Darunavir/cobicistat for the treatment of HIV-1: a new era for compact drugs with high genetic barrier to resistance

Lessons learnt from the preclinical discovery and development of ensitrelvir as a COVID-19 therapeutic option

INTRODUCTION

The COVID-19 pandemic stimulated the development of several therapeutic tools with several degrees of success. Ensitrelvir, a protease inhibitor that blocks the replication of SARS-CoV-2, can reduce the viral load and the severity of symptoms in infected patients and become available for emergency use in Japan. Clinical trials showed a good tolerability profile although the potential for interactions with substrates, inhibitors, and inducers of CYP3A must be considered. The occurrence of resistance is also a matter of investigation.

AREAS COVERED

In this article, the authors describe the development of ensitrelvir starting from the identification of the molecule to the pre-clinical and clinical trials up to the post-authorization phase.

EXPERT OPINION

Ensitrelvir was developed in a late phase of the pandemic when the availability of patients that can be candidate to enter the clinical trial was limited with consequences for the possibility of assessing certain outcomes and for the robustness of results. Although the evidence about the benefits of ensitrelvir in COVID-19 is not questionable, the problems of interactions with other drugs, emerging resistant variants, the availability of alternative therapeutic options, costs, and accessibility will concur to its probable limited clinical use in the future.

Associations between treatment burden, self-reported treatment qualities, antiretroviral therapy obtainment, and health-related quality of life among Ugandan PLWH

BACKGROUND

Understanding related risk factors of health-related quality of life (HRQoL) could avoid treatment failure and provide an insight of personalized treatment approach among people living with HIV/AIDS (PLWH). The objective of this study was to identify factors associated with self-reported treatment qualities and domains of health-related quality of life (HRQoL) among PLWH in Uganda.

METHOD

Data were from "Life on antiretroviral therapy: People's adaptive coping and adjustment to living with HIV as a chronic condition in Wakiso District, Uganda" in English. The World Health Organization Quality of Life Brief Version (WHOQOL-BREF) questionnaire was used to assess the HRQoL of 263 PLWH in the sample. Considering variance inflation factors, multiple regression analyses were performed to assess the associations between demographic factors, ART obtainment, treatment burden, and self-reported treatment qualities, associations between demographic factors, self-reported treatment qualities, and HRQoL, and association between ART obtainment and HRQoL. Controlling for the confounding effects, several regression anatomies were employed to explore the associations between self-reported treatment qualities and six domains of HRQoL.

RESULTS

In the sample, the geographical distribution were urban (5.70%), semi-urban (37.26%), and rural (57.03%). 67.30% of the participants were females. The mean age of the sample was 39.82 years (standard deviation = 9.76) ranging from 22 to 81 years. Multiple logistic regressions reported statistically significant associations of distance to ART facility with self-reported quality of services, advice, manners, and counseling, statistically significant association between self-reported manners quality and four domains of HRQoL, and statistically significant association between TASO membership and domains of HRQoL. Plots from regression anatomies reported that self-reported treatment qualities had statistically significant associations with six domains of HRQoL.

CONCLUSIONS

Treatment burden, self-reported treatment qualities, ART obtainment, and TASO were possible determinants of individual domains of HRQoL among PLWH in Uganda. PLWH's HRQoL might be improved by promoting medical quality and optimizing ART obtainment in the healthcare providers' practice. Findings in this study had important implications for the redesign of clinical guidelines, healthcare delivery, and health care co-ordination among PLWH globally.

Non-nucleoside structured compounds with antiviral activity—past 10 years (2010–2020)

Nucleosides and their derivatives are a well-known and well-described class of compounds with antiviral activity. Currently, in the era of the COVID-19 pandemic, scientists are also looking for compounds not related to nucleosides with antiviral properties. This review aims to provide an overview of selected synthetic antiviral agents not associated to nucleosides developed against human viruses and introduced to preclinical and clinical trials as well as drugs approved for antiviral therapy over the last 10 years. The article describes for the first time the wide classification of such antiviral drugs and drug candidates and briefly summarizes the biological target and clinical applications of the compounds. The described compounds are arranged according to the antiviral mechanism of action. Knowledge of the drug's activity toward specific molecular targets may be the key to researching new antiviral compounds and repositioning drugs already approved for clinical use. The paper also briefly discusses the future directions of antiviral therapy. The described examples of antiviral compounds can be helpful for further drug development.

Drugs and liver injury: a not to be overlooked binomial in COVID-19

SARS-CoV-2 infection (COVID-19) results predominantly in pulmonary involvement but a direct, virus-induced liver damage may also occur, whose mechanisms are being actively investigated. Accordingly, it appears of utmost importance to monitor liver function and carefully evaluate hepatic safety of the various drugs administered during COVID-19. In this respect, many drugs, biological agents and novel molecules, whose efficacy in COVID-19 is under scrutiny, have also been shown to potentially cause or worsen liver damage. In this article, we review safety data of established as well as promising agents for COVID-19.

Comparative safety review of recommended, first-line single-tablet regimens in patients with HIV

Introduction Different single-tablet regimens (STRs), containing one or two nucleoside reverse transcriptase inhibitors (NRTIs) plus an anchor drug, are available for the use in naïve, HIV-infected patients. Despite some restrictions in the use of particular regimens in certain situations (e.g., HBV coinfection), International guidelines do not provide indications to prefer any regimen over others concerning the tolerability profile. We aimed to assess advantages and disadvantages of the most prescribed STRs.Areas covered An extensive review of articles published in English language was conducted on PubMed, looking for evidence about STRs in naïve, HIV-infected population. Safety outcomes of registrational trials were assessed, giving priority to studies directly comparing STRs included in our research (abacavir/lamivudine/dolutegravir, tenofovir alafenamide/emtricitabine/bictegravir, lamivudine/dolutegravir, tenofovir alafenamide/emtricitabine/darunavir/cobicistat, tenovofir disoproxil fumarate/lamivudine/doravirine). Data from cohort studies and meta-analyses were also assessed, extrapolating the main evidence about the combinations of interest.Expert opinion Integrase inhibitors (InsTIs)-based regimens have few interruptions for adverse events and few drug-related adverse events, with tenofovir alafenamide/emtricitabine/dolutegravir and lamivudine/dolutegravir being the most tolerable ones. However, neuropsychiatric adverse events and metabolic issues could prompt the alternative use of darunavir or doravirine-based combinations, even if a superior safety profile of these combinations over InSTIs has yet to be demonstrated.

Transmitted drug resistance among HIV-1 drug-naïve patients in Greece

OBJECTIVES

Despite the success of antiretroviral treatment (ART), the persisting transmitted drug resistance (TDR) and HIV genetic heterogeneity affect the efficacy of treatment. This study explored the prevalence of TDR among ART-naïve HIV patients in Greece during the period 2016-2019.

METHODS

Genotypic resistance testing was available for 438 ART-naïve HIV patients. Multivariable Poisson regression models were fitted.

RESULTS

The majority of patients were male, and there was a slight predominance of Hellenic (26.5%) over non-Hellenic (21.9%) nationality. The prevalence of TDR was 7.8%. There was a predominance of mutations for non-nucleoside reverse-transcriptase inhibitors (5.7%) over nucleoside reverse-transcriptase inhibitors (0.2%). No mutations to protease inhibitors were detected. The prevalence of resistance was 22.1% based on all mutations identified through the HIVdb interpretation system. The most frequent resistance sites were E138A (9.6%), K103N (6.4%), and K101E (2.1%). The majority of detected mutations were confined to subtype A (52.6%), followed by B (19.6%). Non-Hellenic nationality was significantly associated with an increased risk of TDR (relative risk 1.32, 95% confidence interval 1.04-1.69).

CONCLUSIONS

Non-B HIV infections predominate in Greece, with an increasing trend in recent years. The prevalence of TDR remains stable. Ongoing surveillance of resistance testing is needed to secure the long-term success of ART.

Effectiveness of Switching to Darunavir/Cobicistat in Virologically Suppressed HIV-Positive Patients Receiving Ritonavir-Boosted Protease Inhibitor-Based Regimen: The "STORE" Study

OBJECTIVE

This study investigates the effectiveness and tolerability of switching to a darunavir/cobicistat (DRV/c)-based antiretroviral regimen from a ritonavir-boosted protease inhibitor (PI/r)-based regimen in virologically suppressed HIV-positive patients. DRV trough values were also investigated.

SETTING

Prospective, multicenter, single-country, noninterventional cohort study.

METHODS

This study included patients on a PI/r-based ART for at least 12 months having plasma HIV-1 RNA <50 copies/mL since at least 6 months. The primary endpoint, defined as HIV-1 RNA <50 copies/mL, was measured at 48 ± 6 weeks from baseline. A secondary analysis was performed using the time to loss of virological response algorithm. Biochemical parameters, including DRV trough samples, were collected as per clinical practice and measured using high-performance liquid chromatography.

RESULTS

Of 336 patients enrolled, 282 completed the study: 70.8% had plasma HIV-1 RNA <50 copies/mL at 48 weeks; using the time to loss of virological response algorithm, 82.7% maintained virological suppression. Virological failure was observed in 6 patients (1.8%). Adverse event-related discontinuations were 4.5%. After 48 weeks, we found a significant improvement in both triglycerides (median, 130 to 113.5 mg/dL, P = 0.0254) and high-density lipoprotein cholesterol (48 to 49 mg/dL, P < 0.0001) but no change in other biomarkers. DRV trough concentrations in 56 subjects showed a median value of 2862.5 (1469.5-4439) ng/mL, higher in women than in men (4221 vs. 2634 ng/mL, P = 0.046).

CONCLUSIONS

In stable HIV-1 positive virologically suppressed patients, the switch to DRV/c-based ART was beneficial in terms of low rates of virological failure and adverse events due to its high tolerability and improvement in triglycerides.

Druggable targets of SARS-CoV-2 and treatment opportunities for COVID-19

COVID-19 caused by the novel SARS-CoV-2 has been declared a pandemic by the WHO is causing havoc across the entire world. As of May end, about 6 million people have been affected, and 367 166 have died from COVID-19. Recent studies suggest that the SARS-CoV-2 genome shares about 80% similarity with the SARS-CoV-1 while their protein RNA dependent RNA polymerase (RdRp) shares 96% sequence similarity. Remdesivir, an RdRp inhibitor, exhibited potent activity against SARS-CoV-2 in vitro. 3-Chymotrypsin like protease (also known as Mpro) and papain-like protease, have emerged as the potential therapeutic targets for drug discovery against coronaviruses owing to their crucial role in viral entry and host-cell invasion. Crystal structures of therapeutically important SARS-CoV-2 target proteins, namely, RdRp, Mpro, endoribonuclease Nsp15/NendoU and receptor binding domain of CoV-2 spike protein has been resolved, which have facilitated the structure-based design and discovery of new inhibitors. Furthermore, studies have indicated that the spike proteins of SARS-CoV-2 use the Angiotensin Converting Enzyme-2 (ACE-2) receptor for its attachment similar to SARS-CoV-1, which is followed by priming of spike protein by Transmembrane protease serine 2 (TMPRSS2) which can be targeted by a proven inhibitor of TMPRSS2, camostat. The current treatment strategy includes repurposing of existing drugs that were found to be effective against other RNA viruses like SARS, MERS, and Ebola. This review presents a critical analysis of druggable targets of SARS CoV-2, new drug discovery, development, and treatment opportunities for COVID-19.

Emerging Therapeutic Modalities against COVID-19

The novel SARS-CoV-2 virus has quickly spread worldwide, bringing the whole world as well as the economy to a standstill. As the world is struggling to minimize the transmission of this devastating disease, several strategies are being actively deployed to develop therapeutic interventions. Pharmaceutical companies and academic researchers are relentlessly working to investigate experimental, repurposed or FDA-approved drugs on a compassionate basis and novel biologics for SARS-CoV-2 prophylaxis and treatment. Presently, a tremendous surge of COVID-19 clinical trials are advancing through different stages. Among currently registered clinical efforts, ~86% are centered on testing small molecules or antibodies either alone or in combination with immunomodulators. The rest ~14% of clinical efforts are aimed at evaluating vaccines and convalescent plasma-based therapies to mitigate the disease's symptoms. This review provides a comprehensive overview of current therapeutic modalities being evaluated against SARS-CoV-2 virus in clinical trials.

Patient-Reported Outcomes in an Observational Cohort of HIV-1-Infected Adults on Darunavir/Cobicistat-Based Regimens: Beyond Viral Suppression

OBJECTIVE

This prospective, multicenter, non-interventional cohort study enrolling human immunodeficiency virus (HIV)-1-infected, virally suppressed adult outpatients in Italy aimed to describe results obtained from patient-reported outcome questionnaires regarding treatment satisfaction and symptom perceptions in HIV-1-positive patients who switched to cobicistat-boosted darunavir antiretroviral regimens, coming from ritonavir-boosted protease inhibitors.

METHODS

Patients entered this study between June 2016 and February 2017, once their treating physician had considered them eligible for cobicistat-boosted darunavir-based treatment as per clinical practice. Patients' satisfaction regarding regimen and current symptom burdens were assessed using two previously validated, patient-reported outcome questionnaires: HIV Treatment Satisfaction Questionnaire (HIV-TSQ) and HIV Symptoms Distress Module (HIV-SDM). These questionnaires were administered at prespecified time-points: enrollment (Visit 1), 4-8 weeks later (Visit 2), and 48 ± 6 weeks after study enrollment (Visit 4). Data of patient-reported outcome total scores for both questionnaires are presented as median with 25th-75th percentiles. Questionnaires scores were analyzed overall and stratified by gender when applicable. A p value of less than 0.05 was considered statistically significant. A sensitivity analysis was conducted to evaluate the role of lost to follow-up, using the "last observation carried forward" method.

RESULTS

A total of 348 patients were enrolled in this study; 296 patients (208 male and 88 female) provided both evaluable HIV-TSQ and HIV-SDM at enrollment and at 4-8 weeks, while 250 patients (174 male and 76 female) provided questionnaire data at enrollment and at 48 ± 6 weeks. The total scores of HIV-TSQ showed improvements in patient satisfaction in the overall population both at Visit 2 and Visit 4 (p < 0.001, sign test) and also when stratified by gender throughout the study period. In addition, the overall burden of symptoms, as shown by the HIV-SDM scores, decreased.

CONCLUSIONS

Switching to a cobicistat-boosted darunavir-based therapy led to overall increased patient satisfaction and reduced symptom burden when compared with previous regimens. The use of patient-reported outcomes in clinical daily practice could provide a useful tool towards achieving guideline goals to achieve "fourth 90", having 90% of virally suppressed patients with a good health-related quality of life.

Switching strategies in the recent era of antiretroviral therapy

INTRODUCTION

Although antiretroviral therapy is highly effective, many patients may benefit from switching strategies. Rapid advances in the development of new antiretroviral drugs could enhance the success of these approaches. In this review, we build on a previous review from 2014 and summarize the current options for switching strategies in virologically suppressed HIV-infected patients. Areas covered: We conduct a critical analysis of scientific evidence for various switching strategies used in the modern era of antiretroviral therapy, as well as reasons for these approaches, other considerations to be taken into account, and alternative strategies. Expert opinion: Current antiretroviral regimens are effective and well tolerated in HIV patients. A number of options may provide benefit to patients, even virologically suppressed patients, possibly enhancing adherence and avoiding adverse effects and toxicities. Cost reduction may also be an important goal of switching strategies. The present scenario is excellent, as many good antiretroviral compounds and regimens allow clinicians to further improve on effective treatments now used in routine practice. Even the current paradigm of triple-drug regimens as the standard of care could change, at least in some patients.

Compliance with clinical guidelines and adherence to antiretroviral therapy among patients living with HIV

Objective: Evaluation of provider compliance with antiretroviral (ARV) treatment guidelines and patient adherence to ARVs is important for HIV care quality assessment; however, there are few current real-world data for guideline compliance and ARV adherence in the US. This study evaluated provider compliance with US Department of Health and Human Services (DHHS) guidelines and patient adherence to ARVs in a US population of patients with HIV.Methods: This was a retrospective claims study of adults with HIV-1 receiving ARV treatment between January 2010-December 2014. Follow-up began at first ARV treatment and ended at health plan disenrollment or study end. ARV regimens for treatment-naïve patients were categorized as "preferred/recommended", "alternative", or "non-preferred/recommended/alternative" according to DHHS guidelines. ARV adherence was evaluated using proportion of days covered (PDC) and medication possession ratio (MPR).Results: The analysis included 25,320 patients (84.4% male, mean age 45.3 years) and 39,071 regimens. Preferred/recommended regimens were most common during each study year, but the proportion of non-preferred/recommended/alternative regimens was substantial (15.9-20.6%). Only 53.6% of patients had optimal adherence by PDC ≥0.95, and 57.9% by MPR ≥0.95. Guideline non-compliance and sub-optimal adherence were more prevalent among female vs male patients (22.6% vs 14.8% [in 2014] and 65.9% vs 53.7%, respectively).Conclusions: Provider non-compliance with DHHS guidelines and sub-optimal ARV adherence among patients with HIV remain common in real-world practice, particularly for female patients. Healthcare providers should follow the latest clinical guidelines to ensure that patients receive recommended therapy, and address non-adherence when selecting ARV regimens.

Darunavir-cobicistat-emtricitabine-tenofovir alafenamide: safety and efficacy of a protease inhibitor in the modern era

A fixed-dose combination consisting of darunavir (Drv), cobicistat (Cobi), emtricitabine (2′,3′-dideoxy-5-fluoro-3′-thiacytidine [FTC]), and tenofovir alafenamide (Taf) has been recently approved by the European Medicines Agency for the treatment of HIV infection, and is the first ever protease-inhibitor-based single-tablet regimen. This article provides a detailed description of its pharmacokinetic, efficacy, and safety profile. The pharmacokinetics of single compounds were analyzed, with a special focus on contrasts between Drv/Cobi and Drv/ritonavir (Rtv). When comparing Cobi and Rtv, multiple interactions must be taken into account: in comparison to Rtv, Cobi is a more selective CYP3A4 inhibitor and has no clinical effect on other isoenzymes inhibited by Rtv (eg, 2C8 and 2C9). Moreover, unlike Cobi, Rtv shows in vivo induction activity on some CYP isoenzymes (eg, 1A2, 2C19, 2C8, 2C9, and 2B6), glucuronyltransferases (eg, UGT1A4), and Pgp. Drv-Cobi-FTC-Taf has recently been demonstrated to be of equal efficacy to Drv-Rtv and other protease inhibitors in both experienced (EMERALD study) and naïve (AMBER study) patients. Moreover, kidney and bone safety profiles have been shown to be good, as has central nervous system tolerance. Total cholesterol:low-density-lipoprotein cholesterol and total cholesterol:high-density-lipoprotein cholesterol ratios are generally high in Drv-Cobi-FTC-Taf vs Rtv-Drv-FTC + tenofovir disoproxil fumarate. An unlikely role of Drv in influencing cardiovascular risk in HIV infection has also been reported. Kidney safety profile is influenced by Cobi, with an increase in creatinine plasma concentration of 0.05–0.1 mg/dL and a parallel glomerular filtration-rate reduction of 10 mL/min within the first 4 weeks after Cobi introduction, which remains stable during treatment. Bone and central nervous system safety profiles were found to be good in randomized clinical trials of both experienced and naïve patients. The efficacy and safety of Drv/Cobi/FTC/Taf are comparable to other drug regimens recommended for HIV treatment.

Efficacy of single-tablet darunavir, cobicistat, emtricitabine, and tenofovir alafenamide in the treatment of HIV-1

INTRODUCTION

HIV eradication is not feasible and lifelong treatment is warranted to manage HIV infection. In this scenario, the advent of single-tablet, once-daily, fixed-dose co-formulations is important for reducing pill burden and maximize long-term drug adherence. Cobicistat-boosted darunavir along with emtricitabine and tenofovir alafenamide co-formulation (DRV/c/FTC/TAF or the trade name Symtuza®) is the first marketed protease inhibitor-based fixed-dose combination regimen for the treatment of HIV infection. It was approved in late 2017 by the European Medical Agency both for naïve patients and treatment-experienced patients with viral suppression. Areas covered: PubMed, ClinicalTrials.gov and presentations at scientific meetings were searched with the terms 'darunavir/cobicistat' and 'tenofovir alafenamide and emtricitabine' for clinical trials either conducted to date or ongoing as well as a review of abstracts from major HIV/AIDS and infectious diseases conferences from 2015 to up to date. Expert opinion: DRV/c/FTC/TAF is a novel unique antiretroviral drug co-formulation that exhibits a convenient dosing, satisfactory safety profile, and high antiviral efficacy, even in patients harboring viruses with resistance to antivirals other than darunavir in the short-midterm. It represents the first fixed-dose combination therapy including a protease inhibitor given as one single pill once daily for drug-naïve patients and as second-line antiretroviral therapy.

Efficacy and safety of boosted darunavir-based antiretroviral therapy in HIV-1-positive patients: results from a meta-analysis of clinical trials

Darunavir/ritonavir (DRV/r) is a second-generation protease inhibitor used in treatment-naïve and -experienced HIV-positive adult patients. To evaluate efficacy and safety in these patient settings, we performed a meta-analysis of randomized controlled trials. We considered eight studies involving 4240 antiretroviral treatment (ART)-naïve patients and 14 studies involving 2684 ART-experienced patients. Regarding efficacy in the ART-naive patients, the virological response rate was not significantly different between DRV/r and the comparator. For the ART-experienced failing patients, the virological response rate was significantly higher with DRV/r than with the comparator (RR 1.45, 95% CI: 1.01-2.08); conversely, no significant differences were found between the treatment-experienced and virologically controlled DRV/r and comparator groups. Regarding safety, the discontinuation rates due to adverse events (AEs) and DRV/r-related serious adverse events (SAEs) did not significantly differ from the rates in the comparator group (RR 0.84, 95% CI: 0.59-1.19 and RR 0.78, 95% CI: 0.57-1.05, respectively). Our meta-analysis indicated that DRV/r-based regimens were effective and tolerable for both types of patients, which was consistent with published data.

Effectiveness, Safety, and Tolerability of a Switch to Dual Therapy with Dolutegravir Plus Cobicistat-Boosted Darunavir in Treatment-Experienced Patients with Human Immunodeficiency Virus

BACKGROUND

Dual regimen with dolutegravir plus cobicistat-boosted darunavir (DTG/DRV/c) is reasonable alternative option for patients with existing resistance and/or intolerance to nucleoside reverse transcriptase inhibitors (NRTIs).

MATERIAL AND METHODS

All patients who switched to DTG/DRV/c among treatment-experienced patients with human immunodeficiency virus (HIV) in a tertiary university hospital were selected. We analyzed the effectiveness, safety, and tolerability based on serial laboratory data and clinical findings. The primary endpoint was defined as the proportion of patients with plasma HIV RNA below 50 copies/mL at week 48 after switch. Secondary endpoints included evaluation of safety and tolerability.

RESULTS

Thirty-one patients were retrospectively analyzed. The main reasons for the change to DTG/DRV/c were treatment failure in 13 patients (41.9%), simplification in 12 patients (38.7%), and adverse drug reaction in 6 patients (19.4%). Among the 13 patients who switched owing to treatment failure, the proportion of patients in whom the viral loads were suppressed to less than 50 copies/mL increased from 0% at baseline to 45% at 4 weeks, 50% at 12 weeks, 50% at 24 weeks, and 66.7% at 48 weeks. HIV virus levels decreased and CD4⁺ T cell counts increased during the follow-up period. In non-treatment failure patients (18 patients), the levels of viral suppression and CD4⁺ T cells were maintained. There were no significant differences in renal function, liver function, glucose levels, and lipid profile before and after regimen changes. The tolerability was very good: 30 patients (96.8%) tolerated the drugs well and only 1 patient discontinued owing to no improvement in renal insufficiency. Two patients (6.4%) in treatment failure group failed to reach viral suppression.

CONCLUSION

The use of DTG/DRV/c in HIV treatment-experienced patients appears to be a very good regimen for switch therapy that is effective and well tolerated, without significant adverse drug reaction.

Differential Effects of Antiretroviral Drugs on Neurons In Vitro: Roles for Oxidative Stress and Integrated Stress Response

Mounting evidence suggests that antiretroviral drugs may contribute to the persistence of HIV-associated neurocognitive disorders (HAND), which impact 30%-50% of HIV-infected patients in the post-antiretroviral era. We previously reported that two first generation HIV protease inhibitors, ritonavir and saquinavir, induced oxidative stress, with subsequent neuronal death in vitro, which was reversed by augmentation of the endogenous antioxidant response by monomethyl fumarate. We herein determined whether two newer-generation PIs, darunavir and lopinavir, were deleterious to neurons in vitro. Further, we expanded our assessment to include three integrase strand transfer inhibitors, raltegravir, dolutegravir, and elvitegravir. We found that only lopinavir and elvitegravir were neurotoxic to primary rat neuroglial cultures as determined by the loss of microtubule-associated protein 2 (MAP2). Intriguingly, lopinavir but not elvitegravir led to oxidative stress and induced the endogenous antioxidant response (EAR). Furthermore, neurotoxicity of lopinavir was blocked by pharmacological augmentation of the endogenous antioxidant heme oxygenase-1 (HO-1), expanding our previous finding that protease inhibitor-induced neurotoxicity was mediated by oxidative stress. Conversely, elvitegravir but not lopinavir led to increased eIF2α phosphorylation, indicating the activation of a common adaptive pathway termed the integrated stress response (ISR), and elvitegravir-mediated neurotoxicity was partially alleviated by the ISR inhibitor trans-ISRIB, suggesting ISR as a promoter of elvitegravir-associated neurotoxicity. Overall, we found that neurotoxicity was induced only by a subset of protease inhibitors and integrase strand transfer inhibitors, providing evidence for class- and drug-specific neurotoxic effects of antiretroviral drugs. Future in vivo studies will be critical to confirm the neurotoxicity profiles of these drugs for incorporation of these findings into patient management. The EAR and ISR pathways are potential access points for the development of adjunctive therapies to complement antiretroviral therapies and limit their contribution to HAND persistence.

[HIV infection : Test and treatment]

In Europe depending on the country 15-80 % of all individuals infected with human immunodeficiency virus (HIV) are either not aware of the diagnosis or are diagnosed later. An early HIV diagnosis could, however, considerably improve the prognosis of individuals infected with HIV and decrease the risk of new infections; therefore, in the presence of indicator diseases, such as sexually transmitted diseases, oral thrush, herpes zoster and lymphoma, the performance of a HIV test is of utmost importance. A newly diagnosed HIV infection represents an indication for starting antiretroviral combination therapy independent of the clinical stage or CD4 cell count. A decline of the viral burden to below the limit of detection and subsequent continuous suppression of viral replication can prevent transition from HIV to acquired immune deficiency syndrome (AIDS) and if started early enough a normal life expectancy can be achieved. Challenges which remain in HIV therapy are the lifelong daily intake of medication and the complex long-term adverse effects.

Significant improvement in triglyceride levels after switching from ritonavir to cobicistat in suppressed HIV-1-infected subjects with dyslipidaemia

OBJECTIVES

Cobicistat seems to have a low rate of adverse events compared with ritonavir.

METHODS

This restrospective observational study to evaluated changes in lipid parameters and the percentage of subjects with dyslipidemia in virologically suppressed HIV-infected patients who were receiving a regimen containing darunavir/ritonavir and were then switched from ritonavir to cobicistat, carried out from December 2015 to May 2016, included 299 HIV-1-infected patients who were on stable antiretroviral treatment including darunavir/ritonavir (monotherapy, bitherapy or triple therapy for at least 6 months) and were then switched from ritonavir to cobicistat. Lipid parameters, as well as plasma HIV-1 RNA and CD4 cell counts, were recorded at baseline just before the switch, and 24 weeks after the switch. Patients were stratified according to the presence of hypercholesterolaemia [baseline total cholesterol > 200 mg/dL and/or low-density lipoprotein (LDL) cholesterol > 130 mg/dL] or hypertriglyceridaemia (baseline triglyceride levels > 200 mg/dL).

RESULTS

Two hundred and ninety-nine patients were enrolled in the study. Fifty-two per cent of the total study population showed dyslipidaemia at baseline. All patients maintained HIV-1 RNA ≤ 50 HIV-1 RNA copies/mL at week 24. No statistically significant changes were seen in CD4 T-cell count from baseline to week 24 [654 (298) to 643 (313) cells/μL; P = 0.173]. When patients were stratified according to the presence of hypercholesterolaemia at baseline (n = 124), significant changes were observed in total cholesterol (P < 0.001), LDL cholesterol (P = 0.047), high-density lipoprotein (HDL) cholesterol (P = 0.002) and triglyceride levels (P = 0.025), and when they were stratified according to the presence of hypertriglyceridaemia at baseline (n = 64), changes from baseline to week 24 in triglyceride level were statistically significant [median (interquartile range) 352 (223, 389) mg/dL at baseline and 229 (131, 279) mg/dL at week 24; P < 0.001].

CONCLUSIONS

Cobicistat as a booster of darunavir in HIV-infected subjects had a beneficial effect on the lipid profile in patients with hypercholesterolaemia or hypertrigliceridaemia at baseline.

Interaction of Rifampin and Darunavir-Ritonavir or Darunavir-Cobicistat In Vitro

Treatment of HIV-infected patients coinfected with Mycobacterium tuberculosis is challenging due to drug-drug interactions (DDIs) between antiretrovirals (ARVs) and antituberculosis (anti-TB) drugs. The aim of this study was to quantify the effect of cobicistat (COBI) or ritonavir (RTV) in modulating DDIs between darunavir (DRV) and rifampin (RIF) in a human hepatocyte-based in vitro model. Human primary hepatocyte cultures were incubated with RIF alone or in combination with either COBI or RTV for 3 days, followed by coincubation with DRV for 1 h. The resultant DRV concentrations were quantified by high-performance liquid chromatography with UV detection, and the apparent intrinsic clearance (CL_int.app.) of DRV was calculated. Both RTV and COBI lowered the RIF-induced increases in CL_int.app. in a concentration-dependent manner. Linear regression analysis showed that log₁₀ RTV and log₁₀ COBI concentrations were associated with the percent inhibition of RIF-induced elevations in DRV CL_int.app., where β was equal to -234 (95% confidence interval [CI] = -275 to -193; P < 0.0001) and -73 (95% CI = -89 to -57; P < 0.0001), respectively. RTV was more effective in lowering 10 μM RIF-induced elevations in DRV CL_int.app. (half-maximal [50%] inhibitory concentration [IC₅₀] = 0.025 μM) than COBI (IC₅₀ = 0.223 μM). Incubation of either RTV or COBI in combination with RIF was sufficient to overcome RIF-induced elevations in DRV CL_int.app., with RTV being more potent than COBI. These data provide the first in vitro experimental insight into DDIs between RIF and COBI-boosted or RTV-boosted DRV and will be useful to inform physiologically based pharmacokinetic (PBPK) models to aid in optimizing dosing regimens for the treatment of patients coinfected with HIV and M. tuberculosis.