Stability of antiretroviral regimens in patients with viral suppression

Predictive factors of viral load high-risk events for virological failure in HIV/AIDS patients receiving long-term antiviral therapy

Background

In the era of anti-retroviral therapy (ART), the plasma HIV viral load (VL) is an important primary indicator for monitoring the HIV treatment response. To optimize the clinical management of HIV/AIDS patients, we investigated VL high-risk events related to virological failure (VF) and further explored the preventive factors of VL high-risk events.

Methods

The data were derived from China’s HIV/AIDS Comprehensive Response Information Management System. HIV infected patients who initiated or received ART in Guangxi between 2003 and 2019 were included. The contributions of VL after 6 months of ART to VF and AIDS-related death were analysed by Kaplan-Meier curves, log-rank tests and Cox regression analyses. Both descriptive analyses and bivariate logistic regression were employed to further explore the preventive factors related to VL high-risk events of VF.

Results

The cumulative rates of VF in the high low-level viremia group (high LLV) (χ² = 18.45; P <  0.001) and non-suppressed group (χ² = 82.99; P <  0.001) were significantly higher than those in the viral suppression (VS) group. Therefore, the VL high-risk events of VF was defined as highest VL > 200 copies/ml after 6 months of ART. Compared with the VS group, the adjusted hazard risk was 7.221 (95% CI: 2.668; 19.547) in the high LLV group and 8.351 (95% CI: 4.253; 16.398) in the non-suppressed group. Compared with single patients, married or cohabiting (AOR = 0.591; 95% CI: 0.408, 0.856) and divorced or separated (AOR = 0.425, 95% CI: 0.207, 0.873) patients were negatively associated with VL high-risk events. So were patients acquired HIV homosexually (AOR = 0.572; 95% CI: 0.335, 0.978). However, patients who had ART modification were 1.728 times (95% CI: 1.093, 2.732) more likely to have VL high-risk events, and patients who used cotrimoxazole during ART were 1.843 times (95% CI: 1.271, 2.672) more likely to have VL high-risk events.

Conclusions

A VL greater than 200 copies/ml is a VL high-risk event for VF. Intervention measurements should be adopted to optimize the surveillance of ART in patients who are single or widowed, who have ART modification, and who use cotrimoxazole during ART.

Medication Side Effects and Retention in HIV Treatment: A Regression Discontinuity Study of Tenofovir Implementation in South Africa and Zambia

Tenofovir is less toxic than other nucleoside reverse-transcriptase inhibitors used in antiretroviral therapy (ART) and may improve retention of human immunodeficiency virus (HIV)-infected patients on ART. We assessed the impact of national guideline changes in South Africa (2010) and Zambia (2007) recommending tenofovir for first-line ART. We applied regression discontinuity in a prospective cohort study of 52,294 HIV-infected adults initiating first-line ART within 12 months (±12 months) of each guideline change. We compared outcomes in patients presenting just before and after the guideline changes using local linear regression and estimated intention-to-treat effects on initiation of tenofovir, retention in care, and other treatment outcomes at 24 months. We assessed complier causal effects among patients starting tenofovir. The new guidelines increased the percentages of patients initiating tenofovir in South Africa (risk difference (RD) = 81 percentage points, 95% confidence interval (CI): 73, 89) and Zambia (RD = 42 percentage points, 95% CI: 38, 45). With the guideline change, the percentage of single-drug substitutions decreased substantially in South Africa (RD = -15 percentage points, 95% CI: -18, -12). Starting tenofovir also reduced attrition in Zambia (intent-to-treat RD = -1.8% (95% CI: -3.5, -0.1); complier relative risk = 0.74) but not in South Africa (RD = -0.9% (95% CI: -5.9, 4.1); complier relative risk = 0.94). These results highlight the importance of reducing side effects for increasing retention in care, as well as the differences in population impact of policies with heterogeneous treatment effects implemented in different contexts.

Immunosenescence and hurdles in the clinical management of older HIV-patients

People living with HIV (PLWH) who are treated with effective highly active antiretroviral therapy (HAART) have a similar life expectancy to the general population. Moreover, an increasing proportion of new HIV diagnoses are made in people older than 50 y. The number of older HIV-infected patients is thus constantly growing and it is expected that by 2030 around 70% of PLWH will be more than 50 y old. On the other hand, HIV infection itself is responsible for accelerated immunosenescence, a progressive decline of immune system function in both the adaptive and the innate arm, which impairs the ability of an individual to respond to infections and to give rise to long-term immunity; furthermore, older patients tend to have a worse immunological response to HAART. In this review we focus on the pathogenesis of HIV-induced immunosenescence and on the clinical management of older HIV-infected patients.

Association Between the Occurrence of Adverse Drug Events and Modification of First-Line Highly Active Antiretroviral Therapy in Ghanaian HIV Patients

INTRODUCTION

Patients initiated on highly active antiretroviral therapy (HAART) generally remain on medication indefinitely. A modification in the HAART regimen may become necessary because of possible acute or chronic toxicities, concomitant clinical conditions, development of virological failure or the advent of adverse drug events. The study documents adverse drug events of HIV-positive Ghanaian patients with HAART modifications. It also investigates the association between documented adverse drug events and HAART modification using an unmatched case-control study design.

METHOD

The study was conducted in the Fevers Unit of the Korle Bu Teaching Hospital and involved patients who attended the HIV Care Clinic between January 2004 and December 2009. Data from 298 modified therapy patients (cases) were compared with 298 continuing therapy patients (controls) who had been on treatment for at least 1 month before the end of study. Controls were sampled from the same database of a cohort of HIV-positive patients on HAART, at the time a case occurred, in terms of treatment initiation ±1 month. Data were obtained from patients' clinical folders and the HIV clinic database linked to the pharmacy database. The nature of the documented adverse drug events of the cases was described and the association between the documented adverse drug events and HAART modification was determined by logistic regression with reported odds ratios (ORs) and their 95 % confidence interval (CI).

RESULTS

Among the 298 modified therapy patients sampled in this study, 52.7 % of them had at least one documented adverse drug event. The most documented adverse drug event was anaemia, recorded in 18.5 % of modified therapy patients, all of whom were on a zidovudine-based regimen. The presence of documented adverse drug events was significantly associated with HAART modification [adjusted OR = 2.71 (95 % CI 2.11-3.48), p < 0.001].

CONCLUSION

Among HIV patients on HAART, adverse drug events play a major role in treatment modification. Occurrence of adverse drug events may be used as a predictor for possible therapy modification. We recommend the institution of active pharmacovigilance in HIV treatment programmes as it permits the proper identification and characterisation of drug-related adverse events. This can help develop approaches towards their management and also justify therapy modifications.

Factors associated with the first antiretroviral therapy modification in older HIV-1 positive patients

Background

Rates of first antiretroviral therapy (cART) modifications are high in most observational studies. The age-related differences in treatment duration and characteristics of first cART modifications remain underinvestigated. With increasing proportion of older patients in HIV population it is important to better understand age-related treatment effects.

Methods

Patients were included into this analysis, if being cART naïve at the first visit at the clinic. Follow-up time was measured from the first visit date until first cART modification or 28 February 2013. First cART modification was defined as any change in the third drug component i.e. protease inhibitor (PI), non-nucleoside reverse transcriptase inhibitor (NNRTI), integrase inhibitor or fusion inhibitor. Cox proportional hazard models were used to identify factors related to first cART modification in three age groups: <30, 30–50 and >50.

Results

In total 2027 patients with 14,965 person-years of follow-up (PYFU) were included. The oldest group included 136 patients with 1901, middle group 1202 with 8416 PYFU and youngest group consisted of 689 patients with 4648 PYFU. Median follow-up time was 5.8 (IQR 3.4–9.4) years, median time on first cART was 4.4 (IQR 2.1–8.5) years. 72.4 % of patients started PI-based and 26.1 % NNRTI-based regimen. In total 1268 (62.5 %) patients had cART modification (non-adherence 30.8 %, toxicity 29.6 %). Durability of first cART was the best in patients over 50 y.o. (log-rank test, p = 0.001). Factors associated with discontinuation in this group were late presentation (HR 0.45, [95 % CI 0.23–0.90], p = 0.02) and PI use (HR 2.17, [95 % CI 1.18–4.0], p = 0.01).

Conclusions

Rates of first cART modifications or discontinuation were comparable in all groups; however older patients were significantly longer on first cART regimen.

Treatment Modifications and Treatment-Limiting Toxicities or Side Effects: Risk Factors and Temporal Trends

Combined antiretroviral treatment (cART) modifications are often required due to treatment failure or side effects. We investigate cART regimens' durability, frequency of treatment-limiting adverse events, and potential risk factors and temporal trends. Data were derived from the Athens Multicenter AIDS Cohort Study (AMACS). Statistical analyses were based on survival techniques, allowing for multiple contributions per individual. Overall, 2,756 individuals, aged >15 years, initiated cART. cART regimens were grouped by their initiation date into four calendar periods (1995-1998, 1999-2002, 2003-2006, and 2007+). Median [95% confidence interval (CI)] time to first treatment modification was 2.11 (1.95-2.33) years; cumulative probabilities at 1 year were 31.6%, 29.0%, 33.1%, and 29.6% for the four periods, respectively. cART modifications were less frequent in more recent years (adjusted HR=0.96 per year; p<0.001). Longer treatment duration was associated with lower HIV-RNA, higher CD4 counts, and being previously ART naive. cART modifications due to treatment failure became less frequent in recent years (adjusted HR=0.91 per year; p<0.001). Estimated (95% CI) 1 year cumulative probabilities of treatment-limiting side effects were 16.4% (12.0-21.3%), 19.3% (15.6-23.3%), 24.9% (20.3-29.7%), and 21.1% (13.4-29.9%) for the four periods, respectively, with no significant temporal trends. Risk of side effects was lower in nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens or triple nucleoside reverse transcriptase inhibitor (NRTI)-based cART regimens. Treatment modifications have become less frequent in more recent years. This could be partly attributed to the lower risk for side effects of NNRTI-based cART regimens and mainly to the improved efficacy of newer drugs. However, the rate of drugs substitutions due to adverse events remains substantially high.

Patterns and Predictors of First-Line Antiretroviral Therapy Modification in HIV-1-Infected Adults in a Large Urban Outpatient Cohort in Nigeria

OBJECTIVE

We described the magnitude, type, and factors associated with first-line antiretroviral therapy (ART) modification in HIV-1-infected adults on ART in Jos, Nigeria.

METHOD

Data on 6309 patients initiated on first-line ART between January 2004 and December 2006 were analyzed retrospectively. Factors predictive of modification to initial ART were assessed by chi-square and multivariable logistic regression analysis.

RESULTS

Overall, 5212 (83%) included patients incurred a modification (73.3% drug substitution and 9.7% drug switch) to their initial first-line ARV regimen during a median (interquartile range) follow-up period of 7 (3-8) years. Drug substitutions of zidovudine (ZDV) were less likely than of tenofovir (TDF; adjusted odd ratio [AOR] 0.6; 95% confidence interval [CI]: 0.51-0.71), and Drug substitutions of efavirenz (EFV) were more likely than of nevirapine (NVP)-containing (AOR 1.82; 95% CI: 1.42-2.33) regimens. Predictors of switch to second-line regimen include older age (AOR 2.05; 95% CI: 1.68-2.51), CD4 count≤100 cells/mm3 (AOR 1.89; 95% CI: 1.49-2.37), EFV compared to NVP (AOR 1.38; 95% CI: 1.02-1.88), and drug toxicity (AOR 1.90; 95% CI: 1.48-2.43).

CONCLUSION

Modification to initial ART was common in this study. Further evaluation of the contribution of guideline changes on regimen modification and treatment outcomes is recommended.

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.

Influence of adverse drug reactions on treatment success: prospective cohort analysis of HIV-infected individuals initiating first-line antiretroviral therapy in India

INTRODUCTION

Adverse drug reactions related to antiretroviral therapy (ART) remain a challenge in resource-limited settings, often causing significant morbidity and impaired adherence leading to treatment failure. This 2-year prospective study aimed to describe patterns and predictors of adverse reactions to first-line ART and assess the impact of these events on treatment success.

METHODS

Between 2010-2013, 321 ART-naïve eligible adults were enrolled at two clinics in southern India. ART regimens included zidovudine or stavudine plus lamivudine, plus nevirapine or efavirenz. Pill count adherence, immunological and virological monitoring, and laboratory-based adverse drug reactions were measured prospectively and analyzed.

RESULTS

Among 321 patients in the study, 289 (90.0%) patients experienced at least 1 adverse reaction, and 85 (26.5%) experienced at least 1 severe reaction. The incidence rate was 52 and 15 per 100 person-years for all reactions and severe reactions respectively. The cumulative incidence of zidovudine-induced anemia was 37.1% over 2 years. At 12 and 24 months, the proportion of patients with optimal adherence, undetectable viral load and CD4 counts >350 cells/mm3 were similar between patients who experienced or did not experience severe adverse drug reactions.

CONCLUSIONS

Our results highlight the high frequency of ART-related adverse drug reactions among individuals initiating first-line ART in India, underscoring the importance of detailed counseling and monitoring for maintaining ART durability. Severe drug-induced anemia needs to be addressed urgently with alternative first-line agents, and close laboratory surveillance. High treatment efficacy despite decreased drug safety seen here may be because patients have limited treatment options. Our results support the use of currently recommended safer first-line ART regimens that minimize the risk of severe life-threatening toxicities and provide for a better quality of life.

TRIAL REGISTRATION

ISRTCN Registry: ISRCTN79261738.

Comparable long-term efficacy of Lopinavir/Ritonavir and similar drug-resistance profiles in different HIV-1 subtypes

BACKGROUND

Analysis of potentially different impact of Lopinavir/Ritonavir (LPV/r) on non-B subtypes is confounded by dissimilarities in the conditions existing in different countries. We retrospectively compared its impact on populations infected with subtypes B and C in Israel, where patients infected with different subtypes receive the same treatment.

METHODS

Clinical and demographic data were reported by physicians. Resistance was tested after treatment failure. Statistical analyses were conducted using SPSS.

RESULTS

607 LPV/r treated patients (365 male) were included. 139 had HIV subtype B, 391 C, and 77 other subtypes. At study end 429 (71%) were receiving LPV/r. No significant differences in PI treatment history and in median viral-load (VL) at treatment initiation and termination existed between subtypes. MSM discontinued LPV/r more often than others even when the virologic outcome was good (p = 0.001). VL was below detection level in 81% of patients for whom LPV/r was first PI and in 67% when it was second (P = 0.001). Median VL decrease from baseline was 1.9±0.1 logs and was not significantly associated with subtype. Median CD4 increase was: 162 and 92cells/µl, respectively, for patients receiving LPV/r as first and second PI (P = 0.001), and 175 and 98, respectively, for subtypes B and C (P<0.001). Only 52 (22%) of 237 patients genotyped while under LPV/r were fully resistant to the drug; 12(5%) were partially resistant. In48%, population sequencing did not reveal resistance to any drug notwithstanding the virologic failure. No difference was found in the rates of resistance development between B and C (p = 0.16).

CONCLUSIONS

Treatment with LPV/r appeared efficient and tolerable in both subtypes, B and C, but CD4 recovery was significantly better in virologically suppressed subtype-B patients. In both subtypes, LPV/r was more beneficial when given as first PI. Mostly, reasons other than resistance development caused discontinuation of treatment.

Medication possession ratio predicts antiretroviral regimens persistence in Peru

Objectives

In developing nations, the use of operational parameters (OPs) in the prediction of clinical care represents a missed opportunity to enhance the care process. We modeled the impact of multiple measurements of antiretroviral treatment (ART) adherence on antiretroviral treatment outcomes in Peru.

Design And Methods

Retrospective cohort study including ART naïve, non-pregnant, adults initiating therapy at Hospital Nacional Cayetano Heredia, Lima-Peru (2006-2010). Three OPs were defined: 1) Medication possession ratio (MPR): days with antiretrovirals dispensed/days on first-line therapy; 2) Laboratory monitory constancy (LMC): proportion of 6 months intervals with ≥1 viral load or CD4 reported; 3) Clinic visit constancy (CVC): proportion of 6 months intervals with ≥1 clinic visit.

Three multi-variable Cox proportional hazard (PH) models (one per OP) were fit for (1) time of first-line ART persistence and (2) time to second-line virologic failure. All models were adjusted for socio-demographic, clinical and laboratory variables.

Results

856 patients were included in first-line persistence analyses, median age was 35.6 years [29.4-42.9] and most were male (624; 73%). In multivariable PH models, MPR (per 10% increase HR=0.66; 95%CI=0.61-0.71) and LMC (per 10% increase 0.83; 0.71-0.96) were associated with prolonged time on first-line therapies.

Among 79 individuals included in time to second-line virologic failure analyses, MPR was the only OP independently associated with prolonged time to second-line virologic failure (per 10% increase 0.88; 0.77-0.99).

Conclusions

The capture and utilization of program level parameters such as MPR can provide valuable insight into patient-level treatment outcomes.

Incidence rate of modifying or discontinuing first combined antiretroviral therapy regimen due to toxicity during the first year of treatment stratified by age

Toxicity is the most frequently reported reason for modifying or discontinuing the first combined antiretroviral therapy regimens, and it can cause significant morbidity, poor quality of life and also can be an important barrier to adherence, ultimately resulting in treatment failure and viral resistance. Elderly patients with HIV/AIDS (≥50 years) may have a different profile in terms of treatment modification due to higher incidence of comorbidities and polypharmacy. The aim of this study was to describe the incidence of modifying or discontinuing first combined antiretroviral therapy regimen due to toxicity (TOX-MOD) during the first year of treatment at the IPEC – FIOCRUZ HIV/AIDS cohort, Rio de Janeiro, Brazil, stratified by age. Demographic, clinical and treatment characteristics from antiretroviral-naïve patients who first received combined antiretroviral therapy between Jan/1996 and Dec/2010 were collected. Incidence rate and confidence interval of each event were estimated using quasipoisson model. To estimate hazard ratio (HR) of TOX-MOD during the first year of combined antiretroviral therapy Cox's proportional hazards regression was applied. Overall, 1558 patients were included; 957 (61.4%), 420 (27.0%) and 181 (11.6%) were aged <40, 40–49, and ≥50 years, respectively. 239 (15.3%) events that led to any modifying or discontinuing within the first year of treatment were observed; 228 (95.4%) of these were TOX-MOD, corresponding to an incidence rate of 16.6/100 PY (95% CI: 14.6–18.9). The most frequent TOX-MOD during first combined antiretroviral therapy regimen were hematologic (59; 26.3%), central nervous system (47; 20.9%), rash (42; 19.1%) and gastrointestinal (GI) (38; 16.7%). In multivariate analysis, incidence ratio of TOX-MOD during the first year of combined antiretroviral therapy progressively increases with age, albeit not reaching statistical significance. This profile was maintained after adjusting the model for sex, combined antiretroviral therapy regimen and year of combined antiretroviral therapy initiation. These results are important because not only patients are living longer and aging with HIV, but also new diagnoses are being made among the elderly. Prospective studies are needed to evaluate the safety profile of first line combined antiretroviral therapy on elderly individuals, especially in resource-limited countries, where initial regimens are mostly NNRTI-based.

Durability of first ART regimen and risk factors for modification, interruption or death in HIV-positive patients starting ART in Europe and North America 2002-2009

OBJECTIVES

To estimate the incidence of and risk factors for modifications to first antiretroviral therapy (ART) regimen, treatment interruption and death.

METHODS

A total of 21 801 patients from 18 cohorts in Europe and North America starting ART on regimens including at least two nucleoside reverse transcriptase inhibitors and boosted protease inhibitor or non-nucleoside reverse transcriptase inhibitor during 2002-2009 were included. Incidence of modifications (change of drug class, substitution/addition within class, or switch to nonstandard regimen), interruption or death and associations with patient characteristics were estimated using competing-risks methods.

RESULTS

During median 28 months follow-up, 8786 (40.3%) patients modified first ART, 2346 (10.8%) interrupted and 427 (2.0%) died before changing regimen. Three-year cumulative percentages of modification, interruption and death were 47, 12 and 2%, respectively. After adjustment, rates of interruption were highest for IDUs and lowest for MSM, and higher for patients starting ART with CD4 cell count above 350 cells/μl than other patients. Compared to efavirenz, patients on lopinavir and other protease inhibitors had higher rates of modification and interruption, on atazanavir had lower rates of class change, and on nevirapine higher rates of interruption. Those on tenofovir/emtricitabine backbone had lowest rates of substitutions and switches to nonstandard regimen, and on abacavir/lamivudine lowest rates of interruption. Rates of substitution and switches to nonstandard regimen were lower in 2006-2009.

CONCLUSION

Rates of modification and interruption were high, particularly in the first year of ART. Decreased rates of substitutions or switches to nonstandard regimen in recent years may be linked to greater use of well tolerated once-daily drugs.

Calendar time trends in the incidence and prevalence of triple-class virologic failure in antiretroviral drug-experienced people with HIV in Europe

BACKGROUND

Despite the increasing success of antiretroviral therapy (ART), virologic failure of the 3 original classes [triple-class virologic failure, (TCVF)] still develops in a small minority of patients who started therapy in the triple combination ART era. Trends in the incidence and prevalence of TCVF over calendar time have not been fully characterised in recent years.

METHODS

Calendar time trends in the incidence and prevalence of TCVF from 2000 to 2009 were assessed in patients who started ART from January 1, 1998, and were followed within the Collaboration of Observational HIV Epidemiological Research Europe (COHERE).

RESULTS

Of 91,764 patients followed for a median (interquartile range) of 4.1 (2.0-7.1) years, 2722 (3.0%) developed TCVF. The incidence of TCVF increased from 3.9 per 1000 person-years of follow-up [95% confidence interval (CI): 3.7 to 4.1] in 2000 to 8.8 per 1000 person-years of follow-up (95% CI: 8.5 to 9.0) in 2005, but then declined to 5.8 per 1000 person-years of follow-up (95% CI: 5.6 to 6.1) by 2009. The prevalence of TCVF was 0.3% (95% CI: 0.27% to 0.42%) at December 31, 2000, and then increased to 2.4% (95% CI: 2.24% to 2.50%) by the end of 2005. However, since 2005, TCVF prevalence seems to have stabilized and has remained below 3%.

CONCLUSIONS

The prevalence of TCVF in people who started ART after 1998 has stabilized since around 2005, which most likely results from the decline in incidence of TCVF from this date. The introduction of improved regimens and better overall HIV care is likely to have contributed to these trends. Despite this progress, calendar trends should continue to be monitored in the long term.

Projected life expectancy of people with HIV according to timing of diagnosis

BACKGROUND AND OBJECTIVES

Effective antiretroviral therapy (ART) has contributed greatly toward survival for people with HIV, yet many remain undiagnosed until very late. Our aims were to estimate the life expectancy of an HIV-infected MSM living in a developed country with extensive access to ART and healthcare, and to assess the effect of late diagnosis on life expectancy.

METHODS

A stochastic computer simulation model of HIV infection and the effect of ART was used to estimate life expectancy and determine the distribution of potential lifetime outcomes of an MSM, aged 30 years, who becomes HIV positive in 2010. The effect of altering the diagnosis rate was investigated.

RESULTS

Assuming a high rate of HIV diagnosis (median CD4 cell count at diagnosis, 432  cells/μl), projected median age at death (life expectancy) was 75.0 years. This implies 7.0 years of life were lost on average due to HIV. Cumulative risks of death by 5 and 10 years after infection were 2.3 and 5.2%, respectively. The 95% uncertainty bound for life expectancy was (68.0,77.3) years. When a low diagnosis rate was assumed (diagnosis only when symptomatic, median CD4 cell count 140  cells/μl), life expectancy was 71.5 years, implying an average 10.5 years of life lost due to HIV.

CONCLUSION

If low rates of virologic failure observed in treated patients continue, predicted life expectancy is relatively high in people with HIV who can access a wide range of antiretrovirals. The greatest risk of excess mortality is due to delays in HIV diagnosis.

Treatment for prevention of HIV transmission in a localised epidemic: the case for South Australia

BACKGROUND

Discussion is currently taking place among international HIV/AIDS groups around increasing HIV testing and initiating earlier use of antiretroviral therapy (ART) among people diagnosed with HIV as a method to reduce the spread of HIV. In this study, we explore the expected epidemiological impact of this strategy in a small population in which HIV transmission is predominantly confined to men who have sex with men (MSM).

METHODS

A deterministic mathematical transmission model was constructed to investigate the impacts of strategies that increase testing and treatment rates, and their likely potential to mitigate HIV epidemics among MSM. Our novel model distinguishes men in the population who are more easily accessible to prevention campaigns through engagement with the gay community from men who are not. This model is applied to the population of MSM in South Australia.

RESULTS

Our model-based findings suggest that increasing testing rates alone will have minimal impact on reducing the expected number of infections compared to current conditions. However, in combination with increases in treatment coverage, this strategy could lead to a 59-68% reduction in the number of HIV infections over the next 5 years. Targeting men who are socially engaged with the gay community would result in the majority of potential reductions in incidence, with only minor improvements possible by reaching all other MSM.

CONCLUSIONS

Investing in strategies that will achieve higher coverage and earlier initiation of treatment to reduce infectiousness of HIV-infected individuals could be an effective strategy for reducing incidence in a population of MSM.

Impact of late diagnosis and treatment on life expectancy in people with HIV-1: UK Collaborative HIV Cohort (UK CHIC) Study

OBJECTIVES

To estimate life expectancy for people with HIV undergoing treatment compared with life expectancy in the general population and to assess the impact on life expectancy of late treatment, defined as CD4 count <200 cells/mm(3) at start of antiretroviral therapy.

DESIGN

Cohort study.

SETTING

Outpatient HIV clinics throughout the United Kingdom. Population Adult patients from the UK Collaborative HIV Cohort (UK CHIC) Study with CD4 count ≤ 350 cells/mm(3) at start of antiretroviral therapy in 1996-2008.

MAIN OUTCOME MEASURES

Life expectancy at the exact age of 20 (the average additional years that will be lived by a person after age 20), according to the cross sectional age specific mortality rates during the study period.

RESULTS

1248 of 17,661 eligible patients died during 91,203 person years' follow-up. Life expectancy (standard error) at exact age 20 increased from 30.0 (1.2) to 45.8 (1.7) years from 1996-9 to 2006-8. Life expectancy was 39.5 (0.45) for male patients and 50.2 (0.45) years for female patients compared with 57.8 and 61.6 years for men and women in the general population (1996-2006). Starting antiretroviral therapy later than guidelines suggest resulted in up to 15 years' loss of life: at age 20, life expectancy was 37.9 (1.3), 41.0 (2.2), and 53.4 (1.2) years in those starting antiretroviral therapy with CD4 count <100, 100-199, and 200-350 cells/mm(3), respectively.

CONCLUSIONS

Life expectancy in people treated for HIV infection has increased by over 15 years during 1996-2008, but is still about 13 years less than that of the UK population. The higher life expectancy in women is magnified in those with HIV. Earlier diagnosis and subsequent timely treatment with antiretroviral therapy might increase life expectancy.

Medication persistence in the treatment of HIV infection: a review of the literature and implications for future clinical care and research

Persistence, continuous treatment with a prescribed medication or intervention, is an important, but underrecognized aspect of medication treatment, especially for HIV. In contrast to adherence, which measures the percentage of patient behavior to a prescribed therapy, persistence measures the duration during which a patient remains on a prescribed therapy. Decreased persistence for HIV treatment, or shorter duration on therapy, is associated with increased rates of virological failure, development of antiretroviral resistance, and increased morbidity and mortality. Additionally, frequency and duration of nonpersistent episodes rather than adherence may be a better predictor of clinical outcomes in HIV-infected patients on certain regimens. In this review, we codify the constructs of persistence and adherence, and further define persistence as either patient or regimen persistence. Furthermore, current literature on the clinical consequences of and factors associated with suboptimal persistence is summarized. Finally, methods to measure persistence as well as interventions that may improve persistence and clinical outcomes are suggested.

Long-term CD4+ T-cell count evolution after switching from regimens including HIV nucleoside reverse transcriptase inhibitors (NRTI) plus protease inhibitors to regimens containing NRTI plus non-NRTI or only NRTI

Background

Data regarding CD4+ recovery after switching from protease inhibitor (PI)-based regimens to regimens not containing PI are scarce.

Methods

Subjects with virological success on first-PI-regimens who switched to NNRTI therapy (NNRTI group) or to nucleoside reverse transcriptase (NRTI)-only (NRTI group) were studied. The effect of the switch on the ongoing CD4+ trend was assessed by two-phase linear regression (TPLR), allowing us to evaluate whether a change in the CD4+ trend (hinge) occurred and the time of its occurrence. Furthermore, we described the evolution of the frequencies in CD4-count classes across four relevant time-points (baseline, before and immediately after the switch, and last visit). Finally, we explored whether the CD4+ counts evolved differently in patients who switched to NNRTI or NRTI-only regimens by considering: the overall CD4+ trends, the time to CD4+≥ 500/mm³ after the switch, and the area-under-the-curve (AUC) of the CD4+ after the switch.

Results

Eight hundred and ninety-six patients, followed for a median of 2,121 days, were included. At TPLR, hinges occurred in 581/844 (68.9%), but in only 40/581 (6.9%) within a time interval (180 days) compatible with a possible relationship to the switch; furthermore, in 19/40 cases, CD4+ counts appeared to decrease after the hinges. In comparison with the NNRTI group, the NRTI group showed CD4+ count greater at baseline (P = 0.0234) and before the switch (P ≤ 0.0001), superior CD4+ T-cell increases after HAART was started, lower probability of not achieving CD4+ ≥ 500/mm³ (P = 0.0024), and, finally, no significant differences in the CD4+ T-cell AUC after the switch after adjusting for possible confounders (propensity score and pre-switch AUC). Persistence at CD4+ < 200/mm³ was observed in 34/435 (7.5%) patients, and a decrease below this level was found in only 10/259 (3.9%) with baseline CD4+ ≥ 350/mm³.

Conclusions

Switching from first-line PI to NNRTI- or NRTI-based regimens did not seem to impair CD4+ trend over long-term follow-up. Although the greater CD4+ increases in patients who switched to the NRTI-only regimen was due to higher CD4+ counts before the switch, several statistical analyses consistently showed that switching to this regimen did not damage the ongoing immune-reconstitution. Lastly, the observation that CD4+ T-cell counts remained low or decreased in the long term despite virological success merits further investigation.

Stavudine toxicity in women is the main reason for treatment change in a 3-year prospective cohort of adult patients started on first-line antiretroviral treatment in Uganda

PURPOSE

In resource-limited settings, there are only a few antiretroviral treatment (ART) options. Our objective was to evaluate the reasons for first-line ART changes in resource-limited settings.

METHODS

Prospective research cohort of patients initiating ART between April 2004 and April 2005 in Kampala, Uganda. The main endpoint was the substitution of at least 1 drug included in the initial combination.

RESULTS

Five hundred Fifty-nine patients initiated on ART, 70% were female, median CD4+ count 98 (21-163) cells per microliter, median HIV RNA log₁₀ 5.4 (5.0-5.8). 413 (74%) patients were started on stavudine, lamivudine, and nevirapine, and 146 (36%) on zidovudine, lamivudine and efavirenz. One hundred Forty-eight (26.5%) had at least one treatment change (incidence rate 14.3 per 100 person-years; confidence interval: 12.2 to 16.9). The main reason for first treatment change was drug toxicity (n = 91, 61.5%). Stavudine accounted for the majority of the toxicities that led to drug substitution (n = 76, 84%). In the multivariate analysis, being female (P = 0.011) and being stage 3-4 as compared with 1-2 at ART initiation were predictive of stavudine substitution (P = 0.05). There was no difference in virologic outcome in patients who changed due to toxicity compared with those who did not.

CONCLUSIONS

The majority of the treatment changes were due to stavudine-related toxicity. Long-term stavudine use is less well tolerated in women.

Life expectancy of HIV-positive adults: a review

We review studies estimating life expectancy (LE), the average number of additional years a person can expect to live, for HIV-positive adults and show variation by sociodemographic factors and level of immunosuppression. The LE of patients starting antiretroviral therapy early in the course of HIV infection and attaining restoration of a normal CD4 count may approach that of the general population. Improvements in treatment and the associated increase in LE imply that increasing numbers of HIV-positive patients will live to older age. Late diagnosis and presentation to care and treatment not concordant with guidelines contribute to reducing LE.

Gastrointestinal tolerability and quality of life in antiretroviral-naive HIV-1-infected patients: data from the CASTLE study

Most ritonavir-boosted protease inhibitor (PI)-based antiretroviral regimens offer comparable levels of virological efficacy. Thus, the tolerability of the regimen becomes a distinguishing factor with implications for patient quality of life (QoL), treatment adherence, and clinical outcome. This article describes results from the CASTLE study (comparing once-daily atazanavir/ritonavir [ATV/RTV] with twice-daily lopinavir/ritonavir [LPV/RTV], both in combination with fixed-dose tenofovir/emtricitabine, in treatment-naive HIV-infected patients) and an evaluation of the impact of gastrointestinal (GI) complications of treatment on patient QoL, as measured by the irritable bowel syndrome (IBS) QoL questionnaire (IBS-QoL). Changes in IBS-QoL from baseline over time (to week 24) were classified as: "Improvement" (> or =2-point positive change from baseline), "No change" (<2-point change), or "Worsening" (> or =2-point negative change). Data were collected on GI adverse events (AEs) and use of GI medications. Of the 599 patients with IBS-QoL-evaluable data through week 24, fewer patients in the ATV/RTV group than in the LPV/RTV group experienced grade 2-4 treatment-related GI AEs including diarrhea (3% versus 10%), nausea (5% versus 7%), and vomiting (<1% on both arms). Nearly three times as many patients receiving LPV/RTV used GI medications. ATV/RTV was associated with an increase in overall IBS-QoL scores and more patients receiving ATV/RTV than LPV/RTV experienced improvement in IBS-QoL through week 24. In contrast to LPV/RTV, ATV/RTV treatment was associated with earlier and more positive improvements in QoL scores across CD4 sub-groups. Differences in the health-related QoL profile between ATV/RTV and LPV/RTV may be important when selecting PI-based antiretroviral regimens.

A comparison of the long-term durability of nevirapine, efavirenz and lopinavir in routine clinical practice in Europe: a EuroSIDA study

OBJECTIVES

The durability of combination antiretroviral therapy (cART) regimens can be measured as time to discontinuation because of toxicity or treatment failure, development of clinical disease or serious long-term adverse events. The aim of this analysis was to compare the durability of nevirapine, efavirenz and lopinavir regimens based on these measures.

METHODS

Patients starting a nevirapine, efavirenz or lopinavir-based cART regimen for the first time after 1 January 2000 were included in the analysis. Follow-up started ≥ 3 months after initiation of treatment if viral load was <500 HIV-1 RNA copies/mL. Durability was measured as discontinuation rate or development/worsening of clinical markers.

RESULTS

A total of 603 patients (21%) started nevirapine-based cART, 1465 (51%) efavirenz, and 818 (28%) lopinavir. After adjustment there was no significant difference in the risk of discontinuation for any reason between the groups on nevirapine and efavirenz (P=0.43) or lopinavir (P=0.13). Compared with the nevirapine group, those on efavirenz had a 48% (P=0.0002) and those on lopinavir a 63% (P<0.0001) lower risk of discontinuation because of treatment failure and a 31% (P=0.01) and 66% (P<.0001) higher risk, respectively, of discontinuation because of toxicities or patient/physician choice. There were no significant differences in the incidence of non-AIDS-related events, worsening anaemia, severe weight loss, increased aspartate aminotransferase (AST)/alanine aminotransferase (ALT) levels or increased total cholesterol. Compared with patients on nevirapine, those on lopinavir had an 80% higher incidence of high-density lipoprotein (HDL) cholesterol decreasing below 0.9 mmol/L (P=0.003), but there was no significant difference in this variable between those on nevirapine and those on efavirenz (P=0.39).

CONCLUSIONS

The long-term durability of nevirapine-based cART, based on risk of all-cause discontinuation and development of long-term adverse events, was comparable to that of efavirenz or lopinavir, in patients in routine clinical practice across Europe who initially tolerated and virologically responded to their regimen.

Ongoing changes in HIV RNA levels during untreated HIV infection: implications for CD4 cell count depletion

BACKGROUND

Understanding of the interplay between plasma HIV RNA level and CD4 cell count depletion in untreated infection remains incomplete.

METHODS

We studied 1169 people with HIV seen for care at a major London clinic while naive to antiretroviral therapy. We considered pairs (n = 5940) of consecutive simultaneously measured CD4 cell count and plasma HIV RNA values from patients who had never started therapy. Baseline was the first date when both measures were known.

RESULTS

HIV RNA levels increased variably and often substantially from baseline (60% experience an increase of over 50 000 copies/ml by 5 years of follow-up). The current HIV RNA level (i.e. first value of the pair) was strongly associated with the time-standardized change in CD4 cell count, with a mean 106 cells/microl per year greater rate of CD4 cell count decline per log-copy/ml higher current HIV RNA level (P < 0.0001). After adjustment for the current level, higher baseline HIV RNA was not associated with CD4 cell count decline. There was no average CD4 cell count decline with current HIV RNA level below 3.0 log-copies/ml, compared with a 159 cells/microl per year decline for those with HIV RNA at least 5.5 log-copies/ml (P < 0.0001). Further, the current CD4 cell count predicted subsequent changes in HIV RNA level (0.04 log-copies/year greater increases per 100 cells/microl lower CD4 cell count; P < 0.0001).

CONCLUSION

The often substantial increases in HIV RNA level observed in untreated HIV infection appear fundamentally linked to CD4 cell count depletion. Research into mechanisms by which HIV RNA levels rise over time should yield insights into the causes of CD4 cell count depletion, as the two processes are intimately linked.

Long-term trends in adherence to antiretroviral therapy from start of HAART

OBJECTIVE

People on antiretroviral therapy are likely to be required to maintain good adherence throughout their lives. We aimed to investigate long-term trends in highly active antiretroviral therapy (HAART) adherence to identify the main predictors and to evaluate whether participants experience periods of low adherence (<or=60%).

METHODS

Participants in the Royal Free Clinic Cohort were followed from the date of start of HAART until the end of the last recorded ART prescription or death. Follow-up was divided into 6-month periods, and for each period, a value of adherence, measured as the percentage of days in the 6-month period covered by a valid prescription for at least three antiretroviral drugs, was calculated.

RESULTS

Patients were assessed for drug coverage adherence for a median of 4.5 years [inter-quartile range (IQR) 2.4-7.2; maximum 9 years] covering a period up to 13 years from start of HAART. There was evidence of a slight increase in adherence over time [adjusted odds ratio (OR) of >95% adherence = 1.02 per year; 95% confidence interval (CI) 1.01-1.04; P = 0.0053]. Independent predictors of adherence were age, demographic group, calendar year period, drug regimen and previous virologic failures. The overall rate of at least one period of low adherence was 0.12 per person-year, but this rate decrease markedly over time to 0.01 in 2007/2008.

CONCLUSION

Adherence, as measured by drug coverage, does not decrease on average over more than a decade from start of HAART. This is encouraging, because it shows that patients could potentially maintain viral suppression for many years.

Novel compounds for the treatment of HIV type-1 infection

Despite the recent licensure of several new antiretroviral compounds, there is still a need to develop additional agents. Problems with antiviral activity, tolerability, ease of administration, extent of cross-resistance and pharmacokinetic as well as pharmacodynamic interactions still represent important obstacles to life-long control of HIV type-1 replication by highly active antiretroviral therapy. Several compounds stem from the same classes as currently available drugs: apricitabine and elvucitabine (nucleoside reverse transcriptase inhibitors), rilpivirine (non-nucleoside reverse transcriptase inhibitor), vicriviroc and INCB009471 (CCR5 inhibitors) and elvitegravir (integrase inhibitor). The potential of other compounds with new modes of action is less clear. Currently, maturation inhibitors appear promising but for other drugs, obstacles to continued development, such as the need of parenteral application (that is, monoclonal antibodies) or toxicity (for example, immune modulating agents and pegylated interferon), are already apparent. For even more compounds in the preclinical development phase, an assessment of their possible clinical role is still premature. This review provides an overview and a summary of the current status of drug development in the field.

[Role of etravirine in combination antiretroviral therapy]

Etravirine (ETR) is a new antiretroviral drug of the non-nucleoside reverse transcriptase inhibitor (NNRTI) family that has recently been approved by the regulatory agencies for the treatment of patients with prior experience with antiretrovirals, evidence of active viral replication, and who harbor multidrug resistant HIV-1 strains. In this context, in Europe, the use of this drug has been authorized combined with boosted protease inhibitors and nucleoside reverse transcriptase inhibitors. This approval was based on the results of the randomized double-blind DUET studies, in which the ETR arm was statistically superior to the placebo arms in terms of virological efficacy, immunological recovery, clinical progression and health- related quality of life. These studies showed that ETR was as well-tolerated as placebo, except for the appearance of rash, which was more common in the ETR arm. However, rash was usually mild or moderate and caused discontinuation of ETR in only 2% of the patients. The characteristics of ETR, i.e., potency, benign safety profile, resistance profile, pharmacokinetic characteristics, and drug interactions suggest that the use of this drug may go beyond its currently approved indications. Nevertheless, the evidence supporting these alternative uses is still scarce, although a randomized, double-blind, placebo controlled trial (SENSE) is under way in treatment-naïve patients. In this trial ETR will be administered once daily and the principal objective is to show that ETR has better tolerability in the central nervous system (CNS) than efavirenz. Moreover, the tolerability profile in the CNS, liver, and even skin suggest that ETR may be a good option when there are toxicity problems, or a risk of toxicity, with first-generation NNRTIs. When there is virological failure with an initial first-generation NNRTI-based regimen, the differential resistance profile of ETR may allow this drug to be used to construct a rescue combination. ETR is not teratogenic and can therefore be safely used in pregnant or fertile women. Finally, ETR has an excellent drug-drug interaction profile, which may be useful in patients administered other medications. This interaction profile may be especially important in areas with a high prevalence of methadone treatment, as both drugs can be coadministered safely. ETR has received approval as advanced rescue therapy. However, the characteristics of this drug suggest that it may be useful in a series of potential indications, due to its antiviral potency, differential resistance profile, safety, tolerability and drug-drug interaction profile.

[Etravirine in special populations]

The choice of antiretroviral treatment in comorbidities requires thorough knowledge of the interactions, pharmacokinetics and adverse effects of the drug to be used. Most drugs carry some risk in certain processes associated or not with HIV infection and drugs that can be used in these situations are of great interest. The development of etravirine, a new non-nucleoside reverse transcriptase inhibitor, will allow its use in these processes, with a lower risk of secondary effects and therefore of worsening the course of the disease and of treatment withdrawal. This is the case of patients coinfected with active hepatitis B and/or C virus and patients with a history of psychiatric disorders or receiving psychotropic drugs. The possible use of etravirine in women of fertile age is also of interest, due to the lower risk of teratogenicity if pregnancy occurs during treatment. Other collectives, such as patients with renal insufficiency or children and adolescents should not be forgotten; although these populations are less well studied, data are beginning to become available.

Triple-class HIV antiretroviral therapy failure in an Australian primary care setting

Objective: To determine the prevalence, characteristics and virological outcomes of triple-class antiretroviral drug failure (TCF) and triple-class virological failure (TCVF) in HIV-infected patients attending an Australian high caseload primary care clinic. Methods: Cross-sectional observational study using a retrospective review of electronic medical records from 1007 patients with HIV attending Holdsworth House Medical Practice in Darlinghurst, Australia, between 2007 and 2008. TCF was defined as failure (virological, immunological, clinical, intolerance or other) of at least one drug in each of the three major classes of highly active antiretroviral therapy. Results: A total of 51 patients (5.1%) with TCF were identified. Of these patients, 31.4% had experienced virological failure of each of the three main drug classes. Eighty-eight percent of patients with TCF and 75% of patients with TCVF had achieved virological suppression (HIV RNA <400 copies mL–1). Total mean (s.d.) duration on antiretroviral therapy (ART) was 12.2 (3.3) years, with patients receiving an average of 18 antiretroviral drugs during this period. Reasons for treatment change included intolerance (88% of patients), virological failure (84%), immunological failure (24%) and poor adherence (20%). Conclusions: The prevalence of TCF and TCVF in patients with long-term HIV infection and extensive antiretroviral experience is low in primary care sites. Despite experiencing failure to the three main classes of ART, successful virological outcomes are still achievable in the majority of such patients.

Initiating and maintaining HAART - aiming for the long term in treatment-naive patients

Efficacy and durability are particularly important when choosing highly active antiretroviral therapy (HAART) for treatment-naive patients with HIV, alongside long-term safety and tolerability, special circumstances (such as pregnancy) and risk of cardiovascular disease. Regimens containing non-nucleoside reverse transcriptase inhibitors (NNRTIs), including nevirapine (NVP), are as effective as efavirenz, and avoiding NVP in patients with CD4 cell counts >250 cells/mL (women) or >400 cells/mL (men) can prevent hepatotoxicity. In women who become pregnant while already on HAART, the current regimen should be maintained unless it involves potentially teratogenic drugs. Pregnancy is not an independent risk factor for developing liver enzyme elevations or rash with NVP. High levels of low-density lipoprotein (LDL) cholesterol should be controlled to a target, with HAART modified if it is suspected to be increasing the LDL. The European AIDS Clinical Society rate NVP as the drug with the lowest metabolic impact among the NNRTIs and other classes of antiretroviral therapy.

Once-daily atazanavir/ritonavir versus twice-daily lopinavir/ritonavir, each in combination with tenofovir and emtricitabine, for management of antiretroviral-naive HIV-1-infected patients: 48 week efficacy and safety results of the CASTLE study

BACKGROUND

Atazanavir/ritonavir is as effective as lopinavir/ritonavir, with a more favourable lipid profile and less gastrointestinal toxicity, in treatment-experienced HIV-1-infected patients. We compared these two combinations directly in treatment-naive patients.

METHODS

In this open-label, international non-inferiority study, 883 antiretroviral-naive, HIV-1-infected patients were randomly assigned to receive atazanavir/ritonavir 300/100 mg once daily (n=440) or lopinavir/ritonavir 400/100 mg twice daily (n=443), in combination with fixed-dose tenofovir/emtricitabine 300/200 mg once daily. Randomisation was done with a computer-generated centralised randomisation schedule and was stratified by baseline levels of HIV RNA (viral load) and geographic region. The primary endpoint was the proportion of patients with viral load less than 50 copies per mL at week 48. The main efficacy analysis was done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00272779.

FINDINGS

At week 48, 343 (78%) of 440 patients receiving atazanavir/ritonavir and 338 (76%) of 443 patients receiving lopinavir/ritonavir had achieved a viral load of less than 50 copies per mL (difference 1.7%, 95% CI -3.8 to 7.1). Mean increases from baseline in CD4 cell count were similar (203 cells per muL in the atazanavir/ritonavir group vs 219 cells per muL in the lopinavir/ritonavir group). 25 (6%) patients in the atazanavir/ritonavir group and 26 (6%) in the lopinavir/ritonavir group were virological failures by week 48. Only two patients, both in the atazanavir/ritonavir group, had non-polymorphic protease inhibitor resistance mutations emerge on treatment, which conferred phenotypic resistance to atazanavir in one patient. Serious adverse events were noted in 51 (12%) of 441 patients in the atazanavir/ritonavir group and in 42 (10%) of 437 patients in the lopinavir/ritonavir group. Fewer patients in the atazanavir/ritonavir group than in the lopinavir/ritonavir group experienced grade 2-4 treatment-related diarrhoea (10 [2%] vs 50 [11%]) and nausea (17 [4%] vs 33 [8%]). Grade 2-4 jaundice was seen in 16 (4%) of 441 patients in the atazanavir/ritonavir group versus none of 437 patients in the lopinavir/ritonavir group; grade 3-4 increases in total bilirubin were seen in 146 (34%) of 435 patients on atazanavir/ritonavir and in one (<1%) of 431 patients on lopinavir/ritonavir.

INTERPRETATION

In treatment-naive patients, atazanavir/ritonavir once-daily demonstrated similar antiviral efficacy to lopinavir/ritonavir twice-daily, with less gastrointestinal toxicity but with a higher rate of hyperbilirubinaemia.