Antiretrovirals and Weight Change: Weighing the Evidence.

Body weight is influenced by an interplay of individual and environmental factors. In people with HIV (PWH), weight is also influenced by disease status with loss accompanying disease progression that is reversed with effective antiretroviral therapy (ART). Weight changes in comparative ART trials differ by regimen, with greater gains observed with the integrase strand transfer inhibitors (INSTIs) dolutegravir and bictegravir, particularly when co-administered with tenofovir alafenamide fumarate (TAF), compared to regimens that include agents such as tenofovir disoproxil fumarate (TDF) that attenuate weight gain. We review weight changes in major randomized trials of pre-exposure prophylaxis (PrEP) and initial and switch HIV therapy, highlighting the challenges to assessing the role of ART in weight change. This examination forms the basis for a model that questions assumptions regarding an association between INSTI and TAF and excessive weight gain and calls for more careful consideration of these data when making HIV treatment decisions.

Limited Weight Impact After Switching From Boosted Protease Inhibitors to Dolutegravir in Persons With Human Immunodeficiency Virus With High Cardiovascular Risk: A Post Hoc Analysis of the 96-Week NEAT-022 Randomized Trial.

BACKGROUND: In the NEAT022 trial, virologically suppressed persons with human immunodeficiency virus (HIV) at high cardiovascular risk switching from protease inhibitors to dolutegravir either immediately (DTG-I) or after 48 weeks (DTG-D) showed noninferior virological suppression and significant lipid and cardiovascular disease risk reductions on switching to dolutegravir relative to continuing protease inhibitors. METHODS: In post hoc analysis, major endpoints were 48-week and 96-week weight and body mass index (BMI) changes. Factors associated with weight/BMI changes within the first 48 weeks of DTG exposure, proportion of participants by category of percentage weight change, proportions of BMI categories over time, and impact on metabolic outcomes were also assessed. RESULTS: Between May 2014 and November 2015, 204 (DTG-I) and 208 (DTG-D) participants were included. Weight significantly increased (mean, +0.810 kg DTG-I arm, and +0.979 kg DTG-D arm) in the first 48 weeks postswitch, but remained stable from 48 to 96 weeks in DTG-I arm. Switching from darunavir, White race, total to high-density lipoprotein cholesterol ratio <3.7, and normal/underweight BMI were independently associated with higher weight/BMI gains. The proportion of participants with ≥5% weight change increased similarly in both arms over time. The proportions of BMI categories, use of lipid-lowering drugs, diabetes and/or use of antidiabetic agents, and hypertension and/or use of antihypertensive agents did not change within or between arms at 48 and 96 weeks. CONCLUSIONS: Switching from protease inhibitors to dolutegravir in persons with HIV with high cardiovascular risk led to modest weight gain limited to the first 48 weeks, which involved preferentially normal-weight or underweight persons and was not associated with negative metabolic outcomes. CLINICAL TRIALS REGISTRATION: NCT02098837 and EudraCT 2013-003704-39.

Incidence of Hypertension and Blood Pressure Changes in Persons With Human Immunodeficiency Virus at High Risk for Cardiovascular Disease Switching From Boosted Protease Inhibitors to Dolutegravir: A Post-hoc Analysis of the 96-week Randomised NEAT-022 Trial.

BACKGROUND: Integrase inhibitors have been recently linked to a higher risk for hypertension. In NEAT022 randomized trial, virologically suppressed persons with human immunodeficiency virus (HIV, PWH) with high cardiovascular risk switched from protease inhibitors to dolutegravir either immediately (DTG-I) or after 48 weeks (DTG-D). METHODS: Primary endpoint was incident hypertension at 48 weeks. Secondary endpoints were changes in systolic (SBP) and diastolic (DBP) blood pressure; adverse events and discontinuations associated with high blood pressure; and factors associated with incident hypertension. RESULTS: At baseline, 191 (46.4%) participants had hypertension and 24 persons without hypertension were receiving antihypertensive medications for other reasons. In the 197 PWH (n = 98, DTG-I arm; n = 99, DTG-D arm) without hypertension or antihypertensive agents at baseline, incidence rates per 100 person-years were 40.3 and 36.3 (DTG-I) and 34.7 and 52.0 (DTG-D) at 48 (P = .5755) and 96 (P = .2347) weeks. SBP or DBP changes did not differed between arms. DBP (mean, 95% confidence interval) significantly increased in both DTG-I (+2.78 mmHg [1.07-4.50], P = .0016) and DTG-D (+2.29 mmHg [0.35-4.23], P = .0211) arms in the first 48 weeks of exposure to dolutegravir. Four (3 under dolutegravir, 1 under protease inhibitors) participants discontinued study drugs due to adverse events associated with high blood pressure. Classical factors, but not treatment arm, were independently associated with incident hypertension. CONCLUSIONS: PWH at high risk for cardiovascular disease showed high rates of hypertension at baseline and after 96 weeks. Switching to dolutegravir did not negatively impact on the incidence of hypertension or blood pressure changes relative to continuing protease inhibitors.

Long-term effects on subclinical cardiovascular disease of switching from boosted protease inhibitors to dolutegravir.

BACKGROUND: In the NEAT022 trial, switching from boosted PIs (PI/r) to dolutegravir in people with HIV (PWH) with high cardiovascular risk decreased plasma lipids, soluble CD14 and adiponectin, and showed consistent favourable, although non-significant, effects on carotid intima-media thickness (CIMT) progression at 48 weeks. We hereby communicate planned final 96 week results on biomarker changes and CIMT progression. METHODS: PWH on a PI/r-based triple therapy regimen were randomly assigned (1:1) to switch the PI/r component to dolutegravir either immediately (DTG-I group) or after 48 weeks (DTG-D group) and were followed up to 96 weeks. We assessed changes in biomarkers associated with inflammation, endothelial dysfunction, monocyte immune activation, oxidation, insulin resistance, hypercoagulability, heart failure, myocardial injury and glomerular and tubular kidney injury, and right and left CIMT progression at 48 and 96 weeks. RESULTS: Of 415 PWH randomized, 287 (69%) and 143 (34%) contributed to the biomarker and CIMT substudies respectively. There were significant 96 week changes in biomarkers associated with inflammation, immune activation, oxidation, insulin resistance and myocardial injury. Most changes were favourable, except for adiponectin reduction, which may suggest higher insulin resistance. We were unable to detect significant changes in the progression of CIMT between arms or within arms at 96 weeks. DISCUSSION: After 96 weeks, switching from PI/r to dolutegravir in PWH with high cardiovascular risk led to significant changes in several biomarkers associated with cardiovascular disease. Although most changes were favourable, adiponectin reduction was not. There were non-significant changes in CIMT progression.

FRAX assessment in people ageing with HIV.

OBJECTIVES: Current British HIV Association (BHIVA) guidelines recommend the use of FRAX for the routine assessment of bone fracture risk in people living with HIV over 50 years of age every 3 years. Bone mineral density measurement with dual-energy X-ray absorptiometry (DXA) scan is recommended for those with increased fracture risk (FRAX major > 10%). Our objectives were to estimate the prevalence of and risk factors for osteoporosis in a population of PLWH aged > 50 years and assess the utility of FRAX in predicting the presence of DXA-proven osteoporosis in this cohort. METHODS: This was a cross-sectional study of a cohort of PLWH aged > 50 years attending the Chelsea and Westminster Hospital and who had a DXA scan between January 2009 and December 2018. FRAX scores were calculated using the Sheffield algorithm. Multiple regression models and Cohen's kappa values were used to assess risk factors for osteoporosis and agreement between FRAX and DXA scan results, respectively. RESULTS: In all, 744 patients were included (92.9% male, mean age 56 ± 5 years). The prevalence rates of osteoporosis (at DXA scans) and osteopenia were 12.2% and 63.7%, respectively. FRAX major was > 10% in only two patients, while 90/91 (98.9%) patients with osteoporosis had a normal FRAX score. The presence of osteoporosis was significantly associated with low body mass index and estimated glomerular filtration rate (p < 0.05). CONCLUSION: Our results indicate that FRAX scores did not predict the presence of osteoporosis in our population of PLWH over 50 years of age and therefore FRAX scores may not be the appropriate tool to define eligibility to perform DXA scans in PLWH.

Factors associated with overweight/obesity in a cohort of people living with HIV over 50 years of age.

Changes in body weight in people living with HIV vary by regimen components, timing of therapy introduction (naive, switch) and demographic factors. Our objective was to evaluate weight change and factors associated in an ageing cohort of treated subjects with HIV at Chelsea and Westminster Hospital. We found that the prevalence of obesity was similar to general population and was associated with a number of health conditions, which increase metabolic risk.

Switching from boosted PIs to dolutegravir decreases soluble CD14 and adiponectin in high cardiovascular risk people living with HIV.

BACKGROUND: Switching from boosted PIs to dolutegravir in people living with HIV (PLWH) with high cardiovascular risk improved plasma lipids at 48 weeks in the NEAT022 trial. Whether this strategy may have an impact on cardiovascular biomarkers is unknown. METHODS: We assessed 48 week changes in biomarkers associated with inflammation, endothelial dysfunction, monocyte immune activation, oxidation, insulin resistance, hypercoagulability, heart failure, myocardial injury, and glomerular and tubular kidney injury. RESULTS: Of 415 PLWH randomized in the NEAT022 study, 313 (75.4%) remained on allocated therapy and had paired samples available. Soluble CD14 (-11%, P < 0.001) and adiponectin (-11%, P < 0.001) significantly declined and high-sensitive C-reactive protein (-13%, P = 0.069) and oxidized LDL (-13%, P = 0.084) tended to decrease with dolutegravir. Switching to dolutegravir remained significantly associated with soluble CD14 and adiponectin reductions after adjustment for baseline variables. There were inverse correlations between soluble CD14 and CD4 count changes (P = 0.05), and between adiponectin and BMI changes (P < 0.001). CONCLUSIONS: Switching from boosted PIs to dolutegravir in PLWH with high cardiovascular risk led to soluble CD14 and adiponectin reductions at 48 weeks. While decreasing soluble CD14 may entail favourable health effects in PLWH, adiponectin reduction may reflect less insulin sensitivity associated with weight gain.

The benefits of tenofovir discontinuation with or without bisphosphonate therapy in osteoporotic people living with HIV.

OBJECTIVES: Treatment with bisphosphonates and discontinuation of tenofovir disoproxil fumarate (TDF) are recommended strategies for managing osteoporosis in people living with HIV (PLHIV). This study aimed to compare the effects on bone mineral density (BMD) of TDF discontinuation with and without bisphosphonate therapy in osteoporotic PLHIV. METHODS: The present study is a retrospective cohort analysis of dual-energy X-ray absorptiometry scan results of PLHIV attending Chelsea and Westminster Hospital HIV clinic between 2009 and 2020. Osteoporotic (T-score < -2.5) patients with ≥ 6 months' TDF exposure were included. Changes in BMD and T-scores at the lumbar spine (LS) and femoral neck (FN) were assessed. RESULTS: A total of 84 participants were included, of whom 43 discontinued TDF only (TS) and 41 switched from TDF and received bisphosphonates (TS+): 86.9% were male; 77.4% were white; median (interquartile range, IQR) age was 54.8 (51.0-58.5) years; and median (IQR) TDF exposure was 6.5 (3.5-10.4) years. At a median follow-up of 2 years after TDF-discontinuation, mean spine BMD increased significantly in both groups, but bisphosphonate recipients had greater improvements (4.83% vs. 7.79%; P < 0.019); LS T-scores improved significantly but changes were comparable between groups (TS, 0.5 vs. TS+, 0.6; P = 0.270). At the FN, no significant increases in BMD were observed (TS, 3.05% vs. TS+, 2.71%; P = 0.205); T-scores significantly improved in bisphosphonate recipients only (+0.2; P = 0.003). A greater proportion recovered from osteoporosis in the TS+ group (34.9% vs. 43.9%), although differences between groups were not significant (P = 0.503). CONCLUSIONS: Our real-world data indicate that although TDF discontinuation significantly improved bone health in osteoporotic PLHIV, combining bisphosphonates with TDF discontinuation resulted in greater improvements in BMD.

Genetic influence of ABCG2, UGT1A1 and NR1I2 on dolutegravir plasma pharmacokinetics.

OBJECTIVES: Dolutegravir has replaced efavirenz as first-line treatment in universal HIV guidelines. We sought to ascertain the contributory effect of SNPs in four key genes linked to dolutegravir disposition (UGT1A1, ABCG2, CYP3A and NR1I2) on plasma dolutegravir pharmacokinetics. METHODS: Paired pharmacogenetic/pharmacokinetic data from 93 subjects were analysed for association using multivariate linear regression. RESULTS: Co-occurring UGT1*28 and NR1I2 c.63396C>T homozygosity was associated with a 79% increase in AUC0-24 (P = 0.001; 27% if analysed individually), whilst combined ABCG2 c.421C>A and NR1I2 c.63396C>T variants were associated with a 43% increase in Cmax (P = 0.002) and a 39% increase in AUC0-24 (P = 0.002). When analysed individually, homozygosity for the NR1I2 c.63396C>T variant alleles was associated with a 28% increase in Cmax (P = 0.033) and homozygosity for the ABCG2 c.421C>A variant alleles was associated with a 28% increase in Cmax (P = 0.047). The UGT1A1*28 (rs8175347) poor metabolizer status (*28/*28; *28/*37; *37/*37) was individually associated with a 27% increase in AUC0-24 (P = 0.020). The combination of UGT1A1*28 poor metabolizer and UGT1A1*6 intermediate metabolizer statuses correlated with a 43% increase in AUC0-24 (P = 0.023). CONCLUSIONS: This study showed a pharmacogenetic association between dolutegravir pharmacokinetics and variants in the ABCG2, UGT1A1 and NR1I2 genes, particularly when combined. Further research is warranted to confirm these associations in population-specific studies and to investigate their putative relationship with dolutegravir pharmacodynamics.

Increased Dolutegravir Peak Concentrations in People Living With Human Immunodeficiency Virus Aged 60 and Over, and Analysis of Sleep Quality and Cognition.

Background: Demographic data show an increasingly aging human immunodeficiency virus (HIV) population worldwide. Recent concerns over dolutegravir-related neuropsychiatric toxicity have emerged, particularly amongst older people living with HIV (PLWH). We describe the pharmacokinetics (PK) of dolutegravir (DTG) 50 mg once daily in PLWH aged 60 and older. Additionally, to address calls for prospective neuropsychiatric toxicodynamic data, we evaluated changes in sleep quality and cognitive functioning in this population after switching to abacavir (ABC)/lamivudine (3TC)/DTG over 6 months. Methods: PLWH ≥60 years with HIV-viral load <50 copies/mL on any non-DTG-based antiretroviral combination were switched to ABC/3TC/DTG. On day 28, 24-hour PK sampling was undertaken. Steady-state PK parameters were compared to a published historical control population aged ≤50 years. We administered 6 validated sleep questionnaires and neurocognitive (Cogstate) testing pre-switch and over 180 days. Results: In total, 43 participants enrolled, and 40 completed the PK phase. Overall, 5 discontinued (2 due to sleep-related adverse events, 4.6%). DTG maximum concentration (Cmax) was significantly higher in patients ≥60 years old versus controls (geometric mean 4246 ng/mL versus 3402 ng/mL, P = .005). In those who completed day 180 (n = 38), sleep impairment (Pittsburgh Sleep Quality Index) was marginally higher at day 28 (P = .02), but not at days 90 or 180. Insomnia, daytime functioning, and fatigue test scores did not change statistically over time. Conclusions: DTG Cmax was significantly higher in older PLWH. Our data provides clinicians with key information on the safety of prescribing DTG in older PLWH.

Immediate Versus Deferred Switching From a Boosted Protease Inhibitor-based Regimen to a Dolutegravir-based Regimen in Virologically Suppressed Patients With High Cardiovascular Risk or Age ≥50 Years: Final 96-Week Results of the NEAT022 Study.

Background: Both immediate and deferred switching from a ritonavir-boosted protease inhibitor (PI/r)-based regimen to a dolutegravir (DTG)-based regimen may improve lipid profile. Methods: European Network for AIDS Treatment 022 Study (NEAT022) is a European, open-label, randomized trial. Human immunodeficiency virus (HIV)-infected adults aged ≥50 years or with a Framingham score ≥10% were eligible if HIV RNA was <50 copies/mL. Patients were randomized to switch from PI/r to DTG immediately (DTG-I) or to deferred switch at week 48 (DTG-D). Week 96 endpoints were proportion of patients with HIV RNA <50 copies/mL, percentage change of lipid fractions, and adverse events (AEs). Results: Four hundred fifteen patients were randomized: 205 to DTG-I and 210 DTG-D. The primary objective of noninferiority at week 48 was met. At week 96, treatment success rate was 92.2% in the DTG-I arm and 87% in the DTG-D arm (difference, 5.2% [95% confidence interval, -.6% to 11%]). There were 5 virological failures in the DTG-I arm and 5 (1 while on PI/r and 4 after switching to DTG) in the DTG-D arm without selection of resistance mutations. There was no significant difference in terms of grade 3 or 4 AEs or treatment-modifying AEs. Total cholesterol and other lipid fractions (except high-density lipoprotein) significantly (P < .001) improved both after immediate and deferred switching to DTG overall and regardless of baseline PI/r strata. Conclusions: Both immediate and deferred switching from a PI/r to a DTG regimen in virologically suppressed HIV-infected patients ≥50 years old or with a Framingham score ≥10% was highly efficacious and well tolerated, and improved the lipid profile. Clinical Trials Registration: NCT02098837 and EudraCT: 2013-003704-39.

Once-daily atazanavir/cobicistat and darunavir/cobicistat exposure over 72 h post-dose in plasma, urine and saliva: contribution to drug pharmacokinetic knowledge.

Background: We investigated the pharmacokinetics (PK) of atazanavir/cobicistat and darunavir/cobicistat once daily over 72 h following drug intake cessation in plasma, saliva and urine. Methods: Healthy volunteers received a fixed-dose combination of 300/150 mg of atazanavir/cobicistat once daily for 10 days, followed by a 10 day washout period and then a fixed-dose combination of 800/150 mg of darunavir/cobicistat once daily for 10 days. Full PK profiles were assessed for each phase for 72 h following day 10 and parameters determined to the last measurable concentration in plasma, saliva and urine by non-compartmental methods. Results: Sixteen subjects completed the study. Geometric mean (GM) terminal elimination half-life values to 72 h of atazanavir and darunavir were 6.77 and 6.35 h, respectively. All subjects had atazanavir concentrations above the suggested minimum effective concentration of 150 ng/mL 24 h post-dose and 14/16 subjects had concentrations higher than this target at 30 h post-dose (GM of 759 and 407 ng/mL, respectively). Thirteen out of 16 subjects had darunavir concentrations higher than the target of 550 ng/mL at 24 h post-dose and 5/16 subjects had concentrations higher than the target at 30 h post-dose (GM of 1033 and 382 ng/mL, respectively). Cobicistat half-life to 72 h was 4.21 h with atazanavir and 3.62 h with darunavir. GM values 24 h after the observed dose ( C 24 ) for atazanavir and darunavir were 141 and 43 ng/mL, respectively, in saliva and 24857 and 11878 ng/mL, respectively, in urine. Concentration decay in saliva/urine mirrored plasma concentrations for both drugs. Conclusions: Different concentration decay patterns were seen for atazanavir and darunavir, which may be partially explained by cobicistat half-life (longer with atazanavir than darunavir). For the first time, we also measured drug PK forgiveness in saliva and urine, which represent easier markers of adherence.

Dolutegravir and elvitegravir plasma concentrations following cessation of drug intake.

OBJECTIVES: To evaluate dolutegravir and elvitegravir/cobicistat pharmacokinetics in HIV-negative volunteers up to 10 days after drug cessation. METHODS: Healthy volunteers received 50 mg of dolutegravir once-daily for 10 days, then underwent a 9 day wash-out period, and then received elvitegravir/cobicistat as part of Stribild(®) (245 mg of tenofovir, 200 mg of emtricitabine, 150 mg of elvitegravir and 150 mg of cobicistat) for 10 days. Serial pharmacokinetic (PK) sampling occurred prior to the final dose of each course and at regular intervals for up to 216 h (10 days) after drug cessation. Concentrations were determined by LC-MS/MS, and PK parameters were illustrated as geometric mean and 90% CI. RESULTS: Seventeen volunteers completed the study. For dolutegravir, plasma terminal elimination t1/2 to the last measurable concentration (within 216 h) was longer than its t1/2 within the dosing interval (0-24 h): 14.3 h (12.9-15.7 h) versus 23.1 h (19.7-26.6 h); conversely, the terminal elimination t1/2 for elvitegravir was lower than its t1/2 within the dosing interval (0-24 h): 10.8 h (9.7-13.0 h) versus 5.2 h (4.7-6.1 h). Dolutegravir concentrations were above the protein-adjusted (PA) IC90 (64 ng/mL) in 100% of subjects after 36 and 48 h and in 94% after 60 and 72 h. All subjects had detectable dolutegravir concentrations at 96 h, a mean of 23.5% above the IC90. Elvitegravir concentrations were above the PA IC95 (45 ng/mL) in 100% of subjects at 24 h, 65% at 36 h but 0% after 48 h. CONCLUSIONS: Our data show marked differences in the elimination rates of dolutegravir and elvitegravir following treatment interruption, which is likely to impact the extent to which drug doses can be delayed or missed. They suggest that clinical differences may emerge in patients who have suboptimal adherence.

Safety and immunogenicity of an adjuvanted herpes zoster subunit candidate vaccine in HIV-infected adults: a phase 1/2a randomized, placebo-controlled study.

BACKGROUND: Human immunodeficiency virus (HIV)-infected individuals are at increased risk of herpes zoster (HZ), even in the antiretroviral therapy (ART) era. Because concerns exist about the use of live-attenuated vaccines in immunocompromised individuals, a subunit vaccine may be an appropriate alternative. METHODS: This phase 1/2, randomized, placebo-controlled study evaluated the immunogenicity and safety of an investigational HZ subunit vaccine (HZ/su). Three cohorts of HIV-infected adults aged ≥18 years were enrolled: 94 ART recipients with a CD4(+) T-cell count of ≥200 cells/mm(3), 14 ART recipients with a CD4(+) T-cell count of 50-199 cells/mm(3), and 15 ART-naive adults with a CD4(+) T-cell count of ≥500 cells/mm(3). Subjects received 3 doses of HZ/su (50 µg varicella-zoster virus glycoprotein E [gE] combined with AS01B adjuvant) or 3 doses of saline at months 0, 2, and 6. RESULTS: One month after dose 3, serum anti-gE antibody concentrations and frequencies of gE-specific CD4(+) T cells were higher following HZ/su vaccination than after receipt of saline (P < .0001). Median cell-mediated immune responses peaked after dose 2. Humoral and cell-mediated immune responses persisted until the end of the study (month 18). No vaccination-related serious adverse events were reported. No sustained impact on HIV load or CD4(+) T-cell count was noted following vaccinations. CONCLUSIONS: HZ/su was immunogenic and had a clinically acceptable safety profile in HIV-infected adults. CLINICAL TRIALS REGISTRATION: NCT01165203.

Plasma Tenofovir, Emtricitabine, and Rilpivirine and Intracellular Tenofovir Diphosphate and Emtricitabine Triphosphate Pharmacokinetics following Drug Intake Cessation.

Pharmacokinetic (PK) data describing a prolonged time course of antiretrovirals in plasma and peripheral blood mononuclear cells (PBMCs) are important for understanding and managing late or missed doses and to assess the appropriateness of compounds for preexposure prophylaxis (PrEP). This study aimed to evaluate the PK of coformulated tenofovir disoproxil fumarate (DF), emtricitabine, and rilpivirine in plasma and of the intracellular (IC) anabolites tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) in healthy volunteers up to 9 days after drug cessation. Individuals received daily tenofovir DF-emtricitabine-rilpivirine (245/200/25 mg) for 14 days. Drug intake was stopped, and serial sampling occurred prior to the final dose and up to 216 h (9 days) after stopping drug intake. Concentrations were quantified and PK parameters calculated. Eighteen volunteers completed the study. The terminal elimination plasma half-lives for tenofovir and emtricitabine over 216 h (geometric mean [90% confidence interval]) were higher than those seen over 0 to 24 h (for tenofovir, 31 h [27 to 40 h] versus 13.3 h [12.5 to 15.1 h]; for emtricitabine, 41 h [36 to 54 h] versus 6.4 h (5.9 to 7.6 h]). Model-predicted IC half-lives (0 to 168 h) were 116 h (TFV-DP) and 37 h (FTC-TP). The plasma rilpivirine concentration at 216 h was 4.5 ng/ml (4.2 to 6.2 ng/ml), and half-lives over 0 to 216 h and 0 to 24 h were 47 h (41 to 59 h) and 35 h (28 to 46 h), respectively. These data contribute to our understanding of drug behavior following treatment interruption; however, adherence to therapy should be promoted. Validated plasma and IC target concentrations are necessary to allow interpretation with respect to sustained virus suppression or HIV prevention. (The trial was conducted in accordance with the Declaration of Helsinki [EudraCT 2012-002781-13].).

Virological efficacy of abacavir: systematic review and meta-analysis.

OBJECTIVES: The efficacy of abacavir/lamivudine has been reported to be inferior to tenofovir/emtricitabine. Several randomized clinical trials (RCTs) investigated the effectiveness and safety of abacavir/lamivudine and tenofovir/emtricitabine combined antiretroviral treatment (cART) and we have reviewed the available evidence. DESIGN: Systematic review and meta-analysis of RCTs using standard Cochrane Collaboration methodologies. METHODS: We calculated risk ratios (RRs) with 95% CIs. The primary outcome was the rate of patients with viral load (VL) below the pre-defined cut-off at 48 weeks and/or at 96 weeks. Where available, results were analysed according to VL screening levels (<100,000 or >100,000 copies/mL) with conventional meta-analytical pooling by subgroups and meta-regression. RESULTS: Meta-analytical pooling of RCTs with a direct comparison of abacavir/lamivudine and tenofovir/emtricitabine according to baseline VL at 48 weeks (six trials, 4118 patients) showed that the proportions of subjects with VL <50 copies/mL were similar in the overall comparison (RR 0.98; 95% CI 0.94-1.03), in the low baseline VL strata (RR 1.01; 95% CI 0.99-1.03) and in the high baseline VL strata (RR 0.96; 95% CI 0.90-1.03). Meta-regression analysis at 48 weeks confirms the results of subgroup analysis. Similar virological results were found at 96 weeks (four trials, 2003 patients). Differences in the occurrence of adverse events requiring discontinuation of treatment favoured tenofovir recipients (RR 1.26; 95% CI 0.99-1.61), but this difference, mostly related to suspected abacavir hypersensitivity reaction, was not statistically significant. CONCLUSIONS: Our cumulative, cross-sectional data suggest a similar virological efficacy of abacavir/lamivudine and tenofovir/emtricitabine regardless of the baseline VL.

Pharmacokinetics of the co-administration of boceprevir and St John's wort to male and female healthy volunteers.

BACKGROUND: St John's wort (SJW; Hypericum perforatum) induces CYP3A4 that is involved in the metabolism of the hepatitis C virus (HCV) protease inhibitor boceprevir. Reduced boceprevir exposure and efficacy would contribute to therapeutic failure and increase the risk for resistance development. Boceprevir is co-administered with interferon/ribavirin, and depression has been described frequently in patients undergoing HCV treatment. Patients may purchase over-the-counter herbals to manage depression, and knowing the interaction between SJW and boceprevir is desirable. METHODS: This Phase I, open-label, three-period, cross-over pharmacokinetic study enrolled healthy males and females who, following consent and screening procedures, were randomized to receive SJW on days 1-14, SJW plus boceprevir (SJW on days 22-35 and together on days 31-35) and boceprevir on days 52-56, separated by 7 day washout periods, or the same treatment in the opposite order. Pharmacokinetic sampling was performed at the end of each phase. RESULTS: Seventeen (11 female) subjects completed the study and no serious adverse events were reported. Geometric mean ratios (GMRs) and 90% CIs for boceprevir (with SJW versus alone) AUC(0-8), C(max) and C8 were 0.91 (0.87-0.96), 0.94 (0.82-1.07) and 1.00 (0.79-1.27), respectively. GMRs and 90% CIs for hypericin, the active component of SJW, (with boceprevir versus alone) AUC(0-8), C(max) and C(8) were 1.23 (1.10-1.38), 1.32 (1.16-1.52) and 1.37 (1.19-1.58), respectively. CONCLUSIONS: SJW did not have a clinically significant effect on boceprevir plasma concentrations (or those of its metabolite), suggesting that SJW and boceprevir can be safely co-administered.

Cobicistat versus ritonavir as a pharmacoenhancer of atazanavir plus emtricitabine/tenofovir disoproxil fumarate in treatment-naive HIV type 1-infected patients: week 48 results.

BACKGROUND: Cobicistat (COBI) is a pharmacoenhancer with no antiretroviral activity in vitro. METHODS: An international, randomized, double-blind, double-dummy, active-controlled trial was conducted to evaluate the efficacy and safety of COBI versus ritonavir (RTV) as a pharmacoenhancer of atazanavir (ATV) in combination with emtricitabine (FTC)/tenofovir disoproxil fumarate (TDF) in treatment-naive patients. The primary end point was a human immunodeficiency virus type 1 (HIV-1) RNA load of <50 copies/mL at week 48 by the Food and Drug Administration snapshot algorithm; the noninferiority margin was 12%. RESULTS: A total of 692 patients were randomly assigned to a treatment arm and received study drug (344 in the COBI group vs 348 in the RTV group). At week 48, virologic success was achieved in 85% of COBI recipients and 87% of RTV recipients (difference, -2.2% [95% confidence interval, -7.4% to 3.0%]); among patients with a baseline HIV-1 RNA load of >100 000 copies/mL, rates were similar (86% vs 86%). Similar percentages of patients in both groups had serious adverse events (10% of COBI recipients vs 7% of RTV recipients) and adverse events leading to discontinuation of treatment with the study drug (7% vs 7%). Median increases in the serum creatinine level were 0.13 and 0.09 mg/dL, respectively, for COBI and RTV recipients. CONCLUSIONS: COBI was noninferior to RTV in combination with ATV plus FTC/TDF at week 48. Both regimens achieved high rates of virologic success. Safety and tolerability profiles of the 2 regimens were comparable. Once-daily COBI is a safe and effective pharmacoenhancer of the protease inhibitor ATV.

Switching to dolutegravir plus rilpivirine versus maintaining current antiretroviral therapy regimen in virologically suppressed people with HIV-1 and the Lys103Asn (K103N) mutation: 48-week results from a randomised, open-label pilot clinical trial.

BACKGROUND: The combination of dolutegravir plus rilpivirine has been studied in people with virologically suppressed HIV with no previous history of treatment failure or resistance. We investigated the potential to maintain viral suppression with dolutegravir plus rilpivirine in people with Lys103Asn mutations whose HIV was previously managed with other treatment regimens. METHODS: In this open-label pilot trial at 32 clinical sites in seven European countries, virologically suppressed, HBsAg-negative adults aged 18 years or older with HIV-1 and Lys103Asn mutations were randomly assigned (2:1) to switch to 50 mg dolutegravir plus 25 mg rilpivirine (given as a single tablet) once daily or to continue their current antiretroviral therapy regimen (control group). After 48 weeks, participants in the control group also switched to dolutegravir plus rilpivirine. Randomisation was stratified by country, and a computer-generated randomisation list with permuted blocks within strata was used to assign participants to treatment groups. The primary endpoints were virological failure (ie, two consecutive measurements of 50 copies or more of HIV RNA per mL at least 2 weeks apart) and virological suppression (the proportion of participants with fewer than 50 copies of HIV RNA per mL) at week 48 (week 96 data will be reported separately). Analyses were done in the modified intention-to-treat population, which included all participants who received at least one dose of the study medication. This trial is registered with ClinicalTrials.gov, NCT05349838, and EudraCT, 2017-004040-38. FINDINGS: Between Nov 5, 2018, and Dec 9, 2020, 140 participants were enrolled and randomly assigned, 95 to the dolutegravir plus rilpivirine group and 45 to the control group. Virological failure was recorded in three participants (3·2%, 95% CI 0·7 to 9·0) in the the dolutegravir plus rilpivirine group and one (2·2%, 0·1 to 11·8) in the control group. The proportion of participants in whom virological suppression was maintained at week 48 was 88·4% (80·2 to 94·1) in the dolutegravir plus rilpivirine group versus 88·9% (75·9 to 96·3) in the control group (difference -0·5, -11·7 to 10·7). Significantly more adverse events were recorded in the dolutegravir plus rilpivirine group than in the control group (234 vs 72; p=0·0034), but the proportion of participants who reported at least one adverse event was similar between groups (76 [80%] of 95 vs 33 [73%] of 45; p=0·39). The frequency of serious adverse events was low and similar between groups. INTERPRETATION: Virological suppression was maintained at week 48 in most participants with Lys103Asn mutations when they switched from standard regimens to dolutegravir plus rilpivirine. The results of this pilot study, if maintained when the week 96 data are reported, support conduct of a large, well-powered trial of dolutegravir plus rilpivirine. FUNDING: ViiV Healthcare.