Nucleoside Reverse Transcriptase Inhibitor Therapy Research Articles

VIR-2218 (elebsiran) plus pegylated interferon-alfa-2a in participants with chronic hepatitis B virus infection: a phase 2 study

Chronic hepatitis B virus (HBV) remains a global concern, with current treatments achieving low rates of HBsAg seroclearance. VIR-2218 (elebsiran), a small interfering RNA agent against HBV transcripts, reduces HBsAg concentrations. We aimed to evaluate the safety and antiviral activity of VIR-2218 with and without pegylated interferon-alpha-2a treatment in participants with chronic HBV. This open-label, phase 2 study was conducted at 23 sites in six countries (New Zealand, Australia, Hong Kong, Thailand, South Korea, and Malaysia). Adults (aged 18-65 years) with chronic HBV infection without cirrhosis and with HBsAg more than 50 IU/mL and HBV DNA less than 90 IU/mL who were on continued nucleoside or nucleotide reverse transcriptase inhibitor (NRTI) therapy for 2 months or longer were eligible. Participants were enrolled into one of six cohorts to receive VIR-2218 200 mg subcutaneously every 4 weeks, with or without 180 μg subcutaneous pegylated interferon-alfa-2a once per week. Cohort 1 received six doses of VIR-2218 (total 20 weeks); cohort 2 received six doses of VIR-2218 starting at day 1, plus 12 doses of pegylated interferon-alfa-2a starting at week 12 (total 24 weeks); cohort 3 received six doses of VIR-2218 and 24 doses of pegylated interferon-alfa-2a (total 24 weeks); cohort 4 received six doses of VIR-2218 and up to 48 doses of pegylated interferon-alfa-2a (total 48 weeks); cohort 5 received up to 13 doses of VIR-2218 and up to 44 doses of pegylated interferon-alfa-2a (total 48 weeks); and cohort 6 received three doses of VIR-2218 and 12 doses of pegylated interferon-alfa-2a (total 12 weeks). The primary endpoints were the incidence of adverse events and clinical assessments (including results of laboratory tests). Secondary endpoints were the mean maximum reduction of serum HBsAg at any timepoint; the proportion of participants with serum HBsAg seroclearance at any timepoint and for more than 6 months after the end of treatment; and the proportion of participants with anti-HBs seroconversion at any timepoint. For patients who were HBeAg-positive, we also assessed the proportion with HBeAg seroclearance or anti-HBe seroconversion at any timepoint. This study is registered with ClinicalTrials.gov, NCT03672188, and is ongoing. Between July 2, 2020, and Nov 2, 2021, 124 individuals were screened for eligibility, 84 of whom were enrolled (15 in cohort 1, 15 in cohort 2, 18 in cohort 3, 18 in cohort 4, 13 in cohort 5, and five in cohort 6). Participants were predominantly HBeAg-negative, Asian, and male (66 [79%] participants were male and 18 [21%] were female). Most treatment emergent adverse events were grades 1-2. Three (20%) participants in cohort 1, four (27%) in cohort 2, eight (44%) in cohort 3, seven (39%) in cohort 4, six (46%) in cohort 5, and two (40%) in cohort 6 reported treatment-emergent adverse events related to VIR-2218. 12 (80%) participants in cohort 2, 12 (67%) in cohort 3, 14 (78%) in cohort 4, 13 (100%) in cohort 5, and three (60%) in cohort 6 reported treatment-emergent adverse events related to pegylated interferon-alfa-2a. Two (13%) participants in cohort 1 had elevations in alanine aminotransferase, compared with 13 (87%) participants in cohort 2, 15 (83%) in cohort 3, 17 (94%) in cohort 4, 11 (85%) in cohort 5, and three (60%) in cohort 6. The mean maximum change from baseline at any timepoint in HBsAg concentration was -2·0 log10 IU/mL (95% CI -2·1 to -1·8) in cohort 1, -2·2 log10 IU/mL (-2·5 to -1·8) in cohort 2, -2·5 log10 IU/mL (-2·8 to -2·1) in cohort 3, -2·4 log10 IU/mL (-3·1 to -1·8) in cohort 4, -3·0 log10 IU/mL (-3·7 to -2·3) in cohort 5, and -1·7 log10 IU/mL (-2·1 to -1·4) in cohort 6. 11 participants (one in cohort 2, one in cohort 3, five in cohort 4, and four in cohort 5) receiving VIR-2218 plus pegylated interferon-alfa-2a had HBsAg seroclearance at any timepoint. Of these, ten (91%; one in cohort 2, five in cohort 4, and four in cohort 5) had anti-HBs seropositivity. Six participants (one in cohort 2, three in cohort 4, and two in cohort 5) had sustained HBsAg seroclearance through to 24 weeks after the end of treatment. No participants receiving VIR-2218 monotherapy (cohort 1) or VIR-2218 plus pegylated interferon-alfa-2a 12-week regimen (cohort 6) had HBsAg seroclearance. 12 (42%) of 26 participants (one of four in cohort 1, two of six in cohort 2, four of seven in cohort 3, four of six in cohort 4, and one of three in cohort 5) who were HBeAg positive at baseline had HBeAg seroclearance or anti-HBe seroconversion. The results of this phase 2 study support further development of VIR-2218 as a potential therapy for patients with chronic HBV infection. Additional clinical trials of VIR-2218 with and without pegylated interferon-alfa-2a in combination with an HBsAg-targeting monoclonal antibody are ongoing. Vir Biotechnology.

Impact of previous HIV resistance and virologic failures on virologic outcome following a switch to dolutegravir with 2 NRTIs among people living with HIV.

There is uncertainty regarding the potential virologic outcome associated with a change in antiretroviral therapy (ARV) among PLHIV who had previous documented virologic failure or who have been exposure to mono/dual nucleoside reverse transcriptase inhibitors (NRTI) therapy. The objective was to measure the potential impact of exposure to previous virologic failure or mono/dual NRTI regimen on virologic outcome of PLHIV following a switch to dolutegravir with 2 NRTIs from a viremia suppressive ARV therapy.Data from the Quebec HIV Cohort including 10219 PLHIV were collected through routine clinical care at 4 clinical sites in Montreal, Canada. This study includes patients whose ARV therapy was switched to dolutegravir with 2 NRTIs since 2013 with undetectable viral load for ≥6 months before switch. The association between exposure and post-switch virologic outcome was measured by marginal hazard ratio estimated using the Inverse probability weighting Cox model.Among the 1199 eligible PLHIV, 478 (39.9%) previously experienced at least one virologic failure or were exposed to mono/dual therapy before dolutegravir switch. Post-switch virologic failure after 30 months occurred in 4.1% (95% CI 2.1–7.9) of exposed compared to 4.1% (95% CI 2.3–7.4) in unexposed participants. The adjusted hazard ratio for the association between exposure and post-switch virologic failure was 0.84 (95% CI 0.35–2.01).Our findings suggest that switch to dolutegravir with 2 NRTIs from a suppressive therapy is a safe option for PLHIV with documented virologic failure and/or previous exposure to mono/dual NRTI therapy.

Treatment Switch to Dolutegravir With 2 Nucleoside Reverse-Transcriptase Inhibitors (NRTI) in Comparison to Continuation With Protease Inhibitor/Ritonavir Among Patients With Human Immunodeficiency Virus at Risk for Prior NRTI Resistance: A Cohort Analysis of Real-World Data.

BackgroundSwitching antiretroviral regimens when human immunodeficiency virus (HIV) viremia is controlled for a new regimen is challenging when there is the potential for prior nucleoside reverse-transcriptase inhibitor (NRTI) resistance. The objective was to study virologic outcomes after switching to dolutegravir compared with remaining on a boosted protease inhibitor (protease inhibitor/ritonavir [PI/r]) regimen in people with HIV (PWH) with prior documented virologic failure and/or exposure to mono/dual NRTIs. MethodsWe used the Quebec HIV Cohort including 10 219 PWH whose data were collected at 4 sites in Montreal, Canada. We included all PWH with documented virologic failure or exposure to mono/dual NRTI therapy who were virologically suppressed on a PI/r-based regimen for at least 6 months on or after January 1, 2014 (n = 532). A marginal structural Cox model analysis was used to estimate the effect of the switch to dolutegravir on virologic outcome compared with remaining on PI/r. The outcome was defined as 2 consecutive viral loads (VLs) >50 copies/mL or 1 VL >50 copies/mL if it occurred at the last VL available. ResultsAmong 532 eligible participants, 216 (40.6%) had their regimen switched to dolutegravir with 2 NRTIs, whereas 316 (59.4%) remained on the PI/r with 2 NRTIs. The weighted hazard ratio for the effect of dolutegravir switch on virologic failure compared with patients whose regimen remained on PI/r was 0.57 (95% confidence interval, 0.21–1.52). ConclusionsWe did not find evidence of an increased risk for virologic failure after switching to dolutegravir from PI/r among patients with previous virologic failure or prior exposure to mono/dual NRTI.

The isoform-specific functions of the c-Jun N-terminal kinase (JNK) in a mouse model of antiretroviral-induced painful peripheral neuropathy

Nucleoside reverse transcriptase inhibitors (NRTIs) are associated with the development of painful neuropathies and may further aggravate sensory neuropathy produced by HIV-1 infection, leading to discontinuation of NRTI therapy by HIV patients. Following antiretroviral-induced peripheral neuropathy, c-Jun N-terminal kinase (JNK) is activated in the dorsal root ganglia (DRG) and spinal cord. However, the contribution of individual JNK genes remains unknown. Here, we have tested the behavioural mechanical sensitivity of JNK1, JNK2 and JNK3 knockout (KO) mice in the von Frey test after treatment with 2’,3’-dideoxycytidine (ddC). Protein expression was investigated in the spinal cord of wild type (wt) and KO mice by western blotting. The onset of neuropathic pain was prevented by the deletion of JNK3, leading us to hypothesize that JNK3 protein plays a major role in the regulation of pain threshold in antiretroviral neuropathy. The growth-associated protein 43 (GAP-43) and the transcription factor c-Jun are involved in regeneration processes. This study revealed an up-regulation of GAP-43 and c-Jun protein, 14 days after ddC administration. JNK1 deletion induced a significant reduction in c-Jun phosphorylation and GAP-43 protein contents. In contrast, there was no difference in ddC-induced reduction of hind paw intraepidermal nerve fibre density in all JNK KO mice. Overall, these findings indicate that JNK3 plays a critical role in regulating ddC neurotoxicity-induced mechanical pain hypersensitivity, while JNK1 is important for activation of c-Jun and GAP-43 as a critical pathway of a regeneration program. These data highlight the impact of individual JNK isoforms on antiretroviral neurotoxicity and neuro-regeneration processes.

Doravirine versus ritonavir-boosted darunavir in antiretroviral-naive adults with HIV-1 (DRIVE-FORWARD): 96-week results of a randomised, double-blind, non-inferiority, phase 3 trial

Doravirine is a novel, non-nucleoside reverse transcriptase inhibitor that has shown non-inferior efficacy to ritonavir-boosted darunavir, with a superior lipid profile, in adults with HIV who were treatment naive at week 48 in the phase 3 DRIVE-FORWARD trial. Here we present the 96-week data for the study. This randomised, controlled, double-blind, multicentre, non-inferiority, phase 3 study was undertaken at 125 clinical centres in 15 countries. Eligible participants were adults (aged ≥18 years) infected with HIV-1 who were naive to antiretroviral therapy, with a plasma HIV-1 RNA concentration of 1000 copies per mL or higher at screening, and no known resistance to any of the study drugs. Participants were randomly assigned (1:1) using an interactive voice and web response system, stratified by baseline HIV-1 RNA concentration and background nucleoside reverse transcriptase inhibitor therapy, to doravirine (100 mg per day) or ritonavir-boosted darunavir (100 mg ritonavir and 800 mg darunavir per day), both with investigator-selected nucleoside reverse transcriptase inhibitors: emtricitabine and tenofovir disoproxil fumarate or abacavir and lamivudine. Participants and investigators were masked to treatment assignment until week 96. The primary efficacy endpoint was the proportion of participants who had a plasma HIV-1 RNA concentration of less than 50 copies per mL at week 48, which has been reported previously. Here we report the key secondary efficacy endpoint of the proportion of participants who achieved this concentration by week 96, assessed in all participants who received at least one dose of any study drug, regardless of whether it was their randomly assigned treatment. We used a US Food and Drug Administration snapshot approach and a margin of 10 percentage points to define the non-inferiority of doravirine to ritonavir-boosted darunavir at 96 weeks. Key safety endpoints were change in fasting serum lipid concentrations, the incidence of adverse events, and time to discontinuation due to an adverse event, assessed in all participants who received at least one dose of any study medication. This study is registered with ClinicalTrials.gov, NCT02275780, and is closed to accrual. Between Dec 1, 2014, and Oct 20, 2015, 1027 individuals were screened, of whom 769 participants were randomly assigned to doravirine (n=385) or ritonavir-boosted darunavir (n=384), and 383 in both groups were given at least one dose of their allocated treatment. Most participants were male (645 [84%] of 766) and white (560 [73%]), with a mean age of 35·2 years (SD 10·6). 292 participants in the doravirine group and 273 in the darunavir group completed 96 weeks of treatment. At week 96, a higher proportion of the doravirine group (277 [73%] of 383) achieved an HIV-1 RNA concentration of less than 50 copies per mL than did of the darunavir group (248 [66%] of 383; difference 7·1%, 95% CI 0·5-13·7). Responses were similar regardless of baseline characteristics. Treatment-emergent resistance to any study drug occurred in two (1%) of 383 participants in the doravirine group and one (<1%) of 383 in the ritonavir-boosted darunavir group. Significant differences were seen between treatment groups in mean changes from baseline in LDL cholesterol (-14·6 mg/dL, 95% CI -18·2 to -11·0) and non-HDL cholesterol (-18·4 mg/dL, -22·5 to -14·3). Frequencies of adverse events were similar between groups. No significant treatment difference (log-rank nominal p=0·063) through week 96 was observed in time to discontinuation due to an adverse event. The most common adverse events (week 0-96) were diarrhoea (65 [17%] in the doravirine group vs 91 [24%] in the ritonavir-boosted darunavir group), nausea (45 [12%] vs 52 [14%]), headache (57 [15%] vs 46 [12%]), and upper respiratory tract infection (51 [13%] vs 30 [8%]). Two participants, one in each group, died during treatment; neither death was considered to be related to study medication. These results through 96 weeks support the efficacy and safety results reported previously for doravirine at 48 weeks, supporting the use of doravirine for the long-term treatment of adults with previously untreated HIV-1 infection. Merck.

Coenzyme Q10 Alleviates Chronic Nucleoside Reverse Transcriptase Inhibitor-Induced Premature Endothelial Senescence.

Human immunodeficiency virus (HIV)-infected patients undergoing antiretroviral therapy are afforded an increased lifespan but also exhibit an elevated incidence of cardiovascular disease. HIV therapy uses a combination drug approach, and nucleoside reverse transcriptase inhibitors (NRTI) are a backbone of this therapy. Endothelial dysfunction is an initiating event in cardiovascular disease etiology, and in our prior studies, NRTIs induced an endothelial dysfunction that was dependent upon mitochondrial oxidative stress. Moreover, short-term NRTI administration induced a mitophagy-associated endothelial toxicity and increased reactive oxygen species (ROS) production that was rescued by coenzyme Q10 (Q10) or overexpression of a mitochondrial antioxidant enzyme. Thus, our objective was to examine mitochondrial toxicity in endothelial cells after chronic NRTI treatment and evaluate Q10 as a potential adjunct therapy for preventing NRTI-induced mitochondrial toxicity. Human aortic endothelial cells (HAEC) were exposed to chronic NRTI treatment, with or without Q10. ROS production, cell proliferation rate, levels of senescence, and mitochondrial bioenergetic function were determined. Chronic NRTI increased ROS production but decreased population doubling. In addition, NRTI increased the accumulation of β-galactosidase, indicative of an accelerated rate of senescence. Moreover, ATP-linked respiration was diminished. Co-treatment with Q10 delayed the onset of NRTI-induced senescence, decreased ROS production and rescued the cells' mitochondrial respiration rate. Thus, our findings may suggest antioxidant enrichment approaches for reducing the cardiovascular side effects of NRTI therapy.

Dolutegravir versus ritonavir-boosted lopinavir both with dual nucleoside reverse transcriptase inhibitor therapy in adults with HIV-1 infection in whom first-line therapy has failed (DAWNING): an open-label, non-inferiority, phase 3b trial

Doubts exist regarding optimal second-line treatment options for HIV-1-infected patients in resource-limited settings. We assessed safety and efficacy of dolutegravir compared with ritonavir-boosted lopinavir, plus two nucleoside reverse transcriptase inhibitors (NRTIs) in adults in whom previous first-line antiretroviral therapy with a non-nucleoside reverse transcriptase inhibitor (NNRTI) plus two NRTIs has failed. DAWNING is a phase 3b, open-label, parallel-group, non-inferiority, active-controlled trial done at 58 sites in 13 countries. Eligible adults were aged at least 18 years and, during at least 6 months of treatment with a first-line treatment containing an NNRTI and two NRTIs, had virological failure (confirmed HIV-1 RNA ≥400 copies per mL). Participants were randomly assigned by a central randomisation system to receive oral dolutegravir (50 mg once daily) or ritonavir-boosted lopinavir (800 mg lopinavir plus 200 mg ritonavir once daily or 400 mg plus 100 mg twice daily), plus two investigator-selected NRTIs (at least one fully active based on resistance testing at screening). The primary outcome was the proportion of participants achieving viral suppression (defined as plasma HIV-1 RNA <50 copies per mL) at week 48 using the snapshot algorithm and a non-inferiority margin of -12%. The primary analysis was done in an intention-to-treat-exposed (ITT-E) population of participants who received at least one dose of study medication, according to original group assignment. Safety was analysed in all participants who received at least one dose of study drug, according to which drug was received. The study was registered at ClinicalTrials.gov, number NCT02227238, and viiv-studyregister.com, number 200304. Between Dec 11, 2014, and June 27, 2016, 968 adults were screened and 627 were randomly assigned to the dolutegravir group (n=312) or the ritonavir-boosted lopinavir group (n=315). Three patients in the ritonavir-boosted lopinavir group did not receive study medication and so 624 were included in the ITT-E population. At week 48, 261 (84%) of 312 participants in the dolutegravir group achieved viral suppression compared with 219 (70%) of 312 in the ritonavir-boosted lopinavir group (adjusted difference 13·8%; 95% CI 7·3-20·3). Non-inferiority was achieved on the basis of the 95% CI of the adjusted treatment difference having a lower bound greater than -12% (prespecified non-inferiority margin). Because the lower bound of the 95% CI is greater than zero (7·3%), superiority of dolutegravir was also concluded (p<0·0001). The safety profile for dolutegravir was favourable compared with that of ritonavir-boosted lopinavir. More grade 2-4 drug-related adverse events occurred with ritonavir-boosted lopinavir than dolutegravir (44 [14%] of 310 with ritonavir-boosted lopinavir vs 11 [4%] of 314 with dolutegravir), mainly driven by gastrointestinal disorders. When administered with two NRTIs, dolutegravir was superior to ritonavir-boosted lopinavir at 48 weeks and can be considered a suitable option for second-line treatment. ViiV Healthcare.

Pretreatment HIV Drug Resistance and Virologic Outcomes to First-Line Antiretroviral Therapy in Peru.

Access to nucleoside reverse transcriptase inhibitor (NRTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) first-line antiretroviral therapy (ART) for HIV has been increasing in Peru since a national ART program was initiated in 2004. Between 2007 and 2009, we found a 1% prevalence of pre-ART HIV drug resistance (PDR) among antiretroviral (ARV)-naive Peruvians. Given that PDR has been associated with virologic failure (VF) of ART, in 2014-2015 we enrolled a follow-up cohort at the same institution to determine whether the rate of transmitted resistance had increased and compared virologic outcomes of those with and without PDR. Blood specimens from ARV-naive individuals were assessed for PDR to NNRTI-based ART by an oligonucleotide ligation assay (OLA) sensitive to 2% mutant within an individual's HIV quasispecies at reverse transcriptase codons M41L, K65R, K103N, Y181C, M184V, and G190A, and by Sanger consensus sequencing (CS). Rates of VF (plasma HIV RNA >200 copies/mL) were compared between those with and without PDR. Among 122 ARV-naive adults, PDR was detected by OLA in 17 (13.9%) adults. Compared with the 2007-2009 cohort, the proportion with PDR at OLA codons was significantly increased (p < .001). A total of 11 of 19 OLA mutations conferring high-level drug resistance were also detected by CS, and 8 additional participants had mutations encoding low-level resistance detected by CS for a total of 25 participants (20.5%). VF at month 6 of NNRTI-ART appeared greater in participants with versus without PDR [4/18 (22.2%) vs. 3/71 (4.2%); p = .03]. An increasing prevalence of PDR was detected among ARV-naive Peruvians. Studies are needed to determine risks of specific PDR mutations.

Increase of neurofilament-H protein in sensory neurons in antiretroviral neuropathy: Evidence for a neuroprotective response mediated by the RNA-binding protein HuD

Nucleoside reverse transcriptase inhibitors (NRTIs) are key components of HIV/AIDS treatment to reduce viral load. However, antiretroviral toxic neuropathy has become a common peripheral neuropathy among HIV/AIDS patients leading to discontinuation of antiretroviral therapy, for which the underlying pathogenesis is uncertain. This study examines the role of neurofilament (NF) proteins in the spinal dorsal horn, DRG and sciatic nerve after NRTI neurotoxicity in mice treated with zalcitabine (2⿲,3⿲-dideoxycitidine; ddC). ddC administration up-regulated NF-M and pNF-H proteins with no effect on NF-L. The increase of pNF-H levels was counteracted by the silencing of HuD, an RNA binding protein involved in neuronal development and differentiation. Sciatic nerve sections of ddC exposed mice showed an increased axonal caliber, concomitantly to a pNF-H up-regulation. Both events were prevented by HuD silencing. pNF-H and HuD colocalize in DRG and spinal dorsal horn axons. However, the capability of HuD to bind NF mRNA was not demonstrated, indicating the presence of an indirect mechanism of control of NF expression by HuD. RNA immunoprecipitation experiments showed the capability of HuD to bind the BDNF mRNA and the administration of an anti-BDNF antibody prevented pNF-H increase. These data indicate the presence of a HuD ⿿ BDNF ⿿ NF-H pathway activated as a regenerative response to the axonal damage induced by ddC treatment to counteract the antiretroviral neurotoxicity. Since analgesics clinically used to treat neuropathic pain are ineffective on antiretroviral neuropathy, a neuroregenerative strategy might represent a new therapeutic opportunity to counteract neurotoxicity and avoid discontinuation or abandon of NRTI therapy.

Higher Prevalence of Hypertension in HIV-1-Infected Patients on Combination Antiretroviral Therapy Is Associated With Changes in Body Composition and Prior Stavudine Exposure

Individuals infected with human immunodeficiency virus (HIV) have a higher risk of cardiovascular disease, potentially partly mediated by a higher prevalence of hypertension. We therefore examined the prevalence and determinants of hypertension in HIV-1-infected patients compared with appropriate HIV-negative controls. Data from 527 HIV-1-infected and 517 HIV-uninfected participants at the time of enrollment into the ongoing AGEhIV Cohort Study were analyzed. Hypertension was defined as systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, and/or self-reported use of antihypertensive drugs. Hypertension prevalence was higher among HIV-1-infected individuals compared with controls (48.2% vs 36.4%; odds ratio [OR], 1.63; 95% confidence interval [CI], 1.27-2.09). In logistic regression models adjusted for age, sex, ethnicity, family history of hypertension, smoking, alcohol use, physical activity, and body mass index, the association between HIV and hypertension remained statistically significant (ORHIV, 1.65; 95% CI, 1.25-2.19), but was attenuated after additional adjustment for waist-to-hip ratio (ORHIV, 1.29; 95% CI, .95-1.76). Among HIV-1-infected individuals, particularly among those with mono/dual nucleoside reverse transcriptase inhibitor therapy prior to combination antiretroviral therapy, stavudine exposure was independently associated with hypertension (ORstavudine, 1.54; 95% CI, 1.04-2.30). This association was attenuated after additional adjustment for either waist-to-hip ratio (ORstavudine, 1.30; 95% CI, .85-1.96) or hip circumference (ORstavudine, 1.40; 95% CI, .93-2.11). Our findings suggest that changes in body composition, involving both abdominal obesity and stavudine-induced peripheral lipoatrophy, might contribute to the higher prevalence of hypertension in HIV-1-infected patients. NCT01466582.

Naringin Reverses Hepatocyte Apoptosis and Oxidative Stress Associated with HIV-1 Nucleotide Reverse Transcriptase Inhibitors-Induced Metabolic Complications.

Nucleoside Reverse Transcriptase Inhibitors (NRTIs) have not only improved therapeutic outcomes in the treatment of HIV infection but have also led to an increase in associated metabolic complications of NRTIs. Naringin’s effects in mitigating NRTI-induced complications were investigated in this study. Wistar rats, randomly allotted into seven groups (n = 7) were orally treated daily for 56 days with 100 mg/kg zidovudine (AZT) (groups I, II III), 50 mg/kg stavudine (d4T) (groups IV, V, VI) and 3 mL/kg of distilled water (group VII). Additionally, rats in groups II and V were similarly treated with 50 mg/kg naringin, while groups III and VI were treated with 45 mg/kg vitamin E. AZT or d4T treatment significantly reduced body weight and plasma high density lipoprotein concentrations but increased liver weights, plasma triglycerides and total cholesterol compared to controls, respectively. Furthermore, AZT or d4T treatment significantly increased oxidative stress, adiposity index and expression of Bax protein, but reduced Bcl-2 protein expression compared to controls, respectively. However, either naringin or vitamin E significantly mitigated AZT- or d4T-induced weight loss, dyslipidemia, oxidative stress and hepatocyte apoptosis compared to AZT- or d4T-only treated rats. Our results suggest that naringin reverses metabolic complications associated with NRTIs by ameliorating oxidative stress and apoptosis. This implies that naringin supplements could mitigate lipodystrophy and dyslipidemia associated with NRTI therapy.

Cabotegravir plus rilpivirine, once a day, after induction with cabotegravir plus nucleoside reverse transcriptase inhibitors in antiretroviral-naive adults with HIV-1 infection (LATTE): a randomised, phase 2b, dose-ranging trial

In phase 1 trials, the HIV-1 integrase strand transfer inhibitor cabotegravir (GSK1265744) was well tolerated, both alone, and in combination with the non-nucleoside reverse transcriptase inhibitor rilpivirine. We assessed cabotegravir plus rilpivirine, as a two-drug oral antiretroviral regimen, for the maintenance of viral suppression in antiretroviral-naive HIV-1-infected individuals. In the phase 2b Long-Acting antireTroviral Treatment Enabling (LATTE) trial, a multicentre study done in Canada and the USA, antiretroviral-naive HIV-1-infected adults (aged ≥18 years) were randomly allocated in a 1:1:1:1 ratio to oral cabotegravir 10 mg once a day, 30 mg once a day, 60 mg once a day, or oral efavirenz 600 mg once a day with dual nucleoside reverse transcriptase inhibitors (NRTIs) for 24 weeks of induction. Patients who were virologically suppressed by week 24 received a two-drug maintenance regimen consisting of their randomly allocated cabotegravir dose plus oral rilpivirine 25 mg or continued efavirenz plus NRTIs for an additional 72 weeks. Patients and investigators were masked to doses of cabotegravir received for 96 weeks, but not to the assignment of cabotegravir or efavirenz. The primary endpoint was the proportion of patients with fewer than 50 copies per mL of HIV-1 RNA (US Food and Drug Administration snapshot algorithm) at week 48. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, NCT01641809. Of 243 patients randomly allocated and treated, 156 (86%) of 181 patients in the cabotegravir groups (52 [87%] of 60, 51 [85%] of 60, and 53 [87%] of 61 patients in the 10 mg, 30 mg, and 60 mg groups, respectively) and 46 (74%) of 62 in the efavirenz group had fewer than 50 copies per mL of HIV-1 RNA after induction therapy. After patients in the cabotegravir groups were changed over from dual NRTIs to rilpivirine at week 24, 149 (82%; 95% CI 77-88) patients in the cabotegravir groups (48 [80%; 70-90], 48 [80%; 70-90], and 53 [87%; 78-95] patients in the 10 mg, 30 mg, and 60 mg groups, respectively) versus 44 (71%; 60-82) in the efavirenz group were virologically suppressed at week 48, and 137 (76%; 69-82) receiving cabotegravir (41 [68%; 57-80], 45 [75%; 64-86], and 51 [84%; 74-93] patients in the 10 mg, 30 mg, and 60 mg groups, respectively) versus 39 (63%; 51-75) in the efavirenz group were virologically suppressed at week 96. Treatment-related adverse events were reported by 93 (51%) cabotegravir-treated patients (28 [47%], 32 [53%], and 33 [54%] patients in the 10 mg, 30 mg, and 60 mg groups, respectively) and 42 (68%) efavirenz-treated patients. Six (3%) patients in the cabotegravir groups (one [2%], one [2%], and four [7%] patients in the 10 mg, 30 mg, and 60 mg groups, respectively) withdrew because of treatment-emergent adverse events compared with nine (15%) in the efavirenz group. Cabotegravir plus dual NRTI therapy had potent antiviral activity during the induction phase. As a two-drug maintenance therapy, cabotegravir plus rilpivirine provided antiviral activity similar to efavirenz plus dual NRTIs until the end of week 96. Combined efficacy and safety results lend support to our selection of oral cabotegravir 30 mg once a day for further assessment. LATTE precedes studies of the assessment of longacting injectable formulations of both drugs as a two-drug regimen for the treatment of HIV-1 infection. ViiV Healthcare and Janssen Research and Development.

Transient Elastography for the Detection of Liver Damage in Patients with HIV.

IntroductionHighly active antiretroviral therapy (HAART) is effective and well tolerated, but hepatotoxicity is relatively common. Different non-invasive methods are available for detecting liver fibrosis in patients with chronic liver disease.MethodsPatients who were HIV positive and who had given their informed consent were included in this cross-sectional study. Transient elastography [FibroScan® (FS); Echosens], serum hyaluronic acid (HA), Hepascore (HS), Fibrosis-4 (FIB-4), and aspartate aminotransferase to platelet ratio index (APRI) were used to detect liver fibrosis in the patients. The agreement between FS and the other methods was evaluated. To observe the hepatotoxicity of HAART, patients with chronic viral hepatitis B or C were excluded by detection of hepatitis B surface antigens and hepatitis C virus antibodies. Patients with chronic alcohol intake were excluded by measuring carbohydrate-deficient transferrin (CDT). FS correlation with the duration of therapy with protease inhibitors (PI), nucleoside reverse transcriptase inhibitors (NRTI), and non-nucleoside reverse transcriptase inhibitors (NNRTI) was evaluated.ResultsOverall, 203 patients were included in the study. The agreement between the different tests ranged from 64% to 77%: FS vs. HA, 72%; FS vs. APRI, 74%; FS vs. HS, 77%; and FS vs. FIB-4, 64%. After excluding patients with chronic hepatitis B or C and elevated CDT, 153 patients remained for studying the hepatotoxicity of HAART. A significant correlation of FS with the duration of medication intake was observed for PIs (P = 0.026; r = 0.18). NRTI and NNRTI therapy duration did not correlate with FS.ConclusionsThe agreement between FS and other tests ranged from 64% to 77%. A significant correlation was found between liver stiffness and the duration of therapy with PIs, which underlines the known hepatotoxicity of this substance group.FundingHeinz-Ansmann Foundation.Electronic supplementary materialThe online version of this article (doi:10.1007/s40121-015-0073-y) contains supplementary material, which is available to authorized users.

Mitochondrial DNA mutations in ageing and disease: implications for HIV?

Mitochondrial DNA (mtDNA) mutations cause neurological and multisystem disease. Somatic (acquired) mtDNA mutations are also associated with degenerative diseases and with normal human ageing. It is well established that certain nucleoside reverse transcriptase inhibitor (NRTI) antiretroviral drugs cause inhibition of the mtDNA polymerase, pol γ, leading to a reduction in mtDNA content (depletion). Given this effect of NRTI therapy on mtDNA replication, it is plausible that NRTI treatment may also lead to increased mtDNA mutations. Here we review recent evidence for an effect of HIV infection or NRTI therapy on mtDNA mutations, as well as discussing the methodological challenges in addressing this question. Finally, we discuss the possible implications for HIV-infected persons, with particular reference to ageing.

Dual therapy with etravirine plus raltegravir for virologically suppressed HIV-infected patients: a pilot study

Clinical use of protease inhibitors (PIs) and nucleoside reverse transcriptase inhibitors (NRTIs) may be hampered by toxicity, interactions or resistance issues. Simple and effective antiretroviral regimens avoiding both drug classes may be needed for selected patients. This was a prospective cohort study. Virologically suppressed patients on PI or NRTI regimens, with problems of tolerability, safety concerns due to comorbidities or risk of drug interactions for both PIs and NRTIs, were given the opportunity to switch their regimen to etravirine plus raltegravir. Patients were required not to have prior virological failure to raltegravir and if there was prior non-nucleoside reverse transcriptase inhibitor (NNRTI) virological failure, only patients in whom efficacy of etravirine could be anticipated through the Stanford Drug Resistance Database were included. Follow-up was scheduled for at least 48 weeks, unless the patient was lost to follow-up or discontinued therapy. Twenty-five patients were included. Their median age was 54 years; they had a median of 16 years on antiretroviral therapy and a median of nine previous regimens; 21 (84%) patients had previous virological failure; and 15 (60%) patients had a genotypic test that showed three or more NRTI mutations in 9 (36%), four or more PI mutations in 11 (44%) and at least one NNRTI mutation in 8 (32%) patients. At 48 weeks efficacy was 84% (95% CI 65.3%-93.6%) by intent-to-treat analysis and 91.3% (95% CI 73.2%-97.6%) by per-protocol analysis. One (4%) patient died, two (8%) discontinued due to intolerance and one (4%) experienced virological failure. The CD4/CD8 ratio and plasma lipids improved. Dual therapy with etravirine plus raltegravir was well tolerated and maintained durable viral suppression in selected virologically suppressed patients for whom both PI and NRTI therapy was challenging.

Cardiovascular Risk Among HIV-Positive Subjects Preceding Exposure to HAART: A Retrospective Claims Analysis

Background: Cardiovascular disease (CVD) causes significant morbidity and mortality in HIV-infected individuals. Advancing age, chronic HIV-associated inflammation and antiretroviral therapy in part contributes to the increased risk of CVD in these patients. Aim: This study aimed to compare the CVD- and HIV-related morbidity of subjects prior to initiating an non-nucleoside reverse transcriptase inhibitor (NNRTI)- versus a protease inhibitor (PI)-based HAART regimen. Methods: Subjects in this retrospective, observational study of medical claims data representing HIV-infected beneficiaries from May 2000 to December 2009 were assigned either to a PI initiator group (n = 2192) or to a NNRTI initiator group (n = 3338). The case mix similarities and differences between the two groups were compared. Results: More subjects in the PI group had previous treatment with nucleoside reverse transcriptase inhibitor therapy or with the fusion inhibitor enfuvirtide, whereas more subjects in the NNRTI group had prior treatment with lamivudine plus zidovudine. Uncontrolled Type 2 diabetes, substance abuse, drug dependence, cardiovascular morbidity, heart failure, nonhypertension kidney dysfunction, depression, AIDS-related diagnosis, Kaposi‘s sarcoma, candidiasis and cachexia were observed more often in the PI group. Subjects in the PI group were more likely to be receiving medications for AIDS conditions. Only smoking cessation medication showed a higher prevalence in the NNRTI group. Conclusion: Subjects initiating PI-based versus NNRTI-based therapy had a greater prevalence of specific comorbidities that may adversely affect CVD risk profile.

Cytomegalovirus Viremia in Thai HIV-Infected Patients on Antiretroviral Therapy: Prevalence and Associated Mortality

Prevalence and risk factors of cytomegalovirus (CMV) viremia in patients infected with human immunodeficiency virus (HIV) starting antiretroviral therapy (ART) in developing countries are understudied. We measured CMV DNA in stored plasma specimens of 293 Thai HIV patients starting ART at CD4 counts <200 cells/mm(3). We examined Cox proportional hazard ratios (HRs) of 24 months mortality and new AIDS-defining illness (ADI). Of 293 patients, 159 (54.3%) were male. The median age was 33 years. The median baseline CD4 count was 82 cells/mm(3), and the median HIV-1 RNA was 4.9 log10 copies/mL. In total, 273 (93.2%) patients started potent combination ART, and 20 (6.8%) started dual nucleoside reverse transcriptase inhibitor (NRTI) therapy. CMV DNA was detected in 77 of 293 patients (26.3%) at baseline, and 9 of 199 patients with available specimen (4.5%) after 6 months of ART. The median CMV DNA was 548 copies/mL (interquartile range [IQR], 129-3849) at baseline and 114 copies/mL (IQR, 75-1099) at 6 months. In univariate analysis, death was associated with baseline CDC stage C, hemoglobin <10 g/dL, lower CD4 count, and CMV viremia. In multivariate analysis, only CMV DNA >500 copies/mL was significantly associated with mortality (HR: 7.28; 95% CI, 1.32-40.29, P = .023). CD4 count was the only variable associated with new ADI (HR: 0.70 per 50 CD4 cells increase; 95% CI, .49-.997, P = .048). In these Thai patients with advanced HIV disease, CMV viremia was frequent, and CMV DNA >500 copies/mL predicted increased mortality despite ART initiation. This calls for increased attention to screening of active CMV infection in advanced HIV patients in developing countries. Trials assessing preemptive anti-CMV therapy may be warranted.

Molecular Analysis of Mitochondrial Compromise in Rodent Cardiomyocytes Exposed Long Term to Nucleoside Reverse Transcriptase Inhibitors (NRTIs)

Despite the highly effective impact of NRTI therapy in patients infected with the human immunodeficiency virus type 1 (HIV-1), long-term treatment has revealed cardiotoxicity, considered to be due to mitochondrial dysfunction. To evaluate mitochondrial damage, and design therapeutic interventions, we established cultures of rat H9c2 and mouse HL-1 cardiomyocytes and exposed them to the NRTIs zidovudine (AZT), and AZT plus didanosine (ddI). Proliferation assays showed that H9c2 cells grew well in 50μM AZT and 50μM AZT/50μM ddI and that HL-1 cells grew well in 10μM AZT and 10μM AZT/10μM ddI. Both types of cells were exposed to the drugs for 39 passages (P), and mitochondrial integrity in the form of oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) was examined by Seahorse XF24 analyzer. In NRTI-exposed H9c2 cells at most passages, OCR was reduced, in both the basal and uncoupled states, compared to unexposed controls (P<0.05). NRTI-exposed HL-1 cells showed a different pattern of mitochondrial compromise, with inhibition of OCR, in basal and uncoupled cells, occurring largely before P14 and after P17 (P<0.05). The ECAR response in uncoupled cells of both types was unchanged at early passages, but increased after P18 (P<0.05). Evaluation of mitochondrial biogenesis in H9c2 cells revealed reduction before P29, no change at P29, and reduction at P39 in NRTI-exposed cells, compared to unexposed cells (P<0.05). Western blotting of transcription factors critical for mitochondrial biogenesis, PGC-1α, Nrf-1 and mtTFA, showed downregulation in NRTI-exposed H9c2 cells compared to unexposed controls. In addition, electron microscopy (EM) revealed increasing mitochondrial morphological damage in H9c2 cells over passages. For both cell types, AZT/ddI was more damaging than AZT alone. These studies demonstrate progressive mitochondrial compromise in cardiomyocytes-exposed long term, and the model will be used to evaluate potentially protective intervention strategies.

Update on emergence of HIV-1 resistance to antiretroviral drug classes in an Italian national database: 2007–2009

We analysed trends of human immunodeficiency virus type 1 (HIV-1) drug resistance during 2007–2009 in the Italian national HIV drug resistance database ‘ARCA’. Prevalence of resistance in each year was examined on the basis of the presence of major International AIDS Society-2009 mutations. Predictors of resistance were analysed by multivariable logistic regression. Nine hundred and sixty-six patients were selected. Resistance to nucleoside reverse transcriptase inhibitors and protease inhibitors showed a significant decline with respect to previous surveys. Resistance to any class of drug and three drug classes remained stable. Independent predictors of three-class resistance were the number of treatment regimens experienced, prior suboptimal nucleoside reverse transcriptase inhibitor therapy and the current use of ritonavir-boosted protease inhibitors.

The evolution of HIV-1 reverse transcriptase in route to acquisition of Q151M multi-drug resistance is complex and involves mutations in multiple domains

BackgroundThe Q151M multi-drug resistance (MDR) pathway in HIV-1 reverse transcriptase (RT) confers reduced susceptibility to all nucleoside reverse transcriptase inhibitors (NRTIs) excluding tenofovir (TDF). This pathway emerges after long term failure of therapy, and is increasingly observed in the resource poor world, where antiretroviral therapy is rarely accompanied by intensive virological monitoring. In this study we examined the genotypic, phenotypic and fitness correlates associated with the development of Q151M MDR in the absence of viral load monitoring.ResultsSingle-genome sequencing (SGS) of full-length RT was carried out on sequential samples from an HIV-infected individual enrolled in ART rollout. The emergence of Q151M MDR occurred in the order A62V, V75I, and finally Q151M on the same genome at 4, 17 and 37 months after initiation of therapy, respectively. This was accompanied by a parallel cumulative acquisition of mutations at 20 other codon positions; seven of which were located in the connection subdomain. We established that fourteen of these mutations are also observed in Q151M-containing sequences submitted to the Stanford University HIV database. Phenotypic drug susceptibility testing demonstrated that the Q151M-containing RT had reduced susceptibility to all NRTIs except for TDF. RT domain-swapping of patient and wild-type RTs showed that patient-derived connection subdomains were not associated with reduced NRTI susceptibility. However, the virus expressing patient-derived Q151M RT at 37 months demonstrated ~44% replicative capacity of that at 4 months. This was further reduced to ~22% when the Q151M-containing DNA pol domain was expressed with wild-type C-terminal domain, but was then fully compensated by coexpression of the coevolved connection subdomain.ConclusionsWe demonstrate a complex interplay between drug susceptibility and replicative fitness in the acquisition Q151M MDR with serious implications for second-line regimen options. The acquisition of the Q151M pathway occurred sequentially over a long period of failing NRTI therapy, and was associated with mutations in multiple RT domains.