794 patients switching to dolutegravir to 794 remaining on efavirenz. Exposed patients had a higher mean change in weight (1.78 kg; 95% confidence interval (CI):1.04,2.52 kg) from start of follow-up to 12 months vs. unexposed. We also found a 14.2 percentage point increase (95% CI: 10.6,17.7) in the risk of hypertension in those exposed to dolutegravir vs those that remained on efavirenz.

INTERPRETATION

In a real-world population, patients gained more weight and were at higher risk of hypertension after switching from efavirenz to dolutegravir than those remaining on efavirenz. Longer follow-up is needed, however, to determine if INSTI-associated weight gain is associated with changes in non-communicable disease risk over the long-term, or whether weight gain is sustained, as seen in clinical trials.

FUNDING

This study has been made possible by the generous support of the American People and the President's Emergency Plan for AIDS Relief (PEPFAR) through the United States Agency for International Development (USAID), under the terms of cooperative agreement cooperative Agreement 72067419CA00004. In addition to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) 1K01MH105320-01A1.

Genotypic correlates of resistance to the HIV-1 strand transfer integrase inhibitor cabotegravir

Cabotegravir (CAB) is an integrase strand transfer inhibitor (INSTI) formulated as a long-acting injectable drug approved for pre-exposure prophylaxis and use with a long acting rilpivirine formulation for therapy in patients with virological suppression. However, there has been no comprehensive review of the genetic mechanisms of CAB resistance. Studies reporting the selection of drug resistance mutations (DRMs) by CAB and the results of in vitro CAB susceptibility testing were reviewed. The impact of integrase mutations on CAB susceptibility was assessed using regularized regression analysis. The most commonly selected mutations in the 24 persons developing virological failure while receiving CAB included Q148R (n = 15), N155H (n = 7), and E138K (n = 5). T97A, G118R, G140 A/R/S, and R263K each developed in 1-2 persons. With the exception of T97A, G118R, and G140 A/R, these DRMs were also selected in vitro while G140R was selected in the SIV macaque model. Although these DRMs are similar to those occurring in persons receiving the related INSTI dolutegravir, Q148R was more likely to occur with CAB while G118R and R263K were more likely to occur with dolutegravir. Regularized regression analysis identified 14 DRMs significantly associated with reduced CAB susceptibility including six primary DRMs which reduced susceptibility on their own including G118R, Q148 H/K/R, N155H, and R263K, and eight accessory DRMs including M50I, L74 F/M, T97A, E138K, and G140 A/C/S. Isolates with Q148 H/K/R in combination with L74M, E138 A/K, G140 A/S, and N155H often had >10-fold reduced CAB susceptibility. M50I, L74M, and T97A are polymorphic mutations that alone did not appear to increase the risk of virological failure in persons receiving a CAB-containing regimen. Careful patient screening is required to prevent CAB from being used during active virus replication. Close virological monitoring is required to minimize CAB exposure to active replication to prevent the emergence of DRMs associated with cross-resistance to other INSTIs.

Integrase Inhibitors Partially Restore Bacterial Translocation, Inflammation and Gut Permeability Induced by HIV Infection: Impact on Gut Microbiota

Introduction

Human immunodeficiency virus (HIV) infection can be considered a chronic disease thanks to the extended use of antiretroviral treatment (ART). In this context, low-grade chronic inflammation related to gut microbiota (GM) dysbiosis and bacterial translocation (BT) among other factors has been observed despite the use of ART. In addition, different ART regimens have demonstrated differential impacts on GM. However, the role of novel integrase strand transfer inhibitors (INSTIs) has not been investigated yet. The aim of this study was to analyse the effects of INSTIs in first-line of treatment on markers of BT, inflammation, cardiovascular risk, gut permeability and GM composition and derived short-chain fatty acids.

Methods

Twenty-six non-HIV-infected volunteers and 30 HIV-infected patients (15 naïve and 15 under INSTIs regimen) were recruited. Blood samples were extracted to analyse biochemical parameters and markers of BT, inflammation, cardiovascular risk, gut permeability and bacterial metabolism. GM composition was analysed using 16S rRNA gene sequencing.

Results

Our results showed that HIV infection increased BT, inflammation, cardiovascular risk and gut permeability, whereas INSTIs counteracted these effects. Regarding GM, the reduction in bacterial richness induced by HIV infection was restored by INSTIs. Beta diversity revealed that HIV-infected people were separated from the control group independently of treatment.

Conclusions

Current antiretroviral regimens based on INSTIs are able to reverse the impact of HIV infection on BT, systemic inflammation, gut permeability and bacterial diversity/richness, reaching similar levels to those observed in an uninfected/control population. These results suggest a protective role of INSTIs in disease progression, subsequent immune activation and in the development of future age-related complications such as cardiovascular events.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-022-00654-4.

Pharmacokinetic drug interactions of integrase strand transfer inhibitors

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

Potential drug-drug interactions in the era of integrase strand transfer inhibitors: a cross-sectional single-center study in Japan

BACKGROUND

Potential drug-drug interactions (PDDIs) commonly occur because of aging and comorbidities in people living with human immunodeficiency virus (HIV; PLWH). Protease inhibitors and non-nucleoside reverse transcriptase inhibitors have been reported to cause PDDIs in these patients. However, there are few reports of PDDIs in the era of treatment using integrase strand transfer inhibitors. Therefore, we investigated PDDIs in Japanese PLWH receiving antiretroviral drugs (ARVs).

METHODS

This was a cross-sectional observational study conducted in Japanese outpatients. All eligible patients who had received ARV therapy for at least 48 weeks were enrolled. The primary endpoint was the incidence of PDDIs detected using the Lexicomp® interface.

RESULTS

Of the 71 eligible patients, 51 (71.8%) were prescribed concomitant non-ARV medications. In 21 patients (29.6%), PDDIs with the potential to reduce the effects of ARVs occurred, although the HIV load was suppressed in all cases. Polypharmacy (the use of ≥5 non-ARVs) was observed in 25 patients (35.2%). There was a significantly higher median number of non-ARV medications in the PDDI group than in the non-PDDI group (6 vs. 3, P <  0.001). Furthermore, the proportion of patients on polypharmacy was significantly higher in those with PDDIs than in those without PDDIs (81.0% vs. 26.7%, P <  0.001).

CONCLUSIONS

The incidence of PDDIs is relatively high in Japanese PLWH, even in the era of treatment using integrase strand transfer inhibitors. Therefore, it is important for patients and health care providers to be constantly aware of PDDIs associated with ARV treatment.

HIV-1 Virologic Rebound Due to Coadministration of Divalent Cations and Bictegravir

A potential drug-drug interaction exists between divalent and trivalent cations (Ca²⁺, Fe³⁺, Mg²⁺, Al³⁺, Zn²⁺) and HIV-1 integrase strand transfer inhibitors (INSTIs). There are limited case reports describing the clinical significance of this potential interaction and none to our knowledge identifying zinc co-administration with INSTIs. In this report we present a patient taking bictegravir/emtricitabine/tenofovir alafenamide who became viremic after ingesting zinc and calcium supplements and later was able to obtain virologic re-suppression after discontinuing supplements. This case represents a potential significant drug interaction between a commonly prescribed antiretroviral drug class and readily available over-the-counter divalent cation products.

The impact of integrase inhibitor-based regimens on markers of inflammation among HIV naïve patients

The use of combination anti-retroviral therapy (cART) correlates with longer and healthier life and with nearly normal life expectancy in people living with HIV. However, cART does not completely restore health. Chronic immune activation and inflammation persist in treated patients and have been described as predictors for clinical events and mortality in HIV-infected patients. Limited information is available on the impact of the various cART regimens on inflammation/immunoactivation. The aim of this work was to explore the impact of elvitegravir, dolutegravir, raltegravir (integrase strand transfer inhibitors, INSTIs) and atazanavir (protease inhibitor, PI) on several soluble markers of immune activation and inflammation during the first year of effective combination anti-retroviral therapy (cART). We conducted an observational retrospective cohort study in HIV-infected cART-naïve patients who initiated an INSTI or atazanavir regimen between March 2015 and February 2016 and a serum sample was available at baseline, 6 and 12 months after initiation. We compared the trend of D-Dimer, TNF- α, IL-2, IL-6, IL-7, IL-10, CCL4/MIP1-β, CCL5/RANTES, s-CD14, s-CD163, hs-CRP levels among the 4 arms of treatment. Percentage of variation from baseline was also measured for all markers. A total of 36 patients were included. We observed heterogeneous modifications in inflammation markers among arms. In particular, we noted that EVG have significant negative effect on s-CD14, hs-CRP, IL-6 and D-Dimer in respect to other INSTIs and this different effect occurs mainly during the first 6 months of cART. IL-7 values increased in the three arms with INSTIs (significantly only in EGV, 159.8%, p = 0.0003) and decreased significantly in patients on PI (-48.96%; p = 0.04) over the period. In conclusion, our results provide further data on changes of inflammatory marker levels, especially for the new INSTIs. Our data show that among INSTIs, EVG seems to have a worse impact on inflammation.

Neuropsychiatric Adverse Events with Dolutegravir and Other Integrase Strand Transfer Inhibitors

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

Which antiretrovirals should be prescribed as first-line treatments? Changes over the past 10 years in France

OBJECTIVE

To describe the changes in first-line antiretroviral (ART) regimens in France between 2005 and 2015 and patients' characteristics related to the use of protease inhibitors in 2015.

METHODS

We extracted all patients starting ART between 2005 and 2015 from a large prospective cohort. Regimens were classified as three nucleoside reverse transcriptase inhibitors (NRTI), or two NRTIs with a boosted protease inhibitor (bPI), with a non-nucleoside reverse transcriptase inhibitor (NNRTI), or with an INSTI. Patients' characteristics at the time of initiation were collected. A multinomial logit model was fitted to analyze characteristics related to the choice of regimen in 2015.

RESULTS

We analyzed data from 15,897 patients. The proportion of patients starting with (i) a bPI decreased from 60% before 2014 to 38.1% in 2015; (ii) an NNRTI decreased from 30% to 17.8% in 2015; (iii) an INSTI gradually increased to 39.4% in 2015. In 2015, patients with an initial viral load ˃5 log copies/mL were less likely to receive NNRTI (OR=0.08) or INSTI regimens (OR=0.69) than bPIs. Patients with initial CD4⁺ T cell count ˂200/mm³ were less likely to receive an NNRTI (OR=0.28) or an INSTI regimen (OR=0.52) than a bPI. Women were less likely to receive an NNRTI (OR=0.79) or an INSTI regimen (OR=0.71) than a bPI; although this depended on age.

CONCLUSION

The use of bPI as first-line ART declined sharply in France from 2005 to 2015. bPI remained of preferential use in patients with high viral load, low CD4⁺ T cell count, and in women.

Recent Advances in Antiretroviral Agents: Potent Integrase Inhibitors

Integrase strand transfer inhibitors (INSTIs) belong to a novel class of antiretroviral agents that have emerged as the new first-line treatments. Three such compounds are currently available, raltegravir, elvitegravir, dolutegravir and two more under development, bictegravir and cabotegravir. These compounds share the same mode of action but exhibit different pharmacokinetic/ pharmacodynamic properties, and drug-drug interactions. A series of studies in the past decade have established their efficacy compared to previous regimens, both in treatment- naïve and experienced patients. INSTIs have demonstrated a favorable safety profile with fewer adverse events and low rates of virological failure. Emergence of resistance to these agents, however, is a worrying concern, particularly for elvitegravir and raltegravir that display a lower genetic barrier than dolutegravir. On-going trials aim at establishing INSTIs as part of dual-drug HIV treatments or even monotherapy. New long-acting, injectable formulations are under investigation for treatment or prevention.

Resistance-Associated Mutations and Polymorphisms among Integrase Inhibitor-Naïve HIV-1 Patients in Kuwait

OBJECTIVES

Resistance-associated mutations (RAMs) in the integrase of different HIV-1 subtypes were investigated in a cohort of patients never exposed to integrase strand transfer inhibitors (INSTIs).

METHODS

The viral RNA was extracted from plasma samples of 53 INSTI-naïve patients, and the integrase genetic region was sequenced and analyzed for subtype assignment and drug resistance.

RESULTS

The median viral load at sampling was 5.28 × 104 RNA copies/mL. Bayesian phylogenetic analysis showed 85% of the HIV-1 isolates were non-B subtypes, with a predominance of subtypes C (22.6%) and CRF01_AE (26.4%). A total of 52 and 110 mutations were found in the integrase region of HIV-1 B and non-B subtypes, respectively. Nonpolymorphic INSTI-RAMs were not detected in this study. However, the accessory mutation E157Q was found in 1 patient with CRF02_AG, and the polymorphic mutations L74M/I that may contribute to a reduced susceptibility to INSTIs in the presence of major mutations were observed in 6 (13.3%) patients with non-B subtypes and 1 (12.5%) patient with the B subtype. Polymorphic mutations at positions known to harbor primary and accessory RAMs were also detected in this study.

CONCLUSION

Our results highlight the importance of monitoring the emergence of INSTI-RAMS before and after the initiation of INSTI-based therapy.

Drug resistance in B and non-B subtypes amongst subjects recently diagnosed as primary/recent or chronic HIV-infected over the period 2013-2016: Impact on susceptibility to first-line strategies including integrase strand-transfer inhibitors

OBJECTIVES

To characterize the prevalence of transmitted drug resistance mutations (TDRMs) by plasma analysis of 750 patients at the time of HIV diagnosis from January 1, 2013 to November 16, 2016 in the Veneto region (Italy), where all drugs included in the recommended first line therapies were prescribed, included integrase strand transfer inhibitors (InNSTI).

METHODS

TDRMs were defined according to the Stanford HIV database algorithm.

RESULTS

Subtype B was the most prevalent HIV clade (67.3%). A total of 92 patients (12.3%) were expected to be resistant to one drug at least, most with a single class mutation (60/68-88.2% in subtype B infected subjectsand 23/24-95.8% in non-B subjects) and affecting mainly NNRTIs. No significant differences were observed between the prevalence rates of TDRMs involving one or more drugs, except for the presence of E138A quite only in patients with B subtype and other NNRTI in subjects with non-B infection. The diagnosis of primary/recent infection was made in 73 patients (9.7%): they had almost only TDRMs involving a single class. Resistance to InSTI was studied in 484 subjects (53 with primary-recent infection), one patient had 143C in 2016, a total of thirteen 157Q mutations were detected (only one in primary/recent infection).

CONCLUSIONS

Only one major InSTI-TDRM was identified but monitoring of TDRMs should continue in the light of continuing presence of NNRTI-related mutation amongst newly diagnosed subjects, sometime impacting also to modern NNRTI drugs recommended in first-line therapy.

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

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

Antiretroviral therapy: current drugs

The rapid advances in drug discovery and the development of antiretroviral therapy is unprecedented in the history of modern medicine. The administration of chronic combination antiretroviral therapy targeting different stages of the human immunodeficiency virus' replicative life cycle allows for durable and maximal suppression of plasma viremia. This suppression has resulted in dramatic improvement of patient survival. This article reviews the history of antiretroviral drug development and discusses the clinical pharmacology, efficacy, and toxicities of the antiretroviral agents most commonly used in clinical practice to date.