Racial differences in response to antiretroviral therapy for HIV infection: an AIDS clinical trials group (ACTG) study analysis

BACKGROUND

In the United States, black individuals infected with human immunodeficiency virus (HIV) have higher rates of virologic failure on antiretroviral therapy (ART) and of death compared to white individuals. The cause for these disparities is uncertain. We sought to examine differences in virologic outcomes among antiretroviral-naive clinical trial participants starting randomized ART and to investigate factors to explain the differences.

METHODS

Individual-level data from participants initiating ART in 5 AIDS Clinical Trials Group studies were analyzed. Included studies were those conducted during 1998-2006 with a primary outcome of virologic failure. The primary outcome measure was time to virologic failure, regardless of ART changes.

RESULTS

A total of 2495 individuals (1151 black; 1344 white) were included with a median follow-up of 129 weeks. Compared to whites, blacks had an increased hazard of virologic failure (hazard ratio [HR]; 1.7; 95% confidence interval [CI], 1.4-1.9; P < .001), with no evidence of heterogeneity across regimens (P = .97); the association remained after adjustment for measured confounders (HR, 1.4; 95% CI, 1.2-1.6; P < .001). Increased hazard of virologic failure was associated with younger age, higher pretreatment HIV type 1 RNA level, lower pretreatment CD4 cell count, hepatitis C antibody, less education, and recent nonadherence to treatment. Sensitivity analyses with different endpoint definitions demonstrated similar results.

CONCLUSIONS

In this analysis, blacks had a 40% higher virologic failure risk than whites that was not explained by measured confounders. The observation was consistent over a range of regimens, suggesting that the difference may be driven by social factors; however, biological factors cannot be ruled out. Further research should identify the sources of racial disparities and develop strategies to reduce them.

Three distinct phases of HIV-1 RNA decay in treatment-naive patients receiving raltegravir-based antiretroviral therapy: ACTG A5248

OBJECTIVE

The goal of this study was to define viral kinetics after initiation of raltegravir (RAL)-based antiretroviral therapy (ART).

METHODS

ART-naive patients received RAL, tenofovir disoproxil fumarate, and emtricitabine for 72 weeks. Human immunodeficiency virus type 1 (HIV-1) RNA were measured by ultrasensitive and single-copy assays, and first (d1)-, second (d2)-, and, third (d3)-phase decay rates were estimated by mixed-effects models. Decay data were compared to historical estimates for efavirenz (EFV)- and ritonavir/lopinavir (LPV/r)-based regimens.

RESULTS

Bi- and tri-exponential models for ultrasensitive assay (n = 38) and single-copy assay (n = 8) data, respectively, provided the best fits over 8 and 72 weeks. The median d1 with ultrasensitive data was 0.563/day (interquartile range [IQR], 0.501-0.610/day), significantly slower than d1 for EFV-based regimens [P < .001]). The median duration of d1 was 15.1 days, transitioning to d2 at an HIV-1 RNA of 91 copies/mL, indicating a longer duration of d1 and a d2 transition at lower viremia levels than with EFV. Median patient-specific decay estimates with the single-copy assay were 0.607/day (IQR, 0.582-0.653) for d1, 0.070/day (IQR, 0.042-0.079) for d2, and 0.0016/day (IQR, 0.0005-0.0022) for d3; the median d1 duration was 16.1 days, transitioning to d2 at 69 copies/mL. d3 transition occurred at 110 days, at 2.6 copies/mL, similar to values for LPV/r-based regimens.

CONCLUSIONS

Models using single-copy assay data revealed 3 phases of decay with RAL-containing ART, with a longer duration of first-phase decay consistent with RAL-mediated blockade of productive infection from preintegration complexes.

Long-acting parenteral nanoformulated antiretroviral therapy: interest and attitudes of HIV-infected patients

AIM

To gauge patient interest in receiving long-acting injectable nanoformulated antiretroviral therapy.

METHODS

Four hundred adult HIV-infected patients currently prescribed antiretroviral therapy were surveyed. χ(2) tests were used for comparisons of interest across groups.

RESULTS

Respondents were 68% male and 53% African-American, with a mean age of 47 years. Overall, 73% of patients indicated that they would definitely or probably try injectable nanoformulated antiretroviral therapy; 61% with weekly dosing; 72% every 2 weekly; and 84% monthly. In total, 48% indicated that they were very concerned about the possible side effects and 35% were very concerned about needle use.

CONCLUSION

The majority of respondents indicated that they definitely or probably would try parenteral nanoformulated antiretroviral therapy.

Unexpected Drug-Drug Interactions in Human Immunodeficiency Virus (HIV) Therapy: Induction of UGT1A1 and Bile Efflux Transporters by Efavirenz

Introduction: Efavirenz is an inducer of drug metabolism enzymes. We studied the effect of efavirenz and ritonavir-boosted darunavir on serum unconjugated and conjugated bilirubin, as probes for UGT1A1 and bile transporters. Materials and Methods: Healthy volunteers were enrolled in a clinical trial. There were 3 periods: Period 1, 10 days of darunavir 900 mg with ritonavir 100 mg once daily; Period 2, 14 days of efavirenz 600 mg with darunavir/ritonavir once daily; and Period 3, 14 days of efavirenz 600 mg once daily. Serum bilirubin (conjugated and unconjugated) concentrations were obtained at baseline, at the end of each phase and at exit. Results: We recruited 7 males and 5 females. One subject developed grade 3 hepatitis on efavirenz and was excluded. Mean serum unconjugated bilirubin concentrations were 6.09 μmol/L (95% confidence interval [CI], 4.99 to 7.19) at baseline, 5.82 (95% CI, 4.88 to 6.76) after darunavir/ritonavir, 4.00 (95% CI, 2.92 to 5.08) after darunavir/ritonavir with efavirenz, 3.55 (95% CI, 2.58 to 4.51) after efavirenz alone and 5.27 (95% CI, 3.10 to 7.44) at exit (P <0.01 for the efavirenz phases). Mean serum conjugated bilirubin concentrations were 3.55 μmol/L (95% CI, 2.73 to 4.36) at baseline, 3.73 (95% CI, 2.77 to 4.68) after darunavir/ritonavir, 2.91 (95% CI, 2.04 to 3.78) after darunavir/ritonavir with efavirenz, 2.64 (95% CI, 1.95 to 3.33) after efavirenz alone and 3.55 (95% CI, 2.19 to 4.90) at exit (P <0.05 for the efavirenz phases). Conclusion: Efavirenz decreased unconjugated bilirubin by 42%, suggesting UGT1A1 induction. Efavirenz also decreased conjugated bilirubin by 26%, suggesting induction of bile efflux transporters. Ritonavir-boosted darunavir had no effect on bilirubin concentrations. These results indicate that efavirenz may reduce concentrations of drugs or endogenous substances metabolized by UGT1A1 or excreted by bile efflux transporters. Key words: Drug-drug interactions, Drug transporters, Efavirenz, HIV Therapy, UGT1A1

Unexpected drug-drug interactions in human immunodeficiency virus (HIV) therapy: induction of UGT1A1 and bile efflux transporters by Efavirenz

INTRODUCTION

Efavirenz is an inducer of drug metabolism enzymes. We studied the effect of efavirenz and ritonavir-boosted darunavir on serum unconjugated and conjugated bilirubin, as probes for UGT1A1 and bile transporters.

MATERIALS AND METHODS

Healthy volunteers were enrolled in a clinical trial. There were 3 periods: Period 1, 10 days of darunavir 900 mg with ritonavir 100 mg once daily; Period 2, 14 days of efavirenz 600 mg with darunavir/ritonavir once daily; and Period 3, 14 days of efavirenz 600 mg once daily. Serum bilirubin (conjugated and unconjugated) concentrations were obtained at baseline, at the end of each phase and at exit.

RESULTS

We recruited 7 males and 5 females. One subject developed grade 3 hepatitis on efavirenz and was excluded. Mean serum unconjugated bilirubin concentrations were 6.09 μmol/L (95% confidence interval [CI], 4.99 to 7.19) at baseline, 5.82 (95% CI, 4.88 to 6.76) after darunavir/ritonavir, 4.00 (95% CI, 2.92 to 5.08) after darunavir/ritonavir with efavirenz, 3.55 (95% CI, 2.58 to 4.51) after efavirenz alone and 5.27 (95% CI, 3.10 to 7.44) at exit (P <0.01 for the efavirenz phases). Mean serum conjugated bilirubin concentrations were 3.55 μmol/L (95% CI, 2.73 to 4.36) at baseline, 3.73 (95% CI, 2.77 to 4.68) after darunavir/ritonavir, 2.91 (95% CI, 2.04 to 3.78) after darunavir/ritonavir with efavirenz, 2.64 (95% CI, 1.95 to 3.33) after efavirenz alone and 3.55 (95% CI, 2.19 to 4.90) at exit (P <0.05 for the efavirenz phases).

CONCLUSION

Efavirenz decreased unconjugated bilirubin by 42%, suggesting UGT1A1 induction. Efavirenz also decreased conjugated bilirubin by 26%, suggesting induction of bile efflux transporters. Ritonavir-boosted darunavir had no effect on bilirubin concentrations. These results indicate that efavirenz may reduce concentrations of drugs or endogenous substances metabolized by UGT1A1 or excreted by bile efflux transporters.

Direct-acting antiviral agents for hepatitis C virus infection

Two selective inhibitors of the hepatitis C virus (HCV) protease nearly double the cure rates for this infection when combined with peginterferon alfa and ribavirin. These drugs, boceprevir and telaprevir, received regulatory approval in 2011 and are the first direct-acting antiviral agents (DAAs) that selectively target HCV. During 2012, at least 30 additional DAAs were in various stages of clinical development. HCV protease inhibitors, polymerase inhibitors, and NS5A inhibitors (among others) can achieve high cure rates when combined with peginterferon alfa and ribavirin and demonstrate promise when used in combination with one another. Current research is attempting to improve the pharmacokinetics and tolerability of these agents, define the best regimens, and determine treatment strategies that produce the best outcomes. Several DAAs will reach the market simultaneously, and resources will be needed to guide the use of these drugs. We review the clinical pharmacology, trial results, and remaining challenges of DAAs for the treatment of HCV.

Safety, tolerability, and pharmacokinetic interactions of the antituberculous agent TMC207 (bedaquiline) with efavirenz in healthy volunteers: AIDS Clinical Trials Group Study A5267

BACKGROUND

Drug-drug interactions complicate management of coinfection with HIV-1 and Mycobacterium tuberculosis. Bedaquiline (formerly TMC207), an investigational agent for the treatment of tuberculosis, is metabolized by cytochrome P450 (CYP) 3A which may be induced by the antiretroviral drug efavirenz.

METHODS

This was a phase 1 pharmacokinetic drug interaction trial. Each healthy volunteer received two 400 mg doses of bedaquiline, the first alone and the second with concomitant steady-state efavirenz. Plasma pharmacokinetic sampling for bedaquiline and its N-monodesmethyl metabolite was performed over 14 days after each bedaquiline dose. Steady-state efavirenz pharmacokinetics were also determined. Efavirenz metabolizer status was based on CYP2B6 composite 516/983 genotype.

RESULTS

Thirty-three of 37 enrolled subjects completed the study. Geometric mean of ratios for bedaquiline with efavirenz versus bedaquiline alone were 0.82 [90% confidence interval (CI): 0.75 to 0.89] for the 14-day area under the concentration-time curve (AUC0-336 h) and 1.00 (90% CI: 0.88 to 1.13) for the maximum concentration (Cmax). For N-monodesmethyl metabolite, the geometric mean of ratios was 1.07 (90% CI: 0.97 to 1.19) for AUC0-336 h and 1.89 (90% CI: 1.66 to 2.15) for C(max). There were no grade 3 or 4 clinical adverse events. One subject developed asymptomatic grade 3 serum transaminase elevation, prompting study drug discontinuation. Efavirenz concentrations stratified by CYP2B6 genotype were similar to historical data.

CONCLUSIONS

Single-dose bedaquiline was well tolerated alone and with steady-state efavirenz. The effect of efavirenz on bedaquiline concentrations is unlikely to be clinically significant.

When a serious adverse event in research occurs, how do other volunteers react?

Serious adverse events in research involving healthy volunteers are rare, but their impact on other volunteers is unknown. We conducted semi-structured interviews with 60 healthy volunteers at an institution where a healthy research volunteer died. Most volunteers (85%) had heard of the event, but few said it changed their thoughts about joining research (17%), approach to studies or questions asked (25%), or future participation (4%). Despite knowing few facts, respondents created narratives about the case that served to distance them from the event and justify their continued participation in research. Downward social comparison theory, optimistic bias, and feelings of responsibility and control may help explain these narratives. Findings underscore the importance of communication and understanding of research risks and protections.

Simultaneous determination of raltegravir and raltegravir glucuronide in human plasma by liquid chromatography-tandem mass spectrometric method

Raltegravir is a highly efficacious inhibitor of HIV integrase. Large pharmacokinetic variability has been reported in clinical trials and this could be due to glucuronidation of raltegravir, the only reported metabolism pathway. In order to precisely evaluate and monitor the raltegravir and raltegravir glucuronide simultaneously, a novel, sensitive and robust liquid chromatography-tandem mass spectrometric method was developed and validated for simultaneous determination of raltegravir and raltegravir glucuronide in human plasma. A simple protein precipitation with acetonitrile was utilized for plasma sample preparation prior to analysis. Baseline chromatographic separation was achieved on a ZORBAX Eclipse XDB-C8 using gradient elution mode. The run time was 9 min at a constant flow rate of 0.4 ml/min. The mass spectrometer was operated under a positive electrospray ionization condition. Excellent linearity (r(2) ≥ 0.9997) was achieved for raltegravir and raltegravir glucuronide in the range of 2-2000 nmol/l. The average recovery of raltegravir and raltegravir glucuronide was 105.8% and 102.2%, respectively. The precision (coefficient of variation) was 1.6-6.6% for raltegravir and 2.1-6.9 for raltegravir glucuronide, respectively. The accuracy was 98.6-106.1% for raltegravir and 96.3-100.3% for raltegravir glucuronide. The plasma samples were tested to be stable after nine freeze-thaw cycles and exposure to room temperature for 24 h. This well-validated assay was applied for the quantification of raltegravir and raltegravir glucuronide in plasma samples within 24 h after a single oral dose of 400 mg raltegravir in six healthy subjects.

Emerging antiretroviral drug interactions

With HIV-infected patients living longer and recommendations to initiate antiretrovirals (ARVs) being made earlier, the likelihood for potential drug-drug interactions between ARVs and concurrent medications used to manage co-morbid conditions will increase. In order to maximize the clinical benefit and minimize potential toxicity of ARVs and co-administered medications, it is important for clinicians to recognize significant drug-drug interactions. This article highlights clinically significant drug-drug interactions with antituberculosis agents, antimalarials, anticoagulants, chemotherapeutic agents and pulmonary antihypertensive agents when they are co-administered with newer ARVs (e.g. darunavir, raltegravir, maraviroc and etravirine).

Darunavir/ritonavir and efavirenz exert differential effects on MRP1 transporter expression and function in healthy volunteers

BACKGROUND

The efflux transporter MRP1 actively transports antiretrovirals and reduces intracellular accumulation in peripheral blood mononuclear cells (PBMCs). We studied MRP1 expression and function in healthy volunteers treated with darunavir/ritonavir and efavirenz.

METHODS

Seven healthy HIV-negative volunteers were recruited. PBMCs were collected at baseline, 9 days after administration of darunavir (900 mg) and ritonavir (100 mg) once daily, 9 days after coadministration of darunavir/ritonavir and efavirenz (600 mg) once daily and 13 days after administration of efavirenz alone. MRP1 expression was measured in PBMCs using flow cytometry with fluorescein isothiocyanate-conjugated antibody against MRP1m6. MRP1 expression was also measured in CD4(+) T-cells with a phycoerythrin-conjugated antibody against CD4. MRP1 efflux function was assessed by incubating PBMCs with carboxyfluorescein diacetate (CFDA) and comparing CFDA fluorescence with and without the modulators MK571 and probenecid.

RESULTS

MRP1 expression was reduced after darunavir/ritonavir administration (geometric mean ratio [GMR] 0.58, 95% confidence interval [95% CI] 0.51-0.65; P<0.001) and darunavir/ritonavir plus efavirenz coadministration (GMR 0.74, 95% CI 0.64-0.84; P=0.001), but not after efavirenz administration alone (GMR 0.82, 95% CI 0.64-1.06; P=0.10). MRP1 protein expression was 41% higher in CD4(+) T-cells. MRP1 efflux function was increased after efavirenz administration (GMR 3.13, 95% CI 2.73-3.59; P<0.001) and darunavir/ritonavir plus efavirenz coadministration (GMR 4.35, 95% CI 3.35-5.68; P<0.001), but not after darunavir/ritonavir administration (GMR 1.06, 95% CI 0.80-1.42; P=0.42).

CONCLUSIONS

Darunavir/ritonavir and efavirenz treatment exerted differential effects on MRP1 expression and function. These effects could potentially alter antiviral activity, especially in CD4(+) T-cells.

Comparison of once-daily versus twice-daily combination antiretroviral therapy in treatment-naive patients: results of AIDS clinical trials group (ACTG) A5073, a 48-week randomized controlled trial

BACKGROUND

Dosing frequency is an important determinant of regimen effectiveness. Methods. To compare efficacy of once-daily (QD) versus twice-daily (BID) antiretroviral therapy, we randomized human immunodeficiency virus (HIV)-positive, treatment-naive patients to lopinavir-ritonavir (LPV/r) administered at a dosage of 400 mg of lopinavir and 100 mg of ritonavir BID (n = 160) or 800 mg of lopinavir and 200 mg of ritonavir QD (n = 161), plus either emtricitabine 200 mg QD and extended-release stavudine at a dosage of 100 mg QD or tenofovir at a dosage of 300 mg QD. Randomization was stratified by screening HIV RNA level <100,000 copies/mL versus > or = 100,000 copies/mL. The primary efficacy end point was sustained virologic response (SVR; defined as reaching and maintaining an HIV RNA level <200 copies/mL) through week 48.

RESULTS

Subjects were 78% male, 33% Hispanic, and 34% black. A total of 82% of subjects completed the study, and 71% continued to receive the initially assigned dosage schedule. The probability of SVR did not differ significantly for the BID versus QD comparison, with an absolute proportional difference of 0.03 (95% confidence interval [CI], -0.07 to 0.12). The comparison depended on the screening RNA stratum (P=.038); in the higher RNA stratum, the probability of SVR was significantly better in the BID arm than in the QD arm: 0.89 (95% CI, 0.79-0.94) versus 0.76 (95% CI, 0.64-0.84), a difference of 0.13 (95% CI, 0.01-0.25). Lopinavir trough plasma concentrations were higher with BID dosing. Adherence to prescribed doses of LPV/r was 90.6% in the QD arm versus 79.9% in the BID arm (P<.001). Conclusions. Although subjects assigned to QD regimens had better adherence, overall treatment outcomes were similar in the QD and BID arms. Subjects with HIV RNA levels > or =100,000 copies/mL had better SVR with BID regimens at 48 weeks, which suggests a possible advantage in this setting for more frequent dosing. Clinical trial registration. ClinicalTrials.gov registration number: NCT00036452.

Age-related changes in plasma concentrations of the HIV protease inhibitor lopinavir

The advent of highly active antiretroviral therapy in the treatment of HIV disease has substantially extended the lifespan of individuals infected with HIV resulting in a growing population of older HIV-infected individuals. The efficacy and safety of antiretroviral agents in the population are important concerns. There have been relatively few studies assessing antiretroviral pharmacokinetics in older patients. Thirty-seven subjects aged 18-30 years and 40 subjects aged 45-79 years, naive to antiretroviral therapy, received lopinavir/ritonavir (400/100) bid, emtricitibine 200 mg qd, and stavudine 40 mg bid. Trough lopinavir concentrations were available for 44 subjects, collected at 24, 36, and 96 weeks. At week 24, older age was associated with higher lopinavir trough concentrations, and a trend was observed toward older age being associated with higher lopinavir trough concentrations when all time points were evaluated. In the young cohort, among subjects with two or more measurements, there was a trend toward increasing intrasubject trough lopinavir concentrations over time. Using a nonlinear, mixed-effects population pharmacokinetic model, age was negatively associated with lopinavir clearance after adjusting for adherence. Adherence was assessed by patient self-reports; older patients missed fewer doses than younger patients (p = 0.02). No difference in grade 3-4 toxicities was observed between the two age group. Older patients have higher trough lopinavir concentrations and likely decreased lopinavir clearance. Age-related changes in the pharmacokinetics of antiretroviral drugs may be of increasing importance as the HIV-infected population ages and as older individuals comprise an increasing proportion of new diagnoses.

Response to vicriviroc in treatment-experienced subjects, as determined by an enhanced-sensitivity coreceptor tropism assay: reanalysis of AIDS clinical trials group A5211

The enhanced-sensitivity Trofile assay (Monogram Biosciences) was used to retest coreceptor use at both study screening and study entry for 118 treatment-experienced subjects in AIDS Clinical Trials Group A5211 who had CCR5-tropic (R5) virus detected by the original Trofile assay at study screening. Among 90 recipients of vicriviroc, a significantly (P< .001) greater mean reduction in HIV-1 RNA was observed in 72 subjects with R5 virus versus 15 subjects reclassified as having dual/mixed-tropic viruses at screening: -1.11 versus -0.09 log(10) copies/mL at day 14 and -1.91 versus -0.57 log(10) copies/mL at week 24, respectively. Results suggest that the enhanced-sensitivity assay is a better screening tool for determining patient eligibility for CCR5 antagonist therapy.

Modified directly observed antiretroviral therapy compared with self-administered therapy in treatment-naive HIV-1-infected patients: a randomized trial

BACKGROUND

Success of antiretroviral therapy depends on high rates of adherence, but few interventions are effective. Our objective was to determine if modified directly observed therapy (mDOT) improves initial antiretroviral success.

METHODS

In an open-label, randomized trial comparing mDOT (Monday-Friday for 24 weeks) and self-administered therapy with lopinavir/ritonavir soft gel capsules (800 mg/200 mg), emtricitabine (200 mg), and either extended-release stavudine (100 mg) or tenofovir (300 mg), all taken once daily, 82 participants received mDOT and 161, self-administered therapy. Participant eligibility included a plasma human immunodeficiency virus RNA level higher than 2000 copies/mL and being naïve to antiretroviral therapy. A total of 243 participants were predominantly male (79%) (median age, 38 years), with 84 Latinos (35%), 74 non-Latino blacks (30%), and 79 non-Latino whites (33%). The study was conducted at 23 AIDS Clinical Trials Group (ACTG) sites in the United States and 1 site in South Africa between October 2002 and January 2006. The primary outcome was virologic success at week 24 and secondary outcomes were virologic success, clinical progression, and adherence at week 48.

RESULTS

Over 24 weeks, mDOT had greater virologic success (0.91; 95% confidence interval [CI], 0.81 to 0.95) than self-administered therapy (0.84; 95% CI, 0.77 to 0.89), but the difference (0.07; lower bound 95% CI, -0.01) did not reach the prespecified threshold of 0.075. Over 48 weeks, virologic success was not significantly different between mDOT (0.72; 95% CI, 0.61 to 0.81) and self-administered therapy (0.78; 95% CI, 0.70 to 0.84) (difference, -0.06; 95% CI, -0.18 to 0.07 [P = .19]).

CONCLUSIONS

The potential benefit of mDOT was marginal and not sustained after discontinuation. Modified DOT should not be incorporated routinely for care of treatment-naïve human immunodeficiency virus type 1-infected patients.

Induction of chemoprotective phase 2 enzymes by ginseng and its components

Phase 2 detoxification enzymes protect against carcinogenesis and oxidative stress. Ginseng ( PANAX spp.) extracts and components were assayed for inducer activity of NQO1 (quinone reductase), a phase 2 enzyme, in Hepa1c1c7 cells. Ginseng extracts were analyzed for ginsenosides and panaxytriol. Korean red PANAX GINSENG extracts demonstrated the most potent phase 2 enzyme induction activity (76,900 U/g dried rhizome powder and 27,800 U/g for two similar preparations). The ginsenoside-enriched HT-1001 American ginseng ( PANAX QUINQUEFOLIUS) extract was the next most potent inducer, with activity of 15,900 U/g, followed by raw American ginseng root with activity of 8700 U/g. Neither a polysaccharide-enriched extract of American ginseng nor a commercial white PANAX GINSENG preparation showed any inducer activity. Pure ginsenosides showed no inducer activity. Protopanaxadiol and protopanaxatriol, deglycosylated ginsenoside metabolic derivatives, showed potent induction activity (approximately 500,000 U/g each). Synthetic panaxytriol was over 10-fold more potent (induction potency 5,760,000 U/g). There was no correlation between ginsenoside content and phase 2 enzyme induction. The most potent inducing red ginseng extract also had the highest panaxytriol content, 120.8 microg/g. We found that ginseng induced NQO1 and that polyacetylenes are the most active components.

Quantitative deep sequencing reveals dynamic HIV-1 escape and large population shifts during CCR5 antagonist therapy in vivo

High-throughput sequencing platforms provide an approach for detecting rare HIV-1 variants and documenting more fully quasispecies diversity. We applied this technology to the V3 loop-coding region of env in samples collected from 4 chronically HIV-infected subjects in whom CCR5 antagonist (vicriviroc [VVC]) therapy failed. Between 25,000–140,000 amplified sequences were obtained per sample. Profound baseline V3 loop sequence heterogeneity existed; predicted CXCR4-using populations were identified in a largely CCR5-using population. The V3 loop forms associated with subsequent virologic failure, either through CXCR4 use or the emergence of high-level VVC resistance, were present as minor variants at 0.8–2.8% of baseline samples. Extreme, rapid shifts in population frequencies toward these forms occurred, and deep sequencing provided a detailed view of the rapid evolutionary impact of VVC selection. Greater V3 diversity was observed post-selection. This previously unreported degree of V3 loop sequence diversity has implications for viral pathogenesis, vaccine design, and the optimal use of HIV-1 CCR5 antagonists.

Lymphoma diagnosis and plasma Epstein-Barr virus load during vicriviroc therapy: results of the AIDS Clinical Trials Group A5211

BACKGROUND

Lack of functional CCR5 increases the severity of certain viral infections, including West Nile virus and tickborne encephalitis. In a phase II trial of the investigational CCR5 antagonist vicriviroc (AIDS Clinical Trials Group protocol A5211), 4 lymphomas occurred in study patients who received vicriviroc. Because of the known association between unregulated Epstein-Barr virus (EBV) replication and lymphoma in immunocompromised patients, we evaluated whether vicriviroc exposure was associated with lymphoma EBV antigen positivity and/or had an effect on plasma levels of EBV DNA.

METHODS

Clinical findings for all 4 patients enrolled in the A5211 study who developed lymphoma (2 Hodgkin and 2 non-Hodgkin) were reviewed, and tumor specimens were assessed for evidence of ongoing EBV replication. Longitudinal plasma samples from 116 patients in the A5211 study were analyzed, and EBV DNA was quantified by real-time polymerase chain reaction.

RESULTS

Plasma EBV DNA was not detected in the 2 patients with non-Hodgkin lymphoma; both patients with Hodgkin lymphoma who had samples tested had EBV DNA levels <3200 copies/mL. One patient with Hodgkin lymphoma had a lymph node core biopsy specimen that was strongly positive for EBV; the other 3 lymphomas were histochemically EBV negative. None of the 116 patients with available samples experienced sustained increases in plasma EBV levels.

CONCLUSIONS

CCR5 antagonism by vicriviroc treatment in treatment-experienced patients was not associated with reactivation of EBV infection.

(3R, 9R, 10R)-Panaxytriol: A molecular-based nutraceutical with possible application to cancer prevention and treatment

Panaxytriol is a nutraceutical-based active constituent of Korean red ginseng and is reported to exhibit potent anti-tumor properties. Its activity may be in part due to its induction of phase 2 chemoprotective enzymes. Its unique properties may have important implications in cancer therapeutics.