Week 96 efficacy and safety of rilpivirine in treatment-naive, HIV-1 patients in two Phase III randomized trials

Population Pharmacokinetics and Pharmacogenetics Analysis of Rilpivirine in HIV-1-Infected Individuals

Rilpivirine (RPV), the latest nonnucleoside reverse transcriptase inhibitor active against HIV-1, is prescribed in a standard dosage of 25 mg once a day in combination with emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF). The aim of this observational study was to characterize the RPV pharmacokinetic profile, to quantify interpatient variability, and to identify potential factors that could influence drug exposure. RPV concentration data were collected from HIV-infected patients as part of routine therapeutic drug monitoring performed in our center (Laboratory of Clinical Pharmacology). A population pharmacokinetic analysis was performed with NONMEM by comparing various structural models. The influence of demographic and clinical covariates, as well as frequent genetic polymorphisms in 5 genes (CYP3A4*22, CYP3A5*3, CYP2C19*2, CYP2C19*17, UGT1A1*28, and UGT1A4*2), on RPV elimination was explored. A total of 325 plasma concentration measurements were obtained from 249 HIV-positive patients. Plasma concentrations ranged from 12 to 255 ng/ml. A one-compartment model with zero-order absorption best characterized RPV pharmacokinetics. The average RPV clearance (CL) was 11.7 liters/h, the average volume of distribution was 401 liters, and the mean absorption time was 4 h. The interinterindividual variability (IIV) for CL was estimated to be 33%. None of the available demographic or genetic covariates showed any influence on RPV pharmacokinetics, but 29% of the patients were predicted to present minimal concentrations below the recently identified target cutoff value of 50 ng/ml. The variability in RPV pharmacokinetics appears to be lower than that for most other antiretroviral drugs. However, under the standard regimen of 25 mg daily, a significant number of patients might be underdosed. It remains to be investigated whether the underexposure has an impact on the development of resistance while patients are on maintenance therapy.

Rilpivirine as a Treatment for HIV-infected Antiretroviral-naïve Adolescents: Week 48 Safety, Efficacy, Virology and Pharmacokinetics

BACKGROUND

Rilpivirine 25 mg qd yields similar exposure in adolescents and adults (Pediatric study in Adolescents Investigating a New NNRTI TMC278 [PAINT] Cohort 1, Part 1). We report rilpivirine safety, efficacy, virology and pharmacokinetics in adolescents during 48 weeks of treatment (Cohort 1, Part 2).

METHODS

PAINT (NCT00799864) is a phase II, ongoing, open-label, single-arm trial of rilpivirine plus 2 investigator-selected nucleoside/nucleotide reverse-transcriptase inhibitors. Cohort 1 of PAINT includes treatment-naïve HIV-1-infected adolescents (≥12 to <18 years). Following approval in adults and after Part 1a in Cohort 1, enrollment was restricted to screening viral load (VL) ≤100,000 copies/mL.

RESULTS

Overall, 20 (56%) of 36 patients were women, 18 (50%) were aged ≥12 to <15 years, 32 (89%) were Black or African American, mostly from South Africa or Uganda, and 28 (78%) had baseline VL ≤100,000 copies/mL. At week 48, adverse events considered possibly related to treatment occurred in 13 (36%) patients, mostly (excluding investigations) somnolence (n = 5, 14%) and nausea (n = 2, 6%). Most adverse events were grade 1 or 2, and 7 (19%) patients had grade 3 or 4 adverse events. Week 48 virologic response (VL <50 copies/mL, time-to-loss-of-virologic-response) was achieved in 26 of the 36 (72%) patients: 22 of the 28 (79%) with baseline VL ≤100,000 copies/mL and 4 of the 8 (50%) with baseline VL >100,000 copies/mL. Median (range) CD4 count increased by 184 (-135 to 740) cells/mm at week 48. Eight patients experienced virologic failure, including 5 who developed rilpivirine resistance-associated mutations, mostly E138K, K101E and M230L. Mean (standard deviation) rilpivirine area-under-the-concentration-time curve from 0 to 24 hours (AUC24h and C0h) were 2391 (991) ng·h/mL and 83.5 (38.7) ng/mL, respectively.

CONCLUSIONS

Rilpivirine safety, virologic and pharmacokinetic profiles were similar in treatment-naïve HIV-1-infected adolescents and adults, supporting use of rilpivirine 25 mg qd, plus other antiretrovirals, in treatment-naïve adolescents with VL ≤100,000 copies/mL at treatment initiation.

Rilpivirine Pharmacokinetics Without and With Darunavir/Ritonavir Once Daily in Adolescents and Young Adults

BACKGROUND

Rilpivirine (RPV), a recently developed, once daily human immunodeficiency virus non-nucleoside reverse transcriptase inhibitor, is not currently approved for pediatric patients, but is sometimes prescribed for adolescents with multiple treatment failures, for regimen simplification or to minimize toxicity. Darunavir/ritonavir (DRV/r) administered once daily is also increasingly used in adolescents and may alter RPV pharmacokinetics (PK). We evaluated the PK interactions between RPV and DRV/r once daily in adolescents and young adults.

METHODS

Human immunodeficiency virus-infected subjects 12 to <24 years old receiving a stable background therapy including RPV 25 mg once daily without or combined with DRV/r 800/100 mg once daily were enrolled. Intensive 24-hour blood sampling was performed, and PK indices were determined using noncompartmental analysis. Protocol-defined target drug exposure ranges based on adult data were used to assess the adequacy of each regimen.

RESULTS

Fifteen subjects receiving RPV without and 14 subjects with DRV/r were enrolled. When dosed without DRV/r, the RPV geometric mean (90% confidence interval) for RPV AUC0-24, Cmax and C24 h were 2.38 μg h/mL (1.92-2.94), 0.14 μg/mL (0.12-0.18) and 0.07 μg/mL (0.03-0.10), respectively, similar to adult values. RPV concentrations were significantly increased with concomitant DRV/r use: RPV AUC24, Cmax and C24 h were 6.74 μg h/mL (4.89-9.28), 0.39 μg/mL (0.27-0.57) and 0.23 μg/mL (0.17-0.32), respectively, well above the target ranges based on adult data. DRV/r PK was not affected by coadministration of RPV.

CONCLUSIONS

RPV PK in this adolescent population was similar to adults when dosed without DRV/r. DRV/r coadministration increased RPV exposure 2- to 3-fold, indicating that drug-related side effects should be closely monitored.

Nanomedicine in the development of anti-HIV microbicides

Prevention plays an invaluable role in the fight against HIV/AIDS. The use of microbicides is considered an interesting potential approach for topical pre-exposure prophylaxis of HIV sexual transmission. The prospects of having an effective product available are expected to be fulfilled in the near future as driven by recent and forthcoming results of clinical trials. Different dosage forms and delivery strategies have been proposed and tested for multiple microbicide drug candidates presently at different stages of the development pipeline. One particularly interesting approach comprises the application of nanomedicine principles to the development of novel anti-HIV microbicides, but its implications to efficacy and safety are not yet fully understood. Nanotechnology-based systems, either presenting inherent anti-HIV activity or acting as drug nanocarriers, may significantly influence features such as drug solubility, stability of active payloads, drug release, interactions between active moieties and virus/cells, intracellular drug delivery, drug targeting, safety, antiviral activity, mucoadhesive behavior, drug distribution and tissue penetration, and pharmacokinetics. The present manuscript provides a comprehensive and holistic overview of these topics as relevant to the development of vaginal and rectal microbicides. In particular, recent advances pertaining inherently active microbicide nanosystems and microbicide drug nanocarriers are discussed.

Adherence to Antiretroviral Therapy and Virologic Failure: A Meta-Analysis

The often cited need to achieve ≥95% (nearly perfect) adherence to antiretroviral therapy (ART) for successful virologic outcomes in HIV may present a barrier to initiation of therapy in the early stages of HIV. This meta-analysis synthesized 43 studies (27,905 participants) performed across >26 countries, to determine the relationship between cut-off point for optimal adherence to ART and virologic outcomes. Meta-analysis was performed using a random-effect model to calculate pooled odds ratios with corresponding 95% confidence intervals. The mean rate of patients reporting optimal adherence was 63.4%. Compared with suboptimal adherence, optimal adherence was associated with a lower risk of virologic failure (0.34; 95% CI: 0.26-0.44). There were no significant differences in the pooled odds ratios among different optimal adherence thresholds (≥98-100%, ≥95%, ≥80-90%). Study design (randomized controlled trial vs observational study) (regression coefficient 0.74, 95% CI: 0.04-1.43, P < 0.05) and study region (developing vs developed countries; regression coefficient 0.56, 95% CI: 0.01-1.12, P < 0.05) remained as independent predictors of between-study heterogeneity, with more patients with optimal adherence from developing countries or randomized controlled trials experiencing virologic failure. The threshold for optimal adherence to achieve better virologic outcomes appears to be wider than the commonly used cut-off point (≥95% adherence). The cut-off point for optimal adherence could be redefined to a slightly lower level to encourage the prescribing ART at an early stage of HIV infection.

[Approaches to antiretroviral therapy in HIV-infected patients with low CD4 lymphocyte counts]

There are increasing numbers of patients with late-stage HIV infection in the Russian Federation. To choose optimal antiretroviral therapy regimens for patients with severe immunosuppression is a relevant problem. According the data obtained in the ECHO and THRIVE, ARTEMIS, CASTLE, SPRING-2 and other trials, the efficacy and/or safety of efavirenz are higher than those of rilpivirine, comparable with those of raltegravir and dolutegravir; darunavir and atazanavir are more effective than lopinavir, but dolutegravir is more effective than raltegravir (in numerical terms) in patients with low CD4 lymphocyte counts (less than 50 cells/μl or 200 cells/μl depending on a trial. To choose therapy for patients with late-stage HIV infection is an intricate problem and requires an individual approach that will take into account not only the efficiency of therapy, but also its possible side effects, as well as potential drug interactions for the treatment of opportunistic infections.

Evaluation of the Aptima(®) HIV-1 Quant Dx assay for HIV-1 RNA viral load detection and quantitation in plasma of HIV-1-infected individuals: A comparison with Abbott RealTime HIV-1 assay

The Hologic Aptima^® HIV‐1 Quant Dx assay (Aptima HIV) is a real‐time transcription‐mediated amplification method CE‐approved for use in diagnosis and monitoring of HIV‐1 infection. The analytical performance of this new assay was compared to the FDA‐approved Abbott RealTime HIV‐1 (RealTime). The evaluation was performed using 220 clinical plasma samples, the WHO 3rd HIV‐1 International Standard, and the QCMD HIV‐1 RNA EQA. Concordance on qualitative results, correlation between quantitative results, accuracy, and reproducibility of viral load data were analyzed. The ability to measure HIV‐1 subtypes was assessed on the second WHO International Reference Preparation Panel for HIV‐1 Subtypes. With clinical samples, inter‐assay agreement for qualitative results was high (91.8%) with Cohen's kappa statistic equal to 0.836. For samples with quantitative results in both assays (n = 93), Lin's concordance correlation coefficient was 0.980 (P  < 0.0001) and mean differences of measurement, conducted according to Bland–Altman method, was low (0.115 log₁₀ copies/ml). The Aptima HIV quantified the WHO 3rd HIV‐1 International Standard diluted from 2000 to 31 cp/ml (5,700–88 IU/ml) at expected values with excellent linearity (R² > 0.970) and showed higher sensitivity compared to RealTime being able to detect HIV‐1 RNA in 10 out of 10 replicates containing down to 7 cp/ml (20 IU/ml). Reproducibility was very high, even at low HIV‐1 RNA values. The Aptima HIV was able to detect and accurately quantify all the main HIV‐1 subtypes in both reference panels and clinical samples. Besides excellent performance, Aptima HIV shows full automation, ease of use, and improved workflow compared to RealTime. J. Med. Virol. 88:1535–1544, 2016. © 2016 Wiley Periodicals, Inc.

Formulation and pharmacology of long-acting rilpivirine

PURPOSE OF REVIEW

Rilpivirine (RPV), a nonnucleoside reverse transcriptase inhibitor, is a potent antiretroviral (ARV) effective for HIV treatment at 25 mg daily oral dose. Its physio-chemical and pharmacological properties enable formulation of RPV as a long-acting injectable nanosuspension. This review summarizes these properties supporting the potential of intermittent parenteral administration of rilpivirine long acting (RPV LA) in both treatment and prevention of HIV-1 infection.

RECENT FINDINGS

RPV is unusual among ARVs in that its stability and solubility enable aqueous suspensions with high drug loading, so that injection volumes can be minimized. Such innovative nanosuspensions are well tolerated in animals and humans after intramuscular injection and provide sustained drug concentrations in systemic circulation. The pharmacological findings support further investigations of RPV LA injections every 4 or 8 weeks, both as a single agent for potential preexposure prophylaxis and as two-drug all-injectable maintenance therapy with cabotegravir long acting.

SUMMARY

By building on expertise with long-acting injectable antipsychotic agents, RPV has been formulated as an agent for infrequent intramuscular dosing, in addition to its conventional oral tablet forms. The advantages of adherence to a regimen of intermittent injections may be significant.

Systematic review to determine the prevalence of transmitted drug resistance mutations to rilpivirine in HIV-infected treatment-naive persons

BACKGROUND

Transmitted drug resistance to antiretrovirals in HIV-1-infected individuals is rising in some regions and could compromise the effectiveness of first-line treatment. It is important to understand the prevalence of resistance to rilpivirine to inform treatment provision.

METHODS

A PUBMED/EMBASE search identified analyses of transmitted genotypic resistance to specific non-nucleoside reverse transcriptase inhibitor mutations worldwide. Patients were to be HIV-1-infected and antiretroviral-naive. Rilpivirine mutations assessed were: L100I, K101E/P, E138A/G/K/Q/R, V179L, Y181C/I/V, Y188L, H221Y, F227C and M230I/L. Additionally, frequency of resistance mutations were extracted and pooled by HIV subtype from the Stanford HIV drug resistance database.

RESULTS

138 eligible articles from 65 countries were identified (n=64,466). Among these 64,466 samples, 7 of the 9 genotypic rilpivirine mutations had a prevalence <0.1%. Two mutations were more prevalent: E138A/G/K/Q/R (0.7%, 95% CI 0.2, 1.3) and Y181C/I/V (0.3%, 95% CI 0.2, 0.4). Prevalence of E138 rilpivirine-related mutations varied between regions: highest in Latin America/Caribbean (3.6%, 95% CI 1.0, 7.6) and in Europe (3.2%, 95% CI 0.7, 6.9). Pooled results from the Stanford database (n=52,680) correlated with these findings indicating a low prevalence of 8/9 rilpivirine mutations (<0.1%), except for E138A/G/K/Q/R (2.9%, 95% CI 1.8, 4.4). Prevalence of the mutations at E138 varied significantly by HIV subtype and was highest for subtype-C (6.1%), subtype-F (5.1%) and subtype-A (3.3%).

CONCLUSIONS

The prevalence of most transmitted rilpivirine-related HIV mutations is generally low in treatment-naive HIV-1-infected individuals (<0.1%). The prevalence of E138A/G/K/Q/R mutations is higher (0.7%) and varies according to geographical region and HIV subtype.

Rilpivirine vs. efavirenz-based single-tablet regimens in treatment-naive adults: week 96 efficacy and safety from a randomized phase 3b study

OBJECTIVES

To compare efficacy, safety, tolerability, and patient-reported outcomes between two single-tablet regimens, rilpivirine/emtricitabine/tenofovir disoproxil fumarate (RPV/FTC/TDF) and efavirenz/emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/TDF), in HIV-1-infected, treatment-naive adults.

DESIGN

This was a phase 3b, 96-week, randomized, open-label, international, noninferiority trial.

METHODS

A total of 799 participants were randomized (1 : 1) to receive RPV/FTC/TDF or EFV/FTC/TDF. The primary efficacy endpoint evaluated proportions of participants with HIV-1 RNA less than 50 copies/ml using the Snapshot algorithm. Additional assessments included CD4 cell counts, genotypic/phenotypic resistance, adverse events, patient-reported outcomes, and quality of life questionnaires.

RESULTS

At week 96, trial completion rates were 80.2% (316/394; RPV/FTC/TDF) and 74.0% (290/392; EFV/FTC/TDF). Overall, RPV/FTC/TDF was noninferior to EFV/FTC/TDF [HIV-1 RNA <50 copies/ml: 77.9 vs. 72.4%, respectively; difference -5.5; 95%CI (-0.6, 11.5); P = 0.076]. RPV/FTC/TDF was significantly more efficacious compared with EFV/FTC/TDF in participants with baseline HIV-1 RNA equal to or less than 100 000 copies/ml (78.8 vs. 71.2%; P = 0.046) and in those with CD4 cell count greater than 200 cells/μl (80.6 vs. 73.0%; P = 0.018). There was no significant between-group difference in the CD4 cell count increase (278 ± 189 vs. 259 ± 191 cells/μl; P = 0.17). Few participants developed resistance after week 48 (1.0% RPV/FTC/TDF; 0.3% EFV/FTC/TDF). Compared with EFV/FTC/TDF, RPV/FTC/TDF was associated with fewer adverse event-related discontinuations (3.0 vs. 11.0%; P<0.001), significantly fewer adverse events due to central nervous system issues and rash, greater improvements in patient-reported symptoms, and significant improvements in the SF-12v2 quality of life questionnaire mental health composite score (P = 0.014).

CONCLUSION

In treatment-naive, HIV-1-infected participants, 96-week RPV/FTC/TDF treatment demonstrated noninferior efficacy and better tolerability than EFV/FTC/TDF.

Selection of Rilpivirine-Resistant HIV-1 in a Seroconverter From the SSAT 040 Trial Who Received the 300-mg Dose of Long-Acting Rilpivirine (TMC278LA)

The injectable long-acting formulation of rilpivirine (TMC278LA) is a promising preexposure prophylaxis (PrEP) candidate for prevention of human immunodeficiency virus type 1 (HIV-1) infection. We evaluated HIV-1 in plasma obtained from an unexpected seroconverter in the 300-mg arm of the SSAT040 TMC278LA pharmacokinetic study for rilpivirine (RPV) resistance. Infection with wild-type HIV-1 was confirmed on day 84 after TMC278LA injection, and the K101E mutation was detected on day 115. Plasma-derived HIV-1 clones containing K101E had 4-fold increased resistance to RPV and 4-8-fold increased cross-resistance to etravirine, nevirapine, and efavirenz compared with wild type HIV-1 plasma-derived clones from the same individual. This case is a unique instance of infection with wild-type HIV-1 and subsequent selection of resistant virus by persistent exposure to long-acting PrEP.

Pharmacokinetic interaction between etravirine or rilpivirine and telaprevir in healthy volunteers: A randomized, two-way crossover trial

Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) may require treatment with an HIV non-nucleoside reverse transcriptase inhibitor (NNRTI), for example, rilpivirine or etravirine, and an HCV direct-acting antiviral drug such as telaprevir. In a two-panel, two-way, crossover study, healthy volunteers were randomized to receive etravirine 200 mg twice daily ± telaprevir 750 mg every 8 hours or rilpivirine 25 mg once daily ± telaprevir 750 mg every 8 hours. Pharmacokinetic assessments were conducted for each drug at steady-state when given alone and when coadministered; statistical analyses were least-square means with 90% confidence intervals. Telaprevir minimum plasma concentration (Cmin), maximum plasma concentration (Cmax), and area under the concentration-time curve (AUC) decreased 25%, 10%, and 16%, respectively, when coadministered with etravirine and 11%, 3%, and 5%, respectively, when coadministered with rilpivirine. Telaprevir did not affect etravirine pharmacokinetics, but increased rilpivirine Cmin, Cmax, and AUC by 93%, 49%, and 78%, respectively. Both combinations were generally well tolerated. The small decrease in telaprevir exposure when coadministered with etravirine is unlikely to be clinically relevant. The interaction between telaprevir and rilpivirine is not likely to be clinically relevant under most circumstances. No dose adjustments are deemed necessary when they are coadministered.

Low Frequency of Drug-Resistant Variants Selected by Long-Acting Rilpivirine in Macaques Infected with Simian Immunodeficiency Virus Containing HIV-1 Reverse Transcriptase

Preexposure prophylaxis (PrEP) using antiretroviral drugs is effective in reducing the risk of human immunodeficiency virus type 1 (HIV-1) infection, but adherence to the PrEP regimen is needed. To improve adherence, a long-acting injectable formulation of the nonnucleoside reverse transcriptase (RT) inhibitor rilpivirine (RPV LA) has been developed. However, there are concerns that PrEP may select for drug-resistant mutations during preexisting or breakthrough infections, which could promote the spread of drug resistance and limit options for antiretroviral therapy. To address this concern, we administered RPV LA to macaques infected with simian immunodeficiency virus containing HIV-1 RT (RT-SHIV). Peak plasma RPV levels were equivalent to those reported in human trials and waned over time after dosing. RPV LA resulted in a 2-log decrease in plasma viremia, and the therapeutic effect was maintained for 15 weeks, until plasma drug concentrations dropped below 25 ng/ml. RT mutations E138G and E138Q were detected in single clones from plasma virus in separate animals only at one time point, and no resistance mutations were detected in viral RNA isolated from tissues. Wild-type and E138Q RT-SHIV displayed similar RPV susceptibilities in vitro, whereas E138G conferred 2-fold resistance to RPV. Overall, selection of RPV-resistant variants was rare in an RT-SHIV macaque model despite prolonged exposure to slowly decreasing RPV concentrations following injection of RPV LA.

Deep sequencing analysis of HIV-1 reverse transcriptase at baseline and time of failure in patients receiving rilpivirine in the phase III studies ECHO and THRIVE

Minority variants (1.0-25.0%) were evaluated by deep sequencing (DS) at baseline and virological failure (VF) in a selection of antiretroviral treatment-naïve, HIV-1-infected patients from the rilpivirine ECHO/THRIVE phase III studies. Linkage between frequently emerging resistance-associated mutations (RAMs) was determined. DS (llIumina®) and population sequencing (PS) results were available at baseline for 47 VFs and time of failure for 48 VFs; and at baseline for 49 responders matched for baseline characteristics. Minority mutations were accurately detected at frequencies down to 1.2% of the HIV-1 quasispecies. No baseline minority rilpivirine RAMs were detected in VFs; one responder carried 1.9% F227C. Baseline minority mutations associated with resistance to other non-nucleoside reverse transcriptase inhibitors (NNRTIs) were detected in 8/47 VFs (17.0%) and 7/49 responders (14.3%). Baseline minority nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) RAMs M184V and L210W were each detected in one VF (none in responders). At failure, two patients without NNRTI RAMs by PS carried minority rilpivirine RAMs K101E and/or E138K; and five additional patients carried other minority NNRTI RAMs V90I, V106I, V179I, V189I, and Y188H. Overall at failure, minority NNRTI RAMs and NRTI RAMs were found in 29/48 (60.4%) and 16/48 VFs (33.3%), respectively. Linkage analysis showed that E138K and K101E were usually not observed on the same viral genome. In conclusion, baseline minority rilpivirine RAMs and other NNRTI/NRTI RAMs were uncommon in the rilpivirine arm of the ECHO and THRIVE studies. DS at failure showed emerging NNRTI resistant minority variants in seven rilpivirine VFs who had no detectable NNRTI RAMs by PS.

Single-Tablet Emtricitabine-Rilpivirine-Tenofovir as HIV Postexposure Prophylaxis in Men Who Have Sex With Men

BACKGROUND

Completion rates for human immunodeficiency virus (HIV) postexposure prophylaxis (PEP) are low. We investigated the adherence and safety of coformulated emtricitabine (FTC), rilpivirine (RPV), and tenofovir disoproxil fumarate (TDF) as a 3-drug, single-tablet regimen for PEP in men who have sex with men (MSM).

METHODS

In an open-label, single-arm study at 2 public sexual health clinics and 2 hospital emergency departments in urban Australia, 100 HIV-uninfected MSM requiring 3-drug PEP received single-tablet FTC-RPV-TDF once daily for 28 days. The primary endpoint was premature PEP cessation or primary HIV infection through week 12. Additional endpoints were adherence (by self-report of doses missed or not ingested with a meal, by pill count, and by plasma concentrations of tenofovir and FTC at week 4); and safety (clinical and laboratory adverse events [AEs]).

RESULTS

PEP completion was 92% (95% confidence interval, 85%-96%); premature cessation resulted from loss to follow-up (6%), AEs (1%), or study burden (1%). No participant was found to acquire HIV through week 12. Adherence was 98.6% (standard deviation [SD], 2.4) by pill count and 98.5% (SD, 2.7) by self-report; 86% reported taking all doses with food, and 88% of the subset tested had plasma tenofovir levels suggesting full adherence (>40 ng/mL). Eighty-eight participants experienced at least 1 clinical AE; 4 had grade 3 AEs or higher, possibly attributable to study drug. Fifty-six participants experienced at least 1 laboratory AE; 4 had AEs of grade 3 or higher, possibly attributable to study drug.

CONCLUSIONS

A single-tablet regimen of FTC-RPV-TDF was well tolerated as once-daily PEP, with high levels of adherence and completion.

CLINICAL TRIALS REGISTRATION

NCT01715636.

Safety, tolerability and pharmacokinetics of rilpivirine following administration of a long-acting formulation in healthy volunteers

OBJECTIVES

This phase I healthy volunteer study (NCT01031589) was carried out to investigate the safety/tolerability and pharmacokinetics of a rilpivirine (RPV; TMC278) long-acting (LA) formulation after single and multiple intramuscular (i.m.) injections.

METHODS

In the first part of the study, which had an open-label design, a single RPV LA i.m. injection (300 mg/mL) of 300 (n = 6) or 600 (n = 5) mg was given to the volunteers. In the second part of the study, which had a double-blind, randomized, placebo-controlled design, three RPV LA i.m. injections (one every 4 weeks) at 1200/600/600 mg (n = 6) or placebo (n = 2) were given. Safety and local tolerability were monitored. RPV plasma concentrations were analysed up to 28 days after injection or until they were < 20 ng/mL.

RESULTS

Grade 1/2 RPV-related adverse events in the 300, 600 and 1200/600/600 mg groups were: rash (zero, one and one subject, respectively, the last of whom discontinued participation in the study); musculoskeletal stiffness (three, zero and zero subjects, respectively); injection site reactions (one, two and two subjects, respectively). After one injection of 300, 600 or 1200 mg RPV LA, the mean (standard deviation) maximum plasma concentration was 39 (25), 48 (13) and 140 (16) ng/mL, and the mean (standard deviation) area under the concentration-time curve (28 days) was 17,090 (8907), 25,240 (8184) and 55,350 (13,550) ng h/mL, respectively. RPV pharmacokinetics were largely comparable after the 1200 mg loading dose and both 600 mg injections of RPV LA. The mean (standard deviation) RPV plasma concentration across the 28-day dosing interval after the last injection in the 1200/600/600 mg group was 79 (19) ng/mL.

CONCLUSIONS

Single and multiple i.m. injections of RPV LA demonstrated favourable local/systemic tolerability in healthy volunteers. RPV pharmacokinetics suggested that clinically relevant plasma concentrations can be achieved with this LA formulation.

Guidelines for antiretroviral therapy in HIV-1 infected adults and adolescents 2014, Thailand

New evidence has emerged regarding when to commence antiretroviral therapy (ART), optimal treatment regimens, management of HIV co-infection with opportunistic infections, and management of ART failure. The 2014 guidelines were developed by the collaborations of the Department of Disease Control, Ministry of Public Health (MOPH) and the Thai AIDS Society (TAS). One of the major changes in the guidelines included recommending to initiating ART irrespective of CD4 cell count. However, it is with an emphasis that commencing HAART at CD4 cell count above 500 cell/mm³ is for public health, in term of preventing HIV transmission and personal benefit. In tuberculosis co-infected patients with CD4 cell counts ≤50 cells/mm³ or with CD4 cell counts >50 cells/mm³ who have severe clinical disease, ART should be initiated within 2 weeks of starting tuberculosis treatment. The preferred initial ART regimen in treatment naïve patients is efavirenz combined with tenofovir and emtricitabine or lamivudine. Plasma HIV viral load assessment should be done twice a year until achieving undetectable results; and will then be monitored once a year. CD4 cell count should be monitored every 6 months until CD4 cell count ≥350 cells/mm³ and with plasma HIV viral load <50 copies/mL; then it should be monitored once a year afterward. HIV drug resistance genotypic test is indicated when plasma HIV viral load >1,000 copies/mL while on ART. Ritonavir-boosted lopinavir or atazanavir in combination with optimized two nucleoside-analogue reverse transcriptase inhibitors is recommended after initial ART regimen failure. Long-term ART-related safety monitoring has also been included in the guidelines.

Effectiveness and safety of rilpivirine, a non-nucleoside reverse transcriptase inhibitor, in treatment-naive adults infected with HIV-1: a meta-analysis

OBJECTIVE

The aim of this study was to determine the effectiveness and safety of rilpivirine in treatment-naive adults infected with HIV-1.

METHODS

We ran duplicate searches of multiple databases and searchable Web sites of major HIV conferences (May to October 2013) to identify randomized controlled trials reporting the effectiveness and safety of rilpivirine in treatment-naive adults infected with HIV-1. Reference lists from retrieved articles were also reviewed. Data were extracted independently in duplicate using predefined data fields. All analyses used random effects models to calculate the summary treatment effect estimates.

RESULTS

Four randomized controlled trials with a total of 2,522 patients were included. The primary efficacy endpoint was the proportion of patients with confirmed HIV-1 RNA levels of <50 copies/mL (viral load) at 48 weeks. Rilpivirine demonstrated noninferior antiviral efficacy in viral load comparable with efavirenz at 48 weeks (relative risk [RR], 1.03; 95% CI, 0.99-1.07). The mean changes from baseline in CD4 count were similar in both rilpivirine and efavirenz (RR, 1.05; 95% CI, 0.85-1.24). Rilpivirine showed higher and significant difference in virological failure rates compared with the efavirenz group (RR, 1.70; 95% CI, 1.21-2.38). The incidences of the most commonly reported adverse events related to study medication, including rash and neurological events, were lower with rilpivirine than with efavirenz (RR, 0.11; 95% CI, 0.03-0.33; RR, 0.52; 95% CI, 0.45-0.60, respectively).

CONCLUSIONS

Current evidence suggests a range of favorable effects and a generally favorable safety profile of rilpivirine in treatment-naive adults infected with HIV-1 at week 48.

Effectiveness and safety of rilpivirine, a non-nucleoside reverse transcriptase inhibitor, in treatment-naive adults infected with HIV-1: a meta-analysis

OBJECTIVES

The aim of this study was to determine the effectiveness and safety of rilpivirine in treatment-naive adults infected with HIV-1.

METHODS

We ran duplicate searches of multiple databases and searchable websites of major HIV conferences (up to October 2013) to identify randomized controlled trials reporting the effectiveness and safety of rilpivirine in treatment-naive adults infected with HIV-1. Reference lists from retrieved articles were also reviewed. Data were extracted independently in duplicate using predefined data fields. All analyses used random-effects models to calculate the summary treatment effect estimates.

RESULTS

Four randomized controlled trials with a total of 2522 patients were included in the inclusion criteria. The primary efficacy endpoint was the proportion of patients with confirmed HIV-1 RNA levels of  < 50 copies/ml (viral load) at 48 weeks. Rilpivirine demonstrated non-inferior antiviral efficacy in viral load comparable with efavirenz at 48 weeks [relative risk (RR) = 1.03, 95% confidence interval (CI): 0.99-1.07]. The mean changes from baseline in CD4 count were similar in both rilpivirine and efavirenz (RR = 1.05, 95% CI: 0.85-1.24). Rilpivirine showed higher and significant difference in virological failure rates comparing with the efavirenz group (RR = 1.70, 95% CI: 1.21-2.38). The incidences of the most commonly reported adverse events related to study medication, including rash, and neurological events, were lower with rilpivirine than with efavirenz (RR = 0.11, 95% CI: 0.03-0.33; RR = 0.52, 95% CI: 0.45-0.60, respectively).

CONCLUSIONS

Current evidence suggests a range of favorable effects and a generally favorable safety profile of rilpivirine in treatment-naive adults infected with HIV-1 at week 48.

HIV and the aging kidney

PURPOSE OF REVIEW

To review unique considerations in the epidemiology, diagnosis, and management of kidney disease in older adults with HIV.

RECENT FINDINGS

HIV infection may accelerate the course of kidney disease associated with traditional risk factors, such as diabetes, which are more common in older adults. The risks of acute and chronic kidney disease are increased both with HIV infection and with older age. Although the prevalence of chronic kidney disease is higher among HIV-infected adults than among HIV-negative adults, the mean age at diagnosis of end-stage renal disease is similar. Recent studies have supported the use of newer creatinine-based kidney function estimates in HIV-infected adults, although data in older adults are limited. These estimates are susceptible to artifact in the setting of newer medications that interfere with the secretion of creatinine, including cobicistat and dolutegravir. The management of kidney disease in older adults with HIV infection may be complicated by polypharmacy and increased risk for medication toxicity.

SUMMARY

With aging of the HIV-infected population, age-related comorbid conditions such as kidney disease are increasingly important causes of morbidity and mortality. Although recent data do not support premature aging of HIV-infected individuals with respect to kidney disease, the risk of acute and chronic kidney disease is increased by HIV infection and its treatment.

A consensus statement on the renal monitoring of Australian patients receiving tenofovir based antiviral therapy for HIV/HBV infection

A number of antiviral agents used against Human Immunodeficiency Virus (HIV) infection and hepatitis B virus (HBV) mono or co-infection have been associated with real nephrotoxicity (including tenofovir disoproxil fumarate (TDF), atazanavir, indinavir and lopinavir) or apparent changes in renal function (e.g. cobicistat, ritonavir, rilpivirine and dolutegravir). Patients with HIV are at higher risk of acute and chronic renal dysfunction, so baseline assessment and ongoing monitoring of renal function is an important part of routine management of patients with HIV.

Given the paucity of evidence in this area, we sought to establish a consensus view on how routine monitoring could be performed in Australian patients on ART regimens, especially those involving TDF. A group of nephrologists and prescribers (an HIV physician and a hepatologist) were assembled by Gilead to discuss practical and reasonable renal management strategies for patients particularly those on TDF-based combination regimens (in the case of those with HIV-infection) or on TDF-monotherapy (in the case of HBV-mono infection). The group considered which investigations should be performed as part of routine practice, their frequency, and when specialist renal referral is warranted. The algorithm presented suggests testing for serum creatinine along with plasma phosphate and an assessment of urinary protein (rather than albumin) and glucose.

Here we advocate baseline tests of renal function at initiation of therapy. If creatinine excretion inhibitors (e.g. cobicistat or rilpivirine) are used as part of the ART regimen, we suggest creatinine is rechecked at 4 weeks and this value used as the new baseline. Repeat testing is suggested at 3-monthly intervals for a year and then at least yearly thereafter if no abnormalities are detected. In patients with abnormal baseline results, renal function assessment should be performed at least 6 monthly. In HBV mono-infected patients advocate that a similar testing protocol may be logical.

Outcomes in older versus younger patients over 96 weeks in HIV-1- infected patients treated with rilpivirine or efavirenz in ECHO and THRIVE

Objectives:

Increasing life expectancy of HIV-1–infected patients raises interest in how trial results apply to older patients. This post-hoc analysis evaluated potential differences in efficacy and safety in older (≥50 years) versus younger (<50 years) patients in the ECHO and THRIVE trials over 96 weeks.

Methods:

HIV-infected, treatment-naÏve adults were randomized to receive rilpivirine (RPV) or efavirenz (EFV), plus a background regimen. Virologic response rates (FDA snapshot analysis; HIV-1 RNA <50 copies/mL) were assessed at Week 96. Total-body bone mineral density was evaluated at baseline and Week 96 by dual-energy X-ray absorptiometry scans. Serum concentrations of 25-hydroxy vitamin D (ECHO trial only) were also measured at baseline, Week 24 and Week 48.

Results:

1368 patients were treated. At Week 96, virologic response rates were similar between older (77%) and younger (76%) RPV-treated patients and numerically higher in older (84%) versus younger (76%) EFV-treated patients. No clinically relevant age-related differences were observed in immunologic responses. Small differences were noted in older versus younger patients in adverse events (higher rates of depression, insomnia, and rash in older EFV-treated patients), laboratory abnormalities (increased low-density lipoprotein cholesterol and hyperglycemia in older EFV-treated patients and increased amylase in older patients across treatments), bone mineral density (larger decreases in older patients across treatments), and progression to severe vitamin D deficiency (greater in older versus younger EFV-treated patients).

Conclusion:

Efficacy and safety outcomes were generally similar in older versus younger patients in the ECHO and THRIVE trials.

Active pharmaceutical ingredients for antiretroviral treatment in low- and middle-income countries: a survey

Active pharmaceutical ingredients (APIs) are the molecular entities that exert the therapeutic effects of medicines. This article provides an overview of the major APIs that are entered into antiretroviral therapy (ART), outlines how APIs are manufactured, and examines the regulatory and cost frameworks of manufacturing ART APIs used in low- and middle-income countries (LMICs). Almost all APIs for ART are prepared by chemical synthesis. Roughly 15 APIs account for essentially all of the ARTs used in LMICs. Nearly all of the ART APIs purchased through the Global Fund for AIDS, TB and Malaria (GFATM) or the United States President's Emergency Plan for AIDS Relief (PEPFAR) are produced by generic companies. API costs are very important because they are the largest contribution to the overall cost of ART. Efficient API production requires substantial investment in chemical manufacturing technologies and the ready availability of raw materials and energy at competitive prices. Generic API production is practiced in only a limited number of countries; the API market for ART is dominated by Indian companies. The quality of these APIs is ensured by manufacturing under good manufacturing practice (GMP), including process validation, testing against previously established specifications and the demonstration of clinical bioequivalence. The investment and personnel costs of a quality management system for GMP contribute significantly to the cost of API production. Chinese companies are the major suppliers for many advanced intermediates in API production. Improved chemistry of manufacturing, economies of scale and optimization of procurement have enabled drastic cost reductions for many ART APIs. The available capacity for global production of quality-assured APIs is likely adequate to meet forecasted demand for 2015. The increased use of ART for paediatric treatment, for second-line and salvage therapy, and the introduction of new APIs and combinations are important factors for the future of treatment in LMICs. The introduction of new fixed-dose combinations for ART and use of new drug delivery technologies could plausibly provide robust, durable ART for all patients in need, at an overall cost that is only moderately higher than what is presently being spent.

Burden of nonnucleoside reverse transcriptase inhibitor resistance in HIV-1-infected patients: a systematic review and meta-analysis

The prevalence of HIV drug resistance varies with geographic location, year, and treatment exposure. This study generated yearly estimates of nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance in treatment-naive (TN) and treatment-experienced (TE) patients in the United States (US), Europe (EU), and Canada. Studies reporting NNRTI resistance identified in electronic databases and 11 conferences were analyzed in three groups: (1) TN patients in one of four geographic regions [US, Canada, EU countries with larger surveillance networks ("EU1"), and EU countries with fewer data ("EU2")]; (2) TE patients from any region; and (3) TN patients failing NNRTI-based treatments in clinical trials. Analysis data included 158 unique studies from 22 countries representing 84 cohorts of TN patients, 21 cohorts of TE patients, and 8 trials reporting resistance at failure. From 1995 to 2000, resistance prevalence in TN patients increased in US and EU1 from 3.1% to 7.5% and 0.8% to 3.6%, respectively. Resistance in both regions stabilized in 2006 onward. Little resistance was identified in EU2 before 2000, and increased from 2006 (5.0%) to 2010 (13.7%). One TN Canadian study was identified and reported resistance of 8.1% in 2006. Half of TN clinical trial patients had resistance after treatment failure at weeks 48-144. Resistance in TE patients increased from 1998 (10.1%) to 2001 (44.0%), then decreased after 2004. Trends in NNRTI resistance among TN patients show an increased burden in the US and some EU countries compared to others. These findings signify a need for alternate first-line treatments in some regions.

Optimizing antiretroviral therapy for women living with HIV

PURPOSE OF REVIEW

This review considers the evidence available to guide clinicians in their choice of optimal antiretroviral therapy (ART) for women with HIV.

RECENT FINDINGS

Cohort and clinical trial data indicate that ART is as efficacious in women as men, although women are more likely to discontinue therapy, which compromises effectiveness. For many drugs, women have higher plasma levels than men, although whether this is secondary to differing metabolism in women or because on average women have a lower body mass than men is not clear. For many drugs, women experience more adverse events secondary to ART. Opinion on the use of efavirenz in pregnancy differs between countries. The average age of women with HIV is increasing. Although virological responses to ART are not affected by age, immunological responses may be poorer. Older women with HIV face issues such as neurocognitive impairment, early menopause, osteoporosis and polypharmacy, which will have the potential to impact on their use of ART.

SUMMARY

When planning ART regimes with women, clinicians need to be mindful of the woman's social situation and stage in the life course, as well as the scientific data on individual drug effectiveness according to sex.

Switching from tenofovir/emtricitabine and nevirapine to a tenofovir/emtricitabine/rilpivirine single-tablet regimen in virologically suppressed, HIV-1-infected subjects

OBJECTIVES

Nevirapine is an inducer of hepatic metabolism. After discontinuation, nevirapine has an inductive effect on cytochrome P450 3A4, which persists for a few weeks and which, after switching to rilpivirine, may reduce rilpivirine exposures and have a negative clinical impact. This study evaluates the virological outcome, pharmacokinetics and safety of switching virologically suppressed, HIV-1-infected patients from nevirapine to rilpivirine.

PATIENTS AND METHODS

This 24 week open-label single-centre study included HIV-1-infected adults with HIV-1 RNA <50 copies/mL for >6 months on tenofovir/emtricitabine and nevirapine, who were willing to simplify their regimen to tenofovir/emtricitabine/rilpivirine. Virological suppression, safety and nevirapine and rilpivirine pharmacokinetics were assessed.

RESULTS

At weeks 12 and 24, all 32 subjects remained virologically suppressed. One subject discontinued at week 1 for rilpivirine-associated insomnia and two patients chose to resume tenofovir/emtricitabine and nevirapine after week 12 because of rilpivirine-associated food constraint. There was no grade 3/4 laboratory abnormality. Rilpivirine trough concentrations were above the mean trough concentrations observed in Phase 3 studies by 1 week post-switch. Twenty-seven out of 32 patients had no measurable levels of nevirapine by 2 weeks post-switch. The meal accompanying tenofovir/emtricitabine/rilpivirine intake satisfied food requirements in 81% of cases. Overall general satisfaction was improved in 90% of the subjects despite food constraints.

CONCLUSION

Nevirapine has a short and limited inductive effect on rilpivirine metabolism, which is not clinically significant. Tenofovir/emtricitabine/rilpivirine is an efficacious and safe option for virologically suppressed HIV-infected patients on nevirapine wishing to simplify their regimen.

Single-Tablet Regimens in HIV Therapy

Combined antiretroviral therapy (cART) has evolved considerably over the past decades leading to a better control of human immunodeficiency virus replication. Recently, regimens have evolved so as to simplify dosing frequency and reduce pill burden to improve adherence. Several national and international guidelines suggest antiretroviral (ARV) regimen simplification as a method of improving adherence. Decreased cART adherence has been associated with both patient-related factors and regimen-related factors. Adherence rates are statistically higher when simpler, once-daily (OD) regimens are combined with smaller daily regimen pill burdens. The avoidance of selective non-adherence, where a patient takes part of a regimen but not the full regimen, is a further potential benefit offered by single-tablet regimens (STRs). Simplification of cART has been associated with a better quality of life (QoL). Although tempered by other factors, better adherence, higher QoL and patients' preferences are all key points which might combine to assure long-lasting efficacy and durability of cART. All studies underlined the favorable tolerability profile of newer STRs. Three STRs are currently available. Tenofovir (TDF) plus emtricitabine (FTC)/efavirenz (EFV) was the first OD complete ARV regimen available as a STR. TDF plus FTC/rilpivirine is a second-generation STR. The most recently approved STR, TDF plus FTC/cobicistat/elvitegravir, is the first non-nucleoside reverse transcriptase inhibitor-based STR. All of them have shown excellent efficacy; safety and tolerability have been improved by more recent formulations. Several other STRs are anticipated both combining completely different drugs, abacavir (ABC) plus lamivudine (3TC)/dolutegravir, utilizing innovative formulations of older drugs, tenofovir alafenamide fumarate, or taking advance of bioequivalent drugs, lamivudine (3TC) plus ABC/EFV. The future challenge would be to develop completely alternative STRs (including for example protease inhibitors or new molecules) to extend the advantages of simplicity to heavily pre-treated individuals.

Week 48 results from a randomized clinical trial of rilpivirine/emtricitabine/tenofovir disoproxil fumarate vs. efavirenz/emtricitabine/tenofovir disoproxil fumarate in treatment-naive HIV-1-infected adults

OBJECTIVES

To compare the safety and efficacy of the two single-tablet regimens (STRs), rilpivirine/emtricitabine/tenofovir disoproxil fumarate (RPV/FTC/TDF) and efavirenz/emtricitabine/tenofovir DF (EFV/FTC/TDF), in HIV-1-infected, treatment-naive adults.

DESIGN

This is a phase 3b, randomized, open-label, multicenter, international, 96-week study.

METHODS

Participants were randomized 1:1 to receive either RPV/FTC/TDF or EFV/FTC/TDF. The primary endpoint was the proportion of participants with HIV-1 RNA less than 50 copies/ml at week 48 by the Snapshot algorithm.

RESULTS

A total of 786 participants were randomized. RPV/FTC/TDF was noninferior to EFV/FTC/TDF (85.8 vs. 81.6%) at week 48 for HIV-1 RNA less than 50 copies/ml [difference 4.1%, 95% confidence interval (CI) -1.1 to 9.2%]. A statistically significant difference in efficacy favoring RPV/FTC/TDF was demonstrated for participants with baseline HIV-1 RNA 100000  copies/ml or less [(n=510) 88.8% RPV/FTC/TDF vs. 81.6% EFV/FTC/TDF (difference 7.2%, 95% CI 1.1-13.4%)]. In participants with baseline HIV-1 RNA more than 100000 copies/ml (n=276), RPV/FTC/TDF demonstrated noninferior efficacy compared with EFV/FTC/TDF (79.9 vs. 81.7%, respectively, difference -1.8%, 95% CI -11.1 to 7.5%). In the RPV/FTC/TDF arm, more virologic failure was observed as baseline HIV-1 RNA levels increased. There were more participants with emergent resistance in the RPV/FTC/TDF arm than in the EFV/FTC/TDF arm (4 vs. 1%, respectively). There were fewer discontinuations because of adverse events with RPV/FTC/TDF (2.5%) than with EFV/FTC/TDF (8.7%).

CONCLUSION

In treatment-naive participants, RPV/FTC/TDF demonstrated noninferior efficacy and improved tolerability compared with EFV/FTC/TDF, as well as a statistically significant difference in efficacy for participants with baseline HIV-1 RNA 100000  copies/ml or less at week 48.

Lipid levels and changes in body fat distribution in treatment-naive, HIV-1-Infected adults treated with rilpivirine or Efavirenz for 96 weeks in the ECHO and THRIVE trials

BACKGROUND

Pooled ECHO/THRIVE lipid and body fat data are presented from the ECHO (Efficacy Comparison in Treatment-Naïve, HIV-Infected Subjects of TMC278 and Efavirenz) and THRIVE (TMC278 Against HIV, in a Once-Daily Regimen Versus Efavirenz) trials.

METHODS

We assessed the 96-week effects on lipids, adverse events (AEs), and body fat distribution (dual-energy x-ray absorptiometry) of rilpivirine (RPV) and EFV plus 2 nucleoside/nucleotide reverse transcriptase inhibitors (N[t]RTIs) in treatment-naive adults infected with human immunodeficiency virus type 1 (HIV-1).

RESULTS

Rilpivirine produced minimal changes in total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides. Compared with RPV, EFV significantly (P < .001) increased lipid levels. Decreases in the TC/HDL-C ratio were similar with RPV and EFV. Background N[t]RTI affected RPV-induced lipid changes; all levels increased with zidovudine/lamivudine (3TC) and abacavir/3TC (except triglycerides, which were unchanged). With emtricitabine/tenofovir, levels of HDL-C were increased, TC and LDL-C were unchanged, and triglycerides were decreased. With EFV, lipid levels increased in each N[t]RTI subgroup (except triglycerides were unchanged with abacavir/3TC). Fewer (P < .001) RPV-treated patients than EFV-treated patients had TC, LDL-C, and triglyceride levels above National Cholesterol Education Program cutoffs. More RPV- than EFV-treated patients had HDL-C values below these cutoffs (P = .02). Dyslipidemia AEs were less common with RPV than with EFV. Similar proportions of patients had a ≥10% decrease in limb fat (16% with RPV and 17% with EFV). Limb fat was significantly (P < .001) increased to a similar extent (by 12% with RPV and 11% with EFV). At week 96, patients receiving zidovudine/3TC had lost limb fat, and those receiving emtricitabine/tenofovir had gained it.

CONCLUSIONS

Over the course of 96 weeks, RPV-based therapy was associated with lower increases in lipid parameters and fewer dyslipidemia AEs than EFV-based treatment. Body fat distribution changes were similar between treatments. The N[t]RTI regimen affected lipid and body fat distribution changes.

HIV-associated lipodystrophy: impact of antiretroviral therapy

In the late 1990s, reports of unusual changes in body fat distribution named 'lipodystrophy' (LD) began to appear in HIV patients mitigating the enormous enthusiasm about improvement of survival and quality of life provided by the combinations of antiretroviral (ARV) drug classes, the so-called highly active antiretroviral therapy (HAART), which had just become available at that time. The objective of this paper is to critically review the literature on LD and to discuss the impact of newer ARV agents, namely atazanavir, darunavir and raltegravir, as well as strategies of the late HAART era, including single-tablet regimens and nucleoside-sparing regimens. Studies in which LD was measured by dual-energy x-ray absorptiometry or by abdominal computed tomography or magnetic resonance imaging scan only, were included. We were unable to identify studies depicting a negative impact of drugs or ARV regimens on limb fat loss. On the contrary, a few studies identified a negative impact of atazanavir/ritonavir or darunavir/ritonavir on trunk fat increase. It should be noted that this anthropometric measure is a poor instrument since it cannot distinguish between subcutaneous and visceral fat. We conclude that presumably the body fat changes currently observed in HIV-infected patients is the net result of competing phenomena: on one side the natural history of lipohypertrophy as a result of HIV and HAART impact, and on the other side the physiological body fat changes observed in the aging population.

Prevalence in the USA of rilpivirine resistance-associated mutations in clinical samples and effects on phenotypic susceptibility to rilpivirine and etravirine

BACKGROUND

The prevalence of rilpivirine resistance-associated mutations (RAMs) in the USA, and their effect on phenotypic susceptibility to rilpivirine and etravirine, was evaluated in clinical samples from HIV-1-infected patients.

METHODS

In total, 15,991 samples submitted to Monogram Biosciences (South San Francisco, CA, USA) for routine resistance testing between January 2010 and June 2011 were assessed for the presence of known rilpivirine RAMs K101E/P, E138A/G/K/Q/R, V179L, Y181C/I/V, Y188L, H221Y, F227C and M230I/L; non-nucleoside reverse transcriptase inhibitor (NNRTI) RAMs K103N, L100I and L100I+K103N; and the nucleoside reverse transcriptase inhibitor (NRTI) RAMs M184I/V and their combinations with rilpivirine RAMs. Phenotypic susceptibility (PhenoSenseGT(®) assay; Monogram Biosciences) was evaluated, with reduced susceptibility defined as fold change (FC) in 50% inhibitory concentration (IC50)>2.0 for rilpivirine and FC>2.9 for etravirine.

RESULTS

Of the 15,991 samples, 17% harboured ≥1 rilpivirine RAMs. The prevalence of most rilpivirine RAMs and combinations of NNRTI RAMs of interest was low (≤3%), except for Y181C (7%). Rilpivirine RAMs were often associated with reduced rilpivirine phenotypic susceptibility. Median FC values >2.0 were observed for clinical isolates with rilpivirine RAMs K101P, E138Q/R, Y181C/I/V, Y188L or M230L, and for the combination of E138K with M184I/V, and K101E with M184I. Most rilpivirine FC values >2.0 were associated with etravirine FC values >2.9 for individual rilpivirine RAMs and those combined with M184I/V. There was no relationship between the presence of K103N and rilpivirine FC. However, the L100I+K103N combination (without rilpivirine RAMs), at <2% prevalence, was associated with a rilpivirine FC>2.0.

CONCLUSIONS

Based on 15,991 US clinical samples from HIV-1-infected patients, the frequency of most known rilpivirine RAMs apart from Y181C was low.

Antiretrovirals and the kidney in current clinical practice: renal pharmacokinetics, alterations of renal function and renal toxicity

Assessment of renal function in HIV-positive patients is of increasing importance in the context of ageing and associated comorbidities. Exposure to nephrotoxic medications is widespread, and several commonly used antiretroviral drugs have nephrotoxic potential. Moreover, specific antiretrovirals inhibit renal tubular transporters resulting in the potential for drug-drug interactions as well as increases in serum creatinine concentrations, which affect estimates of glomerular filtration rate in the absence of changes in actual glomerular filtration rate. This review explores the effects of antiretroviral therapy on the kidney and offers an understanding of mechanisms that lead to apparent and real changes in renal function.

Has the time come to abandon efavirenz for first-line antiretroviral therapy?

Efavirenz has been recommended as a preferred third agent together with two nucleos(t)ides for first-line combination antiretroviral therapy (ART) for >15 years. The availability of efavirenz in a fixed-dose combination makes it very attractive. However, because of (i) adverse events associated with efavirenz, (ii) a poorer overall efficacy of efavirenz compared with newer antiretrovirals, (iii) the ranking of efavirenz as FDA Pregnancy Category D and (iv) the relatively high prevalence of transmitted drug-resistance mutations, there is a need to reconsider the role of efavirenz in first-line ART. We review the available evidence that challenges efavirenz's current position in first-line HIV treatment guidelines. Apart from its animal teratogenic potential, and moderate neuropsychiatric adverse events associated with its use, efavirenz has recently been associated with an increased risk of suicidality when compared with other antiretroviral drugs. Most importantly, efavirenz has demonstrated overall inferior efficacy to various comparator drugs, which include rilpivirine, raltegravir and dolutegravir, in antiretroviral-naive patients. Furthermore, epidemiological data indicate that the prevalence of non-nucleoside reverse transcriptase inhibitor resistance has reached 5%-8% in various parts of the world, and minority transmitted non-nucleoside reverse transcriptase inhibitor resistance-associated mutations can have a negative impact on the outcome of first-line efavirenz-based ART. Based on considerations of efficacy, toxicity and resistance, it is time to reconsider the routine use of efavirenz in ART. This, of course, presupposes that other antiretrovirals will be available in place of efavirenz, and may not be applicable in certain developing country settings where this is not the case.

Simplification to rilpivirine/emtricitabine/tenofovir disoproxil fumarate from ritonavir-boosted protease inhibitor antiretroviral therapy in a randomized trial of HIV-1 RNA-suppressed participants

OBJECTIVE

To evaluate the efficacy and safety of antiretroviral simplification from a ritonavir-boosted protease inhibitor-based regimen [protease inhibitor+RTV+two nucleos(t)ide reverse transcriptase inhibitors (NRTIs); ≥6 months of exposure prior to study entry with no prior treatment failure] to the single-tablet regimen (STR) rilpivirine/emtricitabine/tenofovir disoproxil fumarate (RPV/FTC/TDF) in virologically suppressed, HIV-1-infected participants.

DESIGN

Phase 3b, randomized, open-label, international, 48-week switch study.

METHODS

Participants were randomized 2 : 1 to switch to RPV/FTC/TDF immediately or stay on their baseline protease inhibitor+RTV+2NRTIs regimen with a delayed switch to RPV/FTC/TDF at week 24. The primary endpoint was noninferiority (12% margin) of RPV/FTC/TDF compared with protease inhibitor+RTV+ two NRTIs in maintaining plasma HIV-1 RNA less than 50 copies/ml at week 24 by Snapshot analysis.

RESULTS

A total of 476 participants were randomized and received at least one dose of study drug. Demographics and baseline characteristics were similar between arms. The primary objective of noninferiority at week 24 was met: HIV-1 RNA less than 50 copies/ml by Snapshot analysis, 93.7% of RPV/FTC/TDF versus 89.9% of protease inhibitor+RTV+ two NRTIs (difference 3.8%, 95% confidence interval -1.6 to 9.1%). Through week 48, 89.3% of participants in the immediate switch group maintained virologic suppression. High rates of suppression were maintained with RPV/FTC/TDF regardless of participant's pre-antiretroviral HIV-1 RNA level. Overall development of resistance mutations after switching to RPV/FTC/TDF was low. Decreases in total cholesterol, low-density lipoprotein (LDL), and triglycerides were significantly greater among RPV/FTC/TDF recipients than those in the protease inhibitor+RTV+ two NRTIs group.

CONCLUSION

Switching to the STR RPV/FTC/TDF from an RTV-boosted protease inhibitor regimen in virologically suppressed, HIV-1-infected participants maintained virologic suppression with a low risk of virologic failure, while improving total cholesterol, LDL, and triglycerides.

[Consensus Statement by GeSIDA/National AIDS Plan Secretariat on antiretroviral treatment in adults infected by the human immunodeficiency virus (Updated January 2013)]

OBJECTIVE

This consensus document is an update of combined antiretroviral therapy (cART) guidelines for HIV-1 infected adult patients.

METHODS

To formulate these recommendations a panel composed of members of the GeSIDA/National AIDS Plan Secretariat (Grupo de Estudio de Sida and the Secretaría del Plan Nacional sobre el Sida) reviewed the efficacy and safety advances in clinical trials, cohort and pharmacokinetic studies published in medical journals (PubMed and Embase) or presented in medical scientific meetings. The strength of the recommendations and the evidence which support them are based on a modification of the criteria of Infectious Diseases Society of America.

RESULTS

cART is recommended in patients with symptoms of HIV infection, in pregnant women, in serodiscordant couples with high risk of transmission, in hepatitisB co-infection requiring treatment, and in HIV nephropathy. cART is recommended in asymptomatic patients if CD4 is <500cells/μl. If CD4 are >500cells/μl cART should be considered in the case of chronic hepatitisC, cirrhosis, high cardiovascular risk, plasma viral load >100.000 copies/ml, proportion of CD4 cells <14%, neurocognitive deficits, and in people aged >55years. The objective of cART is to achieve an undetectable viral load. The first cART should include 2 reverse transcriptase inhibitors (RTI) nucleoside analogs and a third drug (a non-analog RTI, a ritonavir boosted protease inhibitor, or an integrase inhibitor). The panel has consensually selected some drug combinations, for the first cART and specific criteria for cART in acute HIV infection, in tuberculosis and other HIV related opportunistic infections, for the women and in pregnancy, in hepatitisB or C co-infection, in HIV-2 infection, and in post-exposure prophylaxis.

CONCLUSIONS

These new guidelines update previous recommendations related to first cART (when to begin and what drugs should be used), how to monitor, and what to do in case of viral failure or adverse drug reactions. cART specific criteria in comorbid patients and special situations are similarly updated.

Dyslipidemia, atherosclerosis and cardiovascular disease: an increasingly important triad in an aging population living with HIV

As a result of major advances in the management of HIV over the last two decades, patients living with HIV are now encountering comorbidities commonly associated with aging. Cardiovascular disease is the leading cause of death worldwide. As the population living with HIV ages, understanding cardiovascular disease in the setting of HIV is of increasing importance. This review examines the complex interplay between cardiovascular disease, HIV infection and the drugs used to treat it, with particular emphasis on the contribution of dyslipidemia.

Rilpivirine inhibits drug transporters ABCB1, SLC22A1, and SLC22A2 in vitro

Rilpivirine is a nonnucleoside reverse transcriptase inhibitor approved for treatment of HIV-1 infection in antiretroviral-naive adult patients. Potential interactions with drug transporters have not been fully investigated. Transport by and inhibition of drug transporters by rilpivirine were analyzed to further understand the mechanisms governing rilpivirine exposure and determine the potential for transporter-mediated drug-drug interactions. The ability of rilpivirine to inhibit or be transported by ABCB1 was determined using ABCB1-overexpressing CEMVBL100 cells and Caco-2 cell monolayers. The Xenopus laevis oocyte heterologous protein expression system was used to clarify if rilpivirine was either transported by or inhibited the function of influx transporters SLCO1A2, SLCO1B1, SLCO1B3, SLC22A2, SLC22A6, and SLC22A8. The ability of rilpivirine to inhibit or be transported by SLC22A1 was determined using SLC22A1-expressing KCL22 cells. Rilpivirine showed higher accumulation in SLC22A1-overexpressing KCL22 cells than control cells (27% increase, P = 0.03) and inhibited the functionality of SLC22A1 and SLC22A2 transport with 50% inhibitory concentrations (IC50s) of 28.5 μM and 5.13 μM, respectively. Inhibition of ABCB1-mediated digoxin transport was determined for rilpivirine, which inhibited digoxin transport in the B-to-A direction with an IC50 of 4.48 μM. The maximum rilpivirine concentration in plasma in patients following a standard 25-mg dosing regimen is around 0.43 μM, lower than that necessary to substantially inhibit ABCB1, SLC22A1, or SLC22A2 in vitro. However, these data indicate that SLC22A1 may contribute to variability in rilpivirine exposure and that interactions of rilpivirine with substrates of SLC22A1, SLC22A2, or ABCB1 may be possible.

Week 96 analysis of rilpivirine or efavirenz in HIV-1-infected patients with baseline viral load ≤ 100 000 copies/mL in the pooled ECHO and THRIVE phase 3, randomized, double-blind trials

OBJECTIVES

These 96-week, ECHO/THRIVE pooled analyses evaluated data for antiretroviral treatment-naïve, HIV-1-infected adults with viral load (VL) ≤ 100 000 HIV-1 RNA copies/mL receiving rilpivirine or efavirenz.

METHODS

ECHO and THRIVE were phase 3, randomized, double-blind trials. Patients received rilpivirine 25 mg once daily (qd) or efavirenz 600 mg qd, with a fixed (ECHO) or investigator-chosen (THRIVE) nucleoside/tide reverse transcriptase inhibitor (N[t]RTI) background regimen. Response rate (the percentage of patients with VL < 50 copies/mL, using an intent-to-treat-population, time-to-loss-of-virological-response algorithm), virological failure (VF), resistance development, safety and tolerability were evaluated.

RESULTS

Baseline characteristics were comparable between the rilpivirine (n = 368) and efavirenz (n = 329) groups. At week 96, response rates [84% for rilpivirine vs. 80% for efavirenz; difference 4.0%; 95% confidence interval (CI) -1.7% to 9.7%] and incidences of VF for the resistance analysis (VFres) (8% for rilpivirine vs. 6% for efavirenz; P = 0.46) were similar in the two groups. Among patients with VFres , a comparable proportion in each group developed nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance-associated mutations (RAMs). Among those with VFres , more patients in the rilpivirine group than in the efavirenz group developed N[t]RTI RAMs, mostly M184I/V. The mean (95% CI) CD4 cell count increased from baseline to week 96 by 224 (208-240) cells/μL in the rilpivirine group and by 206 (188-225) cells/μL in the efavirenz group. Treatment-related grade 2-4 overall adverse events, any rash and dizziness were less frequent for rilpivirine than for efavirenz (P < 0.0001).

CONCLUSIONS

Rilpivirine demonstrated antiviral efficacy similar to that of efavirenz in antiretroviral treatment-naïve adults with baseline VL ≤ 100 000 copies/mL over 96 weeks. Frequencies of VFres and emergent NNRTI RAMs in each group were similar. More patients with VFres in the rilpivirine group than in the efavirenz group developed N[t]RTI RAMs (mostly M184I/V). Rilpivirine had a more favourable safety/tolerability profile than efavirenz.