Use Of Non-nucleoside Reverse Transcriptase Inhibitors Research Articles

Chronic Liver Enzyme Elevation and Use of Contemporary ARVs Among People With HIV.

While use of some older antiretroviral drugs (ARVs) is associated with chronic liver enzyme elevation (cLEE), the impact of newer ARVs remains unknown. People with HIV enrolled in the RESPOND cohort who started an ARV after January 1, 2012 were included (baseline). The primary outcome was first cLEE individuals were censored at first of cLEE, last visit, death, or December 31, 2021. Incidence rates (IRs; events/1000 person-years) were calculated for each ARV overall and by ARV exposure (6-12 months, 1-2 years, and 2+ years). Poisson regression was used to estimate the incidence rate ratio (IRR) of cLEE and its association with individual ARVs and ARV class. Of 17 106 individuals included contributing 87 924 person-years of follow-up, 1932 (11.3%) experienced cLEE (incidence rate [IR], 22.0; 95% CI, 21.0-23.0). There was no evidence of a cumulative ARV effect on cLEE incidence, (6-12 months: IR, 45.8; 95% CI, 41.4-50.19; 1-2 years: IR, 34.3; 95% CI, 31.5-37.4; and 2+ years: IR, 18.5; 95% CI, 17.4-19.7). Any use (vs no prior use) of non-nucleoside reverse transcriptase inhibitors (NNRTIs) as a class and tenofovir disoproxil fumarate (TDF) was independently associated with an increased IRR of cLEE, and any use of darunavir (DRV) was associated with a decreased risk of cLEE. cLEE is common and more frequent during the first year after initiating new ARVs. With a >5-year median follow-up, we found no short-term liver safety concerns with the use of INSTIs. Use of NNRTIs and TDF was associated with an increased cLEE risk, while DRV was associated with lower risk.

Patterns and prognosis of holding regimens for people living with HIV in Asian countries.

The use of holding regimens for people living with HIV (PLWH) without effective antiretroviral options can have effects on outcomes and future treatment options. We aimed to investigate the use of holding regimens for PLWH in Asian countries. Data from adults enrolled in routine HIV care in IeDEA Asia-Pacific cohorts were included. Individuals were considered to be on holding regimen if they had been on combination antiretroviral therapy for at least 6 months, had two confirmed viral loads (VL) ≥1000 copies/mL, and had remained on the same medications for at least 6 months. Survival time was analyzed using Fine and Gray's competing risk regression. Factors associated with CD4 changes and VL <1000 copies/mL were analyzed using linear regression and logistic regression, respectively. A total of 425 PLWH (72.9% male; 45.2% high-income and 54.8% low-to-middle-income country) met criteria for being on a holding regimen. From high-income countries, 63.0% were on protease inhibitors (PIs); from low-to-middle-income countries, 58.4% were on non-nucleoside reverse transcriptase inhibitors (NNRTIs); overall, 4.5% were on integrase inhibitors. The combination of lamivudine, zidovudine, and efavirenz was the most commonly used single regimen (n = 46, 10.8%), followed by lamivudine, zidovudine, and nevirapine (n = 37, 8.7%). Forty-one PLWH (9.7%) died during follow-up (mortality rate 2.0 per 100 person-years). Age >50 years compared to age 31-40 years (sub-hazard ratio [SHR] 3.29, 95% CI 1.45-7.43, p = 0.004), and VL ≥1000 copies/ml compared to VL <1000 copies/mL (SHR, 2.14, 95% CI 1.08-4.25, p = 0.029) were associated with increased mortality, while higher CD4 counts were protective. In our Asia regional cohort, there was a diversity of holding regimens, and the patterns of PI vs. NNRTI use differed by country income levels. Considering the high mortality rate of PLWH with holding regimen, efforts to extend accessibility to additional antiretroviral options are needed in our region.

Antiretroviral drug class and anaemia risk in the current treatment era among people living with HIV in the USA: a clinical cohort study.

ObjectiveAnaemia is common among people living with HIV (PLWH) and has been associated with certain, often older, antiretroviral medications. Information on current antiretroviral therapy (ART) and anaemia is limited. The objective was to compare the associations between anaemia incidence or haemoglobin change with core ART classes in the current ART era.DesignRetrospective cohort study.SettingUSA-based prospective clinical cohort of PLWH aged 18 and above receiving care at eight sites between January 2010 and March 2018.Participants16 505 PLWH were included in this study.Main outcome measuresAnaemia risk and haemoglobin change were estimated among PLWH for person-time on a protease inhibitor (PI) or an integrase strand transfer inhibitor (INSTI)-based regimen, relative to a non-nucleoside reverse transcriptase inhibitor (NNRTI)-based reference. We also examined PLWH on regimens containing multiple core classes. Cox proportional hazards regression analyses were conducted to measure the associations between time-updated ART classes and incident anaemia or severe anaemia. Linear mixed effects models were used to examine the relationships between ART classes and haemoglobin change.ResultsDuring a median of 4.9 years of follow-up, 1040 developed anaemia and 488 developed severe anaemia. Compared with NNRTI use, INSTI-based regimens were associated with an increased risk of anaemia (adjusted HR (aHR) 1.26, 95% CI 1.00 to 1.58) and severe anaemia (aHR 1.51, 95% CI 1.07 to 2.11) and a decrease in haemoglobin level. Time on multiple core classes was also associated with increased anaemia risk (aHR 1.39, 95% CI 1.13 to 1.70), while no associations were found for PI use.ConclusionThese findings suggest INSTI use may increase the risk of anaemia. If confirmed, screening for anaemia development in users of INSTIs may be beneficial. Further research into the underlying mechanisms is warranted.

Switching at Low HIV-1 RNA into Fixed Dose Combinations: TDF/FTC/RPV is non-inferior to TDF/FTC/EFV in first-line suppressed patients living with HIV.

BackgroundIn low- and middle-income countries (LMICs), a substantial unmet need for affordable single-tablet regimen (STR) options remains. Rilpivirine (RPV, TMC278) is formulated in a low-cost STR with tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC).ObjectivesSwitching at Low HIV-1 RNA into Fixed Dose Combinations (SALIF) compared RPV with efavirenz (EFV), both as STRs with TDF and FTC, in maintaining virologic suppression.MethodsSALIF was a phase 3b, randomised, open-label, non-inferiority study in virologically suppressed adults (HIV-1 RNA < 50 copies/mL) on non-nucleoside reverse transcriptase inhibitor (NNRTI)-based first-line antiretroviral therapy (ART) in Cameroon, Kenya, Senegal, South Africa, Uganda and Thailand. Patients (N = 426), stratified by NNRTI use, were randomised 1:1 to receive TDF/FTC/RPV (300/200/25 mg qd) or TDF/FTC/EFV (300/200/600 mg qd). Primary endpoint was proportion of patients with virologic suppression (HIV-1 RNA < 400 copies/mL) at week 48 (intent-to-treat, modified Food and Drug Administration Snapshot, 10% non-inferiority margin).ResultsPatients received TDF/FTC/RPV (n = 213) or TDF/FTC/EFV (n = 211). At week 48, virologic suppression was maintained in 200/213 (93.9%) patients in the RPV arm and 203/211 (96.2%) in the EFV arm (difference –2.3%; 95% confidence interval: −6.4, +1.8), demonstrating non-inferiority of TDF/FTC/RPV. One patient in each arm experienced virologic failure without treatment-emergent resistance. Twenty-seven patients discontinued prematurely (8.0% RPV vs. 4.7% EFV), the most frequent reasons being adverse events (3.3% vs. 0.5%, respectively), site closure (1.9% vs. 0.5%), loss to follow-up (0.9% vs. 1.4%) and consent withdrawal (0.9% vs. 1.4%).ConclusionIn adults with suppressed viral load on first-line NNRTI-based ART in LMICs, switching to an STR of TDF/FTC/RPV was non-inferior to TDF/FTC/EFV in maintaining high rates of viral suppression with a comparable tolerability profile.

Recent Advances in the Design and Development of Non-nucleoside Reverse Transcriptase Inhibitor Scaffolds.

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) have always been an important part of the anti-HIV-1 combination therapy known as combination antiretroviral therapy (cART) since 1996. The use of NNRTIs for about 22 years has led to some mutations in the residues that compose the reverse transcriptase active site, resulting in the emergence of drug-resistant viruses. Thus, the search for new potent NNRTIs with an improved safety profile and activity against drug-resistant HIV strains is indispensable, and many hit and lead NNRTIs have been discovered in the last decade. This review provides an overview of the development in this field from 2013 to August 2018.

571. In a Well-Characterized Cohort with Universal Access to Care and Medications Racial Disparities in HIV Virologic Outcomes Are No Longer Observed

BackgroundHIV-infected African-Americans [AA] are more likely to experience virologic failure (VF) compared with other ethnic groups. Decreased access to healthcare has been postulated as a potential cause. Using data from the US Military Natural History Study (NHS), we examined the effects of race on VF. The NHS is a longitudinal cohort comprised of Department of Defense (DoD) beneficiaries with unrestricted access to healthcare.MethodsWe included NHS participants who contributed follow-up after 2001. Demographic characteristics, antiretroviral therapy (ART) history, and serial viral loads (VL) were obtained from the database. Pharmacy records were used to calculate adherence. VF was defined as a VL of 3200 copies/mL on two consecutive measurements or one VL of >1,000 c/mL. A Cox model with time-updated covariates was used to examine the association between race and VF.ResultsA total of 1,521 subjects contributed follow-up after 2001 (41% AA; 95% male). Median age, CD4 count and VL at ART initiation (AI) were 31.6 years [IQR 26–39], 367 cells/μl [IQR 271–489] and 4.6 log10 copies/mL [IQR 4.0–5.0], respectively. Subjects were followed for a median of 4.8 years [IQR 2.7–7.9], and 13.2% (n = 201) met criteria for VF. Most subjects initiated ART with a non-nucleoside reverse transcriptase inhibitor (NNRTI) (64%), integrase strand transferase inhibitor (InSTI) (15%) or a boosted protease inhibitor (PI) (14%)-based regimen. Results of the adjusted Cox model are in the table below.ConclusionIn the NHS, in recent years, AA and Caucasians have similar responses to ART. NNRTI and InsTI use was protective, reinforcing that simpler medications with fewer adverse effects improve outcomes. Unrestricted access to care and modernization of ART should help narrow the disparities observed in virologic outcomes. Characteristics HR (95% CI) Race Ref.African-American0.78 (0.54–1.13)Caucasian0.70 (0.44–1.11)Hispanic/otherAge* (per 10-year)0.63 (0.50–0.79)VL at ART (per log10)1.27 (1.05–1.54)HIV Dx to AI* (per 5-year)1.25 (0.99–1.57)Use of antiretrovirals before ART1.95 (1.19–3.21)CD4 count* (per 100-cell)0.93 (0.87–1.00) ART regimen* Ref.Boosted PI0.36 (0.16–0.77)InSTI0.55 (0.35–0.86)NNRTI1.35 (0.79–2.29)Other combinations Adherence >90% vs. ≤90% 0.28 (0.20–0.41)*Time-updated covariate.Disclosures All authors: No reported disclosures.

Cocaine use may induce telomere shortening in individuals with HIV infection

BackgroundAlthough cocaine use may induce/accelerate HIV-associated comorbidities in HIV-infected individuals on antiretroviral therapy (ART), and that HIV itself may accelerate aging, the issue of whether cocaine use plays a role in HIV-associated aging in HIV-infected cocaine users has not been reported. The goals of this study were (1) to explore factor(s) associated with peripheral blood leukocyte telomere length, a marker of cellular replicative history, and telomere shortening in HIV-infected individuals, and (2) to assess whether cocaine use plays a role in accelerating telomere shortening in cocaine users with HIV infection. MethodsBetween June 2010 and December 2016, 147 HIV-infected participants in Baltimore, Maryland, were enrolled in a cross-sectional study investigating factor(s) associated with telomere length. Of these 147, 93 participated in a follow-up study to examine factor(s) associated with telomere shortening. Robust regression model was used to analyze cross-sectional data and the generalized estimating equation approach was used to analyze follow-up data. ResultsCross-sectional analyses demonstrated that (1) both daily alcohol consumption and use of non-nucleoside reverse transcriptase inhibitors (NNRTIs) were independently associated with telomere length, and cocaine use modified the associations of daily alcohol use and NNRTI use with telomere length. Longitudinal analyses suggested that both daily alcohol consumption and duration of NNRTI use were independently associated with telomere shortening, and (2) cocaine use induced/accelerated telomere shortening in HIV-infected individuals. ConclusionsOur findings suggest that cocaine use may promote premature aging in HIV-infected individuals who are on ART. Our results emphasize the importance of cocaine abstinence/reduced use, which may retard HIV-associated premature aging.

Low bone mineral density and associated risk factors in HIV-infected patients.

Aging of persons with human immunodeficiency virus (HIV) resulted in high rates of osteopenia and osteoporosis. Multiple cohort studies have reported an increased prevalence of bone demineralization among HIV-infected individuals. The aim of this study was to evaluate bone mineral density (BMD) and risk factors for osteopenia/osteoporosis among HIV-positive patients attending the National Institute for Infectious Diseases "Prof.Dr. Matei Balș", Bucharest, Romania. We performed a cross-sectional study that enrolled 60 patients with HIV. The association between BMD and lifestyle habits (smoking), body mass index (BMI), nadir cluster of differentiation 4 (CD4) cell count, current CD4 cell count, HIV viral load and history of combination antiretroviral therapy (cART) were investigated. The BMD was measured at the lumbar spine, hips and total body using dual-energy X-ray absorptiometry (DEXA). In the present study, DEXA evaluation showed an overall prevalence of osteoporosis of 16.66% (ten patients) and a prevalence of osteopenia of 48.33% (29 patients). In men, low BMI and cigarette smoking showed significant association with the diagnosis of lumbar spine demineralization (p=0.034 and p=0.041, respectively). Duration of exposure to cART classes in relation to BMD was also evaluated. The use of non-nucleoside reverse-transcriptase inhibitors (NNRTIs) was associated with low lumbar spine BMD in all patients (p=0.015). Reduced BMD was significantly associated with protease inhibitors (PIs)-containing treatment (p=0.043) in women. At lumbar spine DEXA, male gender was statistically associated with reduced BMD. At the left hip Ward's area, decreased BMD T scores were significantly associated with aging. The reduced BMD was higher in patients receiving PI- or NNRTI-containing regimens.

Progression of Liver Fibrosis and Modern Combination Antiretroviral Therapy Regimens in HIV-Hepatitis C-Coinfected Persons.

Liver diseases progress faster in human immunodeficiency virus (HIV)-hepatitis C virus (HCV)-coinfected persons than HIV-monoinfected persons. The aim of this study was to compare rates of liver fibrosis progression (measured by the aspartate-to-platelet ratio index [APRI]) among HIV-HCV-coinfected users of modern protease inhibitor (PI)- and nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens with a backbone of tenofovir/emtricitabine (TDF/FTC) or abacavir/lamivudine (ABC/3TC). Data from a Canadian multicenter cohort study were analyzed, including 315 HCV polymerase chain reaction-positive persons who initiated antiretroviral therapy with a PI or NNRTI and a backbone containing either TDF/FTC or ABC/3TC. Multivariate linear regression analyses with generalized estimating equations were performed after propensity score matching to balance covariates across classes of anchor agent. A backbone of TDF/FTC was received by 67% of PI users and 69% of NNRTI users. Both PI and NNRTI use was associated with increases in APRI over time when paired with a backbone of ABC/3TC: 16% per 5 years (95% confidence interval [CI], 4%, 29%) and 11% per 5 years (95% CI, 2%, 20%), respectively. With TDF/FTC use, no clear association was found among PI users (8% per 5 years, 95% CI, -3%, 19%) or NNRTI users (3% per 5 years, 95% CI, -7%, 12%). Liver fibrosis progression was more influenced by the backbone than by the class of anchor agent in HIV-HCV-coinfected persons. Only ABC/3TC-containing regimens were associated with an increase of APRI score over time, regardless of the class of anchor agent used.

Cancer risk and use of protease inhibitor or nonnucleoside reverse transcriptase inhibitor-based combination antiretroviral therapy: the D: A: D study.

The association between combination antiretroviral therapy (cART) and cancer risk, especially regimens containing protease inhibitors (PIs) or nonnucleoside reverse transcriptase inhibitors (NNRTIs), is unclear. Participants were followed from the latest of D:A:D study entry or January 1, 2004, until the earliest of a first cancer diagnosis, February 1, 2012, death, or 6 months after the last visit. Multivariable Poisson regression models assessed associations between cumulative (per year) use of either any cART or PI/NNRTI, and the incidence of any cancer, non-AIDS-defining cancers (NADC), AIDS-defining cancers (ADC), and the most frequently occurring ADC (Kaposi sarcoma, non-Hodgkin lymphoma) and NADC (lung, invasive anal, head/neck cancers, and Hodgkin lymphoma). A total of 41,762 persons contributed 241,556 person-years (PY). A total of 1832 cancers were diagnosed [incidence rate: 0.76/100 PY (95% confidence interval: 0.72 to 0.79)], 718 ADC [0.30/100 PY (0.28-0.32)], and 1114 NADC [0.46/100 PY (0.43-0.49)]. Longer exposure to cART was associated with a lower ADC risk [adjusted rate ratio: 0.88/year (0.85-0.92)] but a higher NADC risk [1.02/year (1.00-1.03)]. Both PI and NNRTI use were associated with a lower ADC risk [PI: 0.96/year (0.92-1.00); NNRTI: 0.86/year (0.81-0.91)]. PI use was associated with a higher NADC risk [1.03/year (1.01-1.05)]. Although this was largely driven by an association with anal cancer [1.08/year (1.04-1.13)], the association remained after excluding anal cancers from the end point [1.02/year (1.01-1.04)]. No association was seen between NNRTI use and NADC [1.00/year (0.98-1.02)]. Cumulative use of PIs may be associated with a higher risk of anal cancer and possibly other NADC. Further investigation of biological mechanisms is warranted.

Switch to Stribild versus continuation of NVP or RPV with FTC and TDF in virologically suppressed HIV adults: a STRATEGY-NNRTI subgroup analysis.

IntroductionSwitch to Stribild (STB) was non-inferior to continuation of a non-nucleoside reverse transcriptase inhibitor (NNRTI) with emtricitabine and tenofovir DF (FTC/TDF) at week 48 in virologically suppressed HIV adults [1]. We report the Week 48 efficacy and safety of STB versus nevirapine (NVP) or rilpivirine (RPV) with FTC/TDF in suppressed subjects.Materials and MethodsVirologically suppressed subjects on an NNRTI with FTC/TDF regimens for ≥6 months were randomized (2:1) to switch to STB versus continue their NNRTI regimen. Eligibility criteria included no documented resistance to FTC and TDF, no history of virologic failure and eGFR ≥70 mL/min. The primary endpoint was the proportion of subjects in the modified ITT population who maintained HIV-1 RNA <50 copies(c)/mL at Week 48 by FDA snapshot algorithm (12% non-inferiority margin). Subgroup analysis by non-EFV NNRTI use (NVP [74]; RPV [19]; etravirine [3]) at screening was pre-specified.ResultsThe mITT population included 433 subjects who were randomized and treated. In the non-EFV NNRTI subgroup, 59 switched to STB; 37 continued a non-EFV NNRTI (27 NVP, 10 RPV) with FTC/TDF. At week 48, 97% STB versus 95% non-EFV NNRTI maintained HIV-1 RNA <50 c/mL. No emergent resistance was detected in either group. No difference in median increases from baseline in CD4 count at week 48 (cells/µL): 25 STB versus 55 non-EFV NNRTI (p=0.78). No discontinuation due to adverse events; no cases of proximal renal tubulopathy. As expected, there were no significant changes in the frequency of neuropsychiatric symptoms (i.e. anxiety, insomnia, dizziness, vivid dreams, weird/intense dreams, and nightmares) reported on the HIV Symptom Index at week 48 compared to baseline after switching to STB. There was a greater but non-progressive decrease from baseline in eGFR in the STB versus non-EFV NNRTI group; median changes (mL/min) at week 48: −9.1 versus −1.4. Switch to STB was associated with a higher treatment ease (convenience, flexibility, demand, lifestyle, understanding) score (range: −15 to 15) at week 4 (median: 14 vs 11; p=0.047) and week 24 (median: 14 vs 12.5; p=0.038).ConclusionsIn this small group of virologically suppressed subjects, switch to STB vs continuation of NVP or RPV with FTC/TDF was safe, well-tolerated, and associated with a high rate of virologic suppression at week 48. There was more treatment ease with STB use.

Efficacy and Safety of Lersivirine Versus Etravirine for the Treatment of HIV-1 Infection in Patients with Prior Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI) Use and Evidence of NNRTI Resistance: A Randomized Phase 2B Trial

Objective: To assess the efficacy and safety of lersivirine versus etravirine in patients with HIV-1 and prior non-nucleoside reverse transcriptase inhibitor (NNRTI) use and evidence of NNRTI resistance. Methods: In this 96-week, phase 2b study, 97 patients were randomized and treated with lersivirine 750 mg qd (n = 31), lersivirine 1,000 mg qd (n = 32), and etravirine 200 mg bid (n = 34), plus one optimized nucleoside reverse transcriptase inhibitor and darunavir/ritonavir 600/100 mg bid. The primary endpoint was the percentage of patients with HIV-1 RNA <50 copies/mL at week 24. Results: At week 24, HIV-1 RNA <50 copies/mL was achieved by fewer patients receiving lersivirine 750 mg (48.4%) and 1,000 mg (43.8%) qd compared with etravirine 200 mg qd (67.7%) (intention to treat [ITT], missing/switch/discontinuation equals failure [MSDF]). At week 48, HIV-1 RNA <50 copies/mL and <400 copies/mL were also achieved by fewer patients receiving lersivirine 750 mg (41.9% and 41.9%, respectively) and 1,000 mg (31.3% and 34.4%, respectively) qd compared with etravirine 200 mg bid (61.8% and 70.6%, respectively) (ITT, MSDF). Least squares means (SE) change from baseline in log transformed HIV-1 RNA at week 48 was -1.42 (0.27) and -0.95 (0.28) copies/mL for lersivirine 750 mg and 1,000 mg qd, respectively, versus -2.02 (0.26) copies/mL for etravirine 200 mg bid (ITT). Lersivirine and etravirine were generally safe and well-tolerated. Conclusions: Lersivirine 750 mg and 1,000 mg qd was associated with lower rates of viral suppression at week 24 and week 48 versus etravirine in patients with prior NNRTI use and evidence of NNRTI resistance. No new safety signals were detected.

Prevalence of etravirine (ETR)-RAMs at NNRTI failure and predictors of resistance to ETR in a large Italian resistance database (ARCA)

AbstractThe prevalence of drug resistance associated with the failure of nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens and the predictors of resistance to Etravirine (ETR) were assessed in 2854 subjects: 39 < 18 (paediatric) and 2815 ≥ 18 (adult) years old. These subjects failed to respond to their current NNRTI treatment, were three-class experienced and had been exposed to NNRTI for ≥ 3 months. A total of 1827 adult (64.9%) and 32 paediatric subjects (82.1%) harboured the virus with at least one ETR mutation. V179I, Y181C and G190A were the most frequent mutations in both groups. A significantly increased risk of ETR resistance with all three algorithms (Monogram (MGR) >3, Tibotec (TBT) >2 and enhanced MGR (ENH) ≥ 4) emerged in the paediatric population. Multivariate analysis revealed an increased risk of developing TBT >2 for NNRTI exposure, ENH ≥ 4 for NNRTI and EFV exposure in paediatric subjects; NVP exposure and higher (≥ 3.5 log10) HIV-RNA values for all three algorithms in adult subjects, whereas CD4 ≥ 200/μL appeared to be protective. The risk of being ETR resistant was more than doubled for paediatric vs. adult subjects, probably due to a more extensive use of NNRTI and an incomplete virological control.

2'-Deoxythymidine Adducts from the Anti-HIV Drug Nevirapine

Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) used against HIV-1. Currently, NVP is the most widely used anti-HIV drug in developing countries, both in combination therapy and to prevent mother-to-child transmission of HIV. Despite its efficacy against HIV, NVP produces a variety of toxic responses, including hepatotoxicity and skin rash. It is also associated with increased incidences of hepatoneoplasias in rodents. In addition, epidemiological data suggest that NNRTI use is a risk factor for non-AIDS-defining cancers in HIV-positive patients. Current evidence supports the involvement of metabolic activation to reactive electrophiles in NVP toxicity. NVP metabolism includes oxidation to 12-hydroxy-NVP; subsequent Phase II sulfonation produces an electrophilic metabolite, 12-sulfoxy-NVP, capable of reacting with DNA to yield covalent adducts. Since 2’-deoxythymidine (dT) adducts from several alkylating agents are regarded as having significant mutagenic/carcinogenic potential, we investigated the formation of NVP-dT adducts under biomimetic conditions. Toward this goal, we initially prepared and characterized synthetic NVP-dT adduct standards using a palladium-mediated Buchwald-Hartwig coupling strategy. The synthetic standards enabled the identification, by LC-ESI-MS, of 12-(2'-deoxythymidin-N3-yl)-nevirapine (N3-NVP-dT) in the enzymatic hydrolysate of salmon testis DNA reacted with 12-mesyloxy-NVP, a synthetic surrogate for 12-sulfoxy-NVP. N3-NVP-dT, a potentially cytotoxic and mutagenic DNA lesion, was also the only dT-specific adduct detected upon reaction of dT with 12-mesyloxy-NVP. Our data suggest that N3-NVP-dT may be formed in vivo and play a role in the hepatotoxicity and/or putative hepatocarcinogenicity of NVP.

The role of etravirine in the management of treatment-experienced pediatric patients with HIV.

Pediatric patients infected with human immunodeficiency virus (HIV) are now living longer, healthier lives due to the advent of combined antiretroviral (ARV) therapy, including regimens that often contain non-nucleoside reverse transcriptase inhibitors (NNRTIs). However, first-generation NNRTIs such as nevirapine (NVP) and efavirenz (EFV) have a low genetic barrier to resistance, and both drugs can become ineffective with a single viral point mutation. New agents with activity against resistant viral strains must be available to salvage children and adolescents with virologic failure after NNRTI use. One such drug, etravirine, an oral second-generation NNRTI approved for use in the US in heavily treatment-experienced HIV-1-infected adults in 2008, is accumulating data in this younger population. Etravirine became approved by the US Food and Drug Administration in early 2012 to be used in combination with other ARV medications in HIV-1-infected children aged 6 years to <18 years who are failing their regimens with HIV-1 strains resistant to NNRTIs and other ARVs. This approval was largely based on data from a prospective, open-label, phase II clinical trial in this age group prescribed etravirine at 5.2 mg/kg twice daily (up to the adult dose of 200 mg twice daily) in combination with an investigator-selected optimized background regimen. Currently available 48-week follow-up data show complete viral suppression (<50 copies/mL) in 56% of the patients, with relatively few serious adverse events attributed to the drug. Additional studies and case reports from the field suggest its utility in clinical practice. This review is designed to increase the background understanding of this drug in pediatric HIV providers, to lay out the current pediatric data to support its use, and to define its practical role in the treatment of HIV-infected children now and in the future.

Rilpivirine Resistance-Associated Mutations Among Antiretroviral-Naive Patients Infected With HIV-1 in Asia

Rilpivirine Resistance-Associated Mutations Among Antiretroviral-Naive Patients Infected With HIV-1 in Asia

No increased risk of hepatotoxicity in long‐term use of nonnucleoside reverse transcriptase inhibitors in HIV‐infected patients

The aim of this study was to assess the incidence of hepatotoxicity in patients who had used nonnucleoside reverse transcriptase inhibitors (NNRTIs) for at least 3 years. The study group consisted of HIV-infected patients under follow-up at our clinic, who had continuously used an NNRTI-containing regimen (efavirenz or nevirapine) for at least 3 years. Patients who had used protease inhibitors (PIs) for the same time span constituted a control group. Hepatotoxicity was graded according to the modified AIDS Clinical Trial Group grading system, using alanine aminotransferase (ALT) as a marker. One hundred and twenty-two patients on an NNRTI regimen and 54 PI-using patients were included in the analysis. The mean follow-up time was nearly 6 years. Eighteen NNRTI-using patients (14.8%) developed a clinically relevant (≥ grade II) event of hepatotoxicity during treatment; five of them (4.1%) developed severe hepatotoxicity (≥ grade III). No significant difference in the hepatotoxicity rate was seen between NNRTI- and PI-using patients (14.8 vs. 18.5%, respectively; P = 0.52) or between patients using efavirenz and nevirapine (13.8% vs. 16.7%, respectively; P = 0.51). A hepatitis C virus (HCV) coinfection was associated with an increased risk of the development of hepatotoxicity during NNRTI therapy [odds ratio (OR) 1.83; 95% confidence interval (CI) 1.33-4.24; P < 0.01]. Finally, we observed that more hepatotoxic events occurred during the first year of NNRTI therapy compared with the entire period after 1 year (6.6 vs. 2.8 events, respectively, per 100 person-years of treatment; P = 0.04). Long-term NNRTI use was not associated with a higher risk of clinically significant liver toxicity in patients who had been treated with NNRTI for at least 3 years.

Serum paraoxonase-3 concentration in HIV-infected patients. Evidence for a protective role against oxidation

We investigated the influence of the HIV infection on serum paraoxonase-3 (PON3) concentration and assessed the relationships with lipoprotein-associated abnormalities, immunological response, and accelerated atherosclerosis. We studied 207 HIV-infected patients and 385 healthy volunteers. Serum PON3 was determined by in-house ELISA, and PON3 distribution in lipoproteins was investigated by fast-performance liquid chromatography (FPLC). Polymorphisms of the PON3 promoter were analyzed by the Iplex Gold MassArray(TM) method. PON3 concentrations were increased (about three times) in HIV-infected patients with respect to controls (P < 0.001) and were inversely correlated with oxidized LDL levels (P = 0.038). Long-term use of nonnucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral therapy was associated with a decrease of PON3 concentrations. In a multivariate linear regression analysis, these relationships were still strong when the main confounding covariates were considered. PON3 was mainly found in HDL in HIV-infected patients, but a substantial amount of the protein was detected in LDL particles. This study reports for the first time an important increase in serum PON3 concentrations in HIV-infected patients that is associated with their oxidative status and their treatment with NNRTI. Long-term, prospective studies are needed to confirm the possible influence of this enzyme on the course of this disease and its possible utility as an analytical biomarker.

Resistance to Antiretroviral Drugs in Treated and Drug-Naive Patients in the Democratic Republic of Congo

We studied virological outcome and drug resistance in patients on antiretroviral therapy (ART) in health care centers in the Democratic Republic of Congo and looked for the presence of drug resistance in antiretroviral-naive patients attending the same clinics. In 2008, we conducted a cross-sectional survey among patients on ART for ≥ 12 months in 4 major cities [Kinshasa (n = 289), Matadi (n = 198), Lubumbashi (n = 77), and Mbuji-Mayi (n = 103)]. Genotypic drug resistance tests were done with an in-house assay on samples with viral load >1000 copies/mL. ART-naive patients (n = 283) were also consecutively enrolled in the same clinics. Of the 667 patients on ART, >98% received Lamivudine + Stavudine/azidothymidine + Nevirapine/Efavirenz as first-line regimen and 74.4% were women. Median time on ART was 25 months [interquartile ratio (IQR), 19-32] in Kinshasa, 26 months (IQR, 19-32) in Matadi, 27 months (IQR, 19-44) in Lubumbashi, and 19 months (IQR, 16-24) in Mbuji-Mayi. A total of 97 patients (14.6%) had viral load >1000 copies/mL, and among the 93 successfully sequenced samples, 78 (83.9%) were resistant to at least 1 drug of their ART regimen: 68 harbored resistance mutations to nucleoside reverse transcriptase inhibitor (NRTI) and nonnucleoside reverse transcriptase inhibitor (NNRTI), 2 to NRTI only, 7 to NNRTI only, and 1 to NRTI + NNRTI + protease inhibitor. The majority of patients, 70/78 (89.7%), were resistant to at least 2 of the 3 drugs from their treatment. The use of next-generation NNRTI, etravirine was already compromised for 19.2% (15/78) of the patients and 7 patients had the K65R mutation compromising the use of tenofovir in second-line regimens. The proportion of antiretroviral-resistant patients increased over time from 8.4% to 18.6% for patients on ART for 12-23 months or >35 months (P = 0.013), respectively. Virological failure and rates of drug resistance were significantly higher among men than women, 19.9% versus 8.8%, respectively (P = 0.0001). Among the 253 recently diagnosed patients, 20 (7.9%) harbored resistance mutations. The accumulation of drug resistance mutations with time on ART needs further attention, and surveillance should be reinforced in ART programs in sub-Saharan Africa.

Twenty Years of HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors: Time to Reevaluate their Toxicity

Twenty years of effective clinical application have consolidated non-nucleoside reverse transcriptase inhibitors (NNRTI) as essential components of the Highly Active Antiretroviral Therapy (HAART) employed in the treatment of Human Immunodeficiency Virus (HIV). However, as the disease has come under control, there has been growing emphasis on the long-term adverse effects induced by this chronic pharmacological therapy. Although traditionally considered to be safe and well-tolerated drugs, there is mounting evidence that associates NNRTI with the onset of cutaneous reactions, neuropsychiatric symptoms, hepatotoxicity, metabolic disturbances and gastrointestinal toxicity. Though the clinical manifestations of these detrimental events are increasingly recognised, the cellular and molecular mechanisms underlying them have received little attention. This review revaluates the toxicities associated with the use of NNRTI by analysing data from both clinical trials and recent in vitro studies. Particular emphasis is placed on the specific characteristics of each of the compounds that comprise this class of anti-HIV drugs, including some that are currently in clinical development. A deeper understanding of the causes of NNRTI-induced side effects would greatly help to improve existing anti-HIV-1 therapies and to develop safer and better tolerated drugs in the future, thus increasing the long term efficacy of NNRTI-containing regimens.