Efficacy and safety of the regimens containing tenofovir alafenamide versus tenofovir disoproxil fumarate in fixed-dose single-tablet regimens for initial treatment of HIV-1 infection: A meta-analysis of randomized controlled trials

Negative impact of a health insurer-mandated de-simplification from a single-tablet regimen to a two-tablet regimen

OBJECTIVES

Antiretroviral therapy (ART) accounts for a considerable proportion of HIV care expenses. In June 2021, a Dutch healthcare insurer implemented a mandatory policy to de-simplify branded RPV/TDF/FTC (Eviplera) into a two-tablet regimen containing rilpivirine (Edurant) and generic TDF/FTC as part of cost-saving measures. The objectives of this study were to evaluate the acceptance of this policy, the trends in ART dispensation, and cost developments.

DESIGN

A retrospective database study.

METHODS

In this study, medication dispensation data were obtained from the Dutch Foundation for Pharmaceutical Statistics (SFK). This database covers 98% of all medication dispensations from Dutch pharmacies including people with HIV who receive ART. We received pseudonymized data exclusively from individuals insured by the insurer for the years 2020-2022. Costs were calculated using Dutch drug prices for each year.

RESULTS

In June 2021, 128 people with HIV were on branded RPV/TDF/FTC. Following the policy implementation, 59 (46%) had switched to RPV + generic TDF/FTC, but after 1.5 years, only 17 of 128 individuals (13%) used the proposed two-tablet regimen. The other 111/128 used RPV/TDF/FTC with prescriptions for 'medical necessity' ( n  = 29), switched to RPV/TAF/FTC ( n  = 51), or other ART ( n  = 31). Despite expectations of cost-savings, costs increased from €72 988 in May 2021 to €75 649 in May 2022.

CONCLUSION

A mandatory switch from an STR to a TTR in people with HIV proved unsuccessful, marked by low acceptance, and increased costs after 1 year. This underscores the necessity of incorporating patient and prescriber involvement in changing medication policies.

Lipid safety of tenofovir alafenamide during 96-week treatment in treatment-naive chronic hepatitis B patients

Background

This study was aimed at investigating the dynamics of lipids and the effect of TAF on the lipid profile of patients including fatty liver disease in CHB patients.

Methods

The data of TC, LDL-c, HDL-c, TG, and TC/HDL ratio were collected at baseline, 24 weeks, 48 weeks, 72 weeks, and 96 weeks. CHB patients with fatty liver at baseline were further analyzed in a subgroup.

Results

A total of 137 CHB patients treated with TAF were enrolled in this study. During 96 weeks of TAF treatment, there was no significant change in TC, LDL-c, HDL-c, and TG level (P > 0.05). The TC/HDL-c ratio was increased with no significant change (+0.24, P > 0.05). In CHB patients with fatty liver (n = 48), TC, LDL-c, and TC/HDL-c ratio increased gradually during TAF treatment, TG levels increased to 146.63 mg/dL at 48 weeks (P = 0.057) and then decreased, but there was still no significant change compared with the baseline level by 96 weeks (P > 0.05).

Conclusion

TAF treatment had a low effect on the lipid profile of CHB patients over the course of 96 weeks, and it was safe even in patients with fatty liver.

Clinical trial registration

[https://www.chictr.org.cn/showproj.html?proj=65123], identifier [ChiCTR2000041005].

Evaluation of Pharmacokinetics of a BCS Class III Drug with Two Different Study Designs: Tenofovir Alafenamide Monofumarate Film-coated Tablet

Tenofovir alafenamide (TAF) is a BCS Class III compound and an oral pro-drug of Tenofovir (TFV) with limited oral bioavailability. The bioavailability of the oral intake increases with food as a result of the low stability of the active substance in the stomach. The reference drug is "Vemlidy® 25 mg Film Tablet", which contains 25 mg of TAF in "hemifumarate" form, is under patent protection until 15.08.2032 by Gilead, and so the "monofumarate" form was used in the present study. At first, a pilot study was conducted involving 12 subjects under fed conditions. The results of the pilot study revealed the test and reference products were not bioequivalent, as a result of insufficient statistical power and high inter-subject variability. Secondly, a physiologically based pharmacokinetic (PBPK) simulation was performed based on the pilot study results and literature data. Finally, the power of the design was increased and the pivotal study design was optimized into a four-period, full-replicated, cross-over study with 34 subjects under fed conditions and it was concluded that the test and reference products were bioequivalent. In conclusion, the present study proved the importance of a correct study design with higher statistical power for a BCS Class III compound with high variability, to present the pharmacokinetics.

Delayed Irreversible Fanconi Syndrome Associated With Vertebral Fracture After Tenofovir Discontinuation

The use of tenofovir disoproxil fumarate (TDF) as an antiretroviral agent has been reported to adversely affect both renal tubules and bone health, leading to pathological fractures. While such an effect is largely reversible, substituting TDF with tenofovir alafenamide (TAF) might result in lower rates of adverse events with the preservation of tenofovir effectiveness. We report a case of a 40-year-old lady with HIV infection who had a vertebral fragility fracture secondary to TDF-associated Fanconi syndrome. The syndrome developed four years after TDF cessation and switching to TAF. Other etiologies for decreased bone mass were excluded, and the diagnosis of Fanconi syndrome was established based on her bone mineral density (BMD) and urine parameters. She was treated conservatively with active vitamin D, calcium, and progesterone/estrogen combination, but her phosphate wasting persisted despite switching to TAF; this likely represents a delayed irreversible effect of TDF on the patient's bone remodeling. This case report highlights the chronic sequelae of TDF therapy and the importance of monitoring for and early detection of renal tubulopathy and osteoporotic fractures in this patient population.

Current practice and recommendations for management of hepatitis B virus in people living with HIV in Asia

BACKGROUND

The prevalence of HIV and hepatitis B virus (HBV) co-infection is higher in Asia than in Europe and North America and varies significantly between different regions within Asia. Important routes of transmission of both these infections include high-risk unprotected sexual contact, intravenous drug use, and transmission of maternal infection perinatally or in early childhood. While life expectancy among people living with HIV has been extended with effective antiretroviral therapy (ART), HBV-induced liver injury and complications have emerged as a leading cause of morbidity and mortality in people living with HIV.

OBJECTIVES

This article describes the prevalence of co-infection, current clinical practice, and recommendations for the management of people living with HIV-HBV co-infection in Asia.

RESULTS AND CONCLUSIONS

Screening for HBV should occur at the time of HIV diagnosis; however, HBV screening rates in people living with HIV in Asia vary widely by region. Similarly, people with HBV should be screened for HIV before initiation of HBV antiviral therapy. People with HIV-HBV co-infection should be assessed for liver damage and risk factors for liver disease and be monitored regularly for liver complications and HBV DNA. Medical treatment with ART is lifelong and includes tenofovir and lamivudine or emtricitabine, unless intolerant or contraindicated, as these are active against both HIV and HBV. HBV vaccination programmes are effective in reducing co-infection rates. Mother-to-child transmission can be prevented through measures such as vaccination, antenatal screening, and treatment of pregnant women who are infected.

A quick algorithmic review on management of viral infectious diseases in pediatric solid organ transplant recipients

Pediatric solid organ transplant is a life-saving procedure for children with end-stage organ failure. Viral infections are a common complication following pediatric solid organ transplantation (SOT), which can lead to increased morbidity and mortality. Pediatric solid organ transplant recipients are at an increased risk of viral infections due to their immunosuppressed state. The most commonly encountered viruses include cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV), varicella-zoster virus (VZV), adenoviruses, and BK polyomavirus. Prevention strategies include vaccination prior to transplantation, post-transplant prophylaxis with antiviral agents, and preemptive therapy. Treatment options vary depending on the virus and may include antiviral therapy and sometimes immunosuppression modification. This review provides a Quick Algorithmic overview of prevention and treatment strategies for viral infectious diseases in pediatric solid organ transplant recipient.

Week 96 Results of Switching from Tenofovir Disoproxil Fumarate-Based Antiretroviral Therapy to Coformulated Elvitegravir, Cobicistat, Emtricitabine, and Tenofovir Alafenamide among HIV/Hepatitis B Virus-Coinfected Patients

Data regarding the durability of tenofovir alafenamide (TAF)-containing antiretroviral therapy (ART) in maintaining hepatitis B virus (HBV) viral suppression among HIV/HBV-coinfected patients are limited. Between February and October 2018, 274 HIV/HBV-coinfected participants who had achieved HIV RNA of <50 copies/mL with tenofovir disoproxil fumarate (TDF)-containing ART and switched to elvitegravir/cobicistat/emtricitabine/TAF were prospectively enrolled. Serial plasma HIV and HBV viral loads, HBV and hepatitis D virus (HDV) serology, renal parameters, metabolic profiles, and bone mineral density (BMD) were assessed through 96 weeks. At baseline and weeks 48, 72, and 96, 5.8%, 5.1%, 5.8%, and 5.1% of the participants had plasma HBV DNA of ≥20 IU/mL, and 0%, 0.7%, 1.5%, and 2.2% had HIV RNA of ≥50 copies/mL, respectively. Hepatitis B surface antigen (HBsAg) loss occurred in 1.5% of 274 participants, and hepatitis B e-antigen (HBeAg) loss or seroconversion occurred in 14.3% of 35 HBeAg-positive participants. Compared with baseline, the median urine protein-to-creatinine ratio (79 versus 63 mg/g, P < 0.001) and β2-microglobulin-to-creatinine ratio (165 versus 83 μg/g, P < 0.001) continued to decrease at week 96. BMD of the spine and hip slightly increased (mean change, +0.9% and +0.5%, respectively). The median triglycerides, total cholesterol, low-density lipoprotein (LDL)-cholesterol and high-density lipoprotein (HDL)-cholesterol increased from baseline to week 96 (116 versus 141, 166 versus 190, 99 versus 117, and 42 versus 47 mg/dL, respectively; all P < 0.001), and most of the increases occurred in the first 48 weeks of the switch. Our study showed that switching from TDF-containing ART to elvitegravir/cobicistat/emtricitabine/TAF maintained HBV and HIV viral suppression through 96 weeks among HIV/HBV-coinfected patients. Proteinuria continued to improve, while fasting lipids increased and BMD stabilized at 96 weeks after the switch. IMPORTANCE Elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide as a maintenance therapy showed durable and high rates of viral suppression for HIV/HBV-coinfected patients, with only 5.1% and 2.2% of patients having HBV DNA of ≥20 IU/mL and HIV RNA of ≥50 copies/mL, respectively, at 96 weeks. Our study fills the data gap on the long-term clinical effectiveness of tenofovir alafenamide-containing antiretroviral therapy in people living with HIV who have HBV coinfection.

Gender and sex considerations in HIV and bone health

PURPOSE OF REVIEW

People with HIV (PWHIV) are at increased risk for osteoporosis and fractures, because of the effects of HIV and inflammation and antiretroviral therapy (ART) initiation as well as traditional risk factors. This review from recent literature focuses on sex differences in rates of bone disease, risk of fractures, and effects of ART.

RECENT FINDINGS

Women with HIV in resource-constrained settings experience bone loss because of the additive effect of initiating TDF-containing ART during pregnancy, lactation, and menopause. Children and adolescents experience lower bone accrual during the pubertal growth years. There has been less focus on bone health in recent trials of ART containing tenofovir alafenamide and/or integrase inhibitors. Very few clinical trials or studies compare sex-specific changes in inflammation, immune activation, response to ART and bone turnover or change in BMD resulting in significant knowledge gaps.

SUMMARY

More data is needed to determine changes in prevalence of osteopenia, osteoporosis, and fractures in the era of immediate initiation of ART at high CD4 cell counts and the use of more bone-friendly ART. The long-term effects of ART and low bone mass on fractures in the ageing population of PWHIV is yet to be realized.

Cell and Tissue Specific Metabolism of Nucleoside and Nucleotide Drugs: Case Studies and Implications for Precision Medicine

Many clinically used antiviral drugs are nucleoside or nucleotide analog drugs, which have a unique mechanism of action that requires intracellular phosphorylation. This dependence on intracellular activation presents novel challenges for the discovery and development of nucleoside/nucleotide analog drugs. Contrary to many small molecule drug development programs that rely on plasma pharmacokinetics and systemic exposures, the precise mechanisms that result in efficacious intracellular nucleoside triphosphate concentrations must be understood in the process of nucleoside/nucleotide drug development. The importance is highlighted here, using the following as case studies: the herpes treatment acyclovir, the cytomegalovirus therapy ganciclovir, and human immunodeficiency virus (HIV) treatments based on tenofovir, which are also in use for HIV prophylaxis. For each drug, the specificity of metabolism that results in its activation in different cells or tissues is discussed, and the implications explored. Acyclovir's dependence on a viral enzyme for activation provides selective pressure for resistance mutations. Ganciclovir is also dependent on a viral enzyme for activation, and suicide gene therapy capitalizes on that for a novel oncology treatment. The tissue of most relevance for tenofovir activation depends on its use as treatment or as prophylaxis, and the pharmacogenomics and drug-drug interactions in those tissues must be considered. Finally, differential metabolism of different tenofovir prodrugs and its effects on toxicity risk are explored. Taken together, these examples highlight the importance of understanding tissue specific metabolism for optimal use of nucleoside/nucleotide drugs in the clinic. SIGNIFICANCE STATEMENT: Nucleoside and nucleotide analogue drugs are cornerstones in current antiviral therapy and prevention efforts that require intracellular phosphorylation for activity. Understanding their cell and tissue specific metabolism enables their rational, precision use for maximum efficacy.

Effectiveness and safety of tenofovir alafenamide in children and adolescents living with HIV: a systematic review

INTRODUCTION

Tenofovir alafenamide (TAF) is approved for paediatric use in fixed-dose combination tablets, but efficacy and safety data in children are limited. We conducted a systematic review on the efficacy/effectiveness and safety of TAF in infants, children and adolescents living with HIV.

METHODS

We searched MEDLINE, Embase, the Cochrane Library, clinical trial registries, reference lists and relevant conferences to identify literature published January 2009-March 2021. We included clinical trials and observational studies assessing the efficacy/effectiveness or safety of TAF through ≥6 months of treatment in participants aged 0-19 years.

RESULTS AND DISCUSSION

Overall 3626 abstracts and 371 full papers were screened. Four single-arm, innovator-funded trials (341 participants) and a pooled analysis of those trials were identified. All four trials included treatment-experienced and virally suppressed children or adolescents. One trial also included treatment-naïve adolescents with baseline viral load >1000 copies/ml. The risk of bias was rated as low in one study and unclear in the other three owing to missing data on study design (all conference presentations). At 48 weeks, 92% (46/50) of treatment-naïve participants were virally suppressed (one trial). Among treatment-experienced participants with viral load at 48 weeks, 214 of 224 participants were virally suppressed. Across the studies, one grade 3/4 adverse event was considered drug-related (intermediate uveitis). There were three discontinuations for adverse events (grade 2 anxiety and insomnia, grade 1 iridocyclitis [drug-related] and grade 1 pulmonary tuberculosis [unrelated to treatment]). One accidental death occurred across the four studies. In the pooled analysis of 223 participants, the median change in bone mineral density z-score (height- and age-adjusted) from baseline to 48 weeks was -0.12 (interquartile range [IQR] -0.46, 0.17) to 0.05 (IQR not reported) for spine, and -0.09 (IQR -0.33, 0.07) to 0.09 (IQR not reported) for total body less head. Weight-for-age z-scores increased by 0.25 from baseline to 48 weeks.

CONCLUSIONS

Four single-arm trials were identified in this systematic review, with initial evidence suggesting good viral suppression and no obvious safety concerns in children and adolescents on TAF-containing regimens over 24-48 weeks. However, further comparative and longer-term safety data are needed in children and adolescents, including on weight and metabolic changes.

Changes in bone quality after switching from a TDF to a TAF based ART: A pilot randomized study

BACKGROUND

The impact of tenofovir disoproxil fumarate (TDF) antiretroviral (ART) regimens on bone health has been characterized mostly by bone mineral density (BMD), but recently also by bone quality (BQ). The aim of this pilot study is to assess the changes in BMD and BQ after switch from TDF to tenofovir alafenamide (TAF) ART.

METHODS

HIV individuals receiving TDF-based ART were randomized to switch to Bictegravir-TAF-Emtricitabine or to remain in the same regimen. At baseline and 24-weeks after randomization, participants underwent bone mineral density (BMD) by DXA and BQ assessment using bone microindentation, a validated technique that measures bone tissue quality expressed as bone material strength index (BMSi). A panel of plasma bone turnover biomarkers were measured by ELISA at the same time-points. Values are expressed as median [interquartile range] and non-parametric tests were used where appropriate.

RESULTS

A total of 24 HIV individuals were included in the study, 19 of which were men (80%). Median age at baseline was 43 years (IQR 38-54). Half of individuals were allocated in the TDF group while the other half changed to TAF treatment. No differences at baseline between both groups were detected in any parameter. Non-significant changes nor in lumbar or femoral BMD at week 24 was found in any regimen. In contrast, there was an increase in BMSi in the TAF arm at 24 weeks, and thus an improvement in BQ[81.6 (79-83) to 86 (80-88) (+5.1%);p=0.041], whereas the TDF arm remained stable from 82 (76-85) at baseline to 82 (73-83);p=0.812. Hence, at week 24 there were significant differences in BQ between arms (p=0.049). A reduction in bone formation markers was found at week 24 in both regimens: N-terminal propeptide of type-1 collagen decreased a 20% (-35 - -0.6); p=0.031 with TAF and -16% (-25 - -5); p=0.032 with TDF. Also a decrease in bone resorption marker C-telopeptide with TAF was detected [-10% (-19 - -5);p=0.028] but not with TDF (p=0.232), suggesting a less metabolically active bone after switching to TAF.

CONCLUSION

A bone quality improvement was found after switching from a TDF to a TAF based ART independently of BMD, suggesting that the bone health benefits of TAF may extend beyond BMD. Future research should be directed to confirm these findings and to identify the underlying mechanisms of ART related bone toxicity.

Comparison of the design and methodology of Phase 3 clinical trials of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) and dolutegravir-based dual therapy (DTG) in HIV: a systematic review of the literature

INTRODUCTION

Current recommended antiretroviral regimens include a combination of two (dual; DT) or three (triple; TT) antiretroviral drugs. This study aims to determine whether the quality of evidence from clinical trials of dolutegravir (dolutegravir/lamivudine [DTG/3TC] or dolutegravir/rilpivirine [DTG/RPV]) is methodologically comparable to that of clinical trials conducted with bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF).

AREAS COVERED

A systematic review of the medical literature was carried out in PubMed without date or language restrictions, following the PRISMA guidelines. All aspects of the methodological design of phase 3 randomized clinical trials (RCTs) of DT and TT, evaluated by the European Medicines Agency (registration trials), were reviewed. The quality of clinical trials was assessed using the Jadad scale.

EXPERT OPINION

The search identified 5, 3 and 2 phase 3 RCTs with BIC/FTC/TAF, DTG/3TC and DTG/RPV, respectively, that met the inclusion criteria. The designs would not be comparable due to differences in pre-randomization losses, blinding, patient recruitment, as well as differences in methodological quality, with the average score of the RCTs conducted with BIC/FTC/TAF, DTG/3TC and DTG/RPV being 4.2 (high quality), 3.0 (medium quality) and 3.0 (medium quality), respectively. Due to methodological differences between the BIC/FTC/TAF, DTG/3TC and DTG/RPV RCTs, the results of these are not comparable.

In Vitro Susceptibility of HIV Isolates with High Growth Capability to Antiretroviral Drugs

It has been considered that reduced susceptibility to antiretroviral drugs is influenced by drug adherence, drug tolerance and drug-resistance-related mutations in the HIV genome. In the present study, we assessed the intrinsic high viral growth capability as a potential viral factor that may influence their susceptibility to antiretroviral drugs using an in vitro model. Phytohemagglutinin-activated peripheral blood mononuclear cells (1.5 × 10⁶ cells) were infected with HIV isolates (10⁶ copies/mL). The culture was carried out at different concentrations (0.001-20 μM) of 13 synthetic antiretroviral compounds (six nucleoside/nucleotide reverse transcriptase inhibitors, one non-nucleoside reverse transcriptase inhibitor, four integrase inhibitors, and two protease inhibitors), and HIV production was assessed using HIV-RNA copies in culture. The 90% inhibitory concentration (IC₉₀) and pharmacokinetics of an antiretroviral agent were used as parameters to determine the reduced antiretroviral drug susceptibility of HIV isolates with high growth capability to synthetic antiretroviral compounds. The high growth capability of HIV isolates without any known drug resistance-related mutation affected their susceptibility to tenofovir (IC₉₀ = 2.05 ± 0.40 μM), lamivudine (IC₉₀ = 6.83 ± 3.96 μM), emtricitabine (IC₉₀ = 0.68 ± 0.37 μM), and efavirenz (IC₉₀ = 3.65 ± 0.77 μM). These antiretroviral drugs showed IC₉₀ values close to or above the maximum plasma concentration against HIV isolates with high growth capability without any known drug resistance-related mutation. Our results may contribute to the development of effective strategies to tailor and individualize antiretroviral therapy in patients harboring HIV isolates with high growth capability.

Characteristics of 2-drug regimen users living with HIV-1 in a real-world setting: A large-scale medical claim database analysis in Japan

Background

Regimen simplification to 2-drug antiretroviral therapy (2-ART) may address potential tolerability issues, increase adherence, and reduce toxicity and potential drug-drug-interactions among people living with HIV-1 (PLWH). However, real-world treatment patterns and characteristics of 2-ART users are unclear.

Methods

This retrospective observational cohort study employed a large-scale medical claim database of Japanese hospitals to extract data on 4,293 PLWH aged ≥18 years with diagnosis of HIV and treated with any ART regimens between April 2008 and April 2019. A 2-ART cohort was compared with a 3-drug antiretroviral therapy (3-ART) cohort in terms of population characteristics, comorbid conditions, and treatment patterns. Treatment switching rates were calculated for each cohort followed by sensitivity analysis to confirm the robustness of the findings.

Results

There were 94 individuals identified in the 2-ART cohort. Compared to the standard 3-ART cohort (n = 3,993), the 2-ART cohort was older (median age 53 [IQR 44–64] vs 42 years [IQR 35–50]), with a lower proportion of males (87.2% vs 93.8%), higher Charlson Comorbidity Index (CCI) (median score 6 [IQR 5–8] vs 5 [IQR 4–6]), more co-medications (median 6 [IQR 4–11] vs 3 [IQR 2–7]), and a higher percentage of AIDS-defining conditions (66.0% vs 42.8%). The most common 2-ART were protease inhibitor (PI) + integrase strand transfer inhibitor (INSTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) + INSTI (33.0% and 31.9%, respectively). Overall, most of the regimens were nucleoside reverse transcriptase inhibitor (NRTI)-sparing (71.3%), with a decreasing trend over time (76.2% to 70.2%). ART regimen switch occurred more often in the 2-ART cohort than in the 3-ART cohort (33.0% vs 21.2%).

Conclusion

The profiles of individuals on 2-ART in Japan were demonstrated to be complex. Most were treated with NRTI-sparing regimens which may reflect an effort to reduce treatment-related toxicities.

Vitamin D and Calcium Supplementation Reverses Tenofovir-Caused Bone Mineral Density Loss in People Taking ART or PrEP: A Systematic Review and Meta-Analysis

Background

The decrease of bone mineral density (BMD) after the intake of Tenofovir disoproxil fumarate (TDF)-based drugs in people living with HIV/AIDS (PLWHA) and HIV-negative key populations under pre-exposure prophylaxis (PrEP) regimen raised concerns. Previous findings on the effects of vitamin D (VD) and calcium supplements and the recovery of BMD loss were inconclusive. The optimal doses of VD and calcium and its supplementary duration remained unknown. Therefore, we conducted a systematic review and meta-analysis to synthesize current evidence on VD and calcium supplements to inform clinical practice.

Methods

We searched PubMed, Web of Science, Cochrane library, and EMBASE databases for all placebo-controlled trials and prospective cohort studies published before March 5, 2021 that investigated VD and calcium supplements in participants taking TDF-based drugs. The keywords calcium, vitamin D, Tenofovir, and BMD were used for the searches. The primary outcome was changes of spine and hip BMD. A subgroup analysis was performed to determine the factors that were related to the effects of VD supplements on BMD. Locally weighted regression (loess) was used to determine the relationships of VD supplements, supplementary duration, and changes of BMD. This study was registered at PROSPERO (No. 42021231000).

Findings

Seven eligible studies including 703 participants were included in the analyses. The meta-analysis found that VD and calcium supplementation was related to a significant increase of BMD in the spine and hip [standardized mean difference (SMD) 0.43; 95% CI, 0.25 to 0.61, p = 0.009]. Moreover, positive dose-response relationships were demonstrated between doses of VD and calcium supplements, supplementary duration, and BMD recovery. Patients who took VD with the dose level of 4,000 IU/D obtained the highest BMD improvement (SMD 0.59, 95% CI, 0.43 to 0.74). No side effects were reported on VD and calcium supplementation.

Interpretation

We found the VD and calcium supplementation was associated with increases of BMD in participants taking TDF-based drugs. An optimal supplementary dose of 4,000 IU/D for VD was suggested for clinicians. The findings could be used in clinical practice to improve the BMD outcomes in people who were taking TDF-based drugs.Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/.

Tenofovir-induced renal and bone toxicity: report of two cases and literature review

Tenofovir Disoproxil Fumarate (TDF) is one of the drugs in the initial first-line antiretroviral regimen for the treatment of hepatitis B and HIV infections. Despite its effectiveness and few adverse effects, it is related to renal and bone toxicity. We described two cases of HIV-positive middle-aged women who had been using TDF for two and four years (cases 1 and 2, respectively) and were admitted to the emergency room. Case 1 presented with metabolic ileum and diffuse bone pain while case 2 presented with bilateral coxo-femoral pain after a fall from standing height. Both cases had similar laboratory tests: hyperchloremic metabolic acidosis, hypophosphatemia, hypokalemia, hypouricemia and elevated plasma creatinine. In urinary exams, there was evidence of renal loss of electrolytes, justifying the serum alterations, in addition to glucosuria and proteinuria. The bone pain investigation identified bone fractures and reduced bone mineral density, together with increased levels of parathyroid hormone, alkaline phosphatase and vitamin D deficiency. These two cases illustrate the spectrum of adverse renal and bone effects associated with TDF use. TDF was discontinued and treatment was focused on correcting the electrolyte disturbances and acidosis, in addition to controlling the bone disease through vitamin D and calcium supplementation. The renal changes found in both cases characterized the Fanconi’s syndrome, and occurred due to TDF toxicity to proximal tubule cells mitochondria. Bone toxicity occurred due to direct interference of TDF in bone homeostasis, in addition to vitamin D deficiency and phosphaturia resulting from tubulopathy. During the follow-up, both cases evolved with chronic kidney disease and in one of them, the Fanconi’s syndrome did not revert. We emphasize the need to monitor markers of bone metabolism and glomerular and tubular functions in patients using TDF.

Evolution in Real-World Therapeutic Strategies for HIV Treatment: A Retrospective Study in Southern Italy, 2014-2020

Changes in HIV treatment guidelines over the last two decades reflect the evolving challenges in this field. Our study examined treatment change patterns throughout a 7-year period in a large Italian cohort of HIV patients as well as the reasons and direction of changes. Treatment-naïve and -experienced HIV patients managed by Cotugno Hospital of Naples between 2014 and 2020 were analyzed. During the period, the proportion of single-tablet regimen treatment sharply increased for the naïve and experienced patients. Regimens containing integrase strand transfer inhibitors rapidly replaced those containing protease inhibitor and non-nucleoside reverse transcriptase inhibitors. The use of the tenofovir alafenamide fumarate/emtricitabine backbone increased rapidly after its introduction in the Italian pharmaceutical market, making up 63.7 and 54.9% of all treatments in naïve and experienced patients, respectively, in 2020. The main reason for treatment changes was optimization and/or simplification (90.6% in 2018; 85.3% in 2019; 95.5 in 2020) followed by adverse effects and virological failure. Our real-world analysis revealed that the majority of treatment-naïve and treatment-experienced patients received antiretroviral drugs listed as preferred/recommended in current recommendations. Regimen optimization and/or simplification is a leading cause of treatment modification, while virologic failure or adverse effects are less likely reasons for modification in the current treatment landscape.

Excess Weight Gain With Integrase Inhibitors and Tenofovir Alafenamide: What Is the Mechanism and Does It Matter?

Numerous studies have detected a greater likelihood of excess weight gain with specific antiretrovirals (ARVs), particularly tenofovir alafenamide and integrase inhibitors, as compared with other agents and classes. The long-term implications and potential reversibility for individuals who have experienced substantial ARV-associated weight accumulation remain poorly understood. Furthermore, the underlying mechanism remains controversial: Is the explanation mitochondrial toxicity and weight suppression from the older agents or direct effects of the newer drugs on appetite, adipocytes, or other unintended targets? This review discusses proposed mechanisms and evidence to date and argues that the question about mechanism is highly clinically relevant because it carries significant implications for ARV management. The existing literature suggests that older ARVs, such as tenofovir disoproxil fumarate and efavirenz, suppress weight gain, but also that integrase inhibitors may stimulate excess weight gain through several plausible biologic pathways. Confirming the mechanisms of ARV-associated excess weight gain should be high priority for future research.

The nucleoside antiviral prodrug remdesivir in treating COVID-19 and beyond with interspecies significance

Infectious pandemics result in hundreds and millions of deaths, notable examples of the Spanish Flu, the Black Death and smallpox. The current pandemic, caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), is unprecedented even in the historical term of pandemics. The unprecedentedness is featured by multiple surges, rapid identification of therapeutic options and accelerated development of vaccines. Remdesivir, originally developed for Ebola viral disease, is the first treatment of COVID-19 (Coronavirus disease 2019) approved by the United States Food and Drug Administration. As demonstrated by in vitro and preclinical studies, this therapeutic agent is highly potent with a broad spectrum activity against viruses from as many as seven families even cross species. However, randomized controlled trials have failed to confirm the efficacy and safety. Remdesivir improves some clinical signs but not critical parameters such as mortality. This antiviral agent is an ester/phosphorylation prodrug and excessive hydrolysis which increases cellular toxicity. Remdesivir is given intravenously, leading to concentration spikes and likely increasing the potential of hydrolysis-based toxicity. This review has proposed a conceptual framework for improving its efficacy and minimizing toxicity not only for the COVID-19 pandemic but also for future ones caused by remdesivir-sensitive viruses.

Update and latest advances in antiretroviral therapy

Since the first cases of AIDS appeared in 1981, human immunodeficiency virus type 1 (HIV-1) infection has reached pandemic proportions. Forty years later, research has led to the approval of more than 30 antiretroviral drugs, while combination therapies have turned HIV-1 infection into a chronic, but manageable disease. Still, drug toxicity and acquired and transmitted drug resistance remain as major threats to therapy success. In this review, we provide an overview on currently available anti-HIV drugs and the latest developments in antiretroviral therapy, focused on new antiretroviral agents acting on known and unexploited antiviral targets, prevention therapies aimed to improve available drug combinations, and research on new long-acting therapies, particularly those involving novel drug candidates such as lenacapavir or islatravir.

Renal adverse drug reactions

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is common in people living with HIV (PLWH) and is related to a multitude of factors. The aim of this review is to provide an overview of the most recent evidence of renal adverse effects of antiretroviral drugs, predictors of CKD risk and areas for future research.

RECENT FINDINGS

Advancing age, cardiometabolic risk factors and adverse effects of antiretroviral drugs contribute to the higher prevalence of CKD in PLWH. Genetic factors and baseline clinical CKD risk are strongly correlated to risk of incident CKD, although it is unclear to what extent gene polymorphisms explain renal adverse effects related to tenofovir disoproxil fumarate (TDF). Switching from TDF to tenofovir alafenamide (TAF) in people with baseline renal dysfunction improves renal parameters; however, the long-term safety and benefit of TAF in individuals at low risk of CKD is an area of ongoing research.

SUMMARY

Several factors contribute to estimated glomerular function decline and CKD in PLWH. Clinical risk scores for CKD may be useful to inform selection of ART in an ageing population. In people with baseline renal dysfunction, potentially nephrotoxic antiretroviral drugs should be avoided.

Pharmacokinetics of Tenofovir Alafenamide Fumarate and Tenofovir in the Chinese People: Effects of Non-Genetic Factors and Genetic Variations

Background

Tenofovir alafenamide fumarate (TAF) was approved for HBV treatment in China in 2018. Despite higher antiviral efficacy and less impact on renal function and bone mineral density, the pharmacokinetic profiles of TAF are highly variable. The objectives of this study were to investigate the pharmacokinetics of TAF in the Chinese population and explore the associations between TAF and genetic polymorphisms and non-genetic factors.

Patients and Methods

A total of 64 healthy Chinese subjects aged 18~65 years old were planned to enroll. According to the dietary intake status, the subjects were divided into two groups (n = 32 per group). The concentrations of TAF and tenofovir were measured by HPLC-MS/MS, and the single-nucleotide polymorphisms were analyzed by MALDI-TOF MS.

Results

All the enrolled participants (18–35 years) completed the clinical trial study. Similar to the results reported in other ethnic populations, the pharmacokinetic profiles of TAF and tenofovir were highly variable in the Chinese people, and the HFHC diet can significantly increase the systemic exposure of TAF. We determined both HFHC diet and rs7311358 (SLCO1B3) genotypes were independently associated with TAF AUC_0-t, while HFHC diet, age and rs3740066 (ABCC2) variants were predictive of t_1/2 of tenofovir (P < 0.05). The subjects with the AA genotype in rs7311358 had significantly higher TAF AUC_0-t values (1.15 times) than those with a G allele, and the t_1/2 of tenofovir in the rs3740066 TT genotype group was 1.23 times longer than that of CC genotype group. Furthermore, there was a trend of higher TAF AUC and shorter tenofovir t_1/2 for the rs2032582 (ABCB1) T allele and rs3742106 (ABCC4) CC variant, respectively, although not statistically significant in the multiple linear regression analysis.

Conclusion

This study provided new evidence to suggest a critical link between both genetic and non-genetic factors and TAF pharmacokinetics in the Chinese people.

Efficacy and safety of tenofovir alafenamide fumarate in nucleoside analogue treatment-naïve patients with chronic hepatitis B

Tenofovir alafenamide fumarate (TAF) is a first-line drug for the antiviral treatment of patients with chronic hepatitis B (CHB) in China. In the present study, the efficacy and renal safety of TAF were evaluated in treatment-naive patients with CHB. Patients with CHB who had not been previously treated with nucleoside analogues (NAs) were recruited before TAF treatment was initiated. Changes in the levels of hepatitis B virus (HBV) DNA, hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) were analyzed at 24 and 48 weeks using immunoassays. In addition, liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) were analyzed using transient elastography, while alanine aminotransferase (ALT), triglyceride (TG), total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) levels, calcium (Ca) and inorganic phosphorus (IP) levels were measured using biochemistry assay. In addition, the estimated glomerular filtration rate (eGFR) was calculated. After 48 weeks, the ALT normalization rate was 95.24% (40/42), the complete virological response (HBV DNA <20 IU/ml) rate was 69.05% (29/42) and the HBeAg seroconversion rate was 8.57% (3/35). The levels of HBV DNA and HBsAg were significantly decreased from the baseline at 5.49±1.95 to 1.26±0.66 log₁₀ IU/ml and from 3.59±0.81 to 3.32±0.55 log₁₀ IU/ml after 48 weeks of treatment, respectively. Compared with that in the baseline measurements, LSM at 48 weeks was significantly decreased from 13.00±8.15 to 8.66±4.45 kPa. No significant differences were observed in the TG, TC, LDL-C, CAP, eGFR, Ca and IP measurements. According to the baseline ALT levels, patients were divided into group A [ALT ≤1 x upper limit of normal (ULN); ULN=50 U/l; n=21], group B (1 x ULN < ALT <2 x ULN; n=22) and group C (ALT ≥2 x ULN; n=18). A significant decrease in HBsAg levels was observed in group B (3.63±0.68 vs. 3.53±0.63 log₁₀ IU/ml) and group C (4.15±0.57 vs. 3.66±0.48 log₁₀ IU/ml) at 24 weeks compared with the baseline. In conclusion, TAF was found to be effective and safe in NA treatment-naive patients with CHB. Moreover, the higher the ALT levels, the more prominent the curative effect from TAF treatment. Therefore, NA treatment-naive CHB patients could benefit from TAF treatment in real world.

What's new in bone disease and fractures in HIV?

PURPOSE OF REVIEW

People living with HIV (PWH) are at greater risk of low bone mineral density (BMD) and fractures compared to the general population. This narrative review summarises recent literature in the field, including the relative contribution of antiretroviral therapy and frailty to low BMD and fractures in PWH.

RECENT FINDINGS

The body of evidence indicating less impact on BMD from the use of tenofovir alafenamide compared to tenofovir disoproxil fumarate continues to grow, although this has not yet translated into data supporting a reduction in fracture incidence. Frailty, common in PWH, is associated with both fractures and alterations in renal-bone metabolism, but is an area that is understudied in relation to interventions to reduce fracture risk in PWH.

SUMMARY

Although a maturing field, research into interventions to reduce fracture incidence in PWH is lacking in both quantity and scope. Development of core outcome datasets for clinical trials along with trials focused on reducing or reversing frailty are required to guide improvements overall bone health outcomes in PWH.

Pharmacokinetics and Bioequivalence Evaluation of 2 Formulations of Tenofovir Alafenamide

The study was conducted to compare the pharmacokinetics and safety profiles of 2 brands of tenofovir alafenamide (TAF) fumarate tablets. This research was a 2-preparation, 2-sequence, 4-period crossover, completely replicated study in 68 healthy Chinese subjects under fasting and fed conditions. The mean values of the area under the concentration-time curve from time 0 to the last time point with blood sample collection (AUC_0-t ), area under the concentration-time curve from time 0 to infinity (AUC_0-∞ ), and maximum concentration (C_max ) for the test and reference products of TAF were 248.5 and 275.7 ng/mL, 148.1 and 157.8 ng • h/mL, and 148.4 and 158.1 ng • h/mL, respectively, under the fasting condition. On the other hand, the mean value of C_max , AUC_0-t , and AUC_0-∞ for the test and reference formulations of TAF were 244.6 and 246.7 ng/mL, 230.4 and 244.9 ng • h/mL, and 233.2 and 246.2 ng • h/mL, respectively, under the fed condition. The 90% confidence intervals for geometric mean ratios of AUC_0-t and AUC_0-∞ of TAF in fasting and fed states were within the bioequivalence acceptance limits when tested using the average-bioequivalence method. The point estimate value for geometric mean ratio of C_max in fasting and fed states (88.4% and 95.5%, respectively) were within the bioequivalence acceptance limits as per the reference-scaled average-bioequivalence method. The safety profiles of the 2 formulations were comparable. Pharmacokinetic analysis demonstrated that the test formulations of TAF exhibited bioequivalence to the reference and were well tolerated by healthy Chinese subjects (Study Registry Identification Number: CTR20190086; CTR20190087).

An Update on Antiretroviral Therapy

Human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) still claim many lives across the world. However, research efforts during the last 40 years have led to the approval of over 30 antiretroviral drugs and the introduction of combination therapies that have turned HIV infection into a chronic but manageable disease. In this chapter, we provide an update on current available drugs and treatments, as well as future prospects towards reducing pill burden and developing long-acting drugs and novel antiretroviral therapies. In addition, we summarize efforts to cure HIV, including pharmaceutical strategies focused on the elimination of the virus.

Tenofovir, pregnancy and renal function changes in pregnant women living with HIV

This retrospective study of 100 pregnant women living with HIV [66 on tenofovir disoproxil fumarate (TDF) compared to 34 women on tenofovir alafenamide (TAF)] found no significant difference in renal function in pregnant women with HIV receiving TDF versus TAF. Our results demonstrate that, in regard to renal toxicity, both TDF and TAF appear to be safe for pregnant women living with HIV, but larger prospective cohort studies in pregnant women living with HIV are encouraged.

3-year Treatment of Tenofovir Alafenamide vs. Tenofovir Disoproxil Fumarate for Chronic HBV Infection in China

BACKGROUND AND AIMS

Tenofovir alafenamide (TAF) has similar efficacy to tenofovir disoproxil fumarate (TDF) but with improved renal and bone safety in chronic hepatitis B patients studied outside of China. We report 3-year results from two phase 3 studies with TAF in China (Clinicaltrials.gov: NCT02836249 and NCT02836236).

METHODS

Chinese hepatitis B e antigen (HBeAg)-positive and -negative chronic hepatitis B patients with viremia and elevated alanine aminotransferase were randomized 2:1 to TAF or TDF treatment groups and treated in a double-blind fashion for 144 weeks (3 years). Efficacy responses were assessed by individual study while safety was assessed by a pooled analysis.

RESULTS

Of the 334 patients (180 HBeAg-positive and 154 HBeAg-negative) randomized and treated, baseline characteristics were similar between groups. The overall mean age was 38 years and 73% were male. The mean HBV DNA was 6.4 log₁₀ IU/mL. The median alanine aminotransferase was 88 U/L, and 37% had a history of antiviral use. At week 144, the proportion with HBV DNA <29 IU/mL was similar among the two groups, with TAF at 83% vs. TDF at 79%, and TAF at 93% vs. TDF at 92% for the HBeAg-positive and -negative patients, respectively. In each study, higher proportions of TAF than TDF patients showed normalized alanine aminotransferase (via the American Association for the Study of Liver Diseases and the China criteria) and showed loss of HBsAg; meanwhile, the HBeAg seroconversion rates were similar. Treatment was well-tolerated among the TAF patients, who showed a smaller median decline in creatinine clearance (-0.4 vs. -3.2 mL/min; p=0.014) and less percentage change in bone mineral density vs. TDF at hip (-0.95% vs. -1.93%) and spine (+0.35% vs. -1.40%).

CONCLUSIONS

In chronic hepatitis B patients from China, TAF treatment provided efficacy similar to TDF but with better renal and bone safety at 3 years.

Efficacy and Safety of Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide as Maintenance Treatment in HIV/HBV-Coinfected Patients

BACKGROUND

The efficacy and safety of switching from tenofovir disoproxil fumarate-based antiretroviral therapy to coformulated elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide (E/C/F/TAF) has not been widely investigated in HIV/hepatitis B virus (HBV)-coinfected Asian population.

METHODS

Between February and October 2018, HIV/HBV-coinfected patients who had achieved HIV viral suppression with tenofovir disoproxil fumarate-containing regimens were switched to E/C/F/TAF. Assessments of plasma HBV and HIV viral load, HBV serology, renal function, lipid profiles, and bone mineral density (BMD) were performed at weeks 24 and 48 after switch.

RESULTS

A total of 274 HIV/HBV-coinfected participants were enrolled, with 12.8% testing HBeAg-positive and 94.2% having plasma HBV DNA <20 IU/mL at baseline. At weeks 24 and 48, 92.7% and 89.8% achieved plasma HBV DNA <20 IU/mL; 4.7% and 5.1% had HBV DNA ≥20 IU/mL; and 2.6% and 5.1% had no data, respectively. At weeks 24 and 48, 95.6% and 94.2% of participants maintained HIV RNA <50 copies/mL, respectively. Compared with baseline, the median urine β2-microglobulin-to-creatinine ratio at week 48 decreased significantly from 165 to 90 μg/g (P < 0.001). The mean BMD of the spine and hip improved at week 48 (+1.77% and +1.33%, respectively). Significantly higher lipid profiles were observed after switch to E/C/F/TAF. Thirteen (4.7%) patients withdrew from the study before week 48, with 7 (2.6%) patients because of adverse effects.

CONCLUSIONS

Switch to E/C/F/TAF maintained HBV and HIV viral suppression and resulted in the improvement of proteinuria and BMD of the spine and hip but increased lipid levels in HIV/HBV-coinfected patients at week 48.

Life-long passion for antiviral research and drug development: 80th birthday of Prof. Dr. Erik De Clercq

Since the 1950s, great efforts have been made to develop antiviral agents against many infectious diseases such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), human cytomegalovirus (HCMV), herpes simplex virus (HSV), and varicella-zoster virus (VZV). Among the list of nearly 106 antiviral agents approved in the past five decades, Prof. Erik De Clercq has contributed to the development of 7 antiviral drugs: tenofovir disoproxil fumarate (Viread®) for HIV and HBV treatment, tenofovir alafenamide (Vemlidy®) for HIV and HBV treatment, brivudine (Zostex®) for HSV-1 and VZV treatment, valacyclovir (Valtrex®) for HSV and VZV treatment, adefovir dipivoxil (Hepsera®) for HBV treatment, stavudine (Zerit®) for HIV treatment, and cidofovir (Vistide®) for treating HCMV retinitis in AIDS patients. In addition to the above antiviral drugs, his contributions include two anti-cancer drugs: rabacfosadine (Tanovea®-CA1) for canine lymphoma and plerixafor (Mozobil®) for multiple myeloma and non-Hodgkin's lymphoma. These achievements are driven by his life-long passions for antiviral research and successful collaborations worldwide. To honor the 80th birthday of Prof. Erik De Clercq, this study highlights his scientific achievements and the importance of life-long passions and collaborations in the success of antiviral research and drug development.

Efficacy and safety of co-formulated elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide in HIV-positive patients: real-world data

OBJECTIVES

Elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) is a recommended and widely used regimen for HIV infection. In this study, we aimed to determine the efficacy and safety of E/C/F/TAF in people living with HIV (PLWH), who are either treatment-naïve or switched from any tenofovir disoproxil fumarate-containing regimen. For switched patients, we aimed to determine the impact of switching from tenofovir disoproxil fumarate (TDF) to TAF on lipid profile and kidney functions.

METHODS

ACTHIV-IST Study Group produced a database, and five dedicated HIV centres in Istanbul entered data of PLWH who switched from any TDF-containing regimen to E/C/F/TAF and treatment-naïve patients who were initiated with the E/C/F/TAF regimen between January 2017 and December 2019. Clinical findings, viral parameters, lipid studies, renal function tests, adverse events and adherence to the treatment were recorded in this prospective observational study.

RESULTS

The study included a total of 614 switched and treatment-naïve patients. Of 430 treatment-experienced patients, 89% (382) were men, and the mean age was 42 ± 12 years. Among them, 47% (181/382) self-identified as men who have sex with men (MSM). The median duration of HIV diagnosis was 54 ± 29 months. The median duration of E/C/F/TAF use was 20 ± 36 months and that of previous treatment was 23 ± 18 months. HIV-RNA was undetectable at baseline and month 12 in 84.1% (360/428) and 86.1% (328/381) of patients, respectively (p > 0.05). Mean CD4 counts were 708 ± 287 cells/µL and 802 ± 305 cells/µL at baseline and month 12, respectively (p < 0.001). Serum creatinine levels remained stable during the treatment period. Mean total cholesterol levels at baseline and month 12 were 172 and 211 mg/dL (p < 0.01), LDL-cholesterol 104 and 138 mg/dL (p < 0.01), HDL-cholesterol 39 and 49 mg/dL (p < 0.01) and triglycerides 134 and 174 mg/dL (p < 0.01), respectively. The treatment was generally well tolerated. Eight patients discontinued the therapy (drug interaction: 3; lost to follow-up: 1; pregnancy: 1; pulmonary tuberculosis: 1; side effect: 1; patient's decision: 1). Of 184 treatment-naïve patients, 88% (162) were men, and the mean age was 36.5± 12 years. Among them, 50% (81/162) self-identified as MSM. The mean duration of HIV infection was 21.6 ± 17.1 months. The mean duration of E/C/F/TAF use was 16 ± 4 months. HIV-RNA was undetectable at baseline and month 12 in 1% and 89.1% of patients, respectively. Mean CD4 counts at baseline and month 12 were 469 ± 223 cells/µL and 740 ± 298 cells/µL, respectively. During the treatment period, creatinine levels remained stable. Total cholesterol, LDL-cholesterol, triglyceride and also HDL-cholesterol levels increased. Mean total cholesterol levels at baseline and month 12 were 167 and 211 mg/dL (p < 0.01), LDL-cholesterol 108 and 143 mg/dL (p < 0.01), HDL-cholesterol 41 and 47 mg/dL (p < 0.01) and triglycerides 136 and 172 mg/dL, respectively (p < 0.01). The treatment was generally well tolerated. Three patients discontinued the therapy (drug interaction: 1; non-responder: 1; patient's decision: 1).

CONCLUSION

Starting with or switching to E/C/F/TAF in PLWH effectively suppresses HIV infection, is associated with an increase in CD4 cell count and is well tolerated in a real-life setting. Renal functions remained stable during the treatment. E/C/F/TAF use was associated with an increase in LDL-cholesterol and triglyceride levels along with an increase in HDL-cholesterol levels.

Advances in Nucleoside and Nucleotide Analogues in Tackling Human Immunodeficiency Virus and Hepatitis Virus Infections

Nucleoside and nucleotide analogues are structurally similar antimetabolites and are promising small-molecule chemotherapeutic agents against various infectious DNA and RNA viruses. To date, these analogues have not been documented in-depth as anti-human immunodeficiency virus (HIV) and anti-hepatitis virus agents, these are at various stages of testing ranging from pre-clinical, to those withdrawn from trials, or those that are approved as drugs. Hence, in this review, the importance of these analogues in tackling HIV and hepatitis virus infections is discussed with a focus on the viral genome and the mechanism of action of these analogues, both in a mutually exclusive manner and their role in HIV/hepatitis coinfection. This review encompasses nucleoside and nucleotide analogues from 1987 onwards, starting with the first nucleoside analogue, zidovudine, and going on to those in current clinical trials and even the drugs that have been withdrawn. This review also sheds light on the prospects of these nucleoside analogues in clinical trials as a treatment option for the COVID-19 pandemic.

Broad spectrum antiviral nucleosides-Our best hope for the future

The current focus for many researchers has turned to the development of therapeutics that have the potential for serving as broad-spectrum inhibitors that can target numerous viruses, both within a particular family, as well as to span across multiple viral families. This will allow us to build an arsenal of therapeutics that could be used for the next outbreak. In that regard, nucleosides have served as the cornerstone for antiviral therapy for many decades. As detailed herein, many nucleosides have been shown to inhibit multiple viruses due to the conserved nature of many viral enzyme binding sites. Thus, it is somewhat surprising that up until very recently, many researchers focused more on "one bug one drug," rather than trying to target multiple viruses given those similarities. This attitude is now changing due to the realization that we need to be proactive rather than reactive when it comes to combating emerging and reemerging infectious diseases. A brief summary of prominent nucleoside analogues that previously exhibited broad-spectrum activity and are now under renewed interest, as well as new analogues, that are currently under investigation against SARS-CoV-2 and other viruses is discussed herein.