Choice of antiretroviral drugs for continued treatment scale-up in a public health approach: what more do we need to know?

INSTIs-centered antiviral regimens for first-line treatment of HIV/AIDS: a network meta-analysis and cost-effectiveness analysis

OBJECTIVE

This study evaluates the efficacy, safety, and cost-effectiveness of INSTI-based antiretroviral regimens compared to the national standard first-line treatment EFV/3TC/TDF for HIV/AIDS in China. The aim is to guide clinical decision-making and improve HIV/AIDS prevention and treatment.

METHODS

A network meta-analysis was conducted using ADDIS software on data from domestic and international randomized controlled trials comparing INSTI-based regimens with EFV/3 TC/TDF. Additionally, a Markov model assessed the cost-effectiveness of the representative INSTI regimen B/F/TAF (Bictegravir/Emtricitabine/Tenofovir Alafenamide) against EFV/3 TC/TDF. Costs and health outcomes were measured in US Dollars ($) and Quality-Adjusted Life Years (QALYs), respectively, evaluating incremental cost-utility ratios (ICERs) against a willingness-to-pay threshold of 1.5 times GDP per capita.

RESULTS

Seventeen trials involving 12,620 patients were analyzed. INSTI regimens showed no significant efficacy or safety advantages over EFV/3 TC/TDF but offered better drug resistance, adherence, and quality of life improvements. Economic analysis from the patient perspective showed that B/F/TAF had an ICER of $12,714.29/QALY, which is below the willingness-to-pay threshold, indicating cost-effectiveness. From the healthcare system perspective, B/F/TAF's ICER was $23,052.77/QALY, which is above the threshold, suggesting it is not cost-effective from this perspective. Sensitivity analyses confirmed these findings, with drug costs for B/F/TAF and the probability of CD4 count increase post-EFV/3TC/TDF treatment being the largest influencing factors. Additionally, probabilistic sensitivity analysis indicated that B/F/TAF has a varying probability of economic viability depending on the willingness-to-pay threshold, highlighting its potential value in specific economic contexts.

CONCLUSION

INSTI-based regimens are as effective and safe as the national standard but offer additional benefits in drug resistance and patient compliance. B/F/TAF is economically viable from the patient perspective but does not present a cost-utility advantage from the healthcare system perspective. This study underscores the need for considering both clinical and economic factors in selecting first-line HIV/AIDS treatments in China.

Bone loss in young adults with HIV following antiretroviral therapy containing tenofovir disoproxil fumarate regimen using machine learning

Objective

Bone mineral density (BMD) monitoring, primarily relying on dual-energy X-ray absorptiometry (DEXA), remains inaccessible in resource-limited regions, making it difficult to promptly address bone loss in people with HIV (PWH) on long-term ART-containing TDF regimens and assess the prevalence of bone loss. Our objective is to identify the frequency of PWH experiencing bone loss after long-term ART with a TDF regimen and to develop a predictive model of HIV-infected high-risk populations containing TDF long-time ART, for providing more appropriate ART regimens for PWH in clinical practice, particularly in resource-limited settings.

Methods

Our study retrospectively screened PWH under long-term follow-up at Peking Union Medical College Hospital (PUMCH) from January 2000 to August 2024. These individuals were either treatment-naive or treatment-experienced and had been on containing TDF ART regimen for over 5 years. BMD was assessed using DEXA every 1-2 years in this center. We selected predictive factors utilizing machine learning methods, including Random Forest, XGBoost, LASSO regression, and logistic regression. The results were visualized using a nomogram.

Results

Our study enrolled a total of 232 PWH who have contained TDF ART regimens for more than 5 years. Twenty-five percent (58/232) of the patients experienced bone loss, primarily including osteopenia and osteoporosis. Further results showed that the LASSO regression model was the most suitable for the current dataset, based on a comparison of LASSO regression, Random Forest, XGBoost, and logistic regression models including age, gender, LPV/r, baseline CD4+ T count, baseline VL, baseline body weight, treatment-naïve TDF, ART duration, percentage of CD38+CD8+T, percentage of HLA-DR+CD8+ T, and CD4+/CD8+ ratio, with AUC values of 0.615, 0.507, 0.593, and 0.588, respectively. We identified age, gender, and LPV/r as the most relevant predictive factors associated with bone loss based on LASSO regression. Then the results were visualized and plotted in a nomogram.

Conclusion

Our study quantified the frequency and established a nomogram based on the LASSO regression model to predict bone loss in PWH on long-term containing TDF ART. The nomogram guides identifying individuals at high risk of bone loss due to prolonged TDF exposure. Clinicians can leverage the predicted risk to design personalized ART regimens at the initiation of therapy or to switch from TDF-containing to TDF-free regimens during treatment. This approach aims to reduce the incidence of bone loss, particularly in resource-limited settings.

Dolutegravir based therapy showed CD4+ T cell count recovery and viral load suppression among ART naïve people living with HIV AIDS: a pilot evaluation

Recently, dolutegravir (DTG)-based combined therapy, a more effective and safer first-line antiretroviral therapy (ART), has been recommended by the World Health Organization for the treatment of Human Immunodeficiency Virus (HIV) since July 2018. However, its effectiveness in CD4+ T-cells count recovery and viral load suppression has not been studied yet in Ethiopia, where HIV is endemic. Therefore, we aimed to conduct a pilot assessment on the effect of DTG-based therapy on CD4+ T-cell count and viral load count among people living with HIV (PLWH) in Ethiopia. A longitudinal prospective cohort study was conducted from July 2020 to February 2021. 109 PLWH who are ART naive but plan to initiate DTG-based therapy were recruited. HIV viral ribonucleic acid (RNA) copies were determined using polymerase chain reaction. To compute the difference in viral load and CD4+ T-cell counts between the baseline, 3rd, and 6th months, a Friedman test was used. The study included 109 PLWH who had never received antiretroviral medication. Participants taking DTG-based treatment showed significantly decreasing median (IQR) values of viral load count (copies/mL) from 446,812 (237649.5-732994.5) at baseline to 34 (23.5-46) at 3 months and 0.0 (0-19) at 6 months of treatment follow-up. Although the treatment increases the proportion of participants with HIV-1 RNA 50 copies/mL from 0 (0% at baseline) to 87 (79.8%) and 100 (91.7%) at the 3rd and 6th months of treatment, respectively, On the other hand, the CD4+ T-cell count increased significantly during treatment: median (IQR): 209 (81.5-417.5) versus 291 (132-522) versus 378 (181-632.5) cells/L at baseline, the 3rd and 6th months of the treatment follow-up period, respectively. We found dolutegravir-based therapy was a promising option with high virological suppression rates and CD4+ T-cell count recovery, demonstrating a restoration of cellular immunity. Moreover, Viral load suppression rates were high after the initiation of the treatment. We recommend further research should be conducted with a larger number of participants to acquire greater awareness of the treatment outcomes.

Synthesis and characterization of two known and one new impurities of dolutegravir: In silico evaluation of certain intermediates against SARS CoV-2 O-ribose methyltransferase (OMTase)

Besides its use against HIV infection the marketed anti-retroviral drug dolutegravir attracted attention as a potential agent against COVID-19 in multiple AI (artificial intelligence) based studies. Due to our interest in accessing the impurities of this drug we report the synthesis and characterization of three impurities of dolutegravir one of which is new. The synthesis of O-methyl ent-dolutegravir was accomplished in three-steps the first one involved the construction of fused 1,3-oxazinane ring. The cleavage of -OEt ether moiety followed by methylation afforded the target compound. The second impurity i.e. N-(2,4-difluorobenzyl)-4-methoxy-3-oxobutanamide was synthesized via a multi-step method involving sequentially the keto group protection, ester hydrolysis, acid chloride formation followed by the reaction with amine and finally keto group deprotection. The synthesis of new or dimer impurity was carried out via another multi-step method similar to the previous one starting from ethyl 4-chloro acetoacetate. The methodology involved preparation of ether derivative, keto group protection, ester hydrolysis, preparation of amide derivative via acid chloride formation in situ and then keto group deprotection for a longer duration. The last step afforded the target compound for which a plausible reaction mechanism has been proposed. All three impurities were prepared in gram scale (minimum 2 g and maximum 8 g). The in silico evaluation of three selected synthesized intermediates e.g. 7, 8 and 9 (structurally similar to dolutegravir) against SARS CoV-2 O-ribose methyltransferase (OMTase) (PDB: 3R24) indicated that compound 7 could be of interest as a possible inhibitor of this protein.

Distribution Evaluation of Tenofovir in the Breast Milk of Mothers With HBeAg-Positive Chronic HBV Infection After Treatment With Tenofovir Alafenamide and Tenofovir Disoproxil Fumarate by a Sensitive UPLC-MS/MS Method

Tenofovir alafenamide (TAF) is a novel prodrug of tenofovir (TFV) that has been approved for the treatment of chronic hepatitis B virus (HBV) infection. It has greater plasma stability and more favorable renal safety than tenofovir disoproxil fumarate (TDF), the first approved oral prodrug of TFV. However, the distribution of TFV in the breast milk of mothers treated with TAF is still unclear. In this study, sixteen participants with chronic HBV infection were enrolled and received antiretroviral therapy with 25 mg of TAF or 300 mg of TDF daily from 24 to 28 weeks of gestation until the 4th week postpartum. For the first time, the distribution of TFV in the breast milk of mothers with chronic HBV infection treated with TAF and its difference from TDF were evaluated by using a sensitive UPLC-MS/MS method. Chromatographic separation was achieved on a Waters ACQUITY UPLC BEH C18 column (1.7 µm 2.1 × 100 mm). Mass spectrometry analysis was performed in positive electrospray ionization mode and multiple reaction monitoring (MRM) conditions of transitions m/z 288.1→176.2 for TFV. This method was linear from 0.5 to 500 ng/ml. Surprisingly, on the third postpartum day, the median Cmax of TFV in the breast milk was much higher in the mothers treated with TAF (101.2 ng/ml) than TDF (21.6 ng/ml) at a similar Tmax of 4 h. Accordingly, the median AUC0-8 value was 755.6 ng h/mL in the mothers taking TAF, which was at a 5-fold higher level than TDF. The concentration of TFV in the breast milk of mothers in both groups decreased with increasing lactation time. These data indicated that there was a relatively higher exposure of TFV in the breast milk of mothers taking TAF, despite the lower dosage compared to TDF. This study provides support for further evaluating the safety of breastfeeding after the administration of TAF and TDF.

Preparation of the Key Dolutegravir Intermediate via MgBr2-Promoted Cyclization

A novel approach for synthesizing the key dolutegravir intermediate is described via MgBr₂-promoted intramolecular cyclization. Condensation of commercially available methyl oxalyl chloride and ethyl 3-(N,N-dimethylamino)acrylate afforded the vinylogous amide in an excellent yield. Subsequent substitution by aminoacetaldehyde dimethyl acetal and methyl bromoacetate gave rise to the expected precursor for cyclization, which was promoted by MgBr₂ to highly selectively convert into pyridinone diester. The key dolutegravir intermediate was finally prepared by the selective hydrolysis of the corresponding diester via LiOH.

Longitudinal change in bone mineral density among Chinese individuals with HIV after initiation of antiretroviral therapy

This is the first study to report changes in BMD and related risk factors among Chinese patients with HIV after initiation of tenofovir disoproxil fumarate (TDF)-containing antiretroviral therapy. Greater bone mineral density (BMD) loss was observed in patients treated with TDF, compared to those on non-TDF-containing regimens. Our findings provide important knowledge regarding the risk factors in the long-term clinical management of patients with HIV in China.

INTRODUCTION

Persons living with HIV (PLWH) are at increased risk for osteoporosis and fracture. Tenofovir disoproxil fumarate (TDF) has been associated with higher rates of bone mineral density (BMD) loss, osteoporosis, and fracture. Few studies have studied the impact among PLWH in Asia.

METHODS

We analyzed retrospectively patients from the outpatient HIV clinic of a large tertiary hospital in Beijing, China, from March 2007 to May 2016. Patients who had dual-energy X-ray absorptiometry testing prior to antiretroviral initiation and at 48 and/or 96 weeks after initiation were included in this analysis.

RESULTS

A total of 136 patients were included (mean age 36.0 ± 10.6 years) and over 90% participants were male and Han Chinese ethnicity. We observed greater declines in BMD at the spine from baseline to week 48 (-2.94% vs. -0.74%) and at the hip from baseline to week 96 (-4.37% vs. -2.34%) in the TDF group compared with the non-TDF group. With regard to HIV-specific parameters, longer duration since HIV diagnosis and undetectable viral load over time were associated with lower BMD at the hip [relative risk (RR) 0.97, 95% confidence index (CI) (0.95, 0.99) per 1 year increase and RR 0.96, 95%CI (0.94, 0.99), respectively] and femoral neck [RR 0.97, 95%CI (0.95, 0.99) per 1 year increase and RR 0.97, 95%CI (0.95, 0.998), respectively] over 96 weeks.

CONCLUSIONS

This is the first study to report changes in BMD among PLWH after initiation of TDF-based antiretroviral therapy in China. Our findings provide important knowledge for the long-term clinical management of PLWH from this region.

Tenofovir alafenamide vs. tenofovir disoproxil fumarate: an updated meta-analysis of 14 894 patients across 14 trials

BACKGROUND

Both tenofovir disoproxil fumarate (TDF)/emtricitabine and tenofovir alafenamide (TAF)/emtricitabine demonstrate excellent efficacy and safety overall, but concerns remain over specific changes in markers of bone and renal function. Lower plasma tenofovir concentrations are seen with TAF and in unboosted regimens. We assess TAF vs. TDF safety with and without booster coformulation.

METHODS

A previous systematic review was updated with recent clinical trials. TAF vs. TDF efficacy and safety were compared in boosted and unboosted subgroups. Efficacy was measured by viral suppression. Key safety endpoints included all adverse events, serious adverse events, Grades 3-4 adverse events and adverse event discontinuation. Further specific renal and bone markers were also assessed.

RESULTS

A total of 14 clinical trials comparing TDF and TAF regimens were identified. A significant difference (P = 0.0004) in efficacy was shown in the boosted subgroup in favour of TAF, but no difference was seen in the unboosted subgroup. There were no significant differences between TAF and TDF for any of the key safety endpoints analysed. No differences were seen for the bone markers analysed. No difference was found for renal tubular events. There was a difference in risk for discontinuation due to renal adverse events when boosted (P = 0.03), but none when unboosted.

CONCLUSION

Across all main safety endpoints, no differences between TAF and TDF are seen. Boosted TDF regimens were associated with lesser comparative efficacy than boosted TAF and a higher risk of renal event discontinuation. However, modern antiretroviral regimens are more commonly unboosted. This study finds no difference in efficacy or safety in unboosted TAF vs. TDF.

Dolutegravir and lamivudine maintenance therapy in HIV-1 virologically suppressed patients: results of the ANRS 167 trial (LAMIDOL)

OBJECTIVES

To evaluate the dolutegravir+lamivudine combination in virologically suppressed patients living with HIV.

METHODS

The ANRS 167 LAMIDOL trial was an open-label, single arm, multicentre trial assessing once-daily dolutegravir (50 mg)+lamivudine (300 mg) in virologically suppressed HIV-1 patients on first-line triple-drug regimens. The main criteria for inclusion in the trial were plasma viral load (pVL) ≤50 copies/mL for ≥2 years, CD4 nadir >200 cells/mm3 and WT HIV prior to treatment initiation. From week -8 (W-8) to day 0 (D0) (Phase 1), the current third agent was switched to dolutegravir. From D0 to W48 (Phase 2), patients received once-daily dolutegravir+lamivudine, except if intolerant or if pVL >50 copies/mL during Phase 1. Virological failure was defined as pVL >50 copies/mL in two consecutive samples. The study was designed to show that the strategy had an efficacy of ≥80%, assuming a 90% success rate with a type I error of 5% and a power of 90%.

RESULTS

In total, 104 of 110 patients enrolled in Phase 1 were included in Phase 2. These 104 patients were 86% male, 72% MSM and 87% CDC stage A. Their characteristics were (median): age 45 years, CD4 nadir 339 cells/mm3, baseline CD4 743 cells/mm3 and duration of viral suppression 4.5 years. The overall success rate at W48 was 97% (95% CI: 94%-100%), meeting the design expectation/assumption. Three therapeutic failures occurred: one virological failure at W4, one lost to follow-up at W32 and one interruption of therapeutic strategy at W40 after a blip (pVL 59 copies/mL but control pVL <50 copies/mL). Three viral blips occurred in two additional patients. Neither M184V nor integrase resistance mutations were detected after failure or blips.

CONCLUSIONS

Dolutegravir+lamivudine is a promising maintenance therapy in HIV-1-infected patients with controlled virological suppression.

Changes in Renal Function After Switching From TDF to TAF in HIV-Infected Individuals: A Prospective Cohort Study

Background

Replacing tenofovir disoproxil fumarate (TDF) with tenofovir alafenamide (TAF) improves renal tubular markers in HIV-infected individuals but the impact on estimated glomerular filtration rate (eGFR) remains unclear.

Methods

In all participants from the Swiss HIV Cohort Study who switched from TDF to TAF-containing antiretroviral regimen or continued TDF, we estimated changes in eGFR and urine protein-to-creatinine ratio (UPCR) after 18 months using mixed-effect models.

Results

Of 3520 participants (26.6% women, median age 50 years), 2404 (68.5%) switched to TAF. Overall, 1664 (47.3%) had an eGFR &lt;90 mL/min and 1087 (30.9%) an UPCR ≥15 mg/mmol. In patients with baseline eGFR ≥90 mL/min, eGFR decreased with the use of TDF and TAF (−1.7 mL/min). Switching to TAF was associated with increases in eGFR of 1.5 mL/min (95% confidence interval [CI], .5–2.5) if the baseline eGFR was 60–89 mL/min, and 4.1 mL/min (95% CI, 1.6–6.6) if &lt;60 mL/min. In contrast, eGFR decreased by 5.8 mL/min (95% CI, 2.3–9.3) with continued use of TDF in individuals with baseline eGFR &lt;60 mL/min. UPCR decreased after replacing TDF by TAF, independent of baseline eGFR.

Conclusions

Switching from TDF to TAF improves eGFR and proteinuria in patients with renal dysfunction.

Adverse events of nucleos(t)ide analogues for chronic hepatitis B: a systematic review

Nucleos(t)ide analogues (NAs) are the main drug category used in chronic hepatitis B (CHB) treatment. Despite the fact that NAs have a favourable safety profile, undesired adverse events (AEs) may occur during the treatment of CHB. Given the eminent number of patients currently receiving NAs, even a small risk of any of these toxicities can represent a major medical issue. The main objective of this review was to analyse information available on AEs associated with the use of NAs in published studies. We choose the following MesH terms for this systematic review: chronic hepatitis B, side effects and treatment. All articles published from 1 January 1990 up to 19 February 2018 in MEDLINE of PubMed, EMBASE, the Cochrane Library and LILACS databases were searched. A total of 120 articles were selected for analysis, comprising 6419 patients treated with lamivudine (LAM), 5947 with entecavir (ETV), 3566 with tenofovir disoproxil fumarate (TDF), 3096 with telbivudine (LdT), 1178 with adefovir dipivoxil (ADV) and 876 with tenofovir alafenamide (TAF). The most common AEs in all NAs assessed were abdominal pain/discomfort, nasopharyngitis/upper respiratory tract infections, fatigue, and headache. TAF displays the highest density of AEs per patient treated among NAs (1.14 AE/treated patient). In conclusion, treatment of CHB with NAs is safe, with a low incidence of AEs. Despite the general understanding TAF being safer than TDF, the number of patients treated with TAF still is too small in comparison to other NAs to consolidate an accurate safety profile. PROSPERO Registration No. CRD42018086471.

Neuropsychological and Syntactic Deficits in HIV Seropositive Males

Objective:

Given the underlying frontal-basal ganglia circuit neuropathogenesis of HIV-infected individuals, it is surprising that little is reported about potential language deficits as part of their higher cognitive dysfunctional profile. This study aims to elucidate whether HIV-positive individuals have linguistic impairments that may originate from or be intensified by deficits in cognitive functions. The research questions address (i) quantitative differences in sentence repetition abilities involving complex syntactic phenomena between adults with HIV and non-HIV healthy controls (ii) correlations of sentence repetition scores with neurocognitive measures and (iii) correlation of sentence repetition performance with duration and severity of HIV.

Methods:

A battery of neuropsychological tests were administered to 40 HIV - seropositive males and 40 demographically matched healthy controls to assess verbal learning/episodic memory, psychomotor speed, executive functions and visuospatial abilities. Language abilities were evaluated using a repetition task that screened specific complex syntactic operations at the sentence-level.

Results:

A significant difference was noted between the two groups regarding correct repetition of the sentence repetition task with the control group outperforming the HIV-seropositive group. For the HIV group, significant correlations were found for correct sentence repetition with years of education, duration of illness, Mini-Mental State Examination, semantic and phonemic fluency, symbol digit modality test scores, and the Trail Making Test (parts A and B).

Conclusion:

Speech-language pathologists and neuropsychologists should screen for language deficits associated with the different clinical syndromes in HIV patients as part of their routine clinical care.

Long term renal function in Asian HIV-1 infected adults receiving tenofovir disoproxil fumarate without protease inhibitors

OBJECTIVES

The risk of kidney dysfunction on the WHO recommended first line regimens containing tenofovir disoproxil fumarate (TDF) without protease inhibitors (PI) remains unclear in Asian patients, especially those with low body weight.

METHODS

Using data collected in a multicenter clinical trial in Thailand and proportional hazard regression models, we compared the risk of a >25% estimated glomerular filtration rate (eGFR) reduction in HIV naïve patients initiating TDF or zidovudine (AZT) containing non-PI regimen.

RESULTS

Of 640 patients included in the analysis, 461 (72%) received a TDF-containing regimen for a median 6.7 years and 179 (28%) an AZT-containing regimen for 6.5 years. The risk of a >25% eGFR reduction was not associated with treatment (HR 1.11, 95% CI 0.84-1.47, P = 0.46). In multivariate analysis, the risk of >25% eGFR reduction form baseline was associated with body weight at baseline (HR 2.12, 95% CI 1.48-3.02 for <48 kg patients and HR 1.64, 95% CI 1.20-2.25 for 48-59.9 kg patients, compared to those with >60 kg, P < 0.001) and hypertension (HR 4.03, 95% CI 2.0-8.0, P < 0.001). The effect of baseline weight on >25% eGFR reduction did not significantly vary with treatment (P = 0.27).

CONCLUSIONS

The risk of eGFR reduction was not higher on TDF- versus AZT-based non-PI regimens. Although the risk of eGFR reduction was greater for patients of lower body weight, this risk was not significantly increased by TDF.

How to achieve the global 90-90-90 target by 2020 in sub-Saharan Africa? A mathematical modelling study

OBJECTIVES

The 90-90-90 target states that by 2020, 90% of people living with HIV should be diagnosed, 90% of those diagnosed treated, and 90% of those treated virally suppressed. We assessed the actions needed in each country of sub-Saharan Africa to achieve the 90-90-90 target.

METHODS

We developed a mathematical model to assess the number of patients needing to start antiretroviral therapy (ART) between 2017 and 2020 to achieve 81% coverage by 2020 in each country, and the proportion of treated patients who are virally suppressed in four scenarios, combining two scenarios of retention (current-level or perfect), and routine viral load monitoring (current or universal coverage). We performed two separate simulations, one using observed failure rates from cohort studies, and one with considerably lower failure rates to set a theoretical lower limit.

RESULTS

Our model projected that 2.9 million people started ART in 2017 in sub-Saharan Africa. If, depending on scenario, at least 2.2-2.7 million patients continue to start ART annually, 81% ART coverage will be reached in 2020 in sub-Saharan Africa on average. In 37% of the countries, a multiple-fold increase in annual number of patients starting ART is needed. Virological suppression >90% in 2020 could be reached only in the best-case scenario assuming low probability of treatment failure, elimination of treatment interruptions, and universal routine viral load monitoring.

CONCLUSION

The 90-90-90 target is realistic in sub-Saharan Africa on average, but not necessarily in all individual countries. Each country should identify and focus on the specific gaps needing attention.

7-Step Flow Synthesis of the HIV Integrase Inhibitor Dolutegravir

Dolutegravir (DTG), an important active pharmaceutical ingredient (API) used in combination therapy for the treatment of HIV, has been synthesized in continuous flow. By adapting the reported GlaxoSmithKline process chemistry batch route for Cabotegravir, DTG was produced in 4.5 h in sequential flow operations from commercially available materials. Key features of the synthesis include rapid manufacturing time for pyridone formation, one-step direct amidation of a functionalized pyridone, and telescoping of multiple steps to avoid isolation of intermediates and enable for greater throughput.

Tenofovir alafenamide versus tenofovir disoproxil fumarate: is there a true difference in efficacy and safety?

BACKGROUND

Higher plasma tenofovir concentrations are associated with higher risks of renal and bone adverse events. The pharmacokinetic boosters ritonavir (RTV) and cobicistat (COBI) significantly increase plasma area under the curve (AUC) concentrations of tenofovir disoproxil fumarate (TDF), by 25-37%. When combined with RTV or COBI, the dose of tenofovir alafenamide (TAF) is lowered from 25 mg to 10 mg daily, but the TDF dose is maintained at 300 mg daily.

OBJECTIVE

To assess the differences in safety and efficacy between tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF) in regimens with and without the pharmacokinetic boosters RTV and COBI.

METHODS

A PubMed/Embase search inclusive of dates up to 17 July 2017 identified 11 randomised head-to-head trials (8111 patients) of TDF versus TAF. The Mantel-Haenszel method was used to calculate pooled risk differences and 95% confidence intervals using random-effects models. A pre-defined sub-group analysis compared TAF with TDF, either when boosted with RTV or COBI, or when unboosted.

RESULTS

Nine clinical trials compared TAF and TDF for treatment of HIV-1 and two were for hepatitis B treatment. The eleven clinical trials documented 4574 patients with boosting RTV or COBI in both arms, covering 7198 patient-years of follow-up. Some 3537 patients received unboosted regimens, totalling 3595 patient-years of follow-up. Boosted TDF-treated patients showed borderline lower HIV RNA suppression <50 copies/mL (P=0.05), more bone fractures (P=0.04), larger decreases in bone mineral density (P<0.001), and more discontinuations for bone (P=0.03) or renal (P=0.002) adverse events. By contrast, there were no significant differences in HIV RNA suppression rates or clinical safety endpoints between unboosted TAF and unboosted TDF.

CONCLUSIONS

TDF boosted with RTV or COBI was associated with higher risks of bone and renal adverse events, and lower HIV RNA suppression rates, compared with TAF. By contrast, when ritonavir and cobicistat were not used, there were no efficacy differences between TAF and TDF, and marginal differences in safety. The health economic value of TAF versus low-cost generic TDF may be limited when these drugs are used without cobicistat or ritonavir.

Accelerating access and scale-up of optimized ART in low-income and middle-income countries: a call for a coordinated end-to-end approach

PURPOSE OF REVIEW

To discuss how aligning the collective power of scientists, regulators, drug companies, donors, implementers and advocates to achieve a single goal - accelerating access to simpler, safer, more robust and more affordable HIV treatment - can rapidly advance antiretroviral optimization efforts and enable scale-up.

RECENT FINDINGS

Harmonization of traditionally sequential processes can address the delays commonly experienced in introducing new products to low-income and middle-income countries, by facilitating an 'end-to-end' approach that mitigates risk and encourages early planning for all aspects of product introduction.

SUMMARY

Planning with the 'end-in-mind' can facilitate healthy markets, benefit the application of new technologies, and accelerate the development of improved products in parallel (versus traditionally sequential efforts).

Candidates for inclusion in a universal antiretroviral regimen: tenofovir alafenamide

PURPOSE OF REVIEW

Tenofovir disoproxil fumarate (TDF) is a standard first-line therapy for HIV. Recently, tenofovir alafenamide (TAF), a different prodrug for the same active moiety, has been approved. In this review, we have conducted a meta-analysis comparing efficacy and safety data for TDF and TAF, to inform a discussion of which drug would be best for a proposed 'universal antiretroviral (ARV) regimen'.

RECENT FINDINGS

We identified 10 randomized controlled trials comparing TDF with TAF (6969 patients, 8043 patient-years of follow-up). Meta-analysis found no difference in treatment efficacy, resistance, or adverse events. There were significant differences favouring TAF in bone mineral density measures and renal function measures, but no significant difference in bone fracture events or discontinuations because of bone toxicity or renal toxicity. TAF arms showed higher lipid levels, and were associated with a slightly greater risk of being started on lipid-lowering therapy.

SUMMARY

TAF has lesser detrimental effects on renal and bone markers, but no difference in adverse events. Data are unavailable for TAF safety in pregnancy, tuberculosis coinfection, and low CD4 count. Data for these groups, and an affordable price, will be required before it can be recommended as part of a 'universal ARV regimen'.

Effect of Cobicistat on Tenofovir Disoproxil Fumarate (TDF): What Is True for TAF May Also Be True for TDF

BACKGROUND

The dose of tenofovir alafenamide is reduced from 25 to 10 mg daily when given with boosting agents. However, such dose reduction has never been adopted for tenofovir disoproxil fumarate (TDF). In this study, we aim to quantify the effect of cobicistat (COBI) both on tenofovir concentrations and TDF durability in real life setting.

METHODS

HIV-positive patients receiving TDF-containing antiretroviral therapies with at least 1 assessment of tenofovir plasma trough concentrations were included in the study. Univariate and multivariate regression analyses were performed considering tenofovir concentration as the dependent variable and clinical characteristics as independent covariates. Subsequently, survival and Cox analyses were performed considering as the primary outcome TDF discontinuation for any reasons.

RESULTS

Patients were given TDF with protease inhibitors/ritonavir (n = 212), non-nucleoside reverse transcriptase inhibitors (n = 176), integrase inhibitors (dolutegravir or raltegravir, n = 46), or with elvitegravir/COBI (ELV/COBI) (n = 76). By multivariate analysis, concomitant antiretroviral therapies resulted significantly associated with tenofovir levels, with the highest drug concentrations measured in patients given ELV/COBI. By survival analysis, we found that patients given TDF with ELV/COBI had the lowest rate of drug durability. Overall, these patients had a 2.3-fold increased risk to experience TDF discontinuation.

CONCLUSIONS

Coadministration with COBI resulted in significantly higher tenofovir concentrations and higher TDF discontinuation compared with other antiretroviral regimens. Accordingly, the possibility that the lack of proper dose adjustment for TDF when given with COBI might have biased the safety comparisons with tenofovir alafenamide during registrative trials cannot be ruled out.

Role of tenofovir alafenamide (TAF) in the treatment and prophylaxis of HIV and HBV infections

Tenofovir (TFV) is the cornerstone of the treatment and prophylaxis of HIV infections. It has been routinely used in its prodrug form TDF (tenofovir disoproxil fumarate) combined with emtricitabine ((-)FTC) and other antiretroviral agents. TDF has now been replaced by TAF (tenofovir alafenamide) which allows better uptake by the lymphoid tissue. In combination with elvitegravir (E), cobicistat (C), emtricitabine (F), TAF can be advocated as an STR (single tablet regimen, Genvoya®) for the treatment of HIV infections. In this combination, E and C may in the future be replaced by bictegravir. The prophylaxis of HIV infection is momentarily based upon Truvada®, the combination of F with TDF, which in the future may also be replaced by TAF. TAF (Vemlidy®) has also replaced TDF (Viread®) for the treatment of hepatitis B virus (HBV) infections. Both TDF and TAF offer little or no risk for virus-drug resistance. As compared to TDF, TAF limits the risk for nephrotoxicity and loss of bone mineral density. What remains to be settled, however, before the universal use of TAF could be recommended, is its safety during pregnancy and its applicability in the treatment of tuberculosis, in combination with rifampicin.

Cost-effectiveness of routine viral load monitoring in low- and middle-income countries: a systematic review

INTRODUCTION

Routine viral load monitoring for HIV-1 management of persons on antiretroviral therapy (ART) has been recommended by the World Health Organization (WHO) to identify treatment failure. However, viral load testing represents a substantial cost in resource constrained health care systems. The central challenge is whether and how viral load monitoring may be delivered such that it maximizes health gains across the population for the costs incurred. We hypothesized that key features of program design and delivery costs drive the cost-effectiveness of viral load monitoring within programs.

METHODS

We conducted a systematic review of studies on the cost-effectiveness of viral load monitoring in low- and middle-income countries (LMICs). We followed the Cochrane Collaboration guidelines and the PRISMA reporting guidelines.

RESULTS AND DISCUSSION

We identified 18 studies that evaluated the cost-effectiveness of viral load monitoring in HIV treatment programs. Overall, we identified three key factors that make it more likely for viral load monitoring to be cost-effective: 1) Use of effective, lower cost approaches to viral load monitoring (e.g. use of dried blood spots); 2) Ensuring the pathway to health improvement is established and that viral load results are acted upon; and 3) Viral load results are used to simplify HIV care in patients with viral suppression (i.e. differentiated care, with fewer clinic visits and longer prescriptions). Within the context of differentiated care, viral load monitoring has the potential to double the health gains and be cost saving compared to the current standard (CD4 monitoring).

CONCLUSIONS

The cost-effectiveness of viral load monitoring critically depends on how it is delivered and the program context. Viral load monitoring as part of differentiated HIV care is likely to be cost-effective. Viral load monitoring in differentiated care programs provides evidence that reduced clinical engagement, where appropriate, is not impacting health outcomes. Introducing viral load monitoring without differentiated care is unlikely to be cost-effective in most settings and results in lost opportunity for health gains through alternative uses of limited resources. As countries scale up differentiated care programs, data on viral suppression outcomes and costs should be collected to evaluate the on-going cost-effectiveness of viral load monitoring as utilized in practice.

Dolutegravir-lamivudine as initial therapy in HIV-1 infected, ARV-naive patients, 48-week results of the PADDLE (Pilot Antiretroviral Design with Dolutegravir LamivudinE) study

Introduction: A proof-of-concept study was designed to evaluate the antiviral efficacy, safety and tolerability of a two-drug regimen with dolutegravir 50 mg once daily (QD) plus lamivudine 300 mg once daily as initial highly active antiretroviral therapy (HAART) among antiretroviral (ARV)-naive patients.

Methods: PADDLE is a pilot study including 20 treatment-naive adults. To be selected, participants had no IAS-USA-defined resistance, HIV-1 RNA ≤100,000 copies/mL at screening and negative HBsAg. Plasma viral load (pVL) was measured at baseline; days 2, 4, 7, 10, 14, 21 and 28; weeks 6, 8 and 12; and thereafter every 12 weeks up to 96 weeks. Primary endpoint was the proportion of patients with HIV-1 RNA <50 copies/mL in an intention to treat (ITT)-exposed analysis at 48 weeks (the FDA snapshot algorithm).

Results: Median HIV-1 RNA at entry was 24,128 copies/mL (interquartile range (IQR): 11,686–36,794). Albeit as per protocol, all patients had pVL ≤100,000 copies/mL at screening as required by inclusion criteria, four patients had ≥100,000 copies/mL at baseline. Median baseline CD4+ T-cell count was 507 per cubic millimetre (IQR: 296–517). A rapid decline in pVL was observed (median VL decay from baseline to week 12 was 2.74 logs). All patients were suppressed at week 8 onwards up to week 24. At week 48, 90% (18/20) reached the primary endpoint of a pVL <50 copies/mL. Median change in CD4 cell count between baseline and week 48 was 267 cells/mm³ (IQR: 180–462). No major tolerability/toxicity issues were observed. Nineteen patients completed 48 weeks of the study, and one patient (with undetectable VL at last visit) committed suicide. One patient presented a low-level protocol-defined confirmed virological failure at week 36, being the only observed failure. This patient had pVL <50 copies/mL at the end-of-study visit without having changed the two-drug regimen. Observed failure rate was 5%. This is the first report of integrase strand transfer inhibitor/lamivudine dual regimen in ARV-naive patients.

Conclusions: This novel dual regimen of dolutegravir and lamivudine warrants further clinical research and consideration as a potential therapeutic option for ARV-therapy-naive patients.

ClinicalTrials.gov Identifier: NCT02211482.

When could new antiretrovirals be recommended for national treatment programmes in low-income and middle-income countries: results of a WHO Think Tank

PURPOSE OF REVIEW

To discuss barriers and opportunities for the introduction of new antiretrovirals into national treatment programmes in low-income and middle-income countries to support further treatment scale-up. Invitees to a WHO Think Tank in February 2017 evaluated recently published results.

RECENT FINDINGS

There is not sufficient clinical experience of dolutegravir (DTG), tenofovir alafenamide (TAF) or efavirenz 400 mg (EFV400) to recommend their use in pregnancy. Outcomes from births and assessment of congenital anomalies need to be evaluated from several hundred pregnant women. Clinical experience of these treatments during rifampicin-based treatment for tuberculosis is also required. This could be difficult for TAF, which is currently contraindicated with TAF. Changes in second-line treatment from two nucleoside analogues + protease inhibitor plus ritonavir will require new randomized trials of alternative combinations.

CONCLUSION

Additional safety and efficacy data on DTG, TAF and EFV400 in some subpopulations are needed before a large introduction in national treatment programmes. There is currently limited support for the introduction of TAF as part of first-line antiretroviral treatment in low-income and middle-income settings. There was an overall agreement for 6-monthly reviews of safety and efficacy data, in parallel with a phased introduction of the new antiretrovirals.

Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide: A Review in HIV-1 Infection

Tenofovir alafenamide (tenofovir AF) is a novel oral prodrug of the nucleos(t)ide reverse transcriptase inhibitor (NRTI) tenofovir that has several pharmacological advantages over tenofovir disoproxil fumarate (tenofovir DF), including increased plasma stability and reduced tenofovir systemic exposure. Tenofovir AF has been coformulated with elvitegravir, cobicistat and emtricitabine as a once-daily, single-tablet regimen (elvitegravir/cobicistat/emtricitabine/tenofovir AF; Genvoya(®)) for the treatment of adults and adolescents with HIV-1 infection. With regard to establishing and/or maintaining virological suppression over 48 weeks in randomized, phase III trials, elvitegravir/cobicistat/emtricitabine/tenofovir AF was noninferior to elvitegravir/cobicistat/emtricitabine/tenofovir DF in antiretroviral therapy (ART)-naive adults, and statistically superior (subsequent to established noninferiority) to ongoing treatment with tenofovir DF-containing regimens in ART-experienced adults with virological suppression. In single-arm, phase III trials, elvitegravir/cobicistat/emtricitabine/tenofovir AF also provided high rates of virological suppression among ART-naive adolescents and ART-experienced adults with stable renal impairment. In general, elvitegravir/cobicistat/emtricitabine/tenofovir AF was well tolerated and associated with more favourable renal and bone parameters, but a less favourable lipid profile, than tenofovir DF-containing regimens. Thus, elvitegravir/cobicistat/emtricitabine/tenofovir AF is an alternative single-tablet regimen for adults and adolescents with HIV-1 infection, particularly those with an estimated creatinine clearance of ≥30 to <50 mL/min or an increased risk of tenofovir DF-related bone toxicity.

HIV-protease inhibitors for the treatment of cancer: Repositioning HIV protease inhibitors while developing more potent NO-hybridized derivatives?

The possible use of HIV protease inhibitors (HIV-PI) as new therapeutic option for the treatment of cancer primarily originated from their success in treating HIV-related Kaposi's sarcoma (KS). While these findings were initially attributed to immune reconstitution and better control of oncogenic viral infections, the number of reports on solid tumors, KS, lymphoma, fibrosarcoma, multiple myeloma and prostate cancer suggest other mechanisms for the anti-neoplastic activity of PIs. However, a major drawback for the possible adoption of HIV-PIs in the therapy of cancer relies on their relatively weak anticancer potency and important side effects. This has propelled several groups to generate derivatives of HIV-PIs for anticancer use, through modifications such as attachment of different moieties, ligands and transporters, including saquinavir-loaded folic acid conjugated nanoparticles and nitric oxide (NO) derivatives of HIV-PIs. In this article, we discuss the current preclinical and clinical evidences for the potential use of HIV-PIs, and of novel derivatives, such as saquinavir-NO in the treatment of cancer.

How can we achieve universal access to low-cost treatment for HIV?

Mass production of low-cost antiretrovirals (ARVs) has already allowed over 17 million individuals to access treatment for HIV infection, mainly in low-income countries. It is possible to manufacture combination ARVs for $110 per person-year, using tenofovir (TDF), lamivudine (3TC) and efavirenz (EFV). New combinations of ARVs costing as little as $60 per person-year will be available in the near future. Pre-exposure prophylaxis using TDF in combination with either 3TC or emtricitabine (FTC) could also be provided for less than $90 per person-year. Voluntary licensing allows people in the poorest countries to access new ARVs at prices close to manufacturing costs. Patents on several key ARVs will expire by 2018 and should allow worldwide access to high-quality, low-cost triple combination therapy, such as TDF/3TC/EFV. Several protease inhibitors will also become available as generics by 2018. However, ongoing patent restrictions will lead to sustained high prices for the most recently developed ARVs in most middle- and high-income countries. These include the nucleotide tenofovir alafenamide, the integrase strand inhibitor dolutegravir and several single combination tablet regimens. We suggest that as patents for ARVs expire, health authorities first need to rapidly import and introduce generic versions of drugs such as abacavir, 3TC, EFV and TDF. Once these low prices have been established for these generics, cost-effectiveness of patented ARVs needs to be re-evaluated. It may no longer be justified to pay high prices for these drugs. A strategy of low-cost generic ARVs for most people, with higher-cost patented alternatives used as switch options, could allow for an increased number of people to receive ARVs in the context of fixed health budgets.

Mortality and survival patterns of people living with HIV-2

PURPOSE OF REVIEW

People living with HIV-2 infected usually initiate antiretroviral therapy (ART) at an advanced period in the course of their infection after a long asymptomatic period characterized by high CD4 cell count and thus at a relatively advanced age. In the new international context of early and universal ART initiation, the aim was to review survival patterns among HIV-2 infected patients, either on ART or not.

RECENT FINDINGS

Very few reports were published on mortality in people living with HIV-2 during the last 5 years. People living with HIV-2 experience high mortality rates although lower than people living with HIV-1 before ART initiation. They seem to survive longer regardless of the conditions of ART use. Mortality is associated with late presentation, male sex, CD4 cell count less than 500 cell/μl, high plasma viral load, hemoglobin rate less than 8 g/dl and body mass index less than 18 kg/m.

SUMMARY

People living with HIV-2 initiate ART later than HIV-1 and HIV duals, resulting in higher disease progression and mortality rate. The clinical management of HIV-2 infected patients should now include early diagnosis and treatment initiation as per international guidelines. Further research needs to explore the 'what to start' question and document specific causes of death in people living with HIV-2 and enrolled in care in Africa.