Cardiometabolic health in people with HIV: expert consensus review.

OBJECTIVES: To develop consensus data statements and clinical recommendations to provide guidance for improving cardiometabolic health outcomes in people with HIV based on the knowledge and experience of an international panel of experts. METHODS: A targeted literature review including 281 conference presentations, peer-reviewed articles, and background references on cardiometabolic health in adults with HIV published between January 2016 and April 2022 was conducted and used to develop draft consensus data statements. Using a modified Delphi method, an international panel of 16 experts convened in workshops and completed surveys to refine consensus data statements and generate clinical recommendations. RESULTS: Overall, 10 data statements, five data gaps and 14 clinical recommendations achieved consensus. In the data statements, the panel describes increased risk of cardiometabolic health concerns in people with HIV compared with the general population, known risk factors, and the potential impact of antiretroviral therapy. The panel also identified data gaps to inform future research in people with HIV. Finally, in the clinical recommendations, the panel emphasizes the need for a holistic approach to comprehensive care that includes regular assessment of cardiometabolic health, access to cardiometabolic health services, counselling on potential changes in weight after initiating or switching antiretroviral therapy and encouraging a healthy lifestyle to lower cardiometabolic health risk. CONCLUSIONS: On the basis of available data and expert consensus, an international panel developed clinical recommendations to address the increased risk of cardiometabolic disorders in people with HIV to ensure appropriate cardiometabolic health management for this population.

Expanded Multivariable Models to Assist Patient Selection for Long-Acting Cabotegravir + Rilpivirine Treatment: Clinical Utility of a Combination of Patient, Drug Concentration, and Viral Factors Associated With Virologic Failure.

BACKGROUND: Previously reported post hoc multivariable analyses exploring predictors of confirmed virologic failure (CVF) with cabotegravir + rilpivirine long-acting (CAB + RPV LA) were expanded to include data beyond week 48, additional covariates, and additional participants. METHODS: Pooled data from 1651 participants were used to explore dosing regimen (every 4 or every 8 weeks), demographic, viral, and pharmacokinetic covariates as potential predictors of CVF. Prior dosing regimen experience was accounted for using 2 populations. Two models were conducted in each population-baseline factor analyses exploring factors known at baseline and multivariable analyses exploring baseline factors plus postbaseline model-predicted CAB/RPV trough concentrations (4 and 44 weeks postinjection). Retained factors were evaluated to understand their contribution to CVF (alone or in combination). RESULTS: Overall, 1.4% (n = 23/1651) of participants had CVF through 152 weeks. The presence of RPV resistance-associated mutations, human immunodeficiency virus-1 subtype A6/A1, and body mass index ≥30 kg/m2 were associated with an increased risk of CVF (P < .05 adjusted incidence rate ratio), with participants with ≥2 of these baseline factors having a higher risk of CVF. Lower model-predicted CAB/RPV troughs were additional factors retained for multivariable analyses. CONCLUSIONS: The presence of ≥2 baseline factors (RPV resistance-associated mutations, A6/A1 subtype, and/or body mass index ≥30 kg/m2) was associated with increased CVF risk, consistent with prior analyses. Inclusion of initial model-predicted CAB/RPV trough concentrations (≤first quartile) did not improve the prediction of CVF beyond the presence of a combination of ≥2 baseline factors, reinforcing the clinical utility of the baseline factors in the appropriate use of CAB + RPV LA.

Recommendations on data sharing in HIV drug resistance research.

• Human immunodeficiency virus (HIV) drug resistance has implications for antiretroviral treatment strategies and for containing the HIV pandemic because the development of HIV drug resistance leads to the requirement for antiretroviral drugs that may be less effective, less well-tolerated, and more expensive than those used in first-line regimens. • HIV drug resistance studies are designed to determine which HIV mutations are selected by antiretroviral drugs and, in turn, how these mutations affect antiretroviral drug susceptibility and response to future antiretroviral treatment regimens. • Such studies collectively form a vital knowledge base essential for monitoring global HIV drug resistance trends, interpreting HIV genotypic tests, and updating HIV treatment guidelines. • Although HIV drug resistance data are collected in many studies, such data are often not publicly shared, prompting the need to recommend best practices to encourage and standardize HIV drug resistance data sharing. • In contrast to other viruses, sharing HIV sequences from phylogenetic studies of transmission dynamics requires additional precautions as HIV transmission is criminalized in many countries and regions. • Our recommendations are designed to ensure that the data that contribute to HIV drug resistance knowledge will be available without undue hardship to those publishing HIV drug resistance studies and without risk to people living with HIV.

A systematic review of adeno-associated virus gene therapy clinical trials for HIV - A potential solution for patients with haemophilia and HIV?

INTRODUCTION: In the past HIV infection was a common complication of haemophilia therapy. Gene therapy trials in Haemophilia patients using rAAV have shown promising results; Unfortunately, the majority of gene therapy trials studies have excluded HIV positive patients. We decided to systematically review the published clinical trials using rAAV for HIV prevention. METHODS: A comprehensive literature search was performed to identify studies evaluating clinical trials using rAAV for HIV. The search was conducted using the MEDLINE/PubMed databases. Search keywords included 'gene therapy', 'adeno-associated virus', 'HIV' and 'clinical trial'. RESULTS: Three studies met our inclusion criteria. Two were phase 1 studies and one was a phase 2 study. One study examined an AAV coding for human monoclonal IgG1 antibody whereas the other two studies delivered a vector coding for viral protease and part of reverse transcriptase. All studies administered the vaccine intramuscularly and showed a response as well a good safety profile. DISCUSSION: The concept of using a viral vector to prevent a viral infection is revolutionary. Due to the paucity of information regarding application of any gene therapy in HIV patients and the potential use of gene therapy in haemophilia patients with HIV in the future warrants attention.

Potential role of doravirine for the treatment of HIV-1-infected persons with transmitted drug resistance.

BACKGROUND: Doravirine has a unique resistance profile but how this profile might increase its usefulness beyond first-line therapy in persons with susceptible viruses has not been well studied. We sought to determine scenarios in which doravirine would retain activity against isolates from ART-naïve persons with transmitted drug resistance (TDR) and to identify gaps in available doravirine susceptibility data. METHODS: We analyzed published in vitro doravirine susceptibility data and applied the results to 42,535 RT sequences from ART-naïve persons published between 2017 and 2021. NNRTI drug resistance mutations (DRMs) were defined as those with a Stanford HIV Drug Resistance Database doravirine penalty score either alone or in combination with other mutations. RESULTS: V106A, Y188L, F227C/L, M230L, and Y318F were associated with the greatest reductions in doravirine susceptibility. However, several NNRTI DRMs and DRM combinations lacking these canonical resistance mutations had > tenfold reduced susceptibility including G190E, one isolate with G190S, three isolates with L100I + K103N, one isolate with K103N + P225H, and isolates with L100I + K103N + V108I and K101E + Y181C + G190A. Of the 42,535 ART-naïve sequences, 3,374 (7.9%) contained a NNRTI DRM of which 2,788 (82.6%) contained 1 DRM (n = 33 distinct mutations), 426 (12.6%) contained 2 DRMs (79 distinct pairs of mutations), and 143 (4.2%) contained ≥ 3 DRMs (86 distinct mutation patterns). Among the 2,788 sequences with one DRM, 112 (4.0%) were associated with ≥ 3.0-fold reduced doravirine susceptibility while 2,625 (94.2%) were associated with < 3.0-fold reduced susceptibility. Data were not available for individual NNRTI DRMs in 51 sequences (1.8%). Among the 426 sequences with two NNRTI DRMs, 180 (42.3%) were associated with ≥ 3.0 fold reduced doravirine susceptibility while just 32 (7.5%) had < 3.0 fold reduced susceptibility. Data were not available for 214 (50.2%) sequences containing two NNRTI DRMs. CONCLUSIONS: First-line therapy containing doravirine plus two NRTIs is expected to be effective in treating most persons with TDR as more than 80% of TDR sequences had a single NNRTI DRM and as more than 90% with a single DRM were expected to be susceptible to doravirine. However, caution is required for the use of doravirine in persons with more than one NNRTI DRM even if none of the DRMs are canonical doravirine-resistance mutations.

Integrase strand transfer inhibitor (INSTI)-resistance mutations for the surveillance of transmitted HIV-1 drug resistance.

BACKGROUND: Integrase strand transfer inhibitors (INSTIs) are expected to be widely adopted globally, requiring surveillance of resistance emergence and transmission. OBJECTIVES: We therefore sought to develop a standardized list of INSTI-resistance mutations suitable for the surveillance of transmitted INSTI resistance. METHODS: To characterize the suitability of the INSTI-resistance mutations for transmitted HIV-1 drug resistance (TDR) surveillance, we classified them according to their presence on published expert lists, conservation in INSTI-naive persons, frequency in INSTI-treated persons and contribution to reduced in vitro susceptibility. Mutation prevalences were determined using integrase sequences from 17302 INSTI-naive and 2450 INSTI-treated persons; 53.3% of the INSTI-naive sequences and 20.0% of INSTI-treated sequences were from non-B subtypes. Approximately 10% of sequences were from persons who received dolutegravir alone or a first-generation INSTI followed by dolutegravir. RESULTS: Fifty-nine previously recognized (or established) INSTI-resistance mutations were present on one or more of four published expert lists. They were classified into three main non-overlapping groups: 29 relatively common non-polymorphic mutations, occurring in five or more individuals and significantly selected by INSTI treatment; 8 polymorphic mutations; and 22 rare mutations. Among the 29 relatively common INSTI-selected mutations, 24 emerged as candidates for inclusion on a list of INSTI surveillance drug-resistance mutations: T66A/I/K, E92G/Q, G118R, F121Y, E138A/K/T, G140A/C/S, Y143C/H/R/S, S147G, Q148H/R/K, N155H, S230R and R263K. CONCLUSIONS: A set of 24 non-polymorphic INSTI-selected mutations is likely to be useful for quantifying INSTI-associated TDR. This list may require updating as more sequences become available from INSTI-experienced persons infected with HIV-1 non-subtype B viruses and/or receiving dolutegravir.

Survival of hepatitis C-infected haemophilia patients is predicted by presence of cirrhosis but not by anti-viral treatment.

BACKGROUND/PURPOSE: Hepatitis C (HCV) is a major cause of morbidity and mortality in haemophilia patients who received clotting factor concentrates before the availability of virus-inactivated factors in the mid-1980s. Recently, it has been suggested that anti-HCV treated patients, particularly those achieving a sustained virological response (SVR) have an improved outcome. We sought to examine the survival of treated and untreated HCV-infected haemophilia patients. MATERIAL AND METHODS: We studied overall and liver-related survival of patients with haemophilia and other congenital bleeding disorders between 2000 and 2010. The outcome was compared in 3 sub-groups: HCV mono-infected (N = 127), HCV/HIV co-infected (N = 28), and patients with either HCV-antibodies negative or persistent HCV RNA-negative (referred to as non-infected) (N = 45). Sixty-two (40%) (HCV and HCV/HIV) patients underwent anti-HCV treatment with an SVR rate of 40.3%. RESULTS: Overall and liver-related 10-year survival were: 82.1 and 89.3%, 95.3 and 99.2 and 100% for HCV/HIV co-infected, HCV mono-infected and non-infected haemophilia patients, respectively (p = 0.015 and 0.023 for comparisons of HCV/HIV vs. HCV; p = 0.003 for comparison of HCV/HIV and non-infected). One HCV mono-infected and 3 co-infected patients died of end-stage liver disease (2 underwent liver transplantation). There was no survival benefit from anti-HCV treatment or from attaining of an SVR. Only clinically suspected cirrhosis remained as an independent predictor of survival. CONCLUSION: The prognosis of haemophilia patients who acquired HCV/HIV co-infection is worse than that of HCV mono-infected or non-infected or haemophiliacs. This is mainly due to liver-related mortality. Anti-HCV treatment or SVR had no observable impact on survival rate.

Antiretroviral treatment sequencing strategies to overcome HIV type 1 drug resistance in adolescents and adults in low-middle-income countries.

Antiretroviral treatment (ART) is expanding to human immunodeficiency virus type 1 (HIV-1)-infected persons in low-middle income countries, thanks to a public health approach. With 3 available drug classes, 2 ART sequencing lines are programmatically foreseen. The emergence and transmission of viral drug resistance represents a challenge to the efficacy of ART. Knowledge of HIV-1 drug resistance selection associated with specific drugs and regimens and the consequent activity of residual drug options are essential in programming ART sequencing options aimed at preserving ART efficacy for as long as possible. This article determines optimal ART sequencing options for overcoming HIV-1 drug resistance in resource-limited settings, using currently available drugs and treatment monitoring opportunities. From the perspective of drug resistance and on the basis of limited virologic monitoring data, optimal sequencing seems to involve use of a tenofovir-containing nonnucleoside reverse-transcriptase inhibitor-based first-line regimen, followed by a zidovudine-containing, protease inhibitor (PI)-based second-line regimen. Other options and their consequences are explored by considering within-class and between-class sequencing opportunities, including boosted PI monotherapies and future options with integrase inhibitors. Nucleoside reverse-transcriptase inhibitor resistance pathways in HIV-1 subtype C suggest an additional reason for accelerating stavudine phase out. Viral load monitoring avoids the accumulation of resistance mutations that significantly reduce the activity of next-line options. Rational use of resources, including broader access to viral load monitoring, will help ensure 3 lines of fully active treatment options, thereby increasing the duration of ART success.

Nucleoside reverse transcriptase inhibitor resistance mutations associated with first-line stavudine-containing antiretroviral therapy: programmatic implications for countries phasing out stavudine.

BACKGROUND: The World Health Organization Antiretroviral Treatment Guidelines recommend phasing-out stavudine because of its risk of long-term toxicity. There are two mutational pathways of stavudine resistance with different implications for zidovudine and tenofovir cross-resistance, the primary candidates for replacing stavudine. However, because resistance testing is rarely available in resource-limited settings, it is critical to identify the cross-resistance patterns associated with first-line stavudine failure. METHODS: We analyzed HIV-1 resistance mutations following first-line stavudine failure from 35 publications comprising 1,825 individuals. We also assessed the influence of concomitant nevirapine vs. efavirenz, therapy duration, and HIV-1 subtype on the proportions of mutations associated with zidovudine vs. tenofovir cross-resistance. RESULTS: Mutations with preferential zidovudine activity, K65R or K70E, occurred in 5.3% of individuals. Mutations with preferential tenofovir activity, ≥ two thymidine analog mutations (TAMs) or Q151M, occurred in 22% of individuals. Nevirapine increased the risk of TAMs, K65R, and Q151M. Longer therapy increased the risk of TAMs and Q151M but not K65R. Subtype C and CRF01_AE increased the risk of K65R, but only CRF01_AE increased the risk of K65R without Q151M. CONCLUSIONS: Regardless of concomitant nevirapine vs. efavirenz, therapy duration, or subtype, tenofovir was more likely than zidovudine to retain antiviral activity following first-line d4T therapy.

Mutations in the protease gene associated with virological failure to lopinavir/ritonavir-containing regimens.

OBJECTIVES: To assess the most frequent resistance-associated mutations (RAMs) to lopinavir/ritonavir in a cohort of patients attended in daily practice. METHODS: We retrospectively identified 195 multitreated subjects with virological failure. Patients were classified as follows: (i) 71 (36.4%) never received lopinavir/ritonavir (lopinavir/ritonavir naive); (ii) 75 (38.5%) had previously failed on lopinavir/ritonavir; and (iii) 49 (25.1%) were on lopinavir/ritonavir at failure. RAM patterns were assessed. Medians, IQRs, percentages, Kruskal-Wallis, χ(2) or Fisher's exact test, and multinomial logistic regression were used whenever appropriate. RESULTS: L10I/F, K20R, L24I, L33F, M36I, M46I/L, I47V, G48V, F53L, I54V, A71V, G73S, V82A, I84V and L90M (all with P ≤ 0.037) were protease RAMs overexpressed in patients with lopinavir/ritonavir failure. L10I, M36I, M46I, I54V, L63P, A71V, V82A, I84V and L90M were the most common in lopinavir/ritonavir-naive patients. Other IAS-USA RAMs for lopinavir/ritonavir (L10R/V, K20M, V32I, I47A, I50V, I54L/A/M/T/S, A71T, L76V and V82F/T/S) were not associated with previous or current failure to lopinavir/ritonavir. Lopinavir/ritonavir failure was associated with the number of protease RAMs (OR = 1.146, 95% CI = 1.287, 1.626), higher exposure to protease inhibitors, and the presence of E44D, L33F, I54V and I84V. CONCLUSIONS: In multitreated patients with previous or current lopinavir/ritonavir failure, some protease mutations are selected at significantly greater rates. L10I, M36I, I54V, L63P, A71V, V82A and L90M were found in >50% of cases. Thus, their presence should be expected when genotypic testing results are not available. The number of protease RAMs and higher prior exposures to protease inhibitors were significantly associated with lopinavir/ritonavir failure.

Exploring predictors of HIV-1 virologic failure to long-acting cabotegravir and rilpivirine: a multivariable analysis.

OBJECTIVE: Efficacy and safety of long-acting cabotegravir (CAB) and rilpivirine (RPV) dosed intramuscularly every 4 or 8 weeks has been demonstrated in three Phase 3 trials. Here, factors associated with virologic failure at Week 48 were evaluated post hoc. DESIGN AND METHODS: Data from 1039 adults naive to long-acting CAB+RPV were pooled in a multivariable analysis to examine the influence of baseline viral and participant factors, dosing regimen and drug concentrations on confirmed virologic failure (CVF) occurrence using a logistic regression model. In a separate model, baseline factors statistically associated with CVF were further evaluated to understand CVF risk when present alone or in combination. RESULTS: Overall, 1.25% (n = 13/1039) of participants experienced CVF. Proviral RPV resistance-associated mutations (RAMs), HIV-1 subtype A6/A1, higher BMI (associated with Week 8 CAB trough concentration) and lower Week 8 RPV trough concentrations were significantly associated (P < 0.05) with increased odds of CVF (all except RPV trough are knowable at baseline). Few participants (0.4%) with zero or one baseline factor had CVF. Only a combination of at least two baseline factors (observed in 3.4%; n = 35/1039) was associated with increased CVF risk (25.7%, n = 9/35). CONCLUSION: CVF is an infrequent multifactorial event, with a rate of approximately 1% in the long-acting CAB+RPV arms across Phase 3 studies (FLAIR, ATLAS and ATLAS-2M) through Week 48. Presence of at least two of proviral RPV RAMs, HIV-1 subtype A6/A1 and/or BMI at least 30 kg/m2 was associated with increased CVF risk. These findings support the use of long-acting CAB+RPV in routine clinical practice.

Clinical implications of genotypic resistance to the newer antiretroviral drugs in HIV-1-infected patients with virological failure.

Virological suppression rates achieved with the new antiretroviral drugs in patients with virological failure and resistance to multiple drug classes are nearly matching the rates seen in treatment-naive patients. Knowledge of cross-resistance patterns to drugs of the same class is key for successful use of etravirine, tipranavir, and darunavir in treatment-experienced patients. Determination of human immunodeficiency virus type 1 (HIV-1) tropism is cardinal for maraviroc. The impressive potency of raltegravir must not preclude its use with other active drugs because of its limited genetic barrier. These new agents have demonstrated superiority in virtually all efficacy parameters in their pivotal salvage trials, but comparative data between them are still very scarce. This review discusses the clinical implication of resistance to these new drugs. Specific genotypic resistance scores have been developed for tipranavir and etravirine, and mutations conferring resistance to darunavir are well understood. Determining the most active drugs and successfully combining them is the key challenge in salvage regimens.

Drug level testing as a strategy to determine eligibility for drug resistance testing after failure of ART: a retrospective analysis of South African adult patients on second-line ART.

INTRODUCTION: When protease inhibitor (PI)-based second-line ART fails, guidelines recommend drug resistance testing and individualized third-line treatment. However, PI-resistant viral strains are rare and drug resistance testing is costly. We investigated whether less costly PI-exposure testing can be used to select those patients who would benefit most from drug resistance testing. METHODS: We performed a retrospective analysis of South African adults living with HIV experiencing failure of ritonavir-boosted-lopinavir (LPV/r)-based second-line ART for whom drug resistance testing results were available. We included patients who received plasma-based drug resistance testing at a central South African reference laboratory in 2017 and patients who received dried blood spots (DBS)-based drug resistance testing at a rural South African clinic between 2009 and 2017. PI-exposure testing was performed on remnant plasma or DBS using liquid chromatography mass spectrometry (LCMS). Additionally, a low-cost immunoassay was used on plasma. Population genotypic drug resistance testing of the pol region was performed on plasma and DBS using standard clinical protocols. RESULTS: Samples from 544 patients (494 plasma samples and 50 DBS) were included. Median age was 41.0 years (IQR: 33.3 to 48.5) and 58.6% were women. Median HIV-RNA load was 4.9 log10 copies/mL (4.3 to 5.4). Prevalence of resistance to the NRTI-backbone was 70.6% (349/494) in plasma samples and 56.0% (28/50) in DBS. Major PI-resistance mutations conferring high-level resistance to LPV/r were observed in 26.7% (132/494) of plasma samples and 12% (6/50) of DBS. PI-exposure testing revealed undetectable LPV levels in 47.0% (232/494) of plasma samples and in 60.0% (30/50) of DBS. In pooled analysis of plasma and DBS samples, detectable LPV levels had a sensitivity of 90% (84% to 94%) and a negative predictive failure of 95% (91% to 97%) for the presence of major LPV/r resistance. CONCLUSIONS: PI-exposure testing revealed non-adherence in half of patients experiencing failure on second-line ART and accurately predicted the presence or absence of clinically relevant PI resistance. PI-exposure testing constitutes a novel screening strategy in patients with virological failure of ART that can differentiate between different underlying causes of therapy failure and may allow for more effective use of limited resources available for drug resistance testing.

HIV-1 drug resistance mutations: an updated framework for the second decade of HAART.

More than 200 mutations are associated with antiretroviral resistance to drugs belonging to six licensed antiretroviral classes. More than 50 reverse transcriptase mutations are associated with nucleoside reverse transcriptase inhibitor resistance including M184V, thymidine analog mutations, mutations associated with non-thymidine analog containing regimens, multi-nucleoside resistance mutations, and several recently identified accessory mutations. More than 40 reverse transcriptase mutations are associated with nonnucleoside reverse transcriptase inhibitor resistance including major primary and secondary mutations, non-polymorphic minor mutations, and polymorphic accessory mutations. More than 60 mutations are associated with protease inhibitor resistance including major protease, accessory protease, and protease cleavage site mutations. More than 30 integrase mutations are associated with the licensed integrase inhibitor raltegravir and the investigational inhibitor elvitegravir. More than 15 gp41 mutations are associated with the fusion inhibitor enfuvirtide. CCR5 inhibitor resistance results from mutations that promote gp120 binding to an inhibitor-bound CCR5 receptor or CXCR4 tropism; however, the genotypic correlates of these processes are not yet well characterized.

Antiretroviral drug resistance testing in adult HIV-1 infection: 2008 recommendations of an International AIDS Society-USA panel.

Resistance to antiretroviral drugs remains an important limitation to successful human immunodeficiency virus type 1 (HIV-1) therapy. Resistance testing can improve treatment outcomes for infected individuals. The availability of new drugs from various classes, standardization of resistance assays, and the development of viral tropism tests necessitate new guidelines for resistance testing. The International AIDS Society-USA convened a panel of physicians and scientists with expertise in drug-resistant HIV-1, drug management, and patient care to review recently published data and presentations at scientific conferences and to provide updated recommendations. Whenever possible, resistance testing is recommended at the time of HIV infection diagnosis as part of the initial comprehensive patient assessment, as well as in all cases of virologic failure. Tropism testing is recommended whenever the use of chemokine receptor 5 antagonists is contemplated. As the roll out of antiretroviral therapy continues in developing countries, drug resistance monitoring for both subtype B and non-subtype B strains of HIV will become increasingly important.

Update of the Drug Resistance Mutations in HIV-1.

The International AIDS Society-USA (IAS-USA) Drug Resistance Mutations Group reviews new data on HIV-1 drug resistance that have been published or presented at recent scientific meetings to maintain a current list of mutations associated with antiretroviral drug resistance.This December 2008 version of the IAS-USA drug resistance mutations figures updates those published in this journal in March/April 2008 (Johnson VA, Brun-Vezinet F, Clotet B, et al, Top HIV Med, 2008;16:62-68). The compilation includes mutations that may contribute to a reduced virologic response to HIV-1 drugs. It should not be assumed that the list presented here is exhaustive. Drugs that have been approved by the US Food and Drug Administration (US FDA) as well as any drugs available in expanded access programs are included and listed in alphabetical order by drug class. The figures are designed for practitioners to use in identifying key mutations associated with viral resistance to antiretroviral drugs and in making therapeutic decisions.

Antiretroviral drug resistance testing in adult HIV-1 infection: 2008 recommendations of an International AIDS Society-USA panel.

Resistance to antiretroviral drugs remains an important limitation to successful human immunodeficiency virus type 1 (HIV-1) therapy. Resistance testing can improve treatment outcomes for infected individuals. The availability of new drugs from various classes, standardization of resistance assays, and the development of viral tropism tests necessitate new guidelines for resistance testing. The International AIDS Society-USA convened a panel of physicians and scientists with expertise in drug-resistant HIV-1, drug management, and patient care to review recently published data and presentations at scientific conferences and to provide updated recommendations. Whenever possible, resistance testing is recommended at the time of HIV infection diagnosis as part of the initial comprehensive patient assessment, as well as in all cases of virologic failure. Tropism testing is recommended whenever the use of chemokine receptor 5 antagonists is contemplated. As the roll out of antiretroviral therapy continues in developing countries, drug resistance monitoring for both subtype B and non-subtype B strains of HIV will become increasingly important.

A randomized, controlled study evaluating an induction treatment strategy in which enfuvirtide was added to an oral, highly active antiretroviral therapy regimen in treatment-experienced patients: the INTENSE study.

OBJECTIVES: The aim of the study was to compare the efficacy and safety of induction with the addition of enfuvirtide to a newly designed oral, highly active antiretroviral therapy (HAART) regimen versus HAART alone followed by a maintenance phase wherein participants were randomized to either continue/discontinue enfuvirtide while maintaining HAART or continue HAART alone (NCT00487188). METHODS: Participants with HIV-1 RNA >/=1000 copies/mL, CD4 count >/=200 cells/mm(3) and genotype sensitivity score >/=2 (excluding enfuvirtide) were randomized 2:1 to enfuvirtide+HAART or HAART alone and assessed every 4 weeks. Participants achieving <50 copies/mL on two consecutive visits by week 24 entered a maintenance phase wherein those receiving enfuvirtide+HAART underwent another randomization 1:1 to maintain enfuvirtide+HAART or discontinue enfuvirtide; those receiving HAART alone continued their regimen. Virological and immunological endpoints were analysed at weeks 24 and 48. RESULTS: At 24 weeks, 20/31 (65%) participants in the enfuvirtide+HAART arm versus 8/16 (50%) participants in the HAART arm achieved <50 copies/mL. Median time to achieving <50 copies/mL was 57 versus 141 days in the enfuvirtide+HAART and HAART arms (P = 0.048). Withdrawals were similar between groups. In the maintenance phase, at 48 weeks, 14/19 (74%) in the original enfuvirtide+HAART arm (regardless of second randomization) versus 4/8 (50%) in the HAART arm had <50 copies/mL. During maintenance, there were two virological failures in the enfuvirtide+HAART continuation arm, one in the enfuvirtide discontinuation arm and none in the HAART arm. CONCLUSIONS: Although limited by small participant numbers, these results suggest that treatment with enfuvirtide added to HAART may be an option for many patients.

Long-distance interactive expert advice in highly treatment-experienced HIV-infected patients.

OBJECTIVES: To determine the feasibility and outcomes of long-distance interactive expert advice for treatment-experienced patients. METHODS: HIV-1-infected patients on failing highly active antiretroviral therapy (HAART) were prospectively submitted for consultation by treating physicians to an expert panel using a standard e-mail form including: resistance tests, antiretroviral history, adherence, CD4 counts, HIV-1-RNA levels and HCV/HBV co-infection. Conference calls (CCs) were scheduled monthly to discuss 10 new patients. RESULTS: One hundred and fifteen patients were discussed (86% male; 45% intravenous drug users). The median length of HIV infection was 10 years and subjects were treated for a median of 8 years with a median of 5.25 previous HAART regimens. Ninety per cent were triple-class experienced [nucleoside reverse transcriptase inhibitors (NRTIs)/non-NRTIs (NNRTIs)/protease inhibitors (PIs)]. Median CD4 cell count was 298 cells/mm(3) and median viral load was 19 700 copies/mL. Overall, 60% had >or=5 reverse transcriptase mutations and 67% had >or=5 protease mutations, and most patients were NNRTI-resistant. Drugs more frequently recommended by experts were: lamivudine/emtricitabine > tenofovir > abacavir > zidovudine > didanosine > stavudine (NRTIs) and tipranavir > lopinavir > atazanavir > saquinavir (PIs). Enfuvirtide was recommended in 65% of cases. Concordance between recommended and prescribed regimens was 74.7%. Virtually all discordances were due to patient refusal of complex regimens. Outcomes at 24 weeks: HIV-1-RNA <50 copies/mL in 42% of patients, HIV-1-RNA <400 copies/mL in 59.4% of patients and median CD4 increase was 77 (14-140) cells/mm(3). CONCLUSIONS: Long-distance interactive expert advice is feasible for complex treatment-experienced HIV patients using e-mail and CCs. Adherence to treatment recommendations is high, with encouraging viro-immunological outcomes at 24 weeks. This strategy merits further investigation, especially in clinical settings where availability of local experts is limited.