Objective and Subjective Improvement of Cognition After Discontinuing Efavirenz in Asymptomatic Patients: A Randomized Controlled Trial

Cognitive impairment in people living with HIV: mechanisms, controversies, and future perspectives

Despite the dramatic decrease in HIV-associated neurocognitive impairment (NCI) in the combined antiretroviral treatment (cART) era, subtler neuropsychological complications remain prevalent. In this review, we discuss the changing pathophysiology of HIV-associated NCI, considering recent evidence of HIV neuropathogenesis, and the pivotal role of cART. Furthermore, we address the multifactorial nature of NCI in people living with HIV, including legacy and ongoing insults to the brain, as well as host-specific factors. We also summarize the ongoing debate about the refinement of diagnostic criteria, exploring the strengths and limitations of these recent approaches. Finally, we present current research in NCI management in people living with HIV and highlight the need for using both pharmacological and nonpharmacological pathways toward a holistic approach.

Influence of efavirenz and 8-hydroxy-efavirenz plasma levels on cognition and central nervous system side effects

OBJECTIVES

To investigate whether efavirenz (EFV) or 8-hydroxy-EFV (8-OH-EFV) plasma levels are associated with neurocognitive impairment and central nervous system (CNS) side effects.

METHODS

We conducted a cross-sectional analysis to explore the potential links between EFV/8-OH-EFV levels and cognitive performance or CNS-related side effects in patients screened within a randomized trial involving a switch from EFV to rilpivirine. The Mann-Whitney test was employed to compare drug levels in patients with or without cognitive impairment, depression, anxiety, sleep disorder or CNS symptoms. Additionally, Spearman's test was used to assess correlations between drug levels and test scores.

RESULTS

Among 104 patients, neither EFV nor 8-OH-EFV levels were linked to cognitive impairment, although trends towards higher EFV levels were observed in those with impaired executive function (p = 0.055) and language performances (p = 0.021). On the other hand, elevated 8-OH-EFV levels, but not EFV levels, were associated with more CNS side effects (222 vs. 151 ng/mL, p = 0.027), depressive symptoms (247 vs. 164 ng/mL, p = 0.067) and sleep impairment (247 vs. 164 ng/mL, p = 0.078). Consistently, a trend towards a correlation between EFV levels and lower z-scores in executive function and motor function was observed, while 8-OH-EFV levels, but not EFV levels, were directly correlated with symptom scores.

CONCLUSIONS

Higher levels of 8-OH-EFV were associated with CNS side effects, while EFV levels were only marginally associated with cognitive performance, thus suggesting that EFV and its metabolite may act differently in determining detrimental neurological effects.

Pharmacogenetics of weight gain following switch from efavirenz- to integrase inhibitor-containing regimens

BACKGROUND

Excessive weight gain affects some persons with HIV after switching to integrase strand transfer inhibitor (INSTI)-containing antiretroviral therapy (ART). We studied associations between CYP2B6 genotype and weight gain after ART switch among ACTG A5001 and A5322 participants.

METHODS

Eligible participants switched from efavirenz- to INSTI-containing ART, had genotype data, and had weight data at least once from 4 weeks to 2 years post-switch. Multivariable linear mixed effects models adjusted for race/ethnicity, CD4, age, BMI and INSTI type assessed relationships between CYP2B6 genotype and estimated differences in weight change.

RESULTS

A total of 159 eligible participants switched ART from 2007 to 2019, of whom 138 had plasma HIV-1 RNA < 200 copies/mL (65 CYP2B6 normal, 56 intermediate, 17 poor metabolizers). Among participants with switch HIV-1 RNA < 200 copies/mL, weight increased in all 3 CYP2B6 groups. The rate of weight gain was greater in CYP2B6 poor than in CYP2B6 normal metabolizers overall, and within 9 subgroups (male, female, White, Black, Hispanic, dolutegravir, elvitegravir, raltegravir, and TDF in the pre-switch regimen); only in Hispanic and elvitegravir subgroups were these associations statistically significant ( P  < 0.05). Compared to normal metabolizers, CYP2B6 intermediate status was not consistently associated with weight gain.

CONCLUSION

CYP2B6 poor metabolizer genotype was associated with greater weight gain after switch from efavirenz- to INSTI-containing ART, but results were inconsistent. Weight gain in this setting is likely complex and multifactorial.

The Effect of Efavirenz on Reward Processing in Asymptomatic People Living with HIV: A Randomized Controlled Trial

Functional magnetic resonance imaging (fMRI) studies have demonstrated that HIV-infection affects the fronto-striatal network. It has not been examined what impact efavirenz (EFV), an antiretroviral drug notorious for its neurocognitive effects, has on the reward system: a key subcomponent involved in depressive and apathy symptoms. Therefore, this study aims to investigate the effect of EFV on reward processing using a monetary incentive delay (MID) task. In this multicenter randomized controlled trial, asymptomatic adult participants stable on emtricitabine/tenofovirdisoproxil fumarate (FTC/TDF)/EFV were randomly assigned in a 2:1 ratio to switch to FTC/TDF/rilpivirine (RPV) (n = 30) or continue taking FTC/TDF/EFV (n = 13). At baseline and 12 weeks after therapy switch, both groups performed an MID task. Behavior and functional brain activity related to reward anticipation and reward outcome were assessed with blood-oxygen-level-dependent fMRI. Both groups were matched for age, education level, and time since HIV diagnosis and on EFV. At the behavioral level, both groups had faster response times and better response accuracy during rewarding versus nonrewarding trials, with no improvement resulting from switching FTC/TDF/EFV to FTC/TDF/RPV. No significant change in activation related to reward anticipation in the ventral striatum was found after switching therapy. Both groups had significantly higher activation levels over time, consistent with a potential learning effect. Similar activity related to reward outcome in the orbitofrontal cortex was found. Discontinuing FTC/TDF/EFV was not found to improve activity related to reward anticipation in asymptomatic people living with HIV, with similar cortical functioning during reward outcome processing. It is therefore likely that EFV does not affect motivational control. Further research is needed to determine whether EFV affects motivational control in HIV populations with different characteristics.

High-content analysis and Kinetic Image Cytometry identify toxicity and epigenetic effects of HIV antiretrovirals on human iPSC-neurons and primary neural precursor cells

INTRODUCTION

Despite viral suppression due to combination antiretroviral therapy (cART), HIV-associated neurocognitive disorders (HAND) continue to affect half of people with HIV, suggesting that certain antiretrovirals (ARVs) may contribute to HAND.

METHODS

We examined the effects of nucleoside/nucleotide reverse transcriptase inhibitors tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) and the integrase inhibitors dolutegravir (DTG) and elvitegravir (EVG) on viability, structure, and function of glutamatergic neurons (a subtype of CNS neuron involved in cognition) derived from human induced pluripotent stem cells (hiPSC-neurons), and primary human neural precursor cells (hNPCs), which are responsible for neurogenesis.

RESULTS

Using automated digital microscopy and image analysis (high content analysis, HCA), we found that DTG, EVG, and TDF decreased hiPSC-neuron viability, neurites, and synapses after 7 days of treatment. Analysis of hiPSC-neuron calcium activity using Kinetic Image Cytometry (KIC) demonstrated that DTG and EVG also decreased the frequency and magnitude of intracellular calcium transients. Longer ARV exposures and simultaneous exposure to multiple ARVs increased the magnitude of these neurotoxic effects. Using the Microscopic Imaging of Epigenetic Landscapes (MIEL) assay, we found that TDF decreased hNPC viability and changed the distribution of histone modifications that regulate chromatin packing, suggesting that TDF may reduce neuroprogenitor pools important for CNS development and maintenance of cognition in adults.

CONCLUSION

This study establishes human preclinical assays that can screen potential ARVs for CNS toxicity to develop safer cART regimens and HAND therapeutics.

Efavirenz Pharmacogenetics and Weight Gain Following Switch to Integrase Inhibitor-Containing Regimens

BACKGROUND

Unwanted weight gain affects some people living with human immunodeficiency virus (HIV) who are prescribed integrase strand transfer inhibitors (INSTIs). Mechanisms and risk factors are incompletely understood.

METHODS

We utilized 2 cohorts to study pharmacogenetics of weight gain following switch from efavirenz- to INSTI-based regimens. In an observational cohort, we studied weight gain at 48 weeks following switch from efavirenz- to INSTI-based regimens among patients who had been virologically suppressed for at least 2 years at a clinic in the United States. Associations were characterized with CYP2B6 and UGT1A1 genotypes that affect efavirenz and INSTI metabolism, respectively. In a clinical trials cohort, we studied weight gain at 48 weeks among treatment-naive participants who were randomized to receive efavirenz-containing regimens in AIDS Clinical Trials Group studies A5095, A5142, and A5202 and did not receive INSTIs.

RESULTS

In the observational cohort (n = 61), CYP2B6 slow metabolizers had greater weight gain after switch (P = .01). This was seen following switch to elvitegravir or raltegravir, but not dolutegravir. UGT1A1 genotype was not associated with weight gain. In the clinical trials cohort (n = 462), CYP2B6 slow metabolizers had lesser weight gain at week 48 among participants receiving efavirenz with tenofovir disoproxil fumarate (P = .001), but not those receiving efavirenz with abacavir (P = .65). Findings were consistent when stratified by race/ethnicity and by sex.

CONCLUSIONS

Among patients who switched from efavirenz- to INSTI-based therapy, CYP2B6 genotype was associated with weight gain, possibly reflecting withdrawal of the inhibitory effect of higher efavirenz concentrations on weight gain. The difference by concomitant nucleoside analogue is unexplained.

Interrogating the impact of combination antiretroviral therapies on HIV-associated neurocognitive disorders

OBJECTIVES

Although the advent of Combination Antiretroviral Therapy (cART) has greatly reduced the prevalence of HIV-Associated Dementia, the most severe form of HIV-Associated Neurocognitive Disorder (HAND), the incidence of the milder forms of HAND have risen. The explanations proposed include persistent central nervous system (CNS) viraemia and the neurotoxicity of chronic cART regimens. Nonetheless, controversies in HAND prevalence estimates, alongside a lack of consensus on the significance of CNS Penetration Effectiveness (CPE) have added to the complexity of elucidating the role of cART in HAND. The present review will evaluate the evidence underlying these explanations, as well as highlighting the need for improved trial designs and the incorporation of emerging biomarkers and neuroimaging tools.

METHODS

A review of the current literature investigating cART neurotoxicity, controversies in HAND prevalence estimates, CNS Penetration Effectiveness, and neuroprotective adjuvant therapies.

CONCLUSIONS

Ultimately, the inadequacy of cART in achieving complete preservation of the CNS underscores the imminent need for neuroprotective adjuvant therapies, where the efficacy of combining multiple adjuvant classes presents a potential therapeutic frontier which must be interrogated.

Efficacy, safety and central nervous system effects after switch from efavirenz/tenofovir/emtricitabine to doravirine/tenofovir/lamivudine

OBJECTIVE

Doravirine is an alternative treatment option for individuals who do not tolerate efavirenz. We assessed efficacy, safety, and CNS effects in adults with HIV-1 and CNS complaints who switched from an efavirenz-based regimen to a doravirine-based regimen.

DESIGN

Multicenter, double-blind, randomized trial (NCT02652260).

METHODS

Virologically suppressed adults receiving efavirenz/emtricitabine/tenofovir (EFV/FTC/TDF), or its components, with ongoing EFV-associated CNS toxicity grade 2 or higher (DAIDS criteria) were switched to doravirine/lamivudine/tenofovir (DOR/3TC/TDF) on day 1 (Immediate Switch Group [ISG]) or after 12 weeks (Deferred Switch Group [DSG]). CNS toxicity data were collected by self-administered questionnaire. The primary endpoint was the proportion of participants with any grade 2 or higher CNS toxicity at week 12. Secondary endpoints included virologic response and effect on fasting lipids.

RESULTS

Eighty-six participants (58% men, 56% black, median age 41 years, median 4 years on prior EFV regimen) were enrolled (43 ISG, 43 DSG) and included in the analyses. At week 12, 42% of ISG and 37% of DSG had at least 1 grade 2 or higher CNS toxicity [difference 4.7%, 95% CI (-16 to 25%); P = 0.33]. At 24 weeks postswitch, HIV-1 RNA less than 50 copies/ml was maintained in 95.3% of participants, and fasting lipids were significantly decreased (LDL-cholesterol -11.0, non-HDL-cholesterol -13.2, HDL-cholesterol -7.7, total cholesterol -20.9, and triglycerides -13.0 mg/dl).

CONCLUSION

In participants who had CNS complaints while receiving EFV/FTC/TDF, improvement in CNS toxicities attributable to EFV was not significantly different after switching to DOR/3TC/TDF compared with remaining on EFV/FTC/TDF. Virologic efficacy was maintained and lipid profiles improved after switching to DOR/3TC/TDF.

Baseline Neurocognitive Impairment (NCI) Is Associated With Incident Frailty but Baseline Frailty Does Not Predict Incident NCI in Older Persons With Human Immunodeficiency Virus (HIV)

BACKGROUND

Neurocognitive impairment (NCI) and frailty are more prevalent among persons with human immunodeficiency virus (HIV, PWH) compared to those without HIV. Frailty and NCI often overlap with one another. Whether frailty precedes declines in neurocognitive function among PWH or vice versa has not been well established.

METHODS

AIDS Clinical Trials Group (ACTG) A5322 is an observational cohort study of older PWH. Participants undergo annual assessments for NCI and frailty. ACTG A5322 participants who developed NCI as indexed by tests of impaired executive functioning and processing speed during the first 3 years were compared to persons who maintained normal cognitive function; those who demonstrated resolution of NCI were compared to those who had persistent NCI. Participants were similarly compared by frailty trajectory. We fit multinomial logistic regression models to assess associations between baseline covariates (including NCI) and frailty, and associations between baseline covariates (including frailty) and NCI.

RESULTS

In total, 929 participants were included with a median age of 51 years (interquartile range [IQR] 46-56). At study entry, 16% had NCI, and 6% were frail. Over 3 years, 6% of participants developed NCI; 5% developed frailty. NCI was associated with development of frailty (odds ratio [OR] = 2.06; 95% confidence interval [CI] = .94, 4.48; P = .07). Further adjustment for confounding strengthened this association (OR = 2.79; 95% CI = 1.21, 6.43; P = .02). Baseline frailty however was not associated with NCI development.

CONCLUSIONS

NCI was associated with increased risk of frailty, but frailty was not associated with development of NCI. These findings suggest that the presence of NCI in PWH should prompt monitoring for the development of frailty and interventions to prevent frailty in this population.

Cognitive and Neurologic Rehabilitation Strategies for Central Nervous System HIV Infection

PURPOSE OF REVIEW

Cognitive impairment leading to disability is increasingly seen in people living with human immunodeficiency virus (PLWH). Rehabilitation can alleviate the effects of cognitive impairment upon function. The aim of this paper is to discuss the strategies that have been used in cognitive and neurologic rehabilitation in PLWH.

RECENT FINDINGS

Studies examining pharmacological and non-pharmacological strategies were analysed. Medical management of HIV and co-morbidities should be optimised. Non-pharmacological strategies, including nerve stimulation techniques, exercise-based interventions, and paper and computer-based cognitive rehabilitation, have some evidence supporting their use in PLWH either as stand-alone interventions or as part of a multidisciplinary approach. Both pharmacological and non-pharmacological rehabilitation strategies have been used with PLWH. More intervention trials are needed to assess cognitive and neurological rehabilitation strategies and further evaluate their potential benefit in PLWH.

Cognitive disorders in people living with HIV

High rates of cognitive disorders in antiretroviral-treated people living with HIV have been described worldwide. The exact prevalence of such cognitive disorders is determined by the definitions used, and the presence of these cognitive disorders significantly impacts the overall wellbeing of people with HIV. With the cohort of people with HIV becoming increasingly older, and having high rates of comorbidities and concomitant medication use, rates of cognitive disorders are likely to increase. Conversely, interventions are being sought to reduce the size of the latent HIV reservoir. If successful, such interventions are likely to also reduce the HIV reservoir in the brain compartment, which could result in improvements in cognitive function and reduced rates of impairment.

High efavirenz levels but not neurofilament light plasma levels are associated with poor neurocognitive functioning in asymptomatic HIV patients

The aim of this study is to assess the effect of efavirenz exposure on neurocognitive functioning and investigate plasma neurofilament light (Nfl) as a biomarker for neurocognitive damage. Sub-analysis of the ESCAPE-study, a randomised controlled trial where virologically suppressed, cognitively asymptomatic HIV patients were randomised (2:1) to switch to rilpivirine or continue on efavirenz. At baseline and week 12, patients underwent an extensive neuropsychological assessment (NPA), and serum efavirenz concentration and plasma Nfl levels were measured. Subgroups of elevated (≥ 4.0 mg/L) and therapeutic (0.74 to< 4.0 mg/L) baseline efavirenz concentration were made. Differences between these groups in baseline NPA Z-scores and in delta scores after efavirenz discontinuation were assessed. Nfl level was measured using an ELISA analysis using single molecule array (Simoa) technology. Correlation of plasma NFL with NPA Z-scores was evaluated using a linear mixed model. The elevated group consisted of 6 patients and the therapeutic group of 48. At baseline, the elevated group showed lower composite Z-scores (median - 1.03; IQR 0.87 versus 0.27; 0.79. p 0.02). This effect was also seen on the subdomains verbal (p 0.01), executive functioning (p 0.02), attention (p < 0.01) and speed (p 0.01). In the switch group, the elevated group improved more on composite scores after discontinuing efavirenz (mean 0.58; SD 0.32 versus 0.22; 0.54, p 0.15). No association between plasma Nfl and composite Z-score was found. High efavirenz exposure is associated with worse cognitive functioning compared with patients with therapeutic concentrations. Plasma Nfl is not a suitable biomarker to measure cognitive damage in this group.

Immunological and Neurometabolite Changes Associated With Switch From Efavirenz to an Integrase Inhibitor

BACKGROUND

The biological mechanisms by which efavirenz (EFV) causes central nervous system (CNS) effects are unclear. The objective of this pilot study was to elucidate the mechanisms underlying these CNS effects by correlating well-described neuropsychological (NP) changes with neurometabolites and immunologic markers following switch off EFV.

SETTING

Two single-arm parallel switch studies among HIV-infected adults in Boston, USA, from 2015 to 2017.

METHODS

Twenty asymptomatic HIV-infected adults on EFV-containing regimens were switched to an integrase strand transfer inhibitor-based regimen for 8 weeks. NP assessments were conducted before and after switch and correlated with neurometabolite changes measured using magnetic resonance spectroscopy and immunological markers. All pre-EFV and post-EFV measures were evaluated using matched-paired analyses.

RESULTS

NP testing demonstrated improvement in the domains of mood, cognition, and sleep off EFV. Magnetic resonance spectroscopy revealed decreases in the neurometabolite glutathione level (P = 0.03), a marker of oxidative stress after switch. Inhibitory neuronal activity as reflected by gamma-amino butyric acid levels increased (P = 0.03), whereas excitatory neurotransmitters glutamine + glutamate (Glx) and aspartate decreased (P = 0.04, 0.001). Switching off EFV was also associated with changes in inflammatory markers; plasma markers sCD14 (P = 0.008) decreased, whereas I-FABP and TNFRI levels increased (P = 0.05, 0.03). Cellular markers CD4 and CD8 HLA-DR-/CD38 subsets both increased (P = 0.05, 0.02).

CONCLUSIONS

Even asymptomatic participants showed improvements in NP parameters when switched off EFV. These improvements were associated with decreased CNS oxidative stress and excitatory neuronal activity. Changes in immune activation biomarkers suggested overall decreased inflammation. EFV may exert CNS effects through oxidative and inflammatory pathways, providing insight into possible mechanisms of EFV neurotoxicity.

Switching from efavirenz to rilpivirine improves sleep quality and self-perceived cognition but has no impact on neurocognitive performances

BACKGROUND

Efavirenz (EFV) association with neurocognitive impairment is debated. Whether switching away from EFV improves neurocognitive performances is still controversial.

METHODS

In a randomized open-label controlled trial, patients under effective treatment with tenofovir disoproxil-fumarate (TDF), emtricitabine (FTC) and EFV, who had altered neurocognitive assessment (z-transformed score below -1 in at least one cognitive domain), depression, anxiety or low sleep-quality, were randomized 1 : 1 to immediate or delayed (24-weeks) switch to TDF/FTC/rilpivirine (RPV). Treatment efficacy, neurocognitive function, symptoms and quality of life were evaluated 12, 24 and 48 weeks after randomization.

FINDINGS

Seventy-four patients were randomized to immediate (36 patients) or delayed switch (38 patients). At baseline, 63 and 25% of patients had z-scores below -1 in at least one or two neurocognitive domains, 31.1, 17.6 and 44.6% had significant depression or anxiety symptoms or low sleep quality. At week 24 (primary end-point), overall neurocognitive improvement was observed, with no statistically significant differences between arms, neither considering the global z score (between arms difference +0.1; P = 0.458), nor domain-specific z scores. Patients switching away from EFV had significant greater improvement of sleep quality index (between-arm difference -1.5; P = 0.011), self-reported cognitive failures (-6.2; P = 0.001) and CNS symptoms score (-5; P = 0.002), but not of anxiety or depression. No protocol defined virological failure, grade at least 3 lab abnormalities or drug-related serious adverse events were reported.

CONCLUSION

Our results do not support the hypothesis that switching to RPV improves cognitive function in patient under stable treatment with EFV. Nonetheless, improvements in neuropsychiatric symptoms, sleep quality and self-perceived cognition were observed.

Improved Central Nervous System Symptoms in People with HIV without Objective Neuropsychiatric Complaints Switching from Efavirenz to Rilpivirine Containing cART

Objective: Occult central nervous system (CNS) symptoms not recognized by people living with HIV (PLWH) receiving efavirenz or their clinicians could occur and impact people’s quality of life. The aim of this study was to determine whether CNS parameters improve in PLWH when switching from efavirenz to rilpivirine. Methods: PLWH receiving tenofovir disoproxil fumarate, emtricitabine, efavirenz (Atripla™) with undetectable HIV RNA, and no CNS symptoms were switched cART to tenofovir disoproxil fumarate, emtricitabine, rilpivirine (Eviplera™). CNS parameters including sleep, anxiety, and depressive symptoms were evaluated using patient-reported outcome measures at baseline, 4, 12, and 24 weeks after switching therapy. A median CNS score was derived from the sum of CNS toxicities of all the grades collected in the study questionnaires. Cognitive function was assessed using a computerized test battery. Results: Of 41 participants, median age was 47 years, Interquartile range (IQR) 31, 92% were male and 80% were of white ethnicity. A significant reduction in total CNS score (10 to 7) was observed at 4 weeks (p = 0.028), but not thereafter. Significant improvements in sleep and anxiety were observed 4, 12 and 24 weeks after switching therapy (p < 0.05). No significant change in global cognitive scores was observed. Conclusions: Switching from efavirenz to rilpivirine based regimens in virologically suppressed PLWH without perceived CNS symptoms was well tolerated and slightly improved overall CNS symptoms.

Efavirenz use and neurocognitive performance among older people living with HIV who were on antiretroviral therapy

This study was to compare global and domain-specific neurocognitive performance between older people living with HIV (PLWH) taking/not taking efavirenz (EFV) and HIV-negative controls. A cross-sectional study was conducted in Yongzhou city, China. All PLWH older than 50 years listed on the registry of Centres for Disease Control and Prevention were invited to join the study. Frequency matching was used to sample HIV-negative controls according to the distribution of age, sex, and years of formal education of older PLWH. A total of 308 older PLWH and 350 HIV-negative controls completed the face-to-face interview and neurocognitive assessment using the comprehensive neuropsychological test battery. After adjusting for significant confounders, older PLWH taking EFV showed poorer performance in memory (p = 0.020), verbal fluency (p = 0.002), and poorer global neurocognitive performance (p = 0.032) than those without EFV use. Compared to HIV-negative controls, older PLWH taking EFV had poorer performance in all neurocognitive domains (p values: <0.001-0.003) and poorer global neurocognitive performance (p < 0.001). Similar trends were observed when comparing older PLWH without using EFV versus HIV-negative controls, with the exception of verbal fluency (p = 0.560). Health care workers should monitor the neuropsychological performance of older PLWH, epically those who were taking EFV. Longitudinal studies are warranted.