Spontaneous reported cardiotoxicity induced by lopinavir/ritonavir in COVID-19. An alleged past-resolved problem

The antiretroviral drug lopinavir/ritonavir has been recently repurposed for the treatment of COVID-19. Its empirical use has been associated with multiple cardiac adverse reactions pertaining to its ancillary multi-channel blocking properties, vaguely characterized until now. We aimed to characterize qualitatively the cardiotoxicity associated with lopinavir/ritonavir in the setting of COVID-19. Spontaneous notifications of cardiac adverse drug reactions reported to the national Pharmacovigilance Network were collected for 8 weeks since March 1st 2020. The Nice Regional Center of Pharmacovigilance, whose scope of expertise is drug-induced long QT syndrome, analyzed the cases, including the reassessment of all available ECGs. QTc ≥ 500 ms and delta QTc > 60 ms from baseline were deemed serious. Twenty-two cases presented with 28 cardiac adverse reactions associated with the empirical use of lopinavir/ritonavir in a hospital setting. Most adverse reactions reflected lopinavir/ritonavir potency to block voltage-gated potassium channels with 5 ventricular arrhythmias and 17 QTc prolongations. An average QTc augmentation of 97 ± 69 ms was reported. Twelve QTc prolongations were deemed serious. Other cases were likely related to lopinavir/ritonavir potency to block sodium channels: 1 case of bundle branch block and 5 recurrent bradycardias. The incidence of cardiac adverse reactions of lopinavir/ritonavir was estimated between 0.3% and 0.4%. These cardiac adverse drug reactions offer a new insight in its ancillary multi-channel blocking functions. Lopinavir/ritonavir cardiotoxicity may be of concern for its empirical use during the COVID-19 pandemic. Caution should be exerted relative to this risk where lopinavir/ritonavir summary of product characteristics should be implemented accordingly.

In utero exposure to protease inhibitor-based antiretroviral regimens delays growth and developmental milestones in mice

Antiretroviral therapy (ART) in pregnancy has dramatically reduced HIV vertical transmission rates. Consequently, there is a growing number of children that are HIV exposed uninfected (CHEUs). Studies suggest that CHEUs exposed in utero to ART may experience developmental delays compared to their peers. We investigated the effects of in utero ART exposure on perinatal neurodevelopment in mice, through assessment of developmental milestones. Developmental milestone tests (parallel to reflex testing in human infants) are reflective of brain maturity and useful in predicting later behavioral outcomes. We hypothesized that ART in pregnancy alters the in utero environment and thereby alters developmental milestone outcomes in pups. Throughout pregnancy, dams were treated with boosted-atazanavir combined with either abacavir/lamivudine (ATV/r/ABC/3TC), or tenofovir/emtricitabine (ATV/r/TDF/FTC), or water as control. Pups were assessed daily for general somatic growth and on a battery of tests for primitive reflexes including surface-righting, negative-geotaxis, cliff-aversion, rooting, ear-twitch, auditory-reflex, forelimb-grasp, air-righting, behaviors in the neonatal open field, and olfactory test. In utero exposure to either ART regimen delayed somatic growth in offspring and evoked significant delays in the development of negative geotaxis, cliff-aversion, and ear-twitch reflexes. Exposure to ATV/r/ABC/3TC was also associated with olfactory deficits in male and forelimb grasp deficits in female pups. To explore whether delays persisted into adulthood we assessed performance in the open field test. We observed no significant differences between treatment arm for males. In females, ATV/r/TDF/FTC exposure was associated with lower total distance travelled and less ambulatory time in the centre, while ATV/r/ABC/3TC exposure was associated with higher resting times compared to controls. In utero PI-based ART exposure delays the appearance of primitive reflexes that involve vestibular and sensory-motor pathways in a mouse model. Our findings suggest that ART could be disrupting the normal progress/maturation of the underlying neurocircuits and encourage further investigation for underlying mechanisms.

Use of Darunavir-Cobicistat as a Treatment Option for Critically Ill Patients with SARS-CoV-2 Infection

We retrospectively reviewed patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections who were admitted to an intensive care unit in Daegu, South Korea. The outcomes of patients who did (cases) or did not (controls) receive darunavir-cobicistat (800-150 mg) therapy were compared. Fourteen patients received darunavir-cobicistat treatment, and 96 received other antiviral therapy (controls). Overall, the darunavir-cobicistat group comprised patients with milder illness, and the crude mortality rate of all patients in the darunavir-cobicistat group was lower than that in the controls [odds ratio (OR) 0.20, 95% confidence interval (CI) 0.04-0.89, p=0.035]. After 1:2 propensity-score matching, there were 14 patients in the darunavir-cobicistat group, and 28 patients in the controls. In propensity score-matched analysis, the darunavir-cobicistat group had lower mortality than the controls (OR 0.07, 95% CI 0.01-0.52, p=0.009). In conclusion, darunavir-cobicistat therapy was found to be associated with a significant survival benefit in critically ill patients with SARS-CoV-2 infection.

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.

Repurposing Antiviral Protease Inhibitors Using Extracellular Vesicles for Potential Therapy of COVID-19

In January 2020, Chinese health agencies reported an outbreak of a novel coronavirus-2 (CoV-2) which can lead to severe acute respiratory syndrome (SARS). The virus, which belongs to the coronavirus family (SARS-CoV-2), was named coronavirus disease 2019 (COVID-19) and declared a pandemic by the World Health Organization (WHO). Full-length genome sequences of SARS-CoV-2 showed 79.6% sequence identity to SARS-CoV, with 96% identity to a bat coronavirus at the whole-genome level. COVID-19 has caused over 133,000 deaths and there are over 2 million total confirmed cases as of April 15th, 2020. Current treatment plans are still under investigation due to a lack of understanding of COVID-19. One potential mechanism to slow disease progression is the use of antiviral drugs to either block the entry of the virus or interfere with viral replication and maturation. Currently, antiviral drugs, including chloroquine/hydroxychloroquine, remdesivir, and lopinavir/ritonavir, have shown effective inhibition of SARS-CoV-2 in vitro. Due to the high dose needed and narrow therapeutic window, many patients are experiencing severe side effects with the above drugs. Hence, repurposing these drugs with a proper formulation is needed to improve the safety and efficacy for COVID-19 treatment. Extracellular vesicles (EVs) are a family of natural carriers in the human body. They play a critical role in cell-to-cell communications. EVs can be used as unique drug carriers to deliver protease inhibitors to treat COVID-19. EVs may provide targeted delivery of protease inhibitors, with fewer systemic side effects. More importantly, EVs are eligible for major aseptic processing and can be upscaled for mass production. Currently, the FDA is facilitating applications to treat COVID-19, which provides a very good chance to use EVs to contribute in this combat.

Pyromellitic dianhydride crosslinked soluble cyclodextrin polymers: Synthesis, lopinavir release from sub-micron sized particles and anti-HIV-1 activity

We report the synthesis of water soluble cyclodextrin (CD) polymers prepared by crosslinking pyromellitic dianhydride (PMDA) with two CD derivatives (methyl-β-CD - MβCD and (2-hydroxy)propyl-β-CD - HPβCD) and their evaluation as functional sub-micron sized carriers in the development of antiretroviral drug delivery systems. Using the protease inhibitor lopinavir (LPV) as model drug, LPV loaded CD polymers (pHPβCD and pMβCD) were prepared and fully characterized. The physicochemical characterization and in vitro drug release confirmed the successful synthesis of pHPβCD and pMβCD, the formation of sub-micron sized particles and a 12-14 fold increase in LPV solubility. Cytotoxicity assays indicated that both pHPβCD and pMβCD were able to improve the safety profile of LPV while the viral infectivity assay revealed a concentration independent anti-HIV-1 effect for both pHPβCD and pMβCD with a maximum percentage inhibition (MPI) of 79 and 91% respectively. After LPV loading, the antiviral profile of pHPβCD was reversed to the sigmoidal dose-response profile of LPV, while pMβCD maintained its dose-independent profile followed by a LPV mediated increase in viral inhibition. Overall, both pHPβCD and pMβCD demonstrated anti-HIV-1 activity, while drug loaded pMβCD indicated its potential as functional sub-micron sized drug delivery polymers for achieving synergistic anti-HIV activity.

Exploring the impact of real-life dosing conditions on intraluminal and systemic concentrations of atazanavir in parallel with gastric motility recording in healthy subjects

This work strived to explore gastrointestinal (GI) dissolution, supersaturation and precipitation of the weakly basic drug atazanavir in humans under different 'real-life' intake conditions. The impact of GI pH and motility on these processes was thoroughly explored. In a cross-over study, atazanavir (Reyataz®) was orally administered to 5 healthy subjects with (i) a glass of water, (ii) a glass of Coca-Cola® and (iii) a glass of water under hypochlorhydric conditions (induced by concomitant intake of a proton-pump inhibitor (PPI)). After intake, GI fluids were aspirated from the stomach and the duodenum and, subsequently, analyzed for atazanavir. In parallel, blood samples were collected to assess systemic concentrations. In general, the results of this study revealed that the acidic gastric pH in combination with gastric residence time played a crucial role in the dissolution of atazanavir along the GI tract. After intake of atazanavir with a glass of water (i.e., reference condition), complete gastric dissolution was observed. After GI transfer, supersaturation was noticed for a limited amount of time (1.25 h). With respect to the Coca-Cola® condition, complete gastric dissolution was also observed. A delay in gastric emptying, highly likely caused by the caloric content (101 kcal), was responsible for delayed arrival of atazanavir into the upper small intestine, creating a longer time window of supersaturated concentrations in the duodenal segment (3.25 h) compared to the water condition. The longer period of supersaturated concentrations resulted in a slightly higher systemic exposure of atazanavir compared to the condition when atazanavir was taken with a glass of water. A remarkable observation was the creation (when the drug was given in the migrating motor complex (MMC) phase 2) or maintenance (when the drug was given in MMC phase 1) of a quiescent phase for up to 80 min. With respect to the PPI condition, negligible gastric and intestinal concentrations were observed, resulting in minimal systemic exposure for all subjects. It can be concluded that gastric pH and residence time play a pivotal role in the intestinal disposition of atazanavir in order to generate sufficiently high concentrations further down in the intestinal tract for a sufficient period of time, thus creating a beneficial driving force for intestinal absorption.

Association of Pharmacogenetic Markers With Atazanavir Exposure in HIV-Infected Women

SORCS2 rs73208473 was recently associated with decreased atazanavir (ATV) concentration in the hair of women with seropositive HIV. Herein, we report on a pharmacogenetic study of women with seropositive HIV demonstrating a similar association between rs73208473 and dose-adjusted plasma ATV concentration in African Americans.

Is Antiretroviral Two-Drug Regimen the New Standard for HIV Treatment in Naive Patients?

The use of a combination antiretroviral therapy (cART) has changed dramatically the prognosis and the life expectancy of people living with HIV. The current treatment guidelines continue the convention of preferred cART based on combining a dual nucleoside reverse-transcriptase inhibitor (NRTI) backbone with a third "anchor" agent, such as a ritonavir (r)- or cobicistat (c)-boosted protease inhibitor (PI), a non-NRTI (NNRTI), or an integrase inhibitor (INI) boosted or unboosted. However, due to toxicities of NRTIs, sparing NRTI regimen has been studied for a long time with moderate success due to low efficacy (especially in patients with high viral load and low CD4) compare to standard triple therapy. New strategy with lamivudine (3TC) plus a boosted PI or INI showed promise results and indicated that modern two-drug regimens might now, in fact, become a reliable treatment for HIV-infected naïve patients. This article discusses recent data from dual therapy studies in naïve HIV-infected patients and the challenges behind this strategy.

HIV protease inhibitors for the treatment of multiple myeloma

Outcomes in multiple myeloma (MM) patients have improved in recent years owing to the introduction of new drugs. Among them, proteasome inhibitors and immunomodulatory imide drugs have become central in the management of newly diagnosed and relapsed MM. However, resistance to these classes of agents develops in most patients and ultimately leads to death from relapsed/refractory disease. A need exists for new classes of antimyeloma drugs, especially ones that are active in the multirefractory setting. The conventional drug development process, which involves extensive preclinical and clinical testing prior to assessment of clinical activity, has fallen short in delivering adequately safe and active novel drug candidates. HIV protease inhibitors such as nelfinavir are safe, US Food and Drug Administration-approved agents that have been shown to have potent antimyeloma activity in both preclinical models and patients with refractory disease. The repurposing of HIV protease inhibitors for treatment of MM is promising in light of their antimyeloma activity in conjunction with their global availability, established safety, and relatively low cost. This review will summarize the preclinical and clinical data available on HIV protease inhibitors for the treatment of refractory MM.

Third-line antiretroviral therapy in low-income and middle-income countries (ACTG A5288): a prospective strategy study

BACKGROUND

Antiretroviral therapy (ART) management is challenging for individuals in resource-limited settings presenting for third-line treatment because of complex resistance patterns, partly due to reduced access to viral load monitoring. We aimed to evaluate use of newer antiretroviral drugs and contemporary management approaches, including population-based sequencing, to select appropriate antiretrovirals, plasma viral load monitoring, and interventions to improve adherence in individuals presenting with second-line viral failure.

METHODS

A5288 was a phase 4, third-line ART strategy study done at 19 urban sites in ten countries that enrolled adult participants with confirmed plasma HIV-1 RNA (viral load) of 1000 copies per mL or more after more than 24 weeks of protease inhibitor-based second-line ART. The primary objective was to use antiretrovirals (raltegravir, etravirine, and ritonavir-boosted darunavir) and diagnostic monitoring technologies, including viral load, genotyping, and adherence support to achieve viral load suppression (defined as ≤200 copies per mL) in 65% or more of participants. ART history and real-time drug resistance genotypes were used to assign participants to one of four cohorts: cohort A (no lopinavir resistance) stayed on second-line ART and cohorts B (B1, best available nucleoside reverse transcriptase inhibitors [NRTIs] plus ritonavir-boosted darunavir plus raltegravir; B2, ritonavir-boosted darunavir plus raltegravir plus etravirine; B3, ritonavir-boosted darunavir, raltegravir, and either tenofovir plus emtricitabine or tenofovir plus lamivudine), C (ritonavir-boosted darunavir plus raltegravir plus tenofovir-emtricitabine or tenofovir plus lamivudine), and D (best available NRTIs plus ritonavir-boosted darunavir plus raltegravir) were defined by increasing levels of resistance and received appropriate regimens, including new antiretrovirals. Participants in Cohort B without detectable hepatitis B surface antigen were assigned by blocked randomisation to cohorts B1 and B2, and those with detectable hepatitis B surface antigen were assigned to cohort B3. The trial is registered with ClinicalTrials.gov, number NCT01641367.

FINDINGS

From Jan 10, 2013, to Sept 10, 2015, 545 participants were enrolled. 287 (53%) were assigned to cohort A, 74 (14%) to B1, 72 (13%) to B2, eight (1%) to B3, 70 (13%) to C, and 34 (6%) to D. Overall, 349 (64%, 95% CI 60-68) participants achieved viral suppression at week 48, with proportions varying from 125 (44%) of 287 in cohort A to 65 (88%) of 74 in cohort B1, 63 (88%) of 72 in B2, eight (100%) of eight in B3, 63 (90%) of 70 in C, and 25 (74%) of 34 in D. Participants in cohort A remained on their second-line protease inhibitor, and had the most participants with grade 3 or higher adverse events (147 [51%]).

INTERPRETATION

Targeted real-time genotyping to select third-line ART can appropriately allocate more costly antiretrovirals to those with greater levels of HIV drug resistance.

FUNDING

National Institutes of Health.

Risk Factors for Adverse Birth Outcomes in the PROMISE 1077BF/1077FF Trial

BACKGROUND

In the multicountry PROMISE 1077BF/1077FF trial, the risk of low birth weight (LBW; <2500 g) and preterm delivery (PTD; <37 weeks) was significantly higher among women initiating a protease inhibitor-based antiretroviral treatment (ART) regimen than those receiving ZDV alone. Among those assigned to a protease inhibitor regimen, tenofovir/emtricitabine was associated with the more severe outcomes of very LBW (<1500 g) and very PTD (<34 weeks) compared with zidovudine/lamivudine.

METHODS

We used multivariate logistic regression to further explore these treatment findings, taking into account demographic baseline clinical and postentry obstetrical factors. We evaluated individual adverse outcomes and composites that included stillbirth and early loss/spontaneous abortion.

RESULTS

Among 3333 women delivering at least 1 live infant, median maternal age at enrollment was 26 years; 661 (20%) were primiparous, and 110 (3.3%) reported at least 1 previous PTD. Seventeen percent of newborns were LBW, 1% were very LBW, 17% had PTD, and 3% had very PTD. Treatment allocation remained strongly associated with multiple adverse outcomes after controlling for other risk factors with both ART regimens exhibiting increased risk relative to ZDV alone. Other risk factors remaining significant in at least one of the multivariate models included the following: country, gestational age at entry, maternal age, maternal body mass index, previous PTD, history of alcohol use, baseline HIV viral titer, multiple gestation, and several obstetric risk factors.

CONCLUSIONS

ART effects on adverse pregnancy outcomes reported in the randomized PROMISE trial remained strongly significant even after controlling for demographic, baseline clinical, and obstetrical risk factors, which were also associated with these outcomes.

Effect of monotherapy with darunavir/cobicistat on viral load and semen quality of HIV-1 patients

Many patients previously using darunavir/ritonavir (DRV/r) (800/100mg) have switched to darunavir/cobicistat (DRV/C) (800/150 mg) either as part of triple therapy (ART) or as monotherapy with DRV (mDRV). The latter approach continues to be used in some countries for patients receiving long-term treatment. However, to date, the behaviour of DRV/C in the seminal compartment has not been analysed. This study explores how the combination behaves in monotherapy, with respect to the control of viral load and seminal quality. To this end, we studied 20 patients who were treated with mDRV/C after previous treatment with mDRV/r for at least 24 weeks. A viral load control in seminal plasma similar to that published in the literature was observed after 24 weeks of treatment with mDRV/C (viral load positivity in 20% of patients). Similarly, semen quality was confirmed (70% normozoospermic) in patients treated with this formulation, as has previously been reported for ART and mDRV/r. The DRV levels measured in seminal plasma were above EC50, regardless of whether the seminal viral load was positive or negative. We conclude that this mDRV/C co-formulation behaves like mDRV/r in seminal plasma in terms of viral load control and semen quality.

High quality of life, treatment tolerability, safety and efficacy in HIV patients switching from triple therapy to lopinavir/ritonavir monotherapy: A randomized clinical trial

Trial design

The QoLKAMON study evaluated quality of life, efficacy and treatment safety in HIV patients receiving lopinavir/ritonavir in monotherapy (MT) versus continuing combined antiretroviral triple treatment with a boosted protease inhibitor (TT).

Methods

This was a 24-week, open-label, multicentre study in virologically-suppressed HIV-infected participants (N = 225) with a 2:1 randomization: 146 patients who switched to MT were compared with 79 patients who remained on a TT regimen. The primary endpoint was change in patient-reported outcomes in quality of life as measured by the MOS-HIV and EQ-5D questionnaires. Secondary endpoints included treatment adherence, patient satisfaction, incidence of adverse events and differences in plasma HIV-1 RNA viral load (VL) and CD4 cell counts.

Results

Baseline quality of life, measured with the MOS-HIV score, was very good (overall score of 83 ± 10.5 in the MT arm and 82.3 ± 11.3 in the TT arm) and suffered no change during the study in any of the arms (at week 24, 83.5 ± 12.2 in MT arm and 81.9 ± 12.7 in TT arm), without statistically significant differences when compared. In regards to adherence to therapy and patient satisfaction, some aspects (number of doses forgotten in the last week and satisfaction of treatment measured with the CESTA score, dimension 1) improved significantly with MT. There were also no differences in the incidence and severity of adverse events, even though 22.8% of those in the MT arm switched their treatment when they were included in the study. Moreover, there was also no significant difference between the immunological and virological evolution of MT and TT. In the MT arm, the VL was always undetectable in 83% of patients (vs 90.7% in the TT arm) and there were only 6.7% of virological failures with VL > 50 copies/mL (vs 2.3% in the TT arm), without resistance mutations and with resuppression of VL after switching back to TT.

Conclusions

In a new clinical trial, monotherapy as a treatment simplification strategy in HIV-1 infected patients with sustained viral suppression has demonstrated quality of life, safety and efficacy profiles comparable to those of conventional triple therapy regimens.

Potential associations between atazanavir exposure and clinical outcome: a pharmacokinetic sub-study from the MODAt randomized trial

The 96-week results of the Monotherapy Once a Day with Atazanavir/r (MODAt) study [NCT01511809] showed an inferior virological efficacy of atazanavir (ATV)/ritonavir monotherapy versus triple therapy, which was promptly retrieved by the reintroduction of nucleoside/nucleotide inhibitors of reverse transcriptase [N(n)RTIs]. We aimed to identify potential relationships between ATV exposure and clinical outcome in HIV-1 subjects treated with ATV/ritonavir monotherapy [ATV/r 300/100 mg] versus ATV/ritonavir triple therapy [ATV/r 300/100 mg+2NRTIs]. A chromatographic method coupled with tandem mass spectrometry was applied to analyze ATV plasma concentrations in a pharmacokinetic sub-study from the MODAt trial. Mixed linear models were used to examine the ATV plasma concentration trend during follow-up and to assess the association between ATV plasma concentrations trajectories with the study arm or the occurrence of treatment failure or drugrelated adverse events or the grading of baseline total bilirubin (<3 vs ≥3). The analyses were performed using SAS Software, release 9.4 (SAS Institute, Cary, NC, USA). Overall, ATV plasma Ctrough concentration did not vary during follow-up (slope: +0.75 ng/mL/week, 95%CI: -0.97 to 2.47, p=0.387); trajectories did not differ between study arms (p=0.527). The unadjusted model-based means (95%CI) of ATV Ctrough during follow-up were 835 (95%CI: 657-1012) ng/ml in the ATV/r monotherapy arm as compared to 911 (95%CI: 740-1082) ng/mL in the ATV/r triple therapy arm (p=0.621). Mean ATV Ctrough was similar in subjects with or without adverse events (AEs). Subjects treated with ATV/r monotherapy showed significantly higher ATV concentrations as compared to subjects without adverse events or treated with ATV/r triple therapy. ATV concentrations were associated with the grading of baseline total bilirubin and the occurrence of drug-related AEs but not with HCV infection. Our findings showed a lack of association between ATV concentrations and treatment failure both in ATV/r monotherapy and triple therapy. Conversely, these data emphasized that ATV concentrations are associated with the development of side-effects in both subjects treated with ATV/r monotherapy and subjects treated with ATV/r triple therapy.

Efficacy and safety of switching from boosted protease inhibitors plus emtricitabine and tenofovir disoproxil fumarate regimens to single-tablet darunavir, cobicistat, emtricitabine, and tenofovir alafenamide at 48 weeks in adults with virologically suppressed HIV-1 (EMERALD): a phase 3, randomised, non-inferiority trial

BACKGROUND

Simplified regimens with reduced pill burden and fewer side-effects are desirable for people living with HIV. We investigated the efficacy and safety of switching to a single-tablet regimen of darunavir, cobicistat, emtricitabine, and tenofovir alafenamide versus continuing a regimen of boosted protease inhibitor, emtricitabine, and tenofovir disoproxil fumarate.

METHODS

EMERALD was a phase-3, randomised, active-controlled, open-label, international, multicentre trial, done at 106 sites across nine countries in North America and Europe. HIV-1-infected adults were eligible to participate if they were treatment-experienced and virologically suppressed (viral load <50 copies per mL for ≥2 months; one viral load of 50-200 copies per mL was allowed within 12 months before screening), and patients with a history of virological failure on non-darunavir regimens were allowed. Randomisation was by computer-generated interactive web-response system and stratified by boosted protease inhibitor use at baseline. Patients were randomly assigned (2:1) to switch to the open-label study regimen or continue the control regimen. The study regimen consisted of a fixed-dose tablet containing darunavir 800 mg, cobicistat 150 mg, emtricitabine 200 mg, and tenofovir alafenamide 10 mg, which was taken once per day for 48 weeks. The primary outcome was the proportion of participants with virological rebound (confirmed viral load ≥50 copies per mL or premature discontinuations, with last viral load ≥50 copies per mL) cumulative through week 48; we tested non-inferiority (4% margin) of the study regimen versus the control regimen in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT02269917.

FINDINGS

The study began on April 1, 2015, and the cutoff date for the week 48 primary analysis was Feb 24, 2017. Of 1141 patients (763 in the study group and 378 in the control group), 664 (58%) had previously received five or more antiretrovirals, including screening antiretrovirals, and 169 (15%) had previous virological failure on a non-darunavir regimen. The study regimen was non-inferior to the control for virological rebound cumulative through week 48 (19 [2·5%] of 763 patients in the study group vs eight (2·1%) of 378 patients in the control group; difference 0·4%, 95% CI -1·5 to 2·2; p<0·0001). No resistance to any study drug was observed. Numbers of discontinuations related to adverse events (11 [1%] of 763 patients in the study group vs four [1%] of 378 patients in the control group) and grade 3-4 adverse events (52 [7%] patients vs 31 [8%] patients) were similar between the two groups. There was a small non-clinically relevant but statistically significant (0·2 [SD 1·1] vs 0·1 [1·1], p=0.010) difference between the two groups in change from baseline in total cholesterol to HDL-cholesterol ratio. Only one serious adverse event (pancreatitis in the study group) was deemed as possibly related to the study regimen.

INTERPRETATION

Our findings show the safety and efficacy of single-tablet darunavir, cobicistat, emtricitabine, and tenofovir alafenamide as a potential switch option for the treatment of HIV-1 infection in adults with viral suppression.

FUNDING

Janssen.

Comparative efficacy and safety of second-line antiretroviral therapy for treatment of HIV/AIDS: a systematic review and network meta-analysis

BACKGROUND

Selection of optimal second-line antiretroviral therapy (ART) has important clinical and programmatic implications. To inform the 2016 revision of the WHO ART guidelines, we assessed the comparative effectiveness and safety of available second-line ART regimens for adults and adolescents in whom first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens have failed.

METHODS

In this systematic review and network meta-analysis, we searched for randomised controlled trials and prospective and retrospective cohort studies that evaluated outcomes in treatment-experienced adults living with HIV who switched ART regimen after failure of a WHO-recommended first-line NNRTI-based regimen. We searched Embase, MEDLINE, and the Cochrane Central Register of Controlled Trials for reports published from Jan 1, 1996, to Aug 8, 2016, and searched conference abstracts published from Jan 1, 2014, to Aug 8, 2016. Outcomes of interest were viral suppression, mortality, AIDS-defining illnesses or WHO stage 3-4 disease, discontinuations, discontinuations due to adverse events, and serious adverse events. We assessed comparative efficacy and safety in a network meta-analysis, using Bayesian hierarchical models.

FINDINGS

We identified 12 papers pertaining to eight studies, including 4778 participants. The network was centred on ritonavir-boosted lopinavir plus two nucleoside or nucleotide reverse transcriptase inhibitors. Ritonavir-boosted lopinavir monotherapy was the only regimen inferior to others. With the lower estimate of the 95% credible interval (CrI) not exceeding the predefined threshold of 15%, evidence at 48 weeks supported the non-inferiority of ritonavir-boosted lopinavir plus raltegravir to regimens including ritonavir-boosted protease inhibitor plus two NRTIs with respect to viral suppression (odds ratio 1·09, 95% CrI 0·88-1·35). Estimated efficacy of ritonavir-boosted darunavir (800 mg once daily) was too imprecise to determine non-inferiority. Overall, regimens did not differ significantly with respect to continuations, AIDS-defining illnesses or WHO stage 3-4 disease, or mortality.

INTERPRETATION

With the exception of ritonavir-boosted lopinavir plus raltegravir, the evidence base is unable to provide strong support to alternative second-line options to ritonavir-boosted protease inhibitor plus two NRTIs, and thus more trials are warranted.

FUNDING

WHO.

Meal Effects Confound Attempts to Counteract Rabeprazole-Induced Hypochlorhydria Decreases in Atazanavir Absorption

PURPOSE

Clinically relevant pharmacokinetic interactions exist between gastric acid-reducing agents and certain weakly basic drugs that rely on acidic environments for optimal oral absorption. In this study, we examine whether the administration of betaine hydrochloride under fed conditions can enhance the absorption of atazanavir, an HIV-1 protease inhibitor, during pharmacologically-induced hypochlorhydria.

METHODS

In this randomized, single-dose, 3 period, crossover study healthy volunteers received ritonavir-boosted atazanavir (atazanavir/ritonavir 300/100 mg) alone, following pretreatment with the proton pump inhibitor rabeprazole (20 mg twice daily), and with 1500 mg of betaine HCl after rabeprazole pretreatment. Atazanavir was administered with a light meal and gastric pH was monitored using the Heidelberg Capsule.

RESULTS

Pretreatment with rabeprazole resulted in significant reductions in atazanavir C_max (p < 0.01) and AUC_0-last (p < 0.001) (71 and 70%, respectively), and modest decreases in ritonavir C_max and AUC_last (p < 0.01) (40% and 41%, respectively). The addition of betaine HCl restored 13% of ATV C_max and 12% of AUC_last lost due to rabeprazole.

CONCLUSIONS

The co-administration of rabeprazole with atazanavir resulted in significant decreases in atazanavir exposure. The addition of betaine HCl did not sufficiently mitigate the loss of ATV exposure observed during RAB-induced hypochlorhydria. Meal effects lead to a marked difference in the outcome of betaine HCl on atazanavir exposure than we previously reported for dasatanib under fasting conditions.

Drug Resistance and Virological Failure among HIV-Infected Patients after a Decade of Antiretroviral Treatment Expansion in Eight Provinces of China

Background

China’s National Free Antiretroviral Treatment Program (NFATP) has substantially increased the survival rate since 2002. However, the emergence of HIV drug resistance (HIVDR) limits the durability and effectiveness of antiretroviral treatment (ART) in at risk patients.

Method

A cross-sectional survey was conducted among patients having received a median of 13.9 months of ART in eight provinces in China. Demographic and clinical information was collected, and venous blood was sampled for CD4 cell counts, measurement of the HIV viral load (VL), and HIV drug resistance (HIVDR) genotyping. Possible risk factors for HIVDR were analyzed by the logistic regression model.

Results

The study included 765 patients. Among them, 65 patients (8.5%) had virological failure (VLF) defined as ≥1,000 copies/ml. Among the individuals with VLF, 64 were successful genotyped, and of these, 33 had one or more HIVDR mutations. The prevalence of HIVDR mutations among patients receiving first-line ART was 4.3% (33/765). All of the patients with HIVDR mutations were resistant to non-nucleoside transcriptase inhibitors, 81.8% were resistant to nucleoside reverse transcriptase inhibitors, and only 3% had mutations that caused resistance to protease inhibitors. Having lower ratios of drug intake in the past month and dwelling in two southwestern provinces were factors independently associated with the emergence of HIVDR.

Conclusion

Most patients receiving first-line ART treatment achieved sound virological and immunological outcomes. However, poor adherence is still a key problem, which has led to the high rate of HIVDR. It was notable that the proportion of drug resistance widely varied among the provinces. More studies are needed to focus on adherence.

[Positioning of lopinavir/ritonavir in antiretroviral treatment schemes]

Lopinavir/ritonavir (LPV/r) was approved for use in the treatment of human immunodeficiency virus (HIV) infection in 2001 and is the protease inhibitor that has been most widely studied in clinical trials. Despite the time interval since its approval, all the evidence accumulated in the last 14 years indicates that LPV/r continues to occupy an important position among antiretroviral drugs. Firstly, LPV/r plus 2 nucleoside/nucleotide analogs is still considered a good option for initial antiretroviral therapy (ART). Secondly, numerous studies have evaluated the efficacy and safety of new initial ART strategies based on LPV/r in dual therapy. The results obtained suggest that LPV/r plus lamivudine (3TC) or raltegravir can be as effective in initial ART as standard triple therapy and justify their consideration as alternative regimens in this scenario. Thirdly, LPV/r is a pioneer drug, as well as being the agent with the largest amount of evidence from clinical trials on simplification to monotherapy (LPV/r) or dual therapy (LPV/r + 3TC). Lastly, LPV/r is highly useful is special situations. It has a low risk of liver toxicity in patients with chronic liver disease, its use is preferred in the treatment of patients with HIV-2, and it is safe and effective in preventing vertical HIV transmission.

Interaction between Darunavir and Etravirine Is Partly Mediated by CYP3A5 Polymorphism

OBJECTIVES

To assess the impact of the loss-of-function CYP3A5*3 allele (rs776746, 6986A>G SNP) on darunavir (DRV) plasma concentrations.

METHODS

135 HIV-1 infected patients treated with DRV-based therapy were included in the study and plasma samples were obtained immediately before drug intake in order to determine DRV trough concentrations using an ultra performance liquid chromatography method (UPLC) with diode-array detection (DAD). Noteworthy is the fact that in 16 (11.9%) patients, etravirine (ETR) was combined with DRV. CYP3A5 genotypes were determined using real time PCR method (TaqMan® genotyping assay). The patients were then classified into CYP3A5 expressors (CYP3A5*1 allele carriers) and non-expressors (CYP3A5*3 homozygous). Subsequently, the association between DRV plasma trough concentration ([DRV]plasma) and CYP3A5 genotype-based expression status was analyzed.

RESULTS

45% of the patients were classified as CYP3A5 expressors. In the whole cohort, mean [DRV]plasma was not different between CYP3A5 expressors and non-expressors (1894ng/ml [CI95%: 1566-2290] versus 1737ng/ml [CI95%: 1468-2057], p = 0.43). However, in the subgroup of the 16 patients receiving DRV combined with ETR, a significantly lower [DRV]plasma was observed for CYP3A5 expressors when compared to non-expressors (1385ng/ml [CI95%:886.3-2165] versus 3141ng/ml [CI95%:2042-4831], p = 0.007).

CONCLUSIONS

Interaction between DRV and ETR is partly mediated by CYP3A5 polymorphism with lower DRV plasma trough concentrations in CYP3A5 expressors suggesting a specific ETR-driven CYP3A5 activation only in CYP3A5 expressors. Consequently, these patients might be more at risk of infra-therapeutic [DRV]plasma. This potentially important observation is a good illustration of a genotype-based drug interaction, which could also have considerable consequences if translated to other CYP3A5-metabolized drugs. Further investigations are thus needed to confirm this association and to explore its clinical impact, mainly in the African population among whom CYP3A5 expressors are more frequent, before recommending systematic CYP3A5 pre-emptive genotyping for DRV-ETR co-administration.

Long-Term Durability of Tenofovir-Based Antiretroviral Therapy in Relation to the Co-Administration of Other Drug Classes in Routine Clinical Practice

Background

In clinical trials, toxicity leading to tenofovir disoproxil fumarate (TDF) discontinuation is rare (3% by 2 years); however in clinical practice it seems to be higher, particularly when TDF is co-administered with ritonavir-boosted protease inhibitors (PI/r). Aims of this study were to assess the rate of TDF discontinuations in clinical practice and to identify factors associated with the risk of stopping TDF.

Methods

All antiretroviral treatment (ART)-naive patients initiating a TDF-based regimen were selected from the ICONA Foundation Study cohort. The primary outcome was TDF discontinuation regardless of the reason; secondary outcome measures were TDF discontinuation due to toxicity and selective TDF discontinuation (that is, TDF discontinuation or substitution, maintaining unchanged the remaining antiretroviral treatment).

Results

3,618 ART-naïve patients were included: 54% started a PI/r-based and 46% a NNRTI-based based regimen. Two-hundred-seventy-seven patients discontinued TDF and reintroduced ART within 30 days without TDF. The probability of TDF discontinuation regardless of the reason was of 7.4% (95%CI:6.4–8.5) by 2 years and 14.1% (95%CI:12.2–16.1) by 5 years. The 5-year KM estimates in the PI/r vs. NNRTI group were 20.4% vs. 7.6%, respectively (log-rank p = 0.0001), for the outcome of stopping regardless of the reason, and 10.7% vs. 4.7% (p = 0.0001) for discontinuation due to toxicity. PI/r use and lower eGFR were associated with an increased risk of discontinuing TDF.

Conclusion

In our cohort, the frequency of TDF discontinuations was higher than that observed in clinical trials. Co-administration of TDF with PI/r was associated with an increased rate of TDF discontinuations. Further studies are needed to clarify the mechanisms that might have led to this outcome.

Efavirenz versus boosted atazanavir-containing regimens and immunologic, virologic, and clinical outcomes: A prospective study of HIV-positive individuals

OBJECTIVE

To compare regimens consisting of either ritonavir-boosted atazanavir or efavirenz and a nucleoside reverse transcriptase inhibitor (NRTI) backbone with respect to clinical, immunologic, and virologic outcomes.

DESIGN

Prospective studies of human immunodeficiency virus (HIV)-infected individuals in Europe and the United States included in the HIV-CAUSAL Collaboration.

METHODS

HIV-positive, antiretroviral therapy-naive, and acquired immune deficiency syndrome (AIDS)-free individuals were followed from the time they started an atazanavir or efavirenz regimen. We estimated an analog of the "intention-to-treat" effect for efavirenz versus atazanavir regimens on clinical, immunologic, and virologic outcomes with adjustment via inverse probability weighting for time-varying covariates.

RESULTS

A total of 4301 individuals started an atazanavir regimen (83 deaths, 157 AIDS-defining illnesses or deaths) and 18,786 individuals started an efavirenz regimen (389 deaths, 825 AIDS-defining illnesses or deaths). During a median follow-up of 31 months, the hazard ratios (95% confidence intervals) were 0.98 (0.77, 1.24) for death and 1.09 (0.91, 1.30) for AIDS-defining illness or death comparing efavirenz with atazanavir regimens. The 5-year survival difference was 0.1% (95% confidence interval: -0.7%, 0.8%) and the AIDS-free survival difference was -0.3% (-1.2%, 0.6%). After 12 months, the mean change in CD4 cell count was 20.8 (95% confidence interval: 13.9, 27.8) cells/mm lower and the risk of virologic failure was 20% (14%, 26%) lower in the efavirenz regimens.

CONCLUSION

Our estimates are consistent with a smaller 12-month increase in CD4 cell count, and a smaller risk of virologic failure at 12 months for efavirenz compared with atazanavir regimens. No overall differences could be detected with respect to 5-year survival or AIDS-free survival.

Probiotics, Soluble Fiber, and L-Glutamine (GLN) Reduce Nelfinavir (NFV)or Lopinavir/Ritonavir (LPV/r)-related Diarrhea

Purpose: Highly active antiretroviral therapy (HAART) can be associated with diarrhea and other gastrointestinal (GI) side effects. Reducing these side effects may improve treatment durability and quality of life (QOL). This study assessed the impact of nutritional co-therapies known to reduce diarrhea in HIV-positive men treated with nelfinavir (NFV)- or lopinavir/ritonavir (LPV/r)-containing regimens. Methods: Thirty-five HIV-positive men treated with NFV (n = 27) or LPV/r (n = 8) with diarrhea (± two liquid stools/day [d]) participated in a 12-week prospective study. Twenty-eight subjects were randomly assigned supplements (S), seven received standard of care (C). Group S received probiotics (1.2g/d) and soluble fiber (11g/d). If diarrhea persisted at week 4, 30g/d L-Glutamine (GLN) was added. Diarrhea incidence, as well as supplement and antidiarrheal use, was assessed monthly. Results: Weight, CD4 count, and HIV RNA were unchanged in both groups. Diarrhea completely resolved in 10 of 28 (36 percent) S subjects. The mean (± SD) number of stools/d declined [3.40 ± 1.25 to 2.54 ± 1.34 (p < 0.01)]. Diarrhea (loose, watery stools/d) lessened in S from 2.84 ± 1.42 to 0.74 ± 1.03 (p < 0.0001). Fifteen S subjects did not obtain full relief with probiotics and fiber, but stools/d decreased from 4.08 ± 1.35 to 3.06 ± 1.68 (p < 0.05) after starting GLN. In C, stools/d, 4.14 ± 4.86 to 3.44 ± 1.68(p = 0.678) and incidence of diarrhea/d, 3.00 ± 4.82 to 1.36 ± 1.29 (p= 0.361) was unchanged. In S, loperamide use decreased from 1.69 ± 2.34 to 0.31 ± 0.69 mg/d (p < 0.01); 18 versus eight subjects used loperamide at 0 and 12 weeks, respectively. Conclusion: Probiotics, soluble fiber, and GLN significantly reduced diarrhea for subjects receiving NFV or LPV/r. Nutritional co-therapies show clinical benefit in HIV-positive men with diarrhea.

Dyslipidemias and Elevated Cardiovascular Risk on Lopinavir-Based Antiretroviral Therapy in Cambodia

BACKGROUND

Lopinavir/ritonavir (LPV/r) is widely used in Cambodia with high efficacy but scarce data exist on long-term metabolic toxicity.

METHODS

We carried out a cross-sectional and retrospective study evaluating metabolic disorders and cardiovascular risk in Cambodian patients on LPV/r-based antiretroviral therapy (ART) for > 1 year followed in Calmette Hospital, Phnom Penh. Data collected included cardiovascular risk factors, fasting blood lipids and glucose, and retrospective collection of bioclinical data. We estimated the 10-year risks of coronary heart disease with the Framingham, Ramathibodi-Electricity Generating Authority of Thailand (Rama-EGAT), and the Data Collection on Adverse Effects of Anti-HIV Drugs (D:A:D) risk equations. We identified patients with LDL above targets defined by the French expert group on HIV and by the HIV Medicine Association of the Infectious Disease Society of America and the Adult AIDS Clinical Trials Group (IDSA-AACTG).

RESULTS

Of 115 patients enrolled-mean age 40.9 years, 69.2% male, mean time on LPV/r 3.8 years-40 (34.8%) had hypercholesterolemia (> 2.40 g/L), and 69 (60.0%) had low HDL cholesterol (< 0.40 g/L). Twelve (10.5%), 28 (24%) and 9 (7.7%) patients had a 10-year risk of coronary heart disease ≥ 10% according to the Framingham, D:A:D, and Rama-EGAT score, respectively. Fifty one (44.4%) and 36 (31.3%) patients had not reached their LDL target according to IDSA-AACTG and French recommendations, respectively.

CONCLUSION

Prevalence of dyslipidemia was high in this cohort of HIV-infected Cambodian patients on LPV/r. Roughly one third had high LDL levels requiring specific intervention.

Cost Effectiveness of Protease Inhibitor Monotherapy Versus Standard Triple Therapy in the Long-Term Management of HIV Patients: Analysis Using Evidence from the PIVOT Trial

BACKGROUND

Protease inhibitor (PI) monotherapy can maintain virological suppression in the majority of patients once it has been established on triple therapy and may also have the potential for substantial cost savings arising from the use of fewer drugs. However, the cost effectiveness of PI monotherapy has yet to be demonstrated.

OBJECTIVES

In this study we examine the cost effectiveness of PI monotherapy with prompt return to combination therapy in the event of viral load rebound compared with ongoing triple therapy (OT) in patients with suppressed viral load on combination antiretroviral therapy (ART) in the UK.

METHODS

The analysis used data from the PIVOT trial in which HIV-positive adults with suppressed viral load for ≥24 weeks on combination ART were randomised to maintain OT or to a strategy of PI monotherapy with prompt return to combination therapy if viral load rebounded. A cost-effectiveness analysis including long-term modelling was conducted. Main outcomes included UK National Health Service (NHS) costs and quality-adjusted life-years (QALYs) with comparative results presented as incremental cost-effectiveness ratios.

RESULTS

PI monotherapy was cost saving as a result of large savings in ART drug costs while being no less effective in terms of QALYs in the within-trial analysis and marginally less effective with lifetime modelling. In the base-case analysis over 3 years, the incremental total cost per patient was -£6424.11 (95 % confidence interval -7418.84 to -5429.38) and incremental QALYs were 0.0051 (95 % CI -0.0479 to 0.0582), resulting in PI monotherapy 'dominating' OT. Multiple scenario analyses found that PI monotherapy was cost saving with no marked differences in QALYs. Modelling of lifetime costs and QALYs showed that PI monotherapy was associated with significant cost savings and was marginally less effective; PI monotherapy was cost effective at accepted cost-effectiveness thresholds in all but one scenario analysis.

CONCLUSIONS

Under most assumptions, PI monotherapy appears to be a cost-effective treatment strategy compared with OT for HIV-infected patients who have achieved sustained virological suppression.

Response to First-Line Ritonavir-Boosted Protease Inhibitors (PI/r)-Based Regimens in HIV Positive Patients Presenting to Care with Low CD4 Counts: Data from the Icona Foundation Cohort

BACKGROUND

There are no data comparing the response to PI/r-based regimens in people presenting for care with low CD4 counts or AIDS (LC).

AIM

To compare the response to LPV/r-, DRV/r- or ATV/r-based cART regimens in LC initiating cART from ART-naive.

METHODS

We included people enrolled in Icona with either CD4 counts ≤350 cells/mm3 (low CD4-LC) or CD4 counts ≤200 cells/mm3 (very low CD4-VLC) and/or AIDS, starting their first PI/r-based regimen after 2008. Initial regimens were compared by intention-to-treat: i) time to viral failure (VF) (first of 2 consecutive VL>200 copies/mL after≥6 months); II) time to PI/r discontinuation/switching for any cause (TD) and for toxicity (TDT); III) treatment failure (TF) (VF or TD). Kaplan-Meier and Cox analyses were used.

RESULTS

1,362 LC patients were included (DRV/r 607; ATV/r 552; LPV/r 203); 813 VLC. In a median of 18 months (IQR:7-35), the 1-year probability of VF and TF were 2.8% (1.9-3.8) and 21.1% (18.7-23.4). In the adjusted analysis, patients initiating ATV/r had a 53% lower chance, and those initiating DRV/r a 61% lower chance of TD, as compared to LPV/r; the risk of TF was more likely in people starting LPV/r. Results were similar among VLC; in this subgroup LPV/r including regimens demonstrated a lower chance of VF.

CONCLUSIONS

We confirmed in LC a low chance of virological failure by 1 year, with small differences according to PI/r. However, larger differences were observed when comparing longer-term endpoints such as treatment failure. These results are important for people presenting late for care.

Dose reduction effective in alleviating symptoms of saquinavir toxicity

Gastrointestinal intolerance is a limitation of boosted saquinavir antiretroviral treatment. We present three HIV-infected individuals whose severe toxicity symptoms started directly after initiation of a standard dose saquinavir hard-gel capsule-containing regimen (saquinavir/ritonavir 1000/100 mg). All patients underwent immediate 12 h pharmacokinetic (PK) assessment and showed extraordinarily high saquinavir plasma exposure. All three patients did not recover until the saquinavir exposure was decreased. This pilot case study anticipates a new concept of 'direct PK'-guided individual dose interventions under close viral load monitoring. Two major reasons for symptomatic saquinavir overexposure were defined: impaired liver function in a chronic hepatitis C virus co-infected individual at normal liver performance parameters and a delayed cytochrome p450 enzyme autoinduction. Overexposure seems to be an independent intolerance factor. Although delayed autoinduction is not well established as a reason for adverse events in saquinavir therapy, this observation may be confirmed in the near future by increased use.

Herpes zoster as an immune restoration disease in AIDS patients during therapy including protease inhibitors

A prospective study to evaluate the incidence of herpes zoster (HZ) as an immune restoration disease in patients with AIDS during highly active antiretroviral therapy (HAART) was conducted in a series of 115 patients diagnosed with AIDS initiated on HAART between 1 January 2000 and 31 July 2001. Of these, a single dermatomal HZ episode occurred in 14 (12%) patients within one and 15 months of HAART (median eight months). The HZ patients were similar to the non-HZ patients in age, sex, and HIV transmission risk factor, but had a more advanced disease. Compared with the baseline values, the viral loads significantly ( P<0.01) decreased, while the mean CD4+ T-cell counts increased by almost four-fold ( P<0.01) in both groups at the time of the HZ episode (or equivalent in non-HZ), but remained below 400/mL in the HZ patients. HZ during HAART is an immunopathological consequence of the improvement of the host immune response, correlating with the beginning of immune restoration.

Integrase inhibitor versus protease inhibitor based regimen for HIV-1 infected women (WAVES): a randomised, controlled, double-blind, phase 3 study

BACKGROUND

Women are under-represented in HIV antiretroviral therapy (ART) studies. Guidelines for selection of ART as initial therapy in patients with HIV-1 infection do not contain sex-specific treatment. We aimed to assess the safety and efficacy of the single tablet integrase inhibitor regimen containing elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate compared with a boosted protease inhibitor regimen of ritonavir-boosted atazanavir with emtricitabine and tenofovir disoproxil fumarate.

METHODS

In this international, randomised, controlled, double-blind, phase 3 study (Women AntiretroViral Efficacy and Safety study [WAVES]), we recruited treatment-naive HIV-infected women with an estimated creatinine clearance of 70 mL/min or higher from 80 centres in 11 countries. Women were randomly assigned (1:1) to receive elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (integrase inhibitor regimen) or ritonavir-boosted atazanavir with emtricitabine and tenofovir disoproxil fumarate (protease inhibitor based regimen); regimens were masked with matching placebos. Randomisation was done by a computer-generated allocation sequence (block size four) and was stratified by HIV-1 RNA viral load and race. Investigators, patients, study staff, and those assessing outcomes were masked to treatment group. All participants who received one dose of study drug were included in the primary efficacy and safety analyses. The main outcome was the proportion of patients with plasma HIV-1 RNA less than 50 copies per mL at week 48 as defined by US Food and Drug Administration snapshot algorithm (prespecified non-inferiority margin of 12%). This study is registered with ClinicalTrials.gov, number NCT01705574.

FINDINGS

Between Nov 28, 2012, and March 12, 2014, 575 women were enrolled. 289 were randomly assigned to receive the integrase inhibitor regimen and 286 to receive the protease inhibitor based regimen. 252 (87%) women in the integrase inhibitor group had plasma HIV-1 RNA less than 50 copies per mL at week 48 compared with 231 (81%) women in the protease inhibitor group (adjusted difference 6·5%; 95% CI 0·4-12·6). No participant had virological failure with resistance in the integrase inhibitor group compared with three participants ([1%]; all Met184Val/Ile) in the protease inhibitor group. 19 women in the protease inhibitor group discontinued because of adverse events compared with five in the integrase inhibitor group.

INTERPRETATION

WAVES shows that clinical trials of ART regimens in global and diverse populations of treatment-naive women are possible. The findings support guidelines recommending integrase inhibitor based regimens in first-line antiretroviral therapy.

FUNDING

Gilead Sciences.

Estimated Glomerular Filtration Rate Trajectories in HIV-Infected Subjects Treated With Different Ritonavir-Boosted Protease Inhibitors and Tenofovir Disoproxil Fumarate or Abacavir

The aim of the study was to evaluate in human immunodeficiency virus (HIV)-infected patients estimated glomerular filtration rate (eGFR) trajectories during treatment with different protease inhibitors (PIs) or a non-nucleoside reverse transcriptase inhibitor (NNRTI) plus tenofovir (TDF) or abacavir (ABC) and lamivudine or emtricitabine (xTC).Retrospective study of patients followed at a single clinical center; all patients who started TDF or ABC for the first time with a NNRTI or lopinavir/r (LPV/r) or atazanavir/r (ATV/r) or darunavir/r (DRV/r), for whom at least 1 eGFR value before the start and during the studied treatment was known, were included in this analysis. eGFR was calculated by means of the CKD-EPI formula. Univariate and multivariate mixed linear model (MLM) was applied to estimate eGFR slope with the considered antiretroviral treatment.In the 1658 patients treated with TDF/xTC (aged 43 [37-48] years, with an eGFR of 105 [96; 113] mL/min/1.73 m, 80% males, 92% Caucasians, 10% coinfected with HCV, 4% with diabetes, 11% with hypertension, 38% naive for antiretroviral therapy (ART), 37% with HIV-RNA <50 copies/mL) the median follow-up was 2.5 (1.2-4.6) years. Their adjusted eGFR slopes (95% CI) were -1.26 (-1.58; -0.95), -0.43 (-1.20; +0.33), -0.86 (-1.28; -0.44), and -0.20 (-0.42; +0.02) mL/min/1.73 m per year in patients treated with ATV/r, DRV/r, LPV/r, and NNRTI, respectively. Patients receiving ATV/r or LPV/r had a greater adjusted decline in eGFR compared with those receiving NNRTIs (difference -1.06 [-1.44; -0.69] mL/min/1.73 m per year, P <0.001; and -0.66 [-1.13; -0.20] mL/min/1.73 m per year, P = 0.005, respectively); adjusted eGFR slopes were similar in patients receiving DRV/r and in those receiving NNRTIs. Patients receiving ATV/r had a greater adjusted eGFR decline than those treated with DRV/r (difference -0.83 [-1.65; -0.02] mL/min/1.73 m per year; P = 0.04), but not than those receiving LPV/r; no significant difference was observed in adjusted eGFR slopes between patients receiving DRV/r and those receiving LPV/r. In the 286 patients treated with ABC and lamivudine, eGFR slopes were similar, independent of the PI.In patients receiving TDF/xTC, eGFR trajectories were small for all regimens and declined less in patients receiving DRV/r or NNRTIs than in those treated with ATV/r or LPV/r.

Heme oxygenase-1-derived bilirubin counteracts HIV protease inhibitor-mediated endothelial cell dysfunction

The use of HIV protease inhibitors (PIs) has extended the duration and quality of life for HIV-positive individuals. However there is increasing concern that this antiviral therapy may promote premature cardiovascular disease by impairing endothelial cell (EC) function. In the present study, we investigated the effect of HIV PIs on EC function and determined if the enzyme heme oxygenase (HO-1) influences the biological action of these drugs. We found that three distinct PIs, including ritonavir, atazanavir, and lopinavir, stimulated the expression of HO-1 protein and mRNA. The induction of HO-1 was associated with an increase in NF-E2-related factor-2 (Nrf2) activity and reactive oxygen species (ROS). PIs also stimulated HO-1 promoter activity and this was prevented by mutating the antioxidant responsive element or by overexpressing dominant-negative Nrf2. In addition, the PI-mediated induction of HO-1 was abolished by N-acetyl-l-cysteine and rotenone. Furthermore, PIs blocked EC proliferation and migration and stimulated the expression of intercellular adhesion molecule-1 and the adhesion of monocytes on ECs. Inhibition of HO-1 activity or expression potentiated the anti-proliferative and inflammatory actions of PIs which was reversed by bilirubin but not carbon monoxide. Alternatively, adenovirus-mediated overexpression of HO-1 attenuated the growth-inhibitory and inflammatory effect of PIs. In contrast, blocking HO-1 activity failed to modify the anti-migratory effect of the PIs. Thus, induction of HO-1 via the ROS-Nrf2 pathway in human ECs counteracts the anti-proliferative and inflammatory actions of PIs by generating bilirubin. Therapeutic approaches targeting HO-1 may provide a novel approach in preventing EC dysfunction and vascular disease in HIV-infected patients undergoing antiretroviral therapy.

Ritonavir Use in Human Immunodeficiency Virus-Positive Surgical Patients Is Not Associated with an Increase in Postoperative Critical Respiratory Events

This study evaluated whether highly active antiretroviral therapy for human immunodeficiency virus (HIV) including ritonavir is independently associated with increased critical respiratory events after general anesthesia with opioid analgesia. The impact of ritonavir on hepatic microsomal enzymes was considered due to the effect of these enzymes on opioid metabolism. Medical records of over 1900 patients were reviewed, and those of 941 patients met inclusion criteria and were analyzed. Chronic treatment with ritonavir was not associated with critical respiratory events in HIV-positive patients.

Tipranavir/Ritonavir (500/200 mg and 500/100 mg) Was Virologically Non-Inferior to Lopinavir/Ritonavir (400/100 mg) at Week 48 in Treatment-Naïve HIV-1-Infected Patients: A Randomized, Multinational, Multicenter Trial

Ritonavir-boosted tipranavir (TPV/r) was evaluated as initial therapy in treatment-naïve HIV-1-infected patients because of its potency, unique resistance profile, and high genetic barrier. Trial 1182.33, an open-label, randomized trial, compared two TPV/r dose combinations versus ritonavir-boosted lopinavir (LPV/r). Eligible adults, who had no prior antiretroviral therapy were randomized to twice daily (BID) 500/100 mg TPV/r, 500/200 mg TPV/r, or 400/100 mg LPV/r. Each treatment group also received Tenofovir 300 mg + Lamivudine 300 mg QD. The primary endpoint was a confirmed viral load (VL) <50 copies/mL at week 48 without prior antiretroviral regimen changes. Primary analyses examined CD4-adjusted response rates for non-inferiority, using a 15% non-inferiority margin. At week 48, VL<50 copies/mL was 68.4%, 69.9%, and 72.4% in TPV/r100, TPV/r200, and LPV/r groups, respectively, and TPV/r groups showed non-inferiority to LPV/r. Discontinuation due to adverse events was higher in TPV/r100 (10.3%) and TPV/r200 (15.3%) recipients versus LPV/r (3.2%) recipients. The frequency of grade ≥3 transaminase elevations was higher in the TPV/r200 group than the other groups, leading to closure of this group. However, upon continued treatment or following re-introduction after treatment interruption, transaminase elevations returned to grade ≤2 in >65% of patients receiving either TPV/r200 or TPV/r100. The trial was subsequently discontinued; primary objectives were achieved and continuing TPV/r100 was less tolerable than standard of care for initial highly active antiretroviral therapy. All treatment groups had similar 48-week treatment responses. TPV/r100 and TPV/r200 regimens resulted in sustained treatment responses, which were non-inferior to LPV/r at 48 weeks. When compared with the LPV/r regimen and examined in the light of more current regimens, these TPV/r regimens do not appear to be the best options for treatment-naïve patients based on their safety profiles.

Cellular Responses and Tissue Depots for Nanoformulated Antiretroviral Therapy

Long-acting nanoformulated antiretroviral therapy (nanoART) induces a range of innate immune migratory, phagocytic and secretory cell functions that perpetuate drug depots. While recycling endosomes serve as the macrophage subcellular depots, little is known of the dynamics of nanoART-cell interactions. To this end, we assessed temporal leukocyte responses, drug uptake and distribution following both intraperitoneal and intramuscular injection of nanoformulated atazanavir (nanoATV). Local inflammatory responses heralded drug distribution to peritoneal cell populations, regional lymph nodes, spleen and liver. This proceeded for three days in male Balb/c mice. NanoATV-induced changes in myeloid populations were assessed by fluorescence-activated cell sorting (FACS) with CD45, CD3, CD11b, F4/80, and GR-1 antibodies. The localization of nanoATV within leukocyte cell subsets was determined by confocal microscopy. Combined FACS and ultra-performance liquid chromatography tandem mass-spectrometry assays determined nanoATV carriages by cell-based vehicles. A robust granulocyte, but not peritoneal macrophage nanoATV response paralleled zymosan A treatment. ATV levels were highest at sites of injection in peritoneal or muscle macrophages, dependent on the injection site. The spleen and liver served as nanoATV tissue depots while drug levels in lymph nodes were higher than those recorded in plasma. Dual polymer and cell labeling demonstrated a nearly exclusive drug reservoir in macrophages within the liver and spleen. Overall, nanoART induces innate immune responses coincident with rapid tissue macrophage distribution. Taken together, these works provide avenues for therapeutic development designed towards chemical eradication of human immunodeficiency viral infection.

A pharmacokinetic model of lopinavir in combination with ritonavir in human

Ritonavir-boosted lopinavir (LPV/r) has been recommended as an alternative regimen for HIV-naive patients who cannot tolerate nevirapine (NVP) and/or efavirenz (EFV). Although combinations of ritonavir and lopinavir have shown higher plasma concentration level of LPV in clinical settings, dosage adjustment is still required to maintain an adequate therapeutic efficacy and reduce side effects. A compartmental pharmacokinetic (PK) model of LPV/r was developed, including a mechanistic description of competitive inhibition. Systematic simulations were performed and predicted plasma drug concentration levels were compared with those from the literature. In particular, the simulated and experimental area under the curve (AUC) based on oral dosing were 76.10 μMol/L, and 76.25 μMol/L, respectively Results from the mathematical model support the hypothesis that the mechanism of LPV/r interaction is due to the competitive inhibition of CYP3A4 in the liver by ritonavir, resulting in an increasing LPV plasma concentration levels. The simulated plasma concentration-time courses were consistent with those from the literature with the goodness of fit (R(2)) of 0.9025 (0.8269-0.9862 95%CI).

Nuke-Sparing Regimens for the Long-Term Care of HIV Infection

With the efficacy of antiretroviral therapy already guaranteed for all practical purposes, the main objective in the management of HIV-positive patients has moved to reduce and prevent potential long-term toxicities. Nucleos(t)ide-sparing regimens could enable the best to address this issue, with a wide range of current options that may allow adaptation to distinct patient populations. Monotherapy with boosted darunavir and lopinavir has been safely prescribed as maintenance therapy to stable patients on stable antiretroviral therapy without nadir CD4 count < 200/mm³, low-level baseline viremia, prolonged viral suppression, and without prior virologic failure. In the presence of all these requirements, dual therapy with lamivudine plus boosted lopinavir or atazanavir has been shown to be equivalent to standard triple therapy. Other nucleoside-sparing dual therapies, especially using raltegravir combined with boosted darunavir or lopinavir and etravirine or rilpivirine in combination with boosted darunavir, have performed well as simplification strategies or rescue interventions in a wide spectrum of patients as long as drug resistance was absent. With current economical constrains, nuke-sparing regimens have attained a degree of maturity that makes it possible to anticipate that they will play an important role in the optimization of antiretroviral therapy in the near future.

State of the Art of Dual Therapy in 2015

Dual therapy refers to combinations of two antiretroviral drugs applied in different clinical settings; they are considered and studied due to possibly reduced drug toxicities. In antiretroviral-naive patients, dual combinations have lower virologic efficacy than standard therapy; the sole efficacious regimen is lamivudine plus lopinavir/ritonavir. Due to a higher possibility of virologic failure, these regimens are generally not allowed in this clinical setting. In antiretroviral-experienced patients, dual regimens are examined in studies with a small sample size, centered on clinical practice, and should be ritonavir-boosted protease inhibitor-based. These combinations have a good virological efficacy; combinations with the integrase inhibitor raltegravir have small sample size and demonstrated efficacy only with etravirine. Virological aspects involving dual therapy should always consider genetic barriers, particularly in simplification strategies, and ritonavir-boosted protease inhibitors are mandatory. As far as immunological aspects are concerned, nucleoside reverse transcriptase inhibitor-sparing regimens have some encouraging data, probably due to the bone marrow toxicity of this class. Combinations with maraviroc were effective in reducing inflammation, but data about immunological recovery are conflicting. The choice of regimen should focus on specific class toxicity since dual regimens are studied in particular for improving safety and tolerability. This review will analyze different dual regimens in the clinical setting, with a peculiar focus on ameliorating toxicities and improving quality of life.

Lopinavir/Ritonavir, an Antiretroviral Drug, Lowers Sperm Quality and Induces Testicular Oxidative Damage in Rats

BACKGROUND

Lopinavir/Ritonavir (Kaletra®) is a protease inhibitor used in the management of HIV infection. The increased incidence of toxicity of antiretroviral therapy (ART) has necessitated proper evaluation of their effects on reproductive health.

PURPOSE

Therefore, this study was designed to investigate the effects of Kaletra® on male reproductive system in Wistar rat.

METHODS

Eighteen rats were assigned into three groups. The first group served as control while the second and third groups received Kaletra® at therapeutic dose (8.3 mg/kg) (Kaletra-T) and twice therapeutic dose (16.6 mg/kg) (Kaletra-2T). Kaletra® was given orally for 21 days.

RESULTS

Administration of Kaletra® caused a significant (p = 0.023) decrease in body weight-gain of rats. Precisely, Kaletra-T and Kaletra-2T decreased body weight-gain by 43% and 48%, respectively. Kaletra-T and kaletra-2T significantly (p = 0.016-0.036) decreased sperm motility and sperm count while kaletra-2T increased total sperm abnormalities in the rats. Also, Kaletra® (at the two doses) caused a significant (p = 0.02-0.04) increase in the levels of testicular lipid peroxidation with a concomitant decrease in antioxidant indices. Specifically, Kaletra-T and Kaletra-2T decreased the activities of glutathione peroxidase by 38% and 57%, catalase by 40% and 48%, glutathione-s-transferase by 32% and 35% and superoxide dismutase by 47% and 52%, respectively while Kaletra-2T decreased reduced glutathione by 49%. Photomicrographs of testis from control and Kaletra-T groups showed normal seminiferous tubules with abundant spermatogenic cells while Kaletra-2T group had few and abnormal shape spermatogenic cells.

CONCLUSION

Kaletra® induces oxidative damage in testis of rats leading to changes in sperm characteristics and antioxidant status of the animals.

[Pharmacokinetic profiles of lopinavir (LPV) in Chinese HIV-infected patients]

OBJECTIVE

To evaluate the pharmacokinetic profiles of lopinavir (LPV) in Chinese HIV-infected patients.

METHODS

A total of 16 patients were enrolled in the LPV pharmacokinetic study. Blood samples were collected before LPV intake and 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 6.0, 8.0, 10.0, 12.0 h after administration. Serum level of LPV was determined by the developed high performance liquid chromatography (HPLC) method. The pharmacokinetic profiles were assessed by WinNonlin software.

RESULTS

The non-compartment model pharmacokinetic (PK) parameters were as follows: the peak time of LPV (T(max)) (3.88 ± 0.23)h, maximum plasma concentration (C(max)) (10.36 ± 3.42) mg/L, minimum plasma concentration (C(min)) (2.18 ± 0.34) mg/L, the 24 h area under plasma-concentration-time curve (AUC0-24) (116.22 ± 15.68) mg · h · L⁻¹, half life (T1/2) (4.5 ± 0.13) h, and clearance rate (CL/F) (3.44 ± 1.34) L/h respectively.

CONCLUSIONS

The pharmacokinetic profiles of LPV in Chinese HIV-1 infected patients demonstrate lower C(min) than those of reported studies, while other parameters are similar. Patients should be educated for compliance based on the narrow gap between C(min) and minimum effect concentration.

Raltegravir non-inferior to nucleoside based regimens in second-line therapy with lopinavir/ritonavir over 96 weeks: a randomised open label study for the treatment of HIV-1 infection

Objective

To determine the durability over 96 weeks of safety and efficacy of lopinavir/ritonavir (LPV/r) and raltegravir (RAL) which was demonstrated to have non-inferior efficacy relative to a regimen of LPV/r with nucleoside/nucleotide reverse transcriptase inhibitors (N(t)RTIs) (Control) in primary analysis at 48 weeks.

Design

Open label, centrally randomised trial.

Setting

Recruitment was from 37 primary and secondary care sites from Africa, Asia, Australia, Europe and Latin America.

Subjects

541 HIV-1 infected adults virologically failing first-line non-NRTI + 2N(t)RTI, with no previous exposure to protease inhibitors or integrase strand transfer inhibitors were analysed, 425 completed 96 weeks follow up on randomised therapy.

Intervention

Randomisation was 1:1 to Control or RAL.

Main outcome measures

Differences between the proportion of participants with plasma HIV-1 RNA (VL) <200 copies/mL by intention to treat were compared with a non-inferiority margin of −12%. Differences in biochemical, haematological and metabolic changes were assessed using T-tests.

Results

VL <200 copies/mL at 96 weeks was: RAL 80.4%, Control 76.0% (difference: 4.4 [95%CI −2.6, 11.3]) and met non-inferiority criteria. The RAL arm had a significantly higher mean change (difference Control-RAL; 95%CI) in haemoglobin (−2.9; −5.7, −1.1), total lymphocytes (−0.2; −0.3, −0.0), total cholesterol (−0.5; −0.8, −0.3), HDL cholesterol (−0.1; −0.1, −0.0) and LDL cholesterol (−0.3; −0.5, −0.2).

Conclusion

At 96 weeks, both RAL and Control maintained efficacy greater than 75% and continued to demonstrate similar safety profiles. These results support the use of a combination LPV/r and RAL regimen as an option following failure of 1st line NNRTI + 2N(t)RTIs.

Trial Registration

ClinicalTrials.gov NCT00931463

Relative Effects of Insulin Resistance and Protease Inhibitor Treatment on Lipid and Lipoprotein Metabolism in HIV-Infected Patients

BACKGROUND

The relationship between insulin resistance, dyslipidemia, HIV infection, and antiretroviral therapy remains unclear, and the atherogenic nature of lipid and lipoprotein profiles in HIV-infected patients has not been fully characterized.

METHOD

We measured plasma lipid and lipoprotein subfractions using Vertical Auto Profile-II methodology and directly measured insulin-mediated glucose disposal in 45 protease inhibitor (PI)-treated and non-PI-treated HIV-infected patients.

RESULTS

PI-treated patients had higher total, LDL, and narrow-density LDL cholesterol (p <.05) and a trend toward higher triglycerides, whereas HDL cholesterol and LDL particle characteristics were unrelated to PI use or history of lipodystrophy. Insulin sensitivity did not differ on the basis of PI therapy, but decreased insulin sensitivity was associated with lower HDL and HDL-3 cholesterol (p <.01); elevated triglyceride (p <.01), VLDL 1+2, and VLDL 3a+3b lipoproteins (p <.01); and smaller, denser (more atherogenic) LDL particle characteristics (p <.01). Thus, the lipoprotein abnormality associated with PI use was increased LDL cholesterol, whereas changes in TG and HDL metabolism were associated with insulin resistance, independent of PI use.

CONCLUSION

The variables of PI-treatment, dyslipidemia, lipodsytrophy, and insulin resistance do not always cluster together in HIV-infected patients, which suggests that the metabolic phenotype emerging in treated patients results from a complex interplay of drug effects, immune restoration, and baseline insulin sensitivity.

Efficacy and Safety of Abacavir Plus Lamivudine Versus Didanosine Plus Stavudine When Combined with a Protease Inhibitor, a Nonnucleoside Reverse Transcriptase Inhibitor, or Both in HIV-1 Positive Antiretroviral-Naive Persons

PURPOSE

The combination of abacavir + lamivudine (ABC+3TC) versus didanosine + stavudine (ddI+d4T), each combined with other classes of antiretrovirals (ARVs) in ARV-naive patients, was compared for the combined endpoint of time to plasma HIV RNA >50 copies/mL (at or after the 8-month visit) or death (primary endpoint) in a nested substudy of an ongoing multicenter randomized trial.

METHOD

The substudy enrolled 182 patients; mean HIV RNA and CD4+ cell counts at baseline were 5.1 log10 copies/mL and 212 cells/mm3, respectively.

RESULTS

After a median follow-up of 28 months, rates of primary endpoint were 57.2 and 67.8 per 100 person-years for the ABC+3TC and ddI+d4T groups (hazard ratio [HR]=0.81, 95% confidence interval [CI] 0.58-1.14, p=.23).

CONCLUSION

There was a trend for treatments containing ABC+3TC to be better than treatments containing ddI+d4T with respect to HIV RNA decreases, CD4+ cell count increases, and tolerability.

Pharmacokinetic Characterization of Different Dose Combinations of Coadministered Tipranavir and Ritonavir in Healthy Volunteers

PURPOSE

To characterize the steady-state pharmacokinetic combination of the nonpeptidic protease inhibitor tipranavir (TPV) with ritonavir (RTV) in 95 healthy adult volunteers, a phase 1, single-center, open-label, randomized, parallel-group trial was conducted.

METHOD

Participants received 250-mg self-emulsifying drug delivery system (SEDDS) capsules of TPV at doses between 250 mg and 1250 mg twice daily for 11 days, then received one or two RTV 100-mg SEDDS capsules, in addition to the TPV capsules, for the next 21 days.

RESULTS

Coadministration of TPV and RTV (TPV/r) resulted in a greater than 20-fold increase in steady-state TPV trough concentrations (Cssmin) as compared with TPV at steady state alone. Mean TPV Cssmin was above a preliminary target threshold of 20 microM with all but one of the RTV-boosted doses; without boosting, none of the TPV-alone doses exceeded the threshold. The average steady-state Cssmin for TPV 500 mg and 750 mg with RTV 100 mg or 200 mg were 20 to 57 times the protein-adjusted TPV IC90R49\CCR418569) for protease inhibitor-resistant HIV-1. An erythromycin breath test, a surrogate marker for cytochrome P450 isoenzyme 3A4 activity, indicated that all TPV/r combinations given provided net inhibition of this isoenzyme. The most frequent treatment-related adverse events were mild gastrointestinal symptoms.

CONCLUSION

This phase 1 study demonstrated that RTV-boosted TPV achieves concentrations that are expected to be effective in treating drug-experienced patients.

Higher Rates of Viral Suppression with Nonnucleoside Reverse Transcriptase Inhibitors Compared to Single Protease Inhibitors Are Not Explained by Better Adherence

BACKGROUND

Although evidence suggests that antiretroviral (ARV) regimens containing nonnucleoside reverse transcriptase inhibitors (NNRTIs) are superior to single-protease inhibitor (PI)-based regimens at suppressing viral load, it is unclear how much of the improved viral suppression is due to intrinsic drug potency versus higher levels of adherence to simpler regimens. We therefore examined adherence and viral suppression in NNRTI and single-PI regimens in a cohort of largely ARV-experienced participants by using objective measures of adherence.

METHOD

Participants were recruited from the Research on Access to Care in the Homeless (REACH) Cohort and were included in the study if they were on single-PI-based or NNRTI-based highly active antiretroviral therapy (HAART) regimens for at least 3 months prior to study entry. Adherence was measured by unannounced pill counts at the participant's usual place of residence. The primary outcome was suppression of HIV viral RNA to <50 copies/mL.

RESULTS

Among 109 individuals who were followed for a median of 8.7 months, the odds of virologic suppression were approximately 8 times higher (p < .01) for participants on NNRTI-based regimens (n = 53) compared with those using single-PI-based regimens (n = 56) when controlling for adherence, as well as other potential confounders in a multivariable analysis. The only other independent predictors of viral suppression in multivariable modeling were ARV adherence (p < .01), CD4 nadir (p = .02), and continuous months on current regimen prior to the start of adherence monitoring (p < .01). There was no significant difference in adherence by unannounced pill counts in participants receiving NNRTI- versus single-PI-containing regimens.

CONCLUSION

A higher proportion of individuals using NNRTI-based regimens had viral suppression when compared to those taking single-PI-containing regimens, and this association was not confounded by higher levels of adherence. These results suggest that improved viral suppression on NNRTI regimens compared to single-PI regimens is more closely associated with regimen potency than higher levels of adherence.

Clinical Impact of Double Protease Inhibitor Boosting with Lopinavir/Ritonavir and Amprenavir as Part of Salvage Antiretroviral Therapy

PURPOSE

Double protease inhibitor (PI) boosting is being explored as a new strategy in salvage antiretroviral (ARV) therapy. However, if a negative drug interaction leads to decreased drug levels of either or both PIs, double PI boosting could lead to decreased virologic response. A negative drug interaction has been described between amprenavir (APV) and lopinavir/ritonavir (LPV/r). This observational cohort study assessed the virologic impact of the addition of APV to a salvage ARV regimen, which also contains LPV/r, compared to a regimen containing LPV/r alone.

METHOD

Patients initiated on a salvage ARV regimen that included LPV/r obtained from the expanded access program in Toronto, Canada, were evaluated. APV (600-1,200 mg bid) was added at the discretion of the treating physician.

RESULTS

Using multivariate Cox proportional hazards models, we found that the addition of APV to a LPV/r-containing salvage regimen was not significantly associated with time to virologic suppression (< 50 copies/mL; adjusted hazard ratio [HR] = 0.75, p =.12) or with time to virologic rebound (adjusted HR = 1.46, p =.34). Those patients who received higher doses of APV had an increased chance of virologic suppression (p =.03). In a subset of 27 patients, the median LPV C(trough) was significantly lower in patients receiving APV (p =.04), and the median APV C(trough) was reduced compared to reported controls.

CONCLUSION

Our data do not support an additional benefit in virologic reduction of double boosting with APV and LPV/r relative to LPV/r alone in salvage ARV therapy. Our study's limitations include its retrospective nature and the imbalance between the two groups potentially confounding the results. Although these factors were adjusted for in the multivariate analysis, a prospective randomized controlled trial is warranted to confirm our findings.

Pilot Study of Saquinavir and Lopinavir/Ritonavir Twice Daily in Protease Inhibitor-Naive HIV-Positive Patients

PURPOSE

Protease inhibitor (PI)-naive patients may have limited reverse transcriptase inhibitor (RTI) options due to resistance and/or toxicity. Effective, well-tolerated nucleoside reverse transcriptase inhibitor (NRTI)-sparing regimens are therefore needed.

METHOD

This prospective study evaluated the efficacy and safety of saquinavir/lopinavir/ritonavir (1000/400/100 mg bid) in PI-naive patients over 48 weeks. The regimen could be intensified with NRTIs if patients did not achieve virologic suppression by 12 weeks. The primary study endpoint was virologic suppression at 48 weeks. Additional study objectives included assessment of safety, CD4 cell counts, blood lipids, PI trough levels, and anthropometrics.

RESULTS

Of the 20 PI-naive study participants, 16 completed 48 weeks of study treatment, with no discontinuations attributed to virologic failure. Fourteen of 16 patients achieved virologic suppression with only the PIs; 2 patients required tenofovir intensification to achieve complete suppression. Median CD4 counts increased significantly over 48 weeks. Adverse events were generally mild and manageable. Extreme lipid elevations were uncommon, although moderate lipid elevations occurred in the majority of patients. Most patients reported some degree of central fat accumulation.

CONCLUSION

Our study demonstrates that saquinavir/lopinavir/ritonavir 1000/400/100 mg bid with tenofovir intensification is a potent nucleoside-sparing regimen for PI-naive patients, associated with durable HIV suppression and improved CD4 cell counts. Fat accumulation and metabolic changes observed in this study warrant confirmation from ongoing trials.

Differences in Durability of Treatment with Initial PI-Based Regimens

The durability of virologic response to antiretroviral therapy is dependent on the potency, tolerability, and adherence level of the regimen. In a prospective, nonrandomized cohort study, we compared the treatment outcome of a nelfinavir-based highly active antiretroviral therapy (HAART) regimen with that of an indinavir-based regimen, over 1 year of routine clinical practice. Information was derived from 134 treatment-naïve HIV-1-infected patients initiated on triple therapy with either nelfinavir (n = 44) or indinavir (n = 90). The proportions of patients achieving a virological response were similar between treatment groups (>1 log(10) reduction in HIV RNA at 3 months in 95% of patients taking nelfinavir and 88% taking indinavir; HIV RNA <50 copies/mL after 1 year in 79% and 69% of patients, respectively). Predicting factors for 1-year virological suppression were initial virological response (p =.02) and adherence >90% (p =.0001). Over 90% adherence was achieved in 70% of patients taking nelfinavir compared with 41% of those taking indinavir (p =.01). The probability of remaining on the initial protease inhibitor (PI) after 12 months was 77% in the nelfinavir group and 66% in the indinavir group, with the median time to changing treatment being 519 days and 462 days, respectively. Gastric intolerance and nephritic colic were the most common reasons for changing therapy in the indinavir group. In the clinical setting, HAART based on initial nelfinavir and indinavir therapy was associated with similarly good virological and immunological suppression at 1 year, however, nelfinavir-based treatment was associated with a longer durability, probably due to a better adherence and tolerance pattern.

Progression of Lipodystrophy (LD) with Continued Thymidine Analogue Usage: Long-Term Follow-Up from a Randomized Clinical Trial (The PIILR Study)

PURPOSE

During the 24-week PIILR study of protease inhibitor (PI) withdrawal, improved lipids and reduction in intraabdominal visceral fat was seen, however, there was also a loss of subcutaneous limb fat in patients with HIV-lipodystrophy (LD). It was hypothesized that overall improvement in LD may require a longer period of time off PIs.

METHOD

Follow-up of patients randomized to stop or continue PI-based therapy for 24 weeks, in a multicenter study, was continued for up to 120 weeks. Biochemistry and lipid parameters were assessed every 3 months. DEXA and CT scans were performed annually. Limb fat, visceral adipose tissue, and the lipodystrophy case definition score (LCDS) were used as indicators of LD severity.

RESULTS

Forty-five male patients with baseline and week 120 body composition data were assessed. There were no significant changes in the limb fat or visceral adipose tissue (VAT) components of LD, with the exception of the LCDS (change from baseline +5.79, p < .001). Control of viral replication was maintained and lipid and glycemic parameters were unchanged over the 120-week follow-up. Linear regression analysis showed on-study usage of stavudine was independently and significantly correlated with both decreased limb fat mass and a higher LCDS.

CONCLUSION

Body composition or metabolic features of LD did not improve over 2 years of observation in patients remaining on predominantly PI-sparing therapy. LD was adversely influenced by continued stavudine use.