Twenty-Five Years of Lamivudine: Current and Future Use for the Treatment of HIV-1 Infection

Eco-friendly graphene quantum dots as a novel spectrofluorimetric probe for lamivudine quantification with evaluation of its greenness and blueness profiles

In this study, graphene quantum dots (GQDs) were employed for quantitatively analyzing lamivudine using a fluorescence quenching technique. This approach allows for sensitive determination of the concentration of lamivudine in different matrices without requiring derivatization. The mechanism behind the fluorescence intensity quenching between GQDs and lamivudine molecules was explored using the Stern Volmer equation, revealing dynamic quenching behavior. Additionally, various factors affecting fluorescence quenching efficiency such as pH, GQDs concentration, and incubation time were carefully tuned. Moreover, our developed method successfully met ICH guidelines for validation parameters including linearity, accuracy, precision, and selectivity demonstrating excellent performance. The results showed good accuracy and precision, with a mean recovery value of 101.91% for method accuracy and a relative standard deviation of 0.682 and 1.489 for intraday and interday precision, respectively. Finally, the greenness and blueness of the developed method were also investigated to assess its environmental friendliness and analytical practicality. Greenness evaluation using the AGREE tool demonstrated that the developed method has a low environmental impact with an AGREE score of 0.75, Besides, the blueness evaluating using the BAGI tool indicated that the developed method is practical, reliable, and well-suited for routine analysis of lamivudine in various samples.

A Review of FDA-Approved Anti-HIV-1 Drugs, Anti-Gag Compounds, and Potential Strategies for HIV-1 Eradication

Acquired immunodeficiency syndrome (AIDS) is an enormous global health threat stemming from human immunodeficiency virus (HIV-1) infection. Up to now, the tremendous advances in combination antiretroviral therapy (cART) have shifted HIV-1 infection from a fatal illness into a manageable chronic disorder. However, the presence of latent reservoirs, the multifaceted nature of HIV-1, drug resistance, severe off-target effects, poor adherence, and high cost restrict the efficacy of current cART targeting the distinct stages of the virus life cycle. Therefore, there is an unmet need for the discovery of new therapeutics that not only bypass the limitations of the current therapy but also protect the body's health at the same time. The main goal for complete HIV-1 eradication is purging latently infected cells from patients' bodies. A potential strategy called "lock-in and apoptosis" targets the budding phase of the life cycle of the virus and leads to susceptibility to apoptosis of HIV-1 infected cells for the elimination of HIV-1 reservoirs and, ultimately, for complete eradication. The current work intends to present the main advantages and disadvantages of United States Food and Drug Administration (FDA)-approved anti-HIV-1 drugs as well as plausible strategies for the design and development of more anti-HIV-1 compounds with better potency, favorable pharmacokinetic profiles, and improved safety issues.

A pilot study to investigate the safety and feasibility of antiretroviral therapy for Alzheimer's disease (ART-AD)

Retrotransposons are viral-like DNA sequences that constitute approximately 41% of the human genome. Studies in Drosophila, mice, cultured cells, and human brain indicate that retrotransposons are activated in settings of tauopathy, including Alzheimer's disease, and causally drive neurodegeneration. The anti-retroviral medication 3TC (lamivudine), a nucleoside analog reverse transcriptase inhibitor, limits retrotransposon activation and suppresses neurodegeneration in tau transgenic Drosophila, two mouse models of tauopathy, and in brain assembloids derived from patients with sporadic Alzheimer's disease. We performed a 24-week phase 2a open-label clinical trial of 300 mg daily oral 3TC (NCT04552795) in 12 participants aged 52-83 years with a diagnosis of mild cognitive impairment due to suspected Alzheimer's disease. Primary outcomes included feasibility, blood brain barrier penetration, effects of 3TC on reverse transcriptase activity in the periphery, and safety. Secondary outcomes included changes in cognition and fluid-based biomarkers of neurodegeneration and neuroinflammation. All participants completed the six-month trial; one event of gastrointestinal bleeding due to a peptic ulcer was reported. 3TC was detected in blood and cerebrospinal fluid (CSF) of all participants, suggestive of adherence to study drug and effective brain penetration. Cognitive measures remained stable throughout the study. Glial fibrillary acidic protein (GFAP) (P=0.03) and Flt1 (P=0.05) were significantly reduced in CSF over the treatment period; Aβ42/40 (P=0.009) and IL-15 (P=0.006) were significantly elevated in plasma. While this is an open label study of small sample size, the significant decrease of some neurodegeneration- and neuroinflammation-related biomarkers in CSF, significantly elevated levels of plasma Aβ42/40, and a trending decrease of CSF NfL after six months of 3TC exposure suggest a beneficial effect on subjects with mild cognitive impairment due to suspected Alzheimer's disease. Feasibility, safety, tolerability, and central nervous system (CNS) penetration assessments further support clinical evaluation of 3TC in a larger placebo-controlled, multi-dose clinical trial.

Efficacy and safety of raltegravir plus lamivudine maintenance therapy

BACKGROUND

Decreasing medication burden with raltegravir plus lamivudine in virologically suppressed persons with HIV (PWH) maintained efficacy and was well tolerated at 24 weeks, but more comprehensive data over longer follow-up are required.

METHODS

Prospective 48 week extension phase of the raltegravir plus lamivudine arm from a previous 24 week pilot randomized clinical trial in which virologically suppressed PWH were randomized 2:1 to switch to fixed-dose combination 150 mg lamivudine/300 mg raltegravir twice daily or to continue therapy. In this 48 week extension phase, raltegravir was dosed at 1200 mg/day and lamivudine 300 mg/day. Primary outcome was the proportion of PWH with treatment failure at Week 48. Secondary outcomes were changes in ultrasensitive plasma HIV RNA, HIV DNA in CD4 cells, serum IL-6, ultrasensitive C-reactive protein and sCD14, body composition, sleep quality, quality of life and adverse effects.

RESULTS

Between May 2018 and June 2019, 33 PWH were enrolled. One participant experienced virological failure without resistance mutations and re-achieved sustained virological suppression without therapy discontinuation, and two others discontinued therapy due to adverse effects. Treatment failure was 9% (95% CI 2%-24%) and 3% (95% CI 0%-17%) in the ITT and on-treatment populations. There were significant changes between baseline and Week 48 in serum cytokines but not in other secondary outcomes.

CONCLUSIONS

Switching to raltegravir and lamivudine in PWH with virological suppression maintains efficacy and is well tolerated. This maintenance regimen might be a cost-effective option for PWH at risk of drug-drug interactions or needing to avoid specific toxicities of certain antiretroviral drugs or their negative impact on comorbidities.

Lamivudine, Doravirine, and Cabotegravir Downregulate the Expression of Human Endogenous Retroviruses (HERVs), Inhibit Cell Growth, and Reduce Invasive Capability in Melanoma Cell Lines

This study explores the impact of antiretroviral administration on the expression of human endogenous retroviruses (HERVs), cell growth, and invasive capability of human melanoma cell lines in culture. We investigated three antiretrovirals-lamivudine, doravirine, and cabotegravir-in A375, FO-1, and SK-Mel-28, BRAF-mutated, and in MeWo, P53-mutated, melanoma cell lines. The findings indicate a general capability of these drugs to downregulate the expression of HERV-K Pol and Env genes and hinder cell viability, mobility, and colony formation capacity of melanoma cells. The antiretroviral drugs also demonstrate selectivity against malignant cells, sparing normal human epithelial melanocytes. The study reveals that the integrase inhibitor cabotegravir is particularly effective in inhibiting cell growth and invasion across different cell lines in comparison with lamivudine and doravirine, which are inhibitors of the viral reverse transcriptase enzyme. The investigation further delves into the molecular mechanisms underlying the observed effects, highlighting the potential induction of ferroptosis, apoptosis, and alterations in cell cycle regulatory proteins. Our findings showed cytostatic effects principally revealed in A375, and SK-Mel-28 cell lines through a downregulation of retinoblastoma protein phosphorylation and/or cyclin D1 expression. Signs of ferroptosis were detected in both A375 cells and FO-1 cells by a decrease in glutathione peroxidase 4 and ferritin expression, as well as by an increase in transferrin protein levels. Apoptosis was also detected in FO-1 and SK-Mel-28, but only with cabotegravir treatment. Moreover, we explored the expression and activity of the stimulator of interferon genes (STING) protein and its correlation with programmed death-ligand 1 (PD-L1) expression. Both the STING activity and PD-L1 expression were decreased, suggesting that the antiretroviral treatments may counteract the detrimental effects of PD-L1 expression activation through the STING/interferon pathway triggered by HERV-K. Finally, this study underscores the potential therapeutic significance of cabotegravir in melanoma treatment. The findings also raise the prospect of using antiretroviral drugs to downregulate PD-L1 expression, potentially enhancing the therapeutic responses of immune checkpoint inhibitors.

Identification of effective anti-HCV and anti-HIV royal jelly constituents and their acute toxicity evaluation in Albino rats

Few studies on royal jelly's (RJ) antiviral activities and toxicity have been conducted. Here, we investigated the antioxidant properties of RJ that was fractionated into soluble fraction (SF), non-soluble fraction (NSF), water-soluble protein fraction (crude protein fraction, CPF), PF30, PF40, PF50, and PF60. The PFs were identified by SDS-PAGE, and phenolic constituents of SF were detected by HPLC. The qualitative anti-HCV, immunomodulatory, and predicted impact of the studied fractions on ERK2/MAPK14 (activated by HCV) were investigated. The influences of RJ fractions on HIV CD4, reverse-transcriptase, and integrase were examined. The acute toxicity of RJ, SF, NSF, and CPF-PF50 (all CPF except PF50) was tested. Results showed that RJ had potent antioxidant efficiency, and its SF contains functional phenolic compounds. PF30, PF40, and PF50 only showed anti-HCV potency, and PF50 had an immunomodulatory effect against HCV and predicted inhibitory influence on ERK2/MAPK14. RJ-PFs, particularly PF60, showed the most effective anti-HIV ingredients. A single ip injection of RJ fractions at different concentrations revealed that SF was the safest one. Whereas NSF was the most toxic at 700-5000 mg/kg b.w., its toxicity was reversed spontaneously after seven days. Thus, this study provides valuable information about the antiviral activities and toxicity of RJ constituents.

The Influence of Nucleoside Reverse Transcriptase Inhibitors on Mitochondrial Activity, Lipid Content, and Fatty-Acid-Binding Protein Levels in Microglial HMC3 Cells

Despite the availability of a wide range of preventive measures and comprehensive treatment options following infection, the development of acquired immunodeficiency syndrome (AIDS) remains a persistent challenge. Nucleoside reverse transcriptase inhibitors (NRTIs) represent the most commonly utilized therapeutic approach, despite being on the pharmaceutical market for nearly four decades. During this time, a spectrum of side effects ranging from mild discomfort and hypersensitivity reactions to the more prevalent nephrotoxicity and hepatotoxicity has been documented. In light of these considerations, our study aimed to investigate the impacts of two NRTIs, lamivudine and zidovudine, on lipid metabolism in HMC3 microglial cells. Our findings revealed statistically significant reductions in the ATP levels (nearly 8%) and increased mitochondrial superoxide levels (around 10%) after 24 h of treatment with the maximum therapeutic concentration of zidovudine compared to the untreated microglial cells. Furthermore, the concentrations of fatty-acid-binding proteins 4 and 5 were significantly lower (approximately 40%) in the microglial cells that were exposed to NRTIs than in the untreated cells. Notably, the total lipid concentration within the microglial cells markedly increased following NRTI administration with a 13% rise after treatment with 10 µM lamivudine and a remarkable 70% surge following the administration of 6 µM zidovudine. These results suggest that the prolonged administration of NRTIs may potentially lead to lipid accumulation, posing a significant risk to the delicate homeostasis of the neuronal system and potentially triggering a pro-inflammatory response in microglial cells.

The Application of Prodrugs as a Tool to Enhance the Properties of Nucleoside Reverse Transcriptase Inhibitors

Antiretroviral Therapy (ART) is an effective treatment for human immunodeficiency virus (HIV) which has transformed the highly lethal disease, acquired immunodeficiency syndrome (AIDS), into a chronic and manageable condition. However, better methods need to be developed for enhancing patient access and adherence to therapy and for improving treatment in the long term to reduce adverse effects. From the perspective of drug discovery, one promising strategy is the development of anti-HIV prodrugs. This approach aims to enhance the efficacy and safety of treatment, promoting the development of more appropriate and convenient systems for patients. In this review, we discussed the use of the prodrug approach for HIV antiviral agents and emphasized nucleoside reverse transcriptase inhibitors. We comprehensively described various strategies that are used to enhance factors such as water solubility, bioavailability, pharmacokinetic parameters, permeability across biological membranes, chemical stability, drug delivery to specific sites/organs, and tolerability. These strategies might help researchers conduct better studies in this field. We also reported successful examples from the primary therapeutic classes while discussing the advantages and limitations. In this review, we highlighted the key trends in the application of the prodrug approach for treating HIV/AIDS.

Lamivudine (3TC), a Nucleoside Reverse Transcriptase Inhibitor, Prevents the Neuropathological Alterations Present in Mutant Tau Transgenic Mice

The dysregulation of transposable elements contributes to neurodegenerative disorders. Previous studies have reported an increase in retrotransposon transcription in Drosophila models as well as in human tauopathies. In this context, we tested the possible protective effects of a reverse transcriptase inhibitor, namely lamivudine (also known as 3TC), in P301S mice, an animal model of Alzheimer's disease based on FTDP-17-tau overexpression. Transgenic P301S mice administered lamivudine through drinking water showed a decrease in the following histopathological marks typical of tauopathies: tau phosphorylation; inflammation; neuronal death; and hippocampal atrophy. Lamivudine treatment attenuated motor deficits (Rotarod test) and improved short-term memory (Y-maze test). To evaluate the role of tau in retrotransposition, we cotransfected HeLa cells with a plasmid containing a complete LINE-1 sequence and a neomycin reporter cassette designed for retrotransposition assays, and a plasmid with the tau sequence. LINE-1 insertion increased considerably in the cotransfection compared to the transfection without tau. In addition, lamivudine inhibited the insertion of LINE-1. Our data suggest that the progression of the tauopathy can be attenuated by the administration of lamivudine upon the first symptoms of neuropathology.

Rapid simultaneous analysis of anti human immunodeficiency virus drugs in pharmaceutical formulation by smart spectrophotometry based on multivariate calibration and least squares support vector machine methods

In this study, two chemometrics methods, including partial least squares regression (PLS) and least squares support vector machine (LS-SVM) were applied for the simultaneous determination of zidovudine (ZDV) and lamivudine (LMV) in synthetic mixtures and anti-HIV pharmaceutical formulation. These approaches along with the spectrophotometric method were used to solve spectral overlapping problems between mentioned components. The results of PLS showed that the number of components for ZDV and LMV were 10 and 10 with mean square prediction error (MSPE) of 0.4045 and 2.1189, respectively. This method revealed recoveries ranging from 99.48% to 100.40% and 99.55% to 101.25% for ZDV and LMV, respectively. By applying leave-one-out cross-validation (LOO-CV), γ (regularization parameter) and σ² (width of the function) values were found to be 50, 1500 and 210, 20 with root mean square error (RMSE) of 0.6156 and 0.3163 for ZDV and LMV, respectively. The mean recoveries obtained by the LS-SVM were 100.82% and 98.93% for ZDV and LMV, respectively. A comparison between the suggested methods and high-performance liquid chromatography (HPLC) as a reference technique was implemented, which did not show a significant difference. The results obtained in this research revealed that the chemometrics approaches can be efficient, simple, inexpensive, and precise for routine analysis and quality control of the drug.

Comparative application of derivative spectrophotometric and HPLC techniques for the simultaneous determination of lamivudine and tenofovir disoproxil fumarate in fixed-dose combined drugs

Background

Lamivudine (LAM) and tenofovir disoproxil fumarate (TDF) are part of a fixed-dose combination (FDC) therapy recommended by WHO. Both drugs exhibit similar solubility in many solvent systems and tend to have overlapping spectra with maxima at 260 and 270 nm, respectively, in the UV spectrum—thus making their spectrophotometric assay difficult in FDCs. A third-order derivative (D3, d3A/dλ3) spectrophotometric technique was applied to simultaneously evaluate TDF and LAM in FDC drugs, with amplitudes at 240 and 262.5 nm, respectively. Pharmacopoeia-recommended chromatographic method was also applied for comparative purpose.

Results

Method performance by the proposed D3 technique showed linearity for LAM and TDF from 2–10 µg mL−1 to 8–24 µg mL−1, respectively (R2 ≥ 0.998), while for HPLC method both drugs ranged from 0.25 to 5.0 µg mL−1 (R2 ≥ 0.999). The intercepts and slopes of the regression equations were ≤ 1.62 × 10−4 and ≤ 3.58 × 10−5, respectively, while calculated standard errors were ≤ 8.04 × 10−5. Limits of detection and quantification for both methods were ≤ 0.46 μg mL−1 and ≤ 1.40 μg mL−1, respectively, for LAM, while corresponding limits for TDF were ≤ 2.61 and ≤ 7.90 μg mL−1. The percentage recovery for both drugs and methods ranged from 94.80 to 100.33%. The amount of LAM and TDF in brands I and II was ≥ 99.59 ± 1.19% and ≥ 99.39 ± 0.63%, respectively, for the proposed D3 spectroscopic method, while corresponding values for the HPLC method were ≥ 99.86 ± 0.50 and ≥ 99.87 ± 0.32%. Statistically, both methods were adjudged to have no significant difference at 95% confidence level as the student’s t-test values; experimental paired t- and F-test values were found satisfactory.

Conclusion

The D3 spectrophotometric technique was time saving, cheap, simple and more environmental friendly and shows reliability, precision and accuracy and could be used for routine analysis of FDCs where HPLC is not available.

Graphical abstract

High-level resistance to non-nucleos(t)ide reverse transcriptase inhibitor based first-line antiretroviral therapy in Ghana; A 2017 study

Expanding access to effective antiretroviral therapy (ART) is a major tool for management of Human Immunodeficiency Virus (HIV) infection. However, rising levels of HIV drug-resistance have significantly hampered the anticipated success of ART in persons living with HIV (PLWH), particularly those from Africa. Though great strides have been made in Ghana toward achieving the UNAIDS “95-95-95” target, a substantial number of PLWH receiving ART have not attained viral suppression. This study investigated patterns of drug resistance mutations in ART naïve as well as ART-experienced PLWH receiving first-line regimen drugs from Ghana. In a cross-sectional study, blood samples were collected from HIV-1 infected adults (≥18 years) attending HIV/AIDS clinic at the Eastern Regional Hospital, Koforidua, Ghana from September to October 2017. Viral RNA isolated from plasma were subjected to genotypic drug resistance testing for Protease Inhibitors (PI), Reverse Transcriptase Inhibitors (RTI), and Integrase Strand Transfer Inhibitors (INSTI). A total of 95 (84 ART experienced, 11 ART naïve) HIV-1 infected participants were sampled in this study. Sixty percent (50/84) of the ART-experienced participants were controlling viremia (viral load < 1,000 copies/ml). Of the 95 patient samples, 32, 34, and 33 were successfully sequenced for protease, reverse-transcriptase, and integrase regions, respectively. The dominant HIV-1 subtypes detected were CRF02_AG (70%), and A3 (10%). Major drug resistance associated mutations were only detected for reverse transcriptase inhibitors. The predominant drug resistance mutations were against nucleos(t)ide reverse transcriptase inhibitors (NRTI)—M184V/I and non-nucleos(t)ide reverse transcriptase inhibitors (NNRTI)—K103N. In the ART-experienced group, M184V/I and K103N were detected in 54% (15/28) and 46% (13/28) of individuals, respectively. Both mutations were each detected in 33% (2/6) of ART naïve individuals. Multiclass resistance to NRTI and NNRTI was detected in 57% of ART-experienced individuals and two ART naïve individuals. This study reports high-level resistance to NNRTI-based antiretroviral therapy in PLWH in Ghana. However, the absence of major PI and INSTI associated-mutations is a good signal that the current WHO recommendation of Dolutegravir in combination with an NRTI backbone will yield maximum benefits as first-line regimen for PLWH in Ghana.

Pharmacological approaches to prevent vertical transmission of HIV and HBV

INTRODUCTION

Mother-to-child transmission (MTCT) is mainly responsible for the global pediatric HIV and HBV epidemic. Vertical transmission can be prevented and reduced through a series of interventions at the primary healthcare level, including extensive screening of pregnant women, administration of antivirals or immune-based treatments, counselling on type of delivery and breastfeeding.

AREAS COVERED

In this narrative review, approved therapeutic options for the treatment of pregnant women living with HIV or HBV are discussed with special focus on efficacy and safety profiles of each agent or drug class examined. The search was performed using Medline (via PubMed), Web of Science, and Google Scholar to identify studies assessing vertical transmission of both HIV and HBV.

EXPERT OPINION

Elimination of MTCT of both infections is firmly endorsed by major global commitments and the integration of tailored preventive interventions into maternal and newborn health services is of strategical importance to achieve this critical target. However, further research centered on antiviral-based and immunization trials among pregnant women is urgently needed to mitigate the risk of maternal and neonatal adverse outcomes, effectively prevent transmission to the offspring and finally eliminate the pediatric HIV and HBV epidemic, one of the key global health challenges of our time.

N-4 Alkyl Cytosine Derivatives Synthesis: A New Approach

The selective N-4 alkylation of cytosine plays a critical role in the synthesis of biologically active molecules. This work focuses on the development of practical reaction conditions toward a regioselective synthesis of N-4-alkyl cytosine derivatives. The sequence includes a direct and selective sulfonylation at the N-1 site of the cytosine, followed by the alkylation of the amino site using KHMDS in CH2Cl2/THF mixture, providing a fast and efficient approach consistent with pyrimidine-based drug design.

[Determination of abacavir in biological objects for the purpose of chemical and toxicological analysis]

Purpose - to develop a technique for isolating abacavir, as well as its detection and quantification in biological objects. Extraction of abacavir from centrifuges was carried out with chloroform at pH 8 in the presence of an electrolyte saturated solution of (NH₄)₂SO₄ once for 3 minutes. The determination of abacavir in extracts from urine, saliva and liver was carried out by thin-layer chromatography in the system of ethyl acetate: trichloromethane: ammonia, a concentrated solution of 25% (17:4:1) ascending method, UV spectrophotometry in a medium of hydrochloric acid 0.1 M, where the absorption spectrum abacavir is characterized by an absorption maximum at a wavelength of 297±1 nm, high performance liquid chromatography, during which one peak with a retention time of 9.5 min was observed on the chromatogram of a standard sample, which coincided with the retention time of abacavir obtained after extraction from biological objects.

Three-year durable efficacy of dolutegravir plus lamivudine in antiretroviral therapy - naive adults with HIV-1 infection

OBJECTIVE

To assess efficacy and safety of dolutegravir (DTG) + lamivudine (3TC) vs. DTG + tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in treatment-naive adults with HIV-1 in the prespecified 144-week secondary analyses of GEMINI-1 and GEMINI-2.

DESIGN

Identical, multicenter, phase III, randomized, non-inferiority studies (double-blind through 96 weeks).

METHODS

Participants with HIV-1 RNA ≤500 000 copies/ml and no major viral resistance mutations to nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, or protease inhibitors were randomized 1:1 to once-daily DTG + 3TC or DTG + TDF/FTC.

RESULTS

At week 144, DTG + 3TC (N = 716) was noninferior to DTG + TDF/FTC (N = 717) in proportion of participants achieving HIV-1 RNA <50 copies/ml (Snapshot algorithm) in the pooled analysis (82% vs. 84%, respectively; adjusted treatment difference [95% confidence interval (CI)], -1.8% [-5.8, 2.1]), GEMINI-1 (-3.6% [-9.4, 2.1]), and GEMINI-2 (0.0% [-5.3, 5.3]). Twelve DTG + 3TC participants and nine DTG + TDF/FTC participants met protocol-defined confirmed virologic withdrawal (CVW) criteria; none developed treatment-emergent resistance. One DTG + 3TC participant who did not meet CVW criteria developed M184V at week 132 and R263R/K at week 144, conferring a 1.8-fold change in susceptibility to DTG; non-adherence to therapy was reported. Significantly fewer drug-related adverse events occurred with DTG + 3TC vs. DTG + TDF/FTC (20% vs. 27%; relative risk [95% CI], 0.76 [0.63-0.92]). Renal and bone biomarker changes favored DTG + 3TC.

CONCLUSIONS

Three-year durable efficacy, long-term tolerability, and high barrier to resistance support first-line use of DTG + 3TC for HIV-1 treatment (see Supplemental Digital Content 1, http://links.lww.com/QAD/C297; video abstract).

Concurrent estimation of lamivudine, tenofovir disoproxil fumarate, and efavirenz in blended mixture and triple combination tablet formulation by a new stability indicating RP-HPLC method

Background

An easy, defined, rapid, and accurate reverse phase high-performance liquid chromatography method was developed and subsequently validated for the concurrent estimation of lamivudine, efavirenz, and tenofovir disoproxil fumarate in their pure blend and combined tablet formulation. An efficient and appropriate separation of the three analytes was attained with Zorbax eclipse XDB-Phenyl column, with a mobile phase of methanol: buffer (0.1% v/v formic acid in water) (73:27 v/v) at a flow rate of 1mL/min and isocratic elution by using 260nm as detection wavelength. Equal ratio of acetonitrile and water was used as diluent.

Results

The retention times of lamivudine, tenofovir disoproxil fumarate, and efavirenz were found at 2.6, 4.4, and 5.9 min respectively. The linear response for lamivudine, tenofovir disoproxil fumarate, and efavirenz was in the range of 15.0–45.0μg/mL, 15.0–45.0μg/mL, and 20.0–60.0 μg/mL respectively. The method validation was done in accordance to ICH guidelines and all validation parameters in compliance with ICH standards. The degradants produced by stress testing were well resolved from the peaks of active analytes, which stipulates the stability-indicating property of the method.

Conclusion

The method has the ability to separate lamivudine, efavirenz, and tenofovir disoproxil fumarate concurrently in blended powder and their combined tablet. All degradants produced by application of stress conditions were separated with high resolution and determined with good sensitivity that ensures the stability-indicating property of the method. Thus, the projected method has high probability to adopt in the pharmaceutical industrial sector.

A new stability indicating RP-UPLC method for simultaneous estimation of Doravirine, Lamivudine and Tenofovir disoproxil fumarate in bulk and their combined pharmaceutical formulation

Background

To establish a simple, sensitive, accurate, precise, efficient, economical RP-UPLC method for simultaneous estimation of Doravirine, Lamivudine and Tenofovir disoproxil fumarate in bulk and their combined pharmaceutical formulations. Optimization of Chromatographic separation was achieved on analytical column HSS C18 (100 × 2.1 mm, 1.8 μ) maintained at temperature 30 °C and mobile phase consisting of 0.01 N Potassium dihydrogen orthophosphate buffer (pH-4.8) and acetonitrile in the ratio 60:40 v/v and at a flow rate 0.3 mL/min in isocratic mode. The injection volume was set as 1 µl detection wavelength is 260 nm. The proposed method validation was done as per International Council on Harmonization Q2 (R1) guidelines.

Results

Doravirine, Lamivudine and Tenofovir disoproxil fumarate were eluted at retention times of 1.2, 1.5, and 1.8 min respectively. The proposed method was identified an excellent linearity over concentration range of 12.5–75.0 µg/mL for Doravirine and 37.5–225.0 µg/mL for Lamivudine and 37.5–225.0 µg/mL for Tenofovir disoproxil fumarate. The percentage relative standard deviation for intra-day and inter-day precision of the present method was less than 2% for Doravirine, Lamivudine and Tenofovir disoproxil fumarate. Accuracy of the present method was evaluated by recovery studies which were in the range of 99.62–99.88% for Doravirine and 98.78–99.44% for Lamivudine and 99.67–100.52% for Tenofovir disoproxil fumarate. The limit of detection and limit of quantification were found to be 0.249 µg/mL and 0.756 µg/mL for Doravirine and 0.24 µg/mL and 0.727 µg/mL for Lamivudine and 0.797 µg/mL and 2.966 µg/mL for Tenofovir disoproxil fumarate. Forced degradation studies were carried out under various stress conditions like acid, base, peroxide, thermal, photo and neutral conditions.

Conclusions

The present method makes sure about no degraded impurity peak interference at the retention time of analyte peak hence can be applied for quality control investigation of Doravirine, Lamivudine and Tenofovir disoproxil fumarate in bulk and pharmaceutical formulations.

Acquired HIV drug resistance and virologic monitoring in a HIV hyper-endemic setting in KwaZulu-Natal Province, South Africa

Background

Introduction of tenofovir (TDF) plus lamivudine (3TC) and dolutegravir (DTG) in first- and second-line HIV treatment regimens in South Africa warrants characterization of acquired HIV-1 drug resistance (ADR) mutations that could impact DTG-based antiretroviral therapy (ART). In this study, we sought to determine prevalence of ADR mutations and their potential impact on susceptibility to drugs used in combination with DTG among HIV-positive adults (≥ 18 years) accessing routine care at a selected ART facility in KwaZulu-Natal, South Africa.

Methods

We enrolled adult participants in a cross-sectional study between May and September 2019. Eligible participants had a most recent documented viral load (VL) ≥ 1000 copies/mL after at least 6 months on ART. We genotyped HIV-1 reverse transcriptase and protease genes by Sanger sequencing and assessed ADR. We characterized the effect of ADR mutations on the predicted susceptibility to drugs used in combination with DTG.

Results

From 143 participants enrolled, we obtained sequence data for 115 (80%), and 92.2% (95% CI 85.7–96.4) had ADR. The proportion with ADR was similar for participants on first-line ART (65/70, 92.9%, 95% CI 84.1–97.6) and those on second-line ART (40/44, 90.9%, 95% CI 78.3–97.5), and was present for the single participant on third-line ART. Approximately 89% (62/70) of those on first-line ART had dual class NRTI and NNRTI resistance and only six (13.6%) of those on second-line ART had major PI mutations. Most participants (82%) with first-line viraemia maintained susceptibility to Zidovudine (AZT), and the majority of them had lost susceptibility to TDF (71%) and 3TC (84%). Approximately two in every five TDF-treated individuals had thymidine analogue mutations (TAMs).

Conclusions

Susceptibility to AZT among most participants with first-line viraemia suggests that a new second-line regimen of AZT + 3TC + DTG could be effective. However, atypical occurrence of TAMs in TDF-treated individuals suggests a less effective AZT + 3TC + DTG regimen in a subpopulation of patients. As most patients with first-line viraemia had at least low-level resistance to TDF and 3TC, identifying viraemia before switch to TDF + 3TC + DTG is important to avoid DTG functional monotherapy. These findings highlight a need for close monitoring of outcomes on new standardized treatment regimens.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12981-021-00393-5.

HBV/HIV Coinfection: Impact on the Development and Clinical Treatment of Liver Diseases

Hepatitis B virus (HBV) infection is a common contributor to chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Approximately 10% of people with human immunodeficiency virus (HIV) also have chronic HBV co-infection, owing to shared transmission routes. HIV/HBV coinfection accelerates the progression of chronic HBV to cirrhosis, end-stage liver disease, or hepatocellular carcinoma compared to chronic HBV mono-infection. HBV/HIV coinfection alters the natural history of hepatitis B and renders the antiviral treatment more complex. In this report, we conducted a critical review on the epidemiology, natural history, and pathogenesis of liver diseases related to HBV/HIV coinfection. We summarized the novel therapeutic options for these coinfected patients.

Algae-mediated processes for the treatment of antiretroviral drugs in wastewater: Prospects and challenges

The prevalence of pharmaceuticals (PCs), especially antiretroviral (ARV) drugs in various aquatic ecosystems has been expansively reported, wherein wastewater treatment plants (WWTPs) are identified as the primary point source. Consequently, the occurrence, ecotoxicity and treatment of ARV drugs in WWTPs have drawn much attention in recent years. Numerous studies have shown that the widely employed activated sludge-based WWTPs are incapable of removing ARV drugs efficiently from wastewater. Recently, algae-based wastewater treatment processes have shown promising results in PCs removal from wastewater, either completely or partially, through different processes such as biosorption, bioaccumulation, and intra-/inter-cellular degradation. Algal species have also shown to tolerate high concentrations of ARV drugs than the reported concentrations in the environmental matrices. In this review, emphasis has been given on discussing the current status of the occurrence of ARV drugs in the aquatic environment and WWTPs. Besides, the current trends and future perspectives of PCs removal by algae are critically reviewed and discussed. The potential pathways and mechanisms of ARV drugs removal by algae have also been discussed.

PIWI silencing mechanism involving the retrotransposon nimbus orchestrates resistance to infection with Schistosoma mansoni in the snail vector, Biomphalaria glabrata

Background

Schistosomiasis remains widespread in many regions despite efforts at its elimination. By examining changes in the transcriptome at the host-pathogen interface in the snail Biomphalaria glabrata and the blood fluke Schistosoma mansoni, we previously demonstrated that an early stress response in juvenile snails, manifested by induction of heat shock protein 70 (Hsp 70) and Hsp 90 and of the reverse transcriptase (RT) domain of the B. glabrata non-LTR- retrotransposon, nimbus, were critical for B. glabrata susceptibility to S. mansoni. Subsequently, juvenile B. glabrata BS-90 snails, resistant to S. mansoni at 25°C become susceptible by the F2 generation when maintained at 32°C, indicating an epigenetic response.

Methodology/Principal findings

To better understand this plasticity in susceptibility of the BS-90 snail, mRNA sequences were examined from S. mansoni exposed juvenile BS-90 snails cultured either at 25°C (non-permissive temperature) or 32°C (permissive). Comparative analysis of transcriptomes from snails cultured at the non-permissive and permissive temperatures revealed that whereas stress related transcripts dominated the transcriptome of susceptible BS-90 juvenile snails at 32°C, transcripts encoding proteins with a role in epigenetics, such as PIWI (BgPiwi), chromobox protein homolog 1 (BgCBx1), histone acetyltransferase (BgHAT), histone deacetylase (BgHDAC) and metallotransferase (BgMT) were highly expressed in those cultured at 25°C. To identify robust candidate transcripts that will underscore the anti-schistosome phenotype in B. glabrata, further validation of the differential expression of the above transcripts was performed by using the resistant BS-90 (25°C) and the BBO2 susceptible snail stock whose genome has now been sequenced and represents an invaluable resource for molecular studies in B. glabrata. A role for BgPiwi in B. glabrata susceptibility to S. mansoni, was further examined by using siRNA corresponding to the BgPiwi encoding transcript to suppress expression of BgPiwi, rendering the resistant BS-90 juvenile snail susceptible to infection at 25°C. Given transposon silencing activity of PIWI as a facet of its role as guardian of the integrity of the genome, we examined the expression of the nimbus RT encoding transcript at 120 min after infection of resistant BS90 piwi-siRNA treated snails. We observed that nimbus RT was upregulated, indicating that modulation of the transcription of the nimbus RT was associated with susceptibility to S. mansoni in BgPiwi-siRNA treated BS-90 snails. Furthermore, treatment of susceptible BBO2 snails with the RT inhibitor lamivudine, before exposure to S. mansoni, blocked S. mansoni infection concurrent with downregulation of the nimbus RT transcript and upregulation of the BgPiwi encoding transcript in the lamivudine-treated, schistosome-exposed susceptible snails.

Conclusions and significance

These findings support a role for the interplay of BgPiwi and nimbus in the epigenetic modulation of plasticity of resistance/susceptibility in the snail-schistosome relationship.

Progress is being made to eliminate schistosomiasis, a tropical disease that remains endemic in the tropics and neotropics. In 2020, WHO proposed controlling the snail population as part of a strategy toward reducing schistosomiasis, a vector borne disease, by 2025. The life cycle of the causative parasite is, however, complex and in the absence of vaccines, new drugs, and access to clean water and sanitation, reduction of schistosomiasis will remain elusive. To break the parasite’s life cycle during the snail stage of its development, a better understanding of the molecular basis of how schistosomes survive, or not, in the snail is required. By examining changes in the transcriptome at the host-pathogen interface in the snail Biomphalaria glabrata and Schistosoma mansoni, we showed that early stress response, manifested by the induction of Heat Shock Proteins (Hsps) and the RT domain of the non-LTR retrotransposon, nimbus, were critical for snail susceptibility. Subsequently, juvenile B. glabrata BS-90 snails, resistant to S. mansoni at 25°C were observed to become susceptible by the F2 generation when maintained at 32°C, indicating an epigenetic response. This study confirms these earlier results and shows an interplay between PIWI and nimbus in the anti-schistosome response in the snail host.

Testicular disposition of clofarabine in rats is dependent on equilibrative nucleoside transporters

Acute lymphoblastic leukemia (ALL) is the most common cancer in children and adolescents. Although the 5-year survival rate is high, some patients respond poorly to chemotherapy or have recurrence in locations such as the testis. The blood-testis barrier (BTB) can prevent complete eradication by limiting chemotherapeutic access and lead to testicular relapse unless a chemotherapeutic is a substrate of drug transporters present at this barrier. Equilibrative nucleoside transporter (ENT) 1 and ENT2 facilitate the movement of substrates across the BTB. Clofarabine is a nucleoside analog used to treat relapsed or refractory ALL. This study investigated the role of ENTs in the testicular disposition of clofarabine. Pharmacological inhibition of the ENTs by 6-nitrobenzylthioinosine (NBMPR) was used to determine ENT contribution to clofarabine transport in primary rat Sertoli cells, in human Sertoli cells, and across the rat BTB. The presence of NBMPR decreased clofarabine uptake by 40% in primary rat Sertoli cells (p = .0329) and by 53% in a human Sertoli cell line (p = .0899). Rats treated with 10 mg/kg intraperitoneal (IP) injection of the NBMPR prodrug, 6-nitrobenzylthioinosine 5'-monophosphate (NBMPR-P), or vehicle, followed by an intravenous (IV) bolus 10 mg/kg dose of clofarabine, showed a trend toward a lower testis concentration of clofarabine than vehicle (1.81 ± 0.59 vs. 2.65 ± 0.92 ng/mg tissue; p = .1160). This suggests that ENTs could be important for clofarabine disposition. Clofarabine may be capable of crossing the human BTB, and its potential use as a first-line treatment to avoid testicular relapse should be considered.

Antiviral Drug Delivery System for Enhanced Bioactivity, Better Metabolism and Pharmacokinetic Characteristics

Antiviral drugs (AvDs) are the primary resource in the global battle against viruses, including the recent fight against corona virus disease 2019 (COVID-19). Most AvDs require multiple medications, and their use frequently leads to drug resistance, since they have poor oral bioavailability and low efficacy due to their low solubility/low permeability. Characterizing the in vivo metabolism and pharmacokinetic characteristics of AvDs may help to solve the problems associated with AvDs and enhance their efficacy. In this review of AvDs, we systematically investigated their structure-based metabolic reactions and related enzymes, their cellular pharmacology, and the effects of metabolism on AvD pharmacodynamics and pharmacokinetics. We further assessed how delivery systems achieve better metabolism and pharmacology of AvDs. This review suggests that suitable nanosystems may help to achieve better pharmacological activity and pharmacokinetic behavior of AvDs by altering drug metabolism through the utilization of advanced nanotechnology and appropriate administration routes. Notably, such AvDs as ribavirin, remdesivir, favipiravir, chloroquine, lopinavir and ritonavir have been confirmed to bind to the severe acute respiratory syndrome-like coronavirus (SARS-CoV-2) receptor and thus may represent anti-COVID-19 treatments. Elucidating the metabolic and pharmacokinetic characteristics of AvDs may help pharmacologists to identify new formulations with high bioavailability and efficacy and help physicians to better treat virus-related diseases, including COVID-19.

Putative Repurposing of Lamivudine, a Nucleoside/Nucleotide Analogue and Antiretroviral to Improve the Outcome of Cancer and COVID-19 Patients

Lamivudine, also widely known as 3TC belongs to a family of nucleotide/nucleoside analogues of cytidine or cytosine that inhibits the Reverse Transcriptase (RT) of retroviruses such as HIV. Lamivudine is currently indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection or for chronic Hepatitis B (HBV) virus infection associated with evidence of hepatitis B viral replication and active liver inflammation. HBV reactivation in patients with HBV infections who receive anticancer chemotherapy can be a life-threatening complication during and after the completion of chemotherapy. Lamivudine is used, as well as other antiretrovirals, to prevent the reactivation of the Hepatitis B virus during and after chemotherapy. In addition, Lamivudine has been shown to sensitize cancer cells to chemotherapy. Lamivudine and other similar analogues also have direct positive effects in the prevention of cancer in hepatitis B or HIV positive patients, independently of chemotherapy or radiotherapy. Recently, it has been proposed that Lamivudine might be also repurposed against SARS-CoV-2 in the context of the COVID-19 pandemic. In this review we first examine recent reports on the re-usage of Lamivudine or 3TC against the SARS-CoV-2, and we present docking evidence carried out in silico suggesting that Lamivudine may bind and possibly work as an inhibitor of the SARS-CoV-2 RdRp RNA polymerase. We also evaluate and propose assessment of repurposing Lamivudine as anti-SARS-CoV-2 and anti-COVID-19 antiviral. Secondly, we summarize the published literature on the use of Lamivudine or (3TC) before or during chemotherapy to prevent reactivation of HBV, and examine reports of enhanced effectiveness of radiotherapy in combination with Lamivudine treatment against the cancerous cells or tissues. We show that the anti-cancer properties of Lamivudine are well established, whereas its putative anti-COVID effect is under investigation. The side effects of lamivudine and the appearance of resistance to 3TC are also discussed.

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

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

Assessing conditional causal effect via characteristic score

Observational studies usually include participants representing the wide heterogeneous population. The conditional causal effect, treatment effect conditional on baseline characteristics, is of practical importance. Its estimation is subject to two challenges. First, the causal effect is not observable in any individual due to counterfactuality. Second, high-dimensional baseline variables are involved to satisfy the ignorable treatment selection assumption and to attain better estimation efficiency. In this work, a nonparametric estimation procedure, along with a pseudo-response, is proposed to estimate the conditional treatment effect through "characteristic score"-a parsimonious representation of baseline variable influence on treatment benefit. Adopting sparse dimension reduction with variable prescreening in the proposed estimation, we aim to identify the key baseline variables that impact the conditional treatment effect and to uncover the characteristic score that best predicts the treatment effect. This approach is applied to an HIV study for assessing the benefit of antiretroviral regimens and identifying the beneficiary subpopulation.

The evidence for using tenofovir disoproxil fumarate plus lamivudine as a nucleoside analogue backbone for the treatment of HIV

This article evaluates the evidence supporting use of the tenofovir disoproxil fumarate (TDF) plus lamivudine (3 ​TC) combination as a dual nucleoside backbone within a triple drug antiretroviral regimen. Key trials that assess the relative efficacy, safety and resistance profile of 3 ​TC and emtricitabine (FTC) are discussed. Clinical use of 3 ​TC and FTC with two tenofovir prodrugs –TDF and tenofovir alafenamide (TAF) – is presented. Recommendations from various international guidelines for the construction of triple and emerging dual regimens are summarised. In conclusion, data suggest the therapeutic equivalence of 3 ​TC and FTC, especially when 3 ​TC is combined with TDF.

Lamivudine/Tenofovir Disoproxil Fumarate is an Appropriate PrEP Regimen

Oral pre-exposure prophylaxis (PrEP) containing tenofovir disoproxil fumarate (TDF) co-formulated with emtricitabine (FTC) or lamivudine (3TC) is recommended as an additional prevention option for persons at substantial risk of HIV infection by both the World Health Organization (WHO) and the US President's Emergency Plan for AIDS Relief (PEPFAR). The WHO and PEPFAR consider 3TC clinically interchangeable with FTC for PrEP given comparable pharmacologic equivalence, resistance and toxicity patterns, and indirect clinical trial evidence from TDF-containing studies. Globally, FTC/TDF has been widely used in clinical trials, open-label extension studies and demonstration projects. Thus, most PrEP efficacy and safety data are based on FTC/TDF use in heterosexual women and men, men who have sex with men, and people who inject drugs. However, generic 3TC/TDF is less expensive than FTC/TDF, is already available in supply chains for HIV drugs, and has 60-70% of the global adult market share, making it particularly appealing in settings with limited availability or affordability of FTC/TDF. Compelling indirect evidence suggests that scaling up use of 3TC/TDF is potentially cost saving for HIV programs in settings where restricting drug choice to FTC/TDF would delay PrEP implementation. Guideline committees and public health decision-makers in countries should encourage flexibility in PrEP drug selection, support off-label use of 3TC/TDF, and approve use of generic formulations to decrease the cost of PrEP medications and accelerate PrEP delivery through the public and private sectors.

Pretreatment HIV drug resistance predicts accumulation of new mutations in ART-naïve Ugandan children

AIM

To assess the prevalence of pretreatment drug resistance (PDR) and its association with virologic outcomes after 24 weeks of antiretroviral therapy (ART), within an urban cohort of Ugandan children.

METHODS

Prospective observational study. Baseline and 24-week assessments of viral load (VL) and genotypic drug resistance to nucleoside reverse transcriptase inhibitors (NRTI) and non-nucleoside reverse transcriptase inhibitors (NNRTI) were performed.

RESULTS

Ninety-nine ART-naïve children (3-12 years) initiated efavirenz-based ART 2015-2016 and 18/90 (20%) had baseline NRTI/NNRTI associated drug resistance mutations (DRMs). By 24 weeks, 72/93 (77%) children had VL < 40 copies/mL and a total of 23 children had DRMs. Children with PDR accumulated new DRMs with a mean number (SD) of 1.4 (2.35) new mutations compared to 0.26 (0.98) in 67 children with wild-type virus (P = .003). High pretreatment VL and PDR (number of baseline DRMs) predicted viremia (P = .003; P = .023) as well as acquired drug resistance (P = .02; P = .04).

CONCLUSION

Pretreatment drug resistance to NNRTI/NRTI was common among ART-naïve Ugandan children and predicted viremia and new resistance mutations after only 24 weeks of efavirenz-based therapy. PDR may compromise long-term ART outcomes-especially when access to resistance testing and VL monitoring is poor. The long-term importance of PDR for non-NNRTI-based regimens needs further evaluation.

Determination of reverse transcriptase inhibitor resistance mutations in HIV-1 infected children in Côte d'Ivoire

Treatment scale-up is leading to a progressive increase in HIV resistance to antiretrovirals, especially in children. To assess resistance to reverse transcriptase inhibitors (RTIs) in HIV-1 infected children in Côte d'Ivoire, genotypic resistance tests were performed and interpreted using the ANRS algorithm (www.hivfrenchresistance.org). Phylogenetic trees were created using BioEdit v7 and Mega7 software. The frequency of resistance to at least one RTI was 79%. It was 88% for nucleoside reverse transcriptase inhibitors (NRTIs), 71% for non-nucleoside reverse transcriptase inhibitors (NNRTIs), and 63% for both classes (NRTI + NNRTI). The frequency of resistance was 50% for the ZDV + 3TC + EFV combination, 42% for the ABC + 3TC + EFV combination, and 8% for the TDF + 3TC + EFV combination. Frequently encountered resistance mutations were for NRTIs: M184V (88%), TAMs (67%), T215F/I/V/Y (33%), and L74I/V (24%); for NNRTIs: K103N/S (74%), P225H (26%), and G190A/E/Q (24%). The synthesis of phylogenetic analyses showed the predominance of the viral subtype CRF02_AG (85%). These results show a high prevalence of resistance to RTIs in children infected with HIV-1. Hence the interest of a more accessible monitoring of viral load and genotypic resistance tests in HIV-1 infected children undergoing treatment in Côte d'Ivoire.

Nucleotide Analogues as Inhibitors of SARS-CoV-2 Polymerase, a Key Drug Target for COVID-19

SARS-CoV-2 is responsible for the current COVID-19 pandemic. On the basis of our analysis of hepatitis C virus and coronavirus replication, and the molecular structures and activities of viral inhibitors, we previously demonstrated that three nucleotide analogues (the triphosphates of Sofosbuvir, Alovudine, and AZT) inhibit the SARS-CoV RNA-dependent RNA polymerase (RdRp). We also demonstrated that a library of additional nucleotide analogues terminate RNA synthesis catalyzed by the SARS-CoV-2 RdRp, a well-established drug target for COVID-19. Here, we used polymerase extension experiments to demonstrate that the active triphosphate form of Sofosbuvir (an FDA-approved hepatitis C drug) is incorporated by SARS-CoV-2 RdRp and blocks further incorporation. Using the molecular insight gained from the previous studies, we selected the active triphosphate forms of six other antiviral agents, Alovudine, Tenofovir alafenamide, AZT, Abacavir, Lamivudine, and Emtricitabine, for evaluation as inhibitors of the SARS-CoV-2 RdRp and demonstrated the ability of these viral polymerase inhibitors to be incorporated by SARS-CoV-2 RdRp, where they terminate further polymerase extension with varying efficiency. These results provide a molecular basis for inhibition of the SARS-CoV-2 RdRp by these nucleotide analogues. If sufficient efficacy of some of these FDA-approved drugs in inhibiting viral replication in cell culture is established, they may be explored as potential COVID-19 therapeutics.

A Continuous Flow Sulfuryl Chloride-Based Reaction-Synthesis of a Key Intermediate in a New Route toward Emtricitabine and Lamivudine

We demonstrate a continuous two-step sequence in which sulfenyl chloride is formed, trapped by vinyl acetate, and chlorinated further via a Pummerer rearrangement. These reactions produce a key intermediate in our new approach to the oxathiolane core used to prepare the antiretroviral medicines emtricitabine and lamivudine. During batch scale-up to tens of grams, we found that the sequence featured a strong exotherm and evolution of hydrogen chloride and sulfur dioxide. Keeping gaseous byproducts in solution and controlling the temperature led to better outcomes. These reactions are ideal candidates for implementation in a continuous mesoscale system for the sake of superior control. In addition, we found that fast reagent additions at controlled temperatures decreased byproduct formation. Herein we discuss the flow implementation and the final reactor design that led to a system with a 141 g/h throughput.

Repurposing anti-inflammasome NRTIs for improving insulin sensitivity and reducing type 2 diabetes development

Innate immune signaling through the NLRP3 inflammasome is activated by multiple diabetes-related stressors, but whether targeting the inflammasome is beneficial for diabetes is still unclear. Nucleoside reverse-transcriptase inhibitors (NRTI), drugs approved to treat HIV-1 and hepatitis B infections, also block inflammasome activation. Here, we show, by analyzing five health insurance databases, that the adjusted risk of incident diabetes is 33% lower in patients with NRTI exposure among 128,861 patients with HIV-1 or hepatitis B (adjusted hazard ratio for NRTI exposure, 0.673; 95% confidence interval, 0.638 to 0.710; P < 0.0001; 95% prediction interval, 0.618 to 0.734). Meanwhile, an NRTI, lamivudine, improves insulin sensitivity and reduces inflammasome activation in diabetic and insulin resistance-induced human cells, as well as in mice fed with high-fat chow; mechanistically, inflammasome-activating short interspersed nuclear element (SINE) transcripts are elevated, whereas SINE-catabolizing DICER1 is reduced, in diabetic cells and mice. These data suggest the possibility of repurposing an approved class of drugs for prevention of diabetes.

Durable Efficacy of Dolutegravir Plus Lamivudine in Antiretroviral Treatment-Naive Adults With HIV-1 Infection: 96-Week Results From the GEMINI-1 and GEMINI-2 Randomized Clinical Trials

Supplemental Digital Content is Available in the Text.

The 2-drug regimen dolutegravir + lamivudine was noninferior to dolutegravir + tenofovir disoproxil fumarate/emtricitabine in achieving HIV-1 RNA <50 copies/mL in treatment-naive adults in the 48-week primary analysis of the GEMINI trials. We present results from the prespecified 96-week secondary analyses.

Pretreatment and Acquired Antiretroviral Drug Resistance Among Persons Living With HIV in Four African Countries

BACKGROUND

Emerging HIV drug resistance (HIVDR) could jeopardize the success of standardized HIV management protocols in resource-limited settings. We characterized HIVDR among antiretroviral therapy (ART)-naive and experienced participants in the African Cohort Study (AFRICOS).

METHODS

From January 2013 to April 2019, adults with HIV-1 RNA >1000 copies/mL underwent ART history review and HIVDR testing upon enrollment at 12 clinics in Uganda, Kenya, Tanzania, and Nigeria. We calculated resistance scores for specific drugs and tallied major mutations to non-nucleoside reverse transcriptase inhibitors (NNRTIs), nucleoside reverse transcriptase inhibitors (NRTIs), and protease inhibitors (PIs) using Stanford HIVDB 8.8 and SmartGene IDNS software. For ART-naive participants, World Health Organization surveillance drug resistance mutations (SDRMs) were noted.

RESULTS

HIVDR testing was performed on 972 participants with median age 35.7 (interquartile range [IQR] 29.7-42.7) years and median CD4 295 (IQR 148-478) cells/mm3. Among 801 ART-naive participants, the prevalence of SDRMs was 11.0%, NNRTI mutations 8.2%, NRTI mutations 4.7%, and PI mutations 0.4%. Among 171 viremic ART-experienced participants, NNRTI mutation prevalence was 83.6%, NRTI 67.8%, and PI 1.8%. There were 90 ART-experienced participants with resistance to both efavirenz and lamivudine, 33 (36.7%) of whom were still prescribed these drugs. There were 10 with resistance to both tenofovir and lamivudine, 8 (80.0%) of whom were prescribed these drugs.

CONCLUSIONS

Participants on failing ART regimens had a high burden of HIVDR that potentially limited the efficacy of standardized first- and second-line regimens. Management strategies that emphasize adherence counseling while delaying ART switch may promote drug resistance and should be reconsidered.

A long-acting 3TC ProTide nanoformulation suppresses HBV replication in humanized mice

Nowadays, there is a strong request for the treatment of chronic HBV-infection with direct acting antivirals. Furthermore, prevalent human immunodeficiency virus (HIV-1) and hepatitis B (HBV) co-infections highlight an immediate need for dual long-acting and easily administered antivirals. To this end, we modified lamivudine (3TC), a nucleoside analog inhibitor of both viruses, into a lipophilic monophosphorylated prodrug (M23TC). Prior work demonstrated that nanoformulation of M23TC (NM23TC) enhanced drug stability, controlled dissolution and improved access to sites of viral replication. The present study evaluated the efficacy of a NM23TC in HBV-infected chimeric liver humanized mice. Levels of HBV DNA and HBsAg in plasma were monitored up to 8 weeks posttreatment. A single intramuscular dose of 75 mg/kg 3TC equivalents of nanoformulated NM23TC provided sustained drug levels and suppressed HBV replication in humanized mice for 4 weeks. The results support further development of this long-acting 3TC nanoformulation for HBV treatment and prevention.

The Impact of Matrix Metalloproteinase-9 on the Sequential Steps of the Metastatic Process

In industrialized countries, cancer is the second leading cause of death after cardiovascular disease. Most cancer patients die because of metastases, which consist of the self-transplantation of malignant cells in anatomical sites other than the one from where the tumor arose. Disseminated cancer cells retain the phenotypic features of the primary tumor, and display very poor differentiation indices and functional regulation. Upon arrival at the target organ, they replace preexisting, normal cells, thereby permanently compromising the patient's health; the metastasis can, in turn, metastasize. The spread of cancer cells implies the degradation of the extracellular matrix by a variety of enzymes, among which the matrix metalloproteinase (MMP)-9 is particularly effective. This article reviews the available published literature concerning the important role that MMP-9 has in the metastatic process. Additionally, information is provided on therapeutic approaches aimed at counteracting, or even preventing, the development of metastasis via the use of MMP-9 antagonists.

Doing More With Less: Review of Dolutegravir-Lamivudine, a Novel Single-Tablet Regimen for Antiretroviral-Naïve Adults With HIV-1 Infection

OBJECTIVE

To review data on efficacy and safety of dolutegravir (DTG) and lamivudine (3TC) in treatment-naïve adults with HIV-1 infection.

DATA SOURCES

Phase III clinical trials and review articles were identified through PubMed (1996 to March 2020) and ClinicalTrials.gov (2000 to May 2020) using the keywords dolutegravir, lamivudine, and HIV.

STUDY SELECTION AND DATA EXTRACTION

Relevant clinical trials and review articles available in English evaluating efficacy and safety of DTG and 3TC were included.

DATA SYNTHESIS

The once-daily, single-tablet regimen of DTG/3TC is the first dual antiretroviral therapy (ART) recommended for initial therapy in treatment-naïve adults with HIV-1 infection. DTG and 3TC were compared with a regimen of DTG and tenofovir disoproxil fumarate/emtricitabine in the GEMINI studies and demonstrated noninferiority for the primary end point of virological suppression at up to 96 weeks. No treatment-emergent resistance mutations were identified in a small group of participants who did not reach virological suppression. The regimen is well tolerated, and the most common adverse events reported in trials include headache, diarrhea, nausea, insomnia, and fatigue.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This dual-ART regimen is a favorable treatment option for ART-naïve patients with HIV-1 RNA <500 000 copies/mL, absence of hepatitis B virus, and no resistance to DTG or 3TC. Benefits of dual ART include reduction in treatment-related adverse events and toxicities, drug interactions, and cost. In addition, the once-daily, single-tablet formulation promotes adherence.

CONCLUSIONS

DTG/3TC has demonstrated efficacy in maintaining virological suppression in ART-naïve patients at up to 96 weeks while minimizing treatment-related adverse events and toxicities.

Pharmacokinetics of nucleoside/nucleotide reverse transcriptase inhibitors for the treatment and prevention of HIV infection

INTRODUCTION

Despite dramatic increases in new drugs and regimens, a combination of two nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) remains the backbone of many regimens to treat HIV.

AREA COVERED

This article summarizes the pharmacokinetic characteristics of approved NRTIs that are currently in the international treatment and prevention guidelines.

EXPERT OPINION

Compared to other NRTIs, tenofovir alafenamide fumarate (TAF) is more advantageous in terms of potency and safety. It is therefore a preferred choice in combination with emtricitabine (FTC) in most HIV treatment guidelines. The efficacy of the two-drug combination of NRTI/Integrase strand-transfer inhibitor, i.e. lamivudine/dolutegravir has been approved as an option for initial therapy. This regimen however has some limitations in patients with HBV coinfection. The two NRTI combinations tenofovir disproxil fumarate (TDF)/FTC and TAF/FTC have also been approved for pre-exposure prophylaxis (PrEP). Interestingly, a promising long-acting nucleoside reverse transcriptase translocation inhibitor, islatravir, formulated for implant was well tolerated and remained effective for up to a year, suggesting its potential as a single agent for PrEP. In the next decade, it remains to be seen whether NRTI-based regimens will remain the backbone of preferred ART regimens, or if the treatment will eventually move toward NRTI-sparing regimens to avoid long-term NRTI-toxicity.

Mitochondrial Toxicogenomics for Antiretroviral Management: HIV Post-exposure Prophylaxis in Uninfected Patients

Background: Mitochondrial genome has been used across multiple fields in research, diagnosis, and toxicogenomics. Several compounds damage mitochondrial DNA (mtDNA), including biological and therapeutic agents like the human immunodeficiency virus (HIV) but also its antiretroviral treatment, leading to adverse clinical manifestations. HIV-infected and treated patients may show impaired mitochondrial and metabolic profile, but specific contribution of viral or treatment toxicity remains elusive. The evaluation of HIV consequences without treatment interference has been performed in naïve (non-treated) patients, but assessment of treatment toxicity without viral interference is usually restricted to in vitro assays.

Objective: The objective of the present study is to determine whether antiretroviral treatment without HIV interference can lead to mtDNA disturbances. We studied clinical, mitochondrial, and metabolic toxicity in non-infected healthy patients who received HIV post-exposure prophylaxis (PEP) to prevent further infection. We assessed two different PEP regimens according to their composition to ascertain if they were the cause of tolerability issues and derived toxicity.

Methods: We analyzed reasons for PEP discontinuation and main secondary effects of treatment withdrawal, mtDNA content from peripheral blood mononuclear cells and metabolic profile, before and after 28 days of PEP, in 23 patients classified depending on PEP composition: one protease inhibitor (PI) plus Zidovudine/Lamivudine (PI plus AZT + 3TC; n = 9) or PI plus Tenofovir/Emtricitabine (PI plus TDF + FTC; n = 14).

Results: Zidovudine-containing-regimens showed an increased risk for drug discontinuation (RR = 9.33; 95% CI = 1.34–65.23) due to adverse effects of medication related to gastrointestinal complications. In the absence of metabolic disturbances, 4-week PEP containing PI plus AZT + 3TC led to higher mitochondrial toxicity (−17.9 ± 25.8 decrease in mtDNA/nDNA levels) than PI plus TDF + FTC (which increased by 43.2 ± 24.3 units mtDNA/nDNA; p < 0.05 between groups). MtDNA changes showed a significant and negative correlation with baseline alanine transaminase levels (p < 0.05), suggesting that a proper hepatic function may protect from antiretroviral toxicity.

Conclusions: In absence of HIV infection, preventive short antiretroviral treatment can cause secondary effects responsible for treatment discontinuation and subclinical mitochondrial damage, especially pyrimidine analogs such as AZT, which still rank as the alternative option and first choice in certain cohorts for PEP. Forthcoming efforts should be focused on launching new strategies with safer clinical and mitotoxic profile.

The Anti-Angiogenic Effects of Anti-Human Immunodeficiency Virus Drugs

The growth and metastasis of malignant tumors benefit from the formation of blood vessels within the tumor area. There, new vessels originate from angiogenesis (the sprouting of pre-existing neighboring vessels) and/or vasculogenesis (the mobilization of bone marrow-derived endothelial cell precursors which incorporate in tumor vasculature and then differentiate into mature endothelial cells). These events are induced by soluble molecules (the angiogenic factors) and modulated by endothelial cell interactions with the perivascular matrix. Given angiogenesis/vasculogenesis relevance to tumor progression, anti-angiogenic drugs are often employed to buttress surgery, chemotherapy or radiation therapy in the treatment of a wide variety of cancers. Most of the anti-angiogenic drugs have been developed to functionally impair the angiogenic vascular endothelial growth factor: however, this leaves other angiogenic factors unaffected, hence leading to drug resistance and escape. Other anti-angiogenic strategies have exploited classical inhibitors of enzymes remodeling the perivascular matrix. Disappointingly, these inhibitors have been found toxic and/or ineffective in clinical trials, even though they block angiogenesis in pre-clinical models. These findings are stimulating the identification of other anti-angiogenic compounds. In this regard, it is noteworthy that drugs utilized for a long time to counteract human immune deficiency virus (HIV) can directly and effectively hamper molecular pathways leading to blood vessel formation. In this review the mechanisms leading to angiogenesis and vasculogenesis, and their susceptibility to anti-HIV drugs will be discussed.

Rapid initiation of antiretroviral therapy at HIV diagnosis: definition, process, knowledge gaps

Initiating antiretroviral therapy (ART) as early as the day of HIV diagnosis is a strategy of increasing global interest to control the HIV epidemic and optimize the health of people living with HIV (PLWH). No detrimental effects of rapid-start ART have been identified in randomized controlled trials undertaken in low- or middle-income countries, or in cohort studies performed in high-income countries. Rapid-start ART may be a key approach in reaching the 2020 Joint United Nations Programme on HIV/AIDS goal of 90% of all PLWH knowing their status, 90% of those diagnosed receiving sustained ART, and 90% of those receiving ART achieving viral suppression; it may also be important for achieving the suggested fourth "90%" goal: improving health-related quality-of-life in PLWH. Presently there is insufficient broad evidence for guidelines to recommend universal test-and-treat strategies for all people, in all settings, at HIV diagnosis; consequently, there is a pressing need to conduct high-quality studies that investigate immediate ART initiation. This article evaluates global evidence regarding rapid-start ART, including same-day start, with particular focus on the implementation of this strategy in high-income countries.

Continuation of emtricitabine/lamivudine within combination antiretroviral therapy following detection of the M184V/I HIV-1 resistance mutation

OBJECTIVES

The aim of the study was to investigate whether lamivudine (3TC) or emtricitabine (FTC) use following detection of M184V/I is associated with better virological outcomes.

METHODS

We identified people with viruses harbouring the M184V/I mutation in UK multicentre data sets who had treatment change/initiation within 1 year. We analysed outcomes of viral suppression (< 200 HIV-1 RNA copies/mL) and appearance of new major drug resistance mutations (DRMs) using Cox and Poisson models, with stratification by new drug regimen (excluding 3TC/FTC) and Bayesian implementation, and estimated the effect of 3TC/FTC adjusted for individual and viral characteristics.

RESULTS

We included 2597 people with the M184V/I resistance mutation, of whom 665 (25.6%) were on 3TC and 458 (17.6%) on FTC. We found a negative adjusted association between 3TC/FTC use and viral suppression [hazard ratio (HR) 0.84; 95% credibility interval (CrI) 0.71-0.98]. On subgroup analysis of individual drugs, there was no evidence of an association with viral suppression for 3TC (n = 184; HR 0.94; 95% CrI 0.73-1.15) or FTC (n = 454; HR 0.99; 95% CrI 0.80-1.19) amongst those on tenofovir-containing regimens, but we estimated a reduced rate of viral suppression for people on 3TC amongst those without tenofovir use (n = 481; HR 0.71; 95% CrI 0.54-0.90). We found no association between 3TC/FTC and detection of any new DRM (overall HR 0.92; 95% CrI 0.64-1.18), but found inconclusive evidence of a lower incidence rate of new DRMs (overall incidence rate ratio 0.69; 95% CrI 0.34-1.11).

CONCLUSIONS

We did not find evidence that 3TC or FTC use is associated with an increase in viral suppression, but it may reduce the appearance of additional DRMs in people with M184V/I. 3TC was associated with reduced viral suppression amongst people on regimens without tenofovir.

Dolutegravir plus lamivudine for the treatment of HIV-1 infection

Introduction: Recent data on the 2-drug regimen (2DR) with dolutegravir (DTG) plus lamivudine (3TC) have shown high efficacy and tolerability both in treatment-naïve and experienced HIV-positive patients. Current guidelines recommend DTG+3TC as an alternative to triple antiretroviral therapy (ART) in selected patients to reduce long-term toxicity and costs.Areas covered: This review is intended to provide insight about the efficacy, safety, and tolerability of a 2DR with DTG+3TC in naïve and treatment-experienced patients.Expert opinion: Data from clinical trials and from real-life show that DTG+3TC is an effective and safe switch option for the treatment of experienced patients. In treatment-naïve patients, DTG+3TC has shown non-inferiority compared to standard 3-drug regimens but is less effective in severely immunocompromised naïve patients (i.e. with a CD4+ cell count below 200 cell/mm3); furthermore, current guidelines have upgraded this dual regimen to recommended first-line strategy, but indicate that it should not be used without genotypic resistance results. Moreover, this regimen is not feasible for HBV-coinfected individuals and should not be used during pregnancy. Currently, out of 2-drug regimens, DTG+3TC is one of clinicians' preferred option as it requires no pharmacokinetic booster, has a low risk of drug interaction, and does not require food intake.

[Chemical and toxicological determination of lamivudine in biological substances]

The purpose of the study is to develop a method for detecting, isolating and quantifying lamivudine in biological substances. Lamivudine was isolated by liquid-liquid and solid phase extraction. The conditions for isolating lamivudine (extractant, pH of the medium, electrolyte, time and frequency of extraction) from aqueous solutions were selected and methods were developed for isolating it from biological substances, including urine, saliva and liver, using liquid-liquid and solid phase extraction methods. Qualitative and quantitative analysis of lamivudine in extracts from urine, saliva and liver was performed by thin layer chromatography, UV spectrophotometry and high-performance liquid chromatography. A validation assessment of the developed techniques indicates their suitability for chemical and toxicological analysis of lamivudine.

Bioequivalence and Food Effect Assessment of 2 Fixed-Dose Combination Formulations of Dolutegravir and Lamivudine

This single‐dose study evaluated the bioequivalence, food effect, and safety of 2 experimental, 2‐drug, fixed‐dose formulations of 50 mg dolutegravir and 300 mg lamivudine (formulation AH and formulation AK) as compared with coadministration of single‐entity tablets of 50 mg dolutegravir and 300 mg lamivudine (reference). In fasted subjects, formulation AH lamivudine exposure was similar to the reference; however, dolutegravir exposure was consistently higher in formulation AH, with area under the concentration‐time curve (AUC) and maximum concentration (C_max) approximately 27% to 28% greater than reference. Formulation AK met bioequivalence standards to the reference for dolutegravir (AUC_0‐∞ and C_max) and lamivudine (AUC_0‐∞ and AUC_0‐t) exposure; however, dolutegravir AUC_0‐t and lamivudine C_max were approximately 16% and 32% higher than the reference, respectively. A high‐fat meal increased dolutegravir AUC and C_max by up to 33% and 21%, respectively, and decreased lamivudine C_max by approximately 30%. Both test and reference formulations were well tolerated. The results support further development of formulation AK as a novel, 2‐drug, fixed‐dose combination tablet treatment for patients with HIV.

A 24-week pilot study of dual maintenance therapy with raltegravir and lamivudine

BACKGROUND

There is an increasing interest in two-drug regimens. We hypothesized that maintenance therapy with raltegravir and lamivudine would keep HIV-1 suppressed and be well tolerated.

METHODS

Virally suppressed HIV-1-infected adults without previous viral failures or known resistance mutations to integrase inhibitors or 3TC/FTC or chronic hepatitis B were randomized 2 : 1 to switch to fixed-dose combination 150 mg lamivudine/300 mg raltegravir twice daily or to continue therapy. Primary outcome was the proportion of patients free of therapeutic failure (defined as viral failure, change in treatment for any reason, consent withdrawal, loss to follow-up or death) at week 24. Secondary outcomes were changes in laboratory, body composition, sleep quality, adherence, and adverse effects.

RESULTS

There were 75 patients included: men 78%; median age 50 years; median CD4 622/μl. At week 24, 7 (9%) patients had therapeutic failure: raltegravir and lamivudine 2 (4%) vs. control 5 (20%). The difference in proportions of therapeutic failures raltegravir and lamivudine minus control was -0.159 (95% confidence interval: -0.353 to -0.012). There was a trend to more weight gain with raltegravir and lamivudine, but no significant changes in other secondary outcomes. Sixty-four percent of patients in each arm had at least one adverse effect. Two (6%) patients in control arm and 4 (7%) patients in raltegravir and lamivudine arm had severe adverse effects.

CONCLUSION

This pilot study suggests that switching to raltegravir along with lamivudine in patients with viral suppression maintains efficacy and is well tolerated. A larger study of longer duration is required to confirm these findings.