Simultaneous pharmacokinetic modeling of unbound and total darunavir with ritonavir in adolescents: a substudy of the SMILE trial.

Darunavir (DRV) is an HIV protease inhibitor commonly used as part of antiretroviral treatment regimens globally for children and adolescents. It requires a pharmacological booster, such as ritonavir (RTV) or cobicistat. To better understand the pharmacokinetics (PK) of DRV in this younger population and the importance of the RTV boosting effect, a population PK substudy was conducted within SMILE trial, where the maintenance of HIV suppression with once daily integrate inhibitor + darunavir/ritonavir in children and adolescents is evaluated. A joint population PK model that simultaneously used total DRV, unbound DRV, and total RTV concentrations was developed. Competitive and non-competitive models were examined to define RTV's influence on DRV pharmacokinetics. Linear and non-linear equations were tested to assess DRV protein binding. A total of 443 plasma samples from 152 adolescents were included in this analysis. Darunavir PK was best described by a one-compartment model first-order absorption and elimination. The influence of RTV on DRV pharmacokinetics was best characterized by ritonavir area under the curve on DRV clearance using a power function. The association of non-linear and linear equations was used to describe DRV protein binding to alpha-1 glycoprotein and albumin, respectively. In our population, simulations indicate that 86.8% of total and unbound DRV trough concentrations were above 0.55 mg/L [10 times protein binding-adjusted EC50 for wild-type (WT) HIV-1] and 0.0243 mg/L (10 times EC90 for WT HIV-1) targets, respectively. Predictions were also in agreement with observed outcomes from adults receiving 800/100 mg DRV/r once a day. Administration of 800/100 mg of DRV/r once daily provides satisfactory concentrations and exposures for adolescents aged 12 years and older.

Machine learning-guided design of potent darunavir analogs targeting HIV-1 proteases: A computational approach for antiretroviral drug discovery.

In the pursuit of novel antiretroviral therapies for human immunodeficiency virus type-1 (HIV-1) proteases (PRs), recent improvements in drug discovery have embraced machine learning (ML) techniques to guide the design process. This study employs ensemble learning models to identify crucial substructures as significant features for drug development. Using molecular docking techniques, a collection of 160 darunavir (DRV) analogs was designed based on these key substructures and subsequently screened using molecular docking techniques. Chemical structures with high fitness scores were selected, combined, and one-dimensional (1D) screening based on beyond Lipinski's rule of five (bRo5) and ADME (absorption, distribution, metabolism, and excretion) prediction implemented in the Combined Analog generator Tool (CAT) program. A total of 473 screened analogs were subjected to docking analysis through convolutional neural networks scoring function against both the wild-type (WT) and 12 major mutated PRs. DRV analogs with negative changes in binding free energy ( ΔΔ G bind ) compared to DRV could be categorized into four attractive groups based on their interactions with the majority of vital PRs. The analysis of interaction profiles revealed that potent designed analogs, targeting both WT and mutant PRs, exhibited interactions with common key amino acid residues. This observation further confirms that the ML model-guided approach effectively identified the substructures that play a crucial role in potent analogs. It is expected to function as a powerful computational tool, offering valuable guidance in the identification of chemical substructures for synthesis and subsequent experimental testing.

Daily ritonavir-boosted darunavir for viral suppression in pregnancy (DRV-P).

BACKGROUND: Ritonavir-boosted darunavir (DRV/r) is a preferred protease inhibitor in pregnant women living with HIV. Current practice at British Columbia's referral centre (the Oak Tree Clinic) is to dose DRV/r as 800/100 mg daily throughout pregnancy, although some guidelines recommend DRV/r 600/100 mg twice daily due to altered pharmacokinetics with once-daily dosing. OBJECTIVES: We describe the effect of once-daily DRV/r on viral suppression, vertical transmission, adverse drug effects and adherence in pregnant women living with HIV. METHODS: This was a retrospective analysis of pregnant women living with HIV in British Columbia. Eligible women gave birth between January 2015 and August 2021, and took DRV/r 800/100 mg daily at any time during pregnancy. RESULTS: Thirty-four women were included in this study. The mean (SD) age was 33 (5) years. Thirty (88%) women were diagnosed with HIV prior to pregnancy, with 22 (73%) having viral suppression at baseline. Four (12%) were diagnosed in pregnancy, with a median baseline viral load of 9616 copies/mL (range 8370-165 000). Viral suppression was achieved by 16 (100%), 24 (75%) and 26 (74%) women in the first, second and third trimesters, respectively. No vertical transmission occurred. This combination was well tolerated, with adverse drug effects that did not result in discontinuation or change in therapy. Most women maintained >75% adherence to once-daily DRV/r at all times during pregnancy. CONCLUSIONS: Ritonavir-boosted darunavir 800/100 mg daily appears to be an appropriate dosing strategy for pregnant women living with HIV who are able to maintain optimal adherence.

Rational design, synthesis and biological evaluation of novel HIV-1 protease inhibitors containing 2-phenylacetamide derivatives as P2 ligands with potent activity against DRV-Resistant HIV-1 variants.

A novel kind of potent HIV-1 protease inhibitors, containing diverse hydroxyphenylacetic acids as the P2-ligands and 4-substituted phenyl sulfonamides as the P2' ligands, were designed, synthesized and evaluated in this work. Majority of the target compounds exhibited good to excellent activity against HIV-1 protease with IC50 values below 200 nM. In particular, compound 18d with a 2-(3,4-dihydroxyphenyl) acetamide as the P2 ligand and a 4- methoxybenzene sulfonamide P2' ligand exhibited inhibitory activity IC50 value of 0.54 nM, which was better than that of the positive control darunavir (DRV). More importantly, no significant decline of the potency against HIV-1DRVRS (DRV-resistant mutation) and HIV-1NL4_3 variant (wild type) for 18d was detected. The molecular docking study of 18d with HIV-1 protease (PDB-ID: 1T3R, www.rcsb.org) revealed possible binding mode with the HIV-1 protease. These results suggested the validity of introducing phenol-derived moieties into the P2 ligand and deserve further optimization which was of great value for future discovery of novel HIV-1 protease.

Plasma Concentrations of Rosmarinic Acid in Patients on Antiretroviral Therapy: In Silico Exploration Based on Clinical Data.

Rosmarinic acid (RA) is a phenolic compound with antiviral properties, often encountered in dietary supplements and herbal drugs. Data on the pharmacokinetics of RA are lacking in cases of the chronic use of supplements containing this compound, and only limited data on the metabolism and distribution of RA are available. The aim of the study was to investigate the plasma levels of RA after 12 weeks of use and determine potential interactions of RA and selected antiretroviral drugs. Patients infected with human immunodeficiency virus took a supplement containing RA for 12 weeks, after which the RA concentrations in the plasma samples were analyzed. A detailed in silico analysis was conducted in order to elucidate the potential interactions between RA and the drugs efavirenz, darunavir and raltegravir. It was found that RA can be detected in patients' plasma samples, mainly in the form of sulphoglucuronide. The potential interactions are suggested on the level of liver metabolizing enzymes and efflux P-glycoprotein, with RA competing with antiretroviral drugs as a substrate in metabolism and distribution systems. The present study suggests that the simultaneous use of RA and antiretroviral therapy (containing efavirenz, darunavir or raltegravir) may affect the plasma levels of RA after prolonged supplementation.

Darunavir/cobicistat/emtricitabine/tenofovir alafenamide in treatment-naïve (AMBER) and virologically suppressed (EMERALD) participants with neurological and/or psychiatric comorbidities: Week 96 subgroup analysis.

OBJECTIVE: Our objective was to evaluate the prevalence of pre-existing neurological and/or psychiatric comorbidities (NPCs) and efficacy/safety outcomes for participants with versus without baseline NPCs in AMBER and EMERALD. METHODS: AMBER (treatment-naïve population) and EMERALD (virologically suppressed population) were phase III randomized studies of darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg. The primary objective of this post hoc analysis was to assess virological response (HIV-1 RNA <50 copies/mL) at week 48 by intent-to-treat US Food and Drug Administration snapshot analysis comparing participants with and without baseline NPCs. RESULTS: Among participants in AMBER, 88/362 (24%) in the D/C/F/TAF arm and 99/363 (27%) in the control arm had baseline NPCs; in EMERALD, 294/763 (39%; D/C/F/TAF) and 166/378 (44%; control) participants had baseline NPCs. At baseline, psychiatric NPCs were more common than neurological NPCs in both studies; the most common of each type were depression and headache, respectively. High virological response rates were achieved with D/C/F/TAF across studies regardless of baseline NPCs at weeks 48 (range 86%-95%) and 96 (range 80%-91%). No participants in either study with a baseline NPC prematurely discontinued because of a study drug-related neurological or psychiatric adverse event. CONCLUSION: D/C/F/TAF may be a suitable treatment option for individuals with HIV-1 and NPCs.

Evaluation of darunavir-derived HIV-1 protease inhibitors incorporating P2' amide-derivatives: Synthesis, biological evaluation and structural studies.

We report here the synthesis and biological evaluation of darunavir derived HIV-1 protease inhibitors and their functional effect on enzyme inhibition and antiviral activity in MT-2 cell lines. The P2' 4-amino functionality was modified to make a number of amide derivatives to interact with residues in the S2' subsite of the HIV-1 protease active site. Several compounds exhibited picomolar enzyme inhibitory and low nanomolar antiviral activity. The X-ray crystal structure of the chloroacetate derivative bound to HIV-1 protease was determined. Interestingly, the active chloroacetate group converted to the acetate functionality during X-ray exposure. The structure revealed that the P2' carboxamide functionality makes enhanced hydrogen bonding interactions with the backbone atoms in the S2'-subsite.

Quality by design tool-evaluated stability-indicating ultra-performance liquid chromatography method for the determination of drugs (ritonavir and darunavir) used to treat the human immunodeficiency virus/acquired immunodeficiency syndrome.

Ritonavir and darunavir were examined using a ultra-performance liquid chromatography (UPLC) approach in pharmaceutical dosage forms. The small number of analytical studies that are currently available do not demonstrate the method's stability or nature. The study sought to assess both chemicals using a stability-indicating approach with a relatively short run time. The HSS C18 (100 × 2.1 mm), 2-mm column was used for the chromatographic separation, and isocratic elution was used to achieve this. In the mobile phase, methanol and 0.01 M phosphate buffer (pH 4.0) were included in a 60:40 (v/v) ratio. Throughout the analysis, the flow rate was kept at 0.2 mL min-1 , and a photodiode array detector set to 266 nm was used to find the major components. The proposed method showed a linear response (r2  > 0.999), and the accuracy was between 98.0% and 102.0%. The precision data showed relative standard deviation ≤1.0%. The UPLC method for quantification of ritonavir and darunavir in pharmaceutical dosage forms using a very short run time of under a minute is the subject of the proposed article. To meet current regulatory criteria, the quality by design idea was used in the method performance verification.

Identification, Isolation, and Structural Characterization of Novel Forced Degradation Products of Darunavir Using Advanced Analytical Techniques Like UPLC-MS, Prep-HPLC, HRMS, NMR, and FT-IR Spectroscopy.

Since the stability of the pharmaceuticals plays a crucial role in efficacy and safety while using them in the treatment of disorders, the evaluation of purity and impurity profiling of pharmaceuticals is of utmost importance using efficient analytical techniques. The present study explains the identification, isolation, and characterization of stress degradation products of the anti-human immunovirus drug Darunavir. The degradation study was performed to evaluate the stability profile of Darunavir in different stress conditions like hydrolytic, oxidative, thermal, and photolytic conditions as per the ICH guidelines. Degradation products were identified using ultra-performance liquid chromatography coupled with mass spectrometry, isolated using semi-preparative high-performance liquid chromatography, and structural characterization by HRMS and 1H, 13C NMR (1D, 2D). Darunavir is relatively stable in oxidative, thermal, and photolytic conditions; however, considerable degradation was observed in acid and base hydrolysis. A total of five degradation products were identified and isolated in acid and base degradation. DP-1, DP -2, & DP-3 were observed in acid conditions, whereas in base conditions, along with DP-2, two more DPs, i.e., DP-4 & DP-5, were identified. Among the five DPs, two degradation products, namely DP-1: N-(4-(N-(3-amino-2-hydroxy-4-phenylbutyl)-N-isobutylsulfamoyl) phenyl) acetimidamide. & DP-3: hexahydrofuro[2,3-b]furan-3-yl(4-((4-acetimidamido-N-isobutylphenyl)sulfonamido)-3-hydroxy-1-phenylbutan-2-yl)carbamate, are novel, remaining degradation products DP-2: 4-amino-N-(3-amino-2-hydroxy-4-phenylbutyl)-N-isobutylbenzenesulfonamide, DP-4: 4-amino-N-(((5S)-4-benzyl-2-oxooxazolidin-5-yl) methyl) -N-isobutyl benzenesulfonamide and DP-5: methyl ((3S)-4-((4-amino-N-isobutylphenyl) sulfonamido)-3-hydroxy-1-phenylbutan-2-yl) carbamate are already reported tentatively using a single analytical technique coupled with mass analysis without any evidence from NMR and IR data. Hence, the present study focused on using High-Resolution Mass, 1D, and 2D 1H, 13C NMR data for concrete confirmation of structures for degradation products. Supplementary Information: The online version contains supplementary material available at 10.1007/s10337-022-04226-z.

PRESTIGIO RING: "A 59-year-old HIV-1 positive, highly treatment-experienced woman failing darunavir/ ritonavir plus raltegravir".

Management of heavily treatment experienced (HTE) people with HIV remains a challenge. Tailored antiretroviral therapy (ART) is needed in this fragile population who almost invariably harbor viral quasispecies with resistance-associated mutations (RAMs). The reference method for HIV genotypic resistance testing (GRT) has long been Sanger sequencing (SS), but next-generation sequencing (NGS), following recent progress in workflow and cost-effectiveness, is replacing SS because of higher sensitivity. From the PRESTIGIO Registry, we present a case of a 59-year-old HTE woman who failed darunavir/ritonavir plus raltegravir at low-viremia levels due mainly to high pill burden and poor adherence. NGS-GRT was performed on HIV-RNA at failure and the results were compared to all past SS-GRT data available (historical genotype). In this case, NGS-GRT did not detect any minority drug-resistant variants. After discussing several therapeutic options, the treatment was changed to dolutegravir 50 mg twice daily plus doravirine 100 mg once a day, based on clinical history, adherence issues, and pill burden, as well as the historical SS-GRT and the latest NGS-GRT results. At six months follow-up visit, the patient had HIV-RNA below 30 copies/ml and CD4+ T cell count increased from 673 cells/ mm3 to 688 cells/ mm3. Close follow-up of this patient is ongoing.

Repurposing HIV Protease Inhibitors Atazanavir and Darunavir as Antifungal Treatments against Candida albicans Infections: An In Vitro and In Vivo Study.

Candida albicans is the chief etiological agent of candidiasis, a mycosis prevalent in individuals with acquired immunodeficiency syndrome (AIDS). In recent years, the introduction of human immunodeficiency virus (HIV) protease inhibitors (HIV-PI) has reduced the prevalence of candidiasis in these patients. Seeking new therapeutic strategies based on the perspective of drug repositioning, we evaluated the effects of two second-generation HIV-PIs, atazanavir (ATV) and darunavir (DRV), on virulence factors of C. albicans and experimental candidiasis. For this, clinical strains of C. albicans were subjected to in vitro and in vivo treatments with ATV or DRV. As a result, ATV and DRV exhibited antifungal activity against fungal cells at 512 µg/mL, reduced the viability and biomass of biofilms, and inhibited filamentation of C. albicans. In addition, these HIV-PIs downregulated the expression of SAP2 and BRC1 genes of C. albicans. In an in vivo study, prophylactic use of ATV and DRV prolonged the survival rate of Galleria mellonella larvae infected with C. albicans. Therefore, ATV and DRV showed activity against C. albicans by reducing cell growth, biofilm formation, filamentation, and expression of virulence genes. Furthermore, ATV and DRV decreased experimental candidiasis, suggesting the repurposing of HIV-PIs as antifungal treatments for C. albicans infections.

The Effect of Rifampicin on Darunavir, Ritonavir, and Dolutegravir Exposure within Peripheral Blood Mononuclear Cells: a Dose Escalation Study.

Ritonavir-boosted darunavir (DRV/r) and dolutegravir (DTG) are affected by induction of metabolizing enzymes and efflux transporters caused by rifampicin (RIF). This complicates the treatment of people living with HIV (PLWH) diagnosed with tuberculosis. Recent data showed that doubling DRV/r dose did not compensate for this effect, and hepatic safety was unsatisfactory. We aimed to evaluate the pharmacokinetics of DRV, ritonavir (RTV), and DTG in the presence and absence of RIF in peripheral blood mononuclear cells (PBMCs). PLWH were enrolled in a dose-escalation crossover study with 6 treatment periods of 7 days. Participants started with DRV/r 800/100 mg once daily (QD), RIF and DTG were added before the RTV dose was doubled, and then they received DRV/r 800/100 twice daily (BD) and then 1,600/200 QD or vice versa. Finally, RIF was withdrawn. Plasma and intra-PBMC drug concentrations were measured through validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Seventeen participants were enrolled but only 4 completed all study phases due to high incidence of liver toxicity. Intra-PBMC DRV trough serum concentration (Ctrough) after the addition of RIF dropped from a median (interquartile range [IQR]) starting value of 261 ng/mL (158 to 577) to 112 ng/mL (18 to 820) and 31 ng/mL (12 to 331) for 800/100 BD and 1,600/200 QD DRV/r doses, respectively. The DRV intra-PBMC/plasma ratio increased significantly (P = 0.003). DTG and RIF intra-PBMC concentrations were in accordance with previous reports in the absence of RIF or DRV/r. This study showed a differential impact of enzyme and/or transporter induction on DRV/r concentrations in plasma and PBMCs, highlighting the usefulness of studying intra-PBMC pharmacokinetics with drug-drug interactions. (This study has been registered at ClinicalTrials.gov under registration no. NCT03892161.).

Health-related quality-of-life in people living with HIV after switching to dual therapy with ritonavir-boosted darunavir + dolutegravir: a DUALIS sub-study.

The DUALIS study demonstrated efficacy and safety of switching to dolutegravir plus ritonavir-boosted darunavir (DRV/r) (2DR) as compared to standard-of-care-therapy with two nucleoside reverse transcriptase inhibitors + DRV/r (3DR) in pretreated people living with HIV (PLWH), 48 weeks after switching. This DUALIS sub-study investigates health-related-quality-of-life (HrQoL) in this study-population. The Hospital Anxiety and Depression Scale (HADS) and the Medical Outcome Survey-HIV (MOS-HIV) were used assessing anxiety and depression symptoms, respectively HrQoL. Data were collected at baseline, 4, 24, and 48 weeks after randomization. Outcome scores were dichotomized and used as criteria in longitudinal models identifying differential developments. Odds ratios (ORs) with 95% confidence intervals (CIs) were computed as main measures of effects. ORs<1 indicate better results for HADS, and worse for MOS-HIV scores in the 2DR compared to 3DR group. In total, 263 subjects were randomized and treated (2DR n=131, 3DR n=132; median age 48 years). Significant different progressions could only be found for HADS-Depression scores (OR=.87, 95% CI: .78, .98, p=.02). While HADS-Depression scores decreased in the 2DR group, they increased in 3DR group. This sub-study showed no disadvantages regarding HrQoL in PLWH after switching to DTG+DRV/r. Considering lifelong requirements for antiretroviral medication, close attention to HrQL is required.

Quality of life and associated factors among people receiving second-line anti-retroviral therapy in Johannesburg, South Africa.

BACKGROUND: Studies which examine quality of life (QOL) provide important insights that are needed to understand the impacts of HIV/AIDS anti-retroviral treatment (ART), comorbid conditions and other factors on the daily activities of people living with HIV/AIDS (PLH). This study aimed to determine the inter-relationships between clinical factors, behavioural, socio-demographic variables and QOL among PLH. METHODS: The secondary analysis used data collected from 293 people living with HIV/AIDS (PLH) receiving second-line ART in Johannesburg in a clinical trial which evaluated the non-inferiority of ritonavir-boosted darunavir (DRV/r 400/100 mg) compared to ritonavir-boosted lopinavir (LPV/r) over a 48 week-period. Physical functioning, cognitive and mental QOL were measured using the Aids Clinical Trial Group questionnaire. Exploratory factor analyses were used to examine the structure, the relationships between and the construct validity of QOL items. Structural equation models which tested the a priori-hypothesised inter-relationships between QOL and other variables were estimated and goodness of fit of the models to the data was assessed. RESULTS: Patients on darunavir presented with lower pill burden. Older patients and women were more likely to report lower QOL scores. Pill burden mediated the effects of age, sex and treatment regimen on physical functioning QOL and adverse effects; the effects of age, sex, treatment regimen and adverse effects on cognitive QOL; and the effects of sex on mental QOL. CONCLUSION: QOL among PLH is associated with socio-demographic and clinical factors. Therefore, QOL could be enhanced by considering PLH characteristics, clinical factors such as regimen side-effects profile, management of comorbid conditions and mitigating risks such as potential adverse drug-to-drug interactions among patients on ART.

Design and Evaluation of Novel HIV-1 Protease Inhibitors Containing Phenols or Polyphenols as P2 Ligands with High Activity against DRV-Resistant HIV-1 Variants.

With the increasing prevalence of drug-resistant variants, novel potent HIV-1 protease inhibitors with broad-spectrum antiviral activity against multidrug-resistant causative viruses are urgently needed. Herein, we designed and synthesized a new series of HIV-1 protease inhibitors with phenols or polyphenols as the P2 ligands and a variety of sulfonamide analogs as the P2' ligands. A number of these new inhibitors showed superb enzymatic inhibitory activity and antiviral activity. In particular, inhibitors 15d and 15f exhibited potent enzymatic inhibitory activity in the low picomolar range, and the latter showed excellent activity against the Darunavir-resistant HIV-1 variant. Furthermore, the molecular modeling studies provided insight into the ligand-binding site interactions between inhibitors and the enzyme cavity, and they sparked inspiration for the further optimization of potent inhibitors.

The effect of protease inhibitor-based dual antiretroviral regimens on CD4/CD8 ratio during the first year of therapy in ART-naïve patients with HIV-infection.

OBJECTIVES: To assess the effect of protease inhibitor (PI)-based dual therapy on CD4/CD8 ratio during the first year of therapy in antiretroviral therapy (ART)-naïve patients using data from randomized controlled clinical trials. METHODS: We pooled data from the GARDEL and ANDES studies, both randomized controlled clinical trials that recruited ART-naïve people living with HIV and randomly assigned them to receive PI-based dual therapy (DT) or triple therapy (TT) aiming to compare viral efficacy. We compared median CD4/CD8 ratios and the proportion of patients with CD4/CD8 ratio > 1 at 48 weeks after ART initiation in both treatment arms using the Mann-Whitney U-test and the χ2 test. We performed subgroup analysis for patients > 50 years old, with baseline CD4 counts ≤ 200 cells/µL, viral load > 100 000 HIV RNA copies/mL, and ritonavir-boosted lopinavir-based therapy. RESULTS: We analysed data from 571 patients: 292 on DT and 279 on TT. No differences were observed in CD4/CD8 ratio (0.632 vs. 0.617, P = 0.729) or in the proportion of patients with CD4/CD8 ratio > 1 (17.9% vs. 19.3%, P = 0.678) 48 weeks after ART initiation. Subgroup analysis showed no further differences. CONCLUSION: The impact of PI-based DT regimens on the CD4/CD8 ratio during the first year of treatment for ART-naïve patients is similar to that of TT.

Virological response and resistance profile in highly treatment-experienced HIV-1-infected patients switching to dolutegravir plus boosted darunavir in clinical practice.

OBJECTIVES: We evaluated the virological response and resistance profile in combined antiretroviral therapy (cART)-experienced HIV-1-infected patients starting a dual therapy with dolutegravir (DTG) and boosted darunavir (bDRV) for the first time. METHODS: Survival analyses were used to evaluate virological success (VS) and virological rebound (VR) in viraemic and virologically suppressed patients, respectively. Major resistance mutations (MRMs) and genotypic susceptibility score (GSS) were evaluated at baseline and after switch. RESULTS: Overall, 130 patients [62 (47.7%) viraemic; 68 (52.3%) virologically suppressed] were retrospectively analysed. At the moment of switch, 81.5% accumulated one or more MRM [protease inhibitor (PI), 35.7%; nucleoside(t)ide reverse transcriptase inhibitor (NRTI), 77.5%; non-NRTI, 69.0%; integrase inhibitor (INI), 10.1%), but 77.7% harboured strains fully susceptible to DTG + bDRV. In viraemic patients, the overall probability of VS by 12 months of treatment was 91.7%. In virologically suppressed patients, the overall probability of VR was 10.5% by 24 months after therapy start. Patients with previous time under virological suppression ≤ 6 months showed a higher VR probability compared with others (37.5% vs. 6.7%, P < 0.002). Among 13 non-responding patients for whom a genotypic resistance test result at failure was available, only two (15.4%) accumulated further resistance in integrase (Y143C/H/R; S147G and N155H) and protease (V32I, L33F, I54L). CONCLUSIONS: In highly treatment-experienced patients, the use of dual therapy based on DTG + bDRV appears to be a very good regimen for switch therapy, with a high rate of virological control in both viraemic and virologically suppressed patients. Among non-responding patients, the selection of further resistance is a rare event.

Week 96 resistance analyses of the once-daily, single-tablet regimen (STR) darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) in adults living with HIV-1 from the phase 3 randomized AMBER and EMERALD trials.

In AMBER and EMERALD, darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg demonstrated high virological response and low virological failure (VF) through week 96. Week 96 resistance analyses are presented. Post-baseline samples for genotyping/phenotyping were analyzed from protocol-defined-VFs with viral load (VL) ≥ 400 copies/ml at failure/later time points. Post-hoc analyses were deep sequencing (AMBER) and HIV-1 proviral DNA sequencing from baseline samples (VL < 50 copies/ml) (EMERALD). Through week 96 across studies, no darunavir, primary protease inhibitor (PI), or tenofovir resistance-associated-mutations (RAMs) occurred in patients continuing (N = 1125) or switching to D/C/F/TAF (N = 715). M184I/V (emtricitabine RAM) was detected in one patient in each arm of AMBER. In EMERALD D/C/F/TAF patients with prior VF and baseline genoarchive data (N = 98), 4% had darunavir RAMs, 36% emtricitabine RAMs, mainly at position 184 (32%), 4% tenofovir RAMs, and 19% ≥3 thymidine-analogue-associated-mutations at screening. The predicted phenotype showed 0% had reduced susceptibility to darunavir, 37% to emtricitabine, and 22% to tenofovir. All achieved VL < 50 copies/ml at week 96/prior discontinuation, with no VF. D/C/F/TAF has a high barrier to resistance; no darunavir, primary PI, or tenofovir RAMs occurred through 96 weeks in AMBER and EMERALD. In EMERALD, baseline archived darunavir, emtricitabine, and tenofovir RAMs in patients with prior VF did not preclude virologic response.

Optimal sampling strategies for darunavir and external validation of the underlying population pharmacokinetic model.

PURPOSE: A variety of diagnostic methods are available to validate the performance of population pharmacokinetic models. Internal validation, which applies these methods to the model building dataset and to additional data generated through Monte Carlo simulations, is often sufficient, but external validation, which requires a new dataset, is considered a more rigorous approach, especially if the model is to be used for predictive purposes. Our first objective was to validate a previously published population pharmacokinetic model of darunavir, an HIV protease inhibitor boosted with ritonavir or cobicistat. Our second objective was to use this model to derive optimal sampling strategies that maximize the amount of information collected with as few pharmacokinetic samples as possible. METHODS: A validation dataset comprising 164 sparsely sampled individuals using ritonavir-boosted darunavir was used for validation. Standard plots of predictions and residuals, NPDE, visual predictive check, and bootstrapping were applied to both the validation set and the combined learning/validation set in NONMEM to assess model performance. D-optimal designs for darunavir were then calculated in PopED and further evaluated in NONMEM through simulations. RESULTS: External validation confirmed model robustness and accuracy in most scenarios but also highlighted several limitations. The best one-, two-, and three-point sampling strategies were determined to be pre-dose (0 h); 0 and 4 h; and 1, 4, and 19 h, respectively. A combination of samples at 0, 1, and 4 h was comparable to the optimal three-point strategy. These could be used to reliably estimate individual pharmacokinetic parameters, although with fewer samples, precision decreased and the number of outliers increased significantly. CONCLUSIONS: Optimal sampling strategies derived from this model could be used in clinical practice to enhance therapeutic drug monitoring or to conduct additional pharmacokinetic studies.

Effects on QT interval of hydroxychloroquine associated with ritonavir/darunavir or azithromycin in patients with SARS-CoV-2 infection.

INTRODUCTION: Most of the drugs associations that have been used to treat patients with SARS-CoV-2 infection increase the risk of prolongation of the corrected QT interval (QTc). OBJECTIVE: To evaluate the effects of an association therapy of hydroxychloroquine (HY) plus ritonavir/darunavir (RD) or azithromycin (AZ) on QTc intervals. METHODS: At the beginning of COVID-19 pandemic patients admitted to our hospital were treated with the empiric association of HY/RD; one week later the therapeutic protocol was modified with the combination of HY/AZ. Patients underwent an ECG at baseline, then 3 and 7 days after starting therapy. We prospectively enrolled 113 patients (61 in the HY/RD group-52 in the HY/AZ group). RESULTS: A significant increase in median QTc was reported after seven days of therapy in both groups: from 438 to 452 ms in HY/RD patients; from 433 to 440 ms in HY/AZ patients (p = 0.001 for both). 23 patients (21.2%) had a QTc > 500 ms at 7 days. The risk of developing a QTc > 500 ms was greater in patients with prolonged baseline QTc values (≥ 440 ms for female and ≥ 460 ms for male patients) (OR 7.10 (95% IC 1.88-26.81); p = 0.004) and in patients with an increase in the QTc > 40 ms 3 days after onset of treatment (OR 30.15 (95% IC 6.96-130.55); p = 0.001). One patient per group suffered a malignant ventricular arrhythmia. CONCLUSION: Hydroxychloroquine with both ritonavir/darunavir or azithromycin therapy significantly increased the QTc-interval at 7 days. The risk of developing malignant arrhythmias remained relatively low when these drugs were administered for a limited period of time.