Protease Inhibitor Resistance Is Uncommon in HIV-1 Subtype C Infected Patients on Failing Second-Line Lopinavir/r-Containing Antiretroviral Therapy in South Africa

Viral suppression after failure of PI-based ART among adolescents and youths with and without drug resistance mutations: a longitudinal analysis in Tanzania

BACKGROUND

People living with HIV (PLHIV) who fail first-line ART have a higher risk of failing subsequent ART. We examined viral suppression (VS) among adolescents and youths (AY) failing PI ART in Tanzania.

METHODS

We conducted a retrospective study nested within a national third-line cohort of PLHIV. We analysed data of 147 AY (aged 10-24 years) with failure of PI-based ART between 2020 and 2022 who were followed for 12 months to assess for VS. Descriptive statistics were summarized by demographics and clinical characteristics, and we used logistic regression to assess factors associated with virological failure (VF) and drug resistance mutations (DRMs).

RESULTS

More than 40% of 147 participants had HIV subtype A, 52% (76/147) harboured major PI DRMs and 35% had NRTI mutations. A PI regimen at ART initiation was associated with a major PI DRM adjusted relative risk (aRR) of 1.66 (95% CI: 1.13-2.44; P = 0.010). Among participants with major PI DRMs, 12.2% had intermediate to high levels of resistance to lopinavir and atazanavir, and 2.1% to darunavir, respectively. V82A was the most frequent PI DRM; NRTI mutations included thymidine analogue mutations and absent K65R. VS occurred in 65% of AY who had PI DRMs compared with 45% of those without DRMs; this difference was not statistically significant.

CONCLUSIONS

More than half of AY who had PI DRMs had a higher proportion of early VS (65%) compared with those without DRMs (45%). Optimal viral load monitoring, adherence intensification and routine drug resistance testing are key strategies to improve VS.

Virologic outcomes with tenofovir-lamivudine-dolutegravir in adults failing PI-based second-line ART

Background

In South African antiretroviral guidelines, selected patients failing second-line protease inhibitor (PI)-based therapy qualify for genotypic resistance testing - those with PI resistance receive darunavir-based third-line regimens; those without PI resistance continue current regimen with adherence support. The Western Cape province, from September 2020, implemented a strategy of tenofovir-lamivudine-dolutegravir (TLD) for patients, provided there was no tenofovir resistance, irrespective of PI resistance.

Objectives

To evaluate virologic outcomes with TLD among adults failing second-line PI regimens with no tenofovir resistance.

Method

An observational cohort study comparing outcomes in patients switched to TLD with those continuing the same PI or switched to darunavir-based regimens. Follow-up was until virologic suppression (HIV-1 RNA < 400 copies/mL), or at the point of censoring.

Results

One hundred and thirty-three patients switched to TLD, 101 to darunavir-based regimens, and 121 continued with the same PI. By 12 months, among patients with PI resistance, 42/47 (89%) in the TLD group had HIV-1 RNA < 400 copies/mL compared to 91/99 (92%) in the darunavir group (hazard ratio, 1.11; 95% confidence interval, 0.77-1.60). In patients without PI resistance, 66/86 (77%) in the TLD group had HIV-1 RNA < 400 copies/mL compared to 42/120 (35%) in those continuing with the same PI (hazard ratio, 4.03; 95% confidence interval, 2.71-5.98). Two patients receiving TLD developed virologic failure with high-level dolutegravir resistance.

Conclusion

Amongst patients failing second-line PI with no PI resistance, switching to TLD was associated with higher virologic suppression, likely due to improved adherence. Virologic outcomes were similar in patients with PI resistance switched to darunavir-based regimens or TLD.

Treatment-Experienced Patients on Third-Line Therapy: A Retrospective Cohort of Treatment Outcomes at the HIV Advanced Treatment Centre, University Teaching Hospital, Zambia

Antiretroviral therapy (ART) uptake continues to increase across sub-Saharan Africa and emergence of drug-resistant HIV mutations poses significant challenges to management of treatment-experienced patients with virologic failure. In Zambia, new third-line ART (TLART) guidelines including use of dolutegravir (DTG) were introduced in 2018. We assessed virologic suppression, immunologic response, and HIV drug-resistant mutations (DRMs) among patients on TLART at the University Teaching Hospital (UTH) in Lusaka, Zambia. We conducted a retrospective review of patients enrolled at UTH on TLART for >6 months between January 2010 and June 30, 2021. CD4 and HIV viral load (VL) at TLART initiation and post-initiation were assessed to determine virologic and immunologic outcomes. Regression analysis using bivariate and multivariate methods to describe baseline characteristics, virologic, and immunologic response to TLART was performed. A total of 345 patients met inclusion criteria; women comprised 57.6% (199/345) of the cohort. Median age at HIV diagnosis was 30 (interquartile range: 17.3-36.8). In 255 (73.8%) patients with at least two VLs, VL decreased from mean of 3.45 log₁₀ copies/mL (standard deviation [SD]: 2.02) to 1.68 log₁₀ copies/mL (SD: 1.79). Common ARVs prescribed included DTG (89.9%), tenofovir disoproxil fumarate (68.7%), and darunavir boosted with ritonavir (66.4%); 170 (49.3%) patients had genotypes; mutations consisted of 88.8% nucleoside reverse transcriptase inhibitor, 86.5% non-nucleoside reverse transcriptase inhibitor, and 55.9% protease inhibitor. VL suppression to <1,000 copies/mL was achieved in 225 (78.9%) patients. DRM frequency ranged from 56% to 89% depending on drug class. Treatment-experienced patients receiving TLART in Zambia achieved high rates of suppression despite high proportions of HIV mutations illustrating TLART effectiveness in the DTG era.

Potential Associations of Mutations within the HIV-1 Env and Gag Genes Conferring Protease Inhibitor (PI) Drug Resistance

An increasing number of patients in Africa are experiencing virological failure on a second-line antiretroviral protease inhibitor (PI)-containing regimen, even without resistance-associated mutations in the protease region, suggesting a potential role of other genes in PI resistance. Here, we investigated the prevalence of mutations associated with Lopinavir/Ritonavir (LPV/r) failure in the Envelope gene and the possible coevolution with mutations within the Gag-protease (gag-PR) region. Env and Gag-PR sequences generated from 24 HIV-1 subtype C infected patients failing an LPV/r inclusive treatment regimen and 344 subtype C drug-naïve isolates downloaded from the Los Alamos Database were analyzed. Fisher’s exact test was used to determine the differences in mutation frequency. Bayesian network probability was applied to determine the relationship between mutations occurring within the env and gag-PR regions and LPV/r treatment. Thirty-five mutations in the env region had significantly higher frequencies in LPV/r-treated patients. A combination of Env and Gag-PR mutations was associated with a potential pathway to LPV/r resistance. While Env mutations were not directly associated with LPV/r resistance, they may exert pressure through the Gag and minor PR mutation pathways. Further investigations using site-directed mutagenesis are needed to determine the impact of Env mutations alone and in combination with Gag-PR mutations on viral fitness and LPV/r efficacy.

Increased acquired protease inhibitor drug resistance mutations in minor HIV-1 quasispecies from infected patients suspected of failing on national second-line therapy in South Africa

BACKGROUND

HIV-1C has been shown to have a greater risk of virological failure and reduced susceptibility towards boosted protease inhibitors (bPIs), a component of second-line combination antiretroviral therapy (cART) in South Africa. This study entailed an evaluation of HIV-1 drug resistance-associated mutations (RAMs) among minor viral populations through high-throughput sequencing genotypic resistance testing (HTS-GRT) in patients on the South African national second-line cART regimen receiving bPIs.

METHODS

During 2017 and 2018, 67 patient samples were sequenced using high-throughput sequencing (HTS), of which 56 samples were included in the final analysis because the patient's treatment regimen was available at the time of sampling. All patients were receiving bPIs as part of their cART. Viral RNA was extracted, and complete pol genes were amplified and sequenced using Illumina HiSeq2500, followed by bioinformatics analysis to quantify the RAMs according to the Stanford HIV Drug Resistance Database.

RESULTS

Statistically significantly higher PI RAMs were observed in minor viral quasispecies (25%; 14/56) compared to non-nucleoside reverse transcriptase inhibitors (9%; 5/56; p = 0.042) and integrase inhibitor RAM (4%; 2/56; p = 0.002). The majority of the drug resistance mutations in the minor viral quasispecies were observed in the V82A mutation (n = 13) in protease and K65R (n = 5), K103N (n = 7) and M184V (n = 5) in reverse transcriptase.

CONCLUSIONS

HTS-GRT improved the identification of PI and reverse transcriptase inhibitor (RTI) RAMs in second-line cART patients from South Africa compared to the conventional GRT with ≥20% used in Sanger-based sequencing. Several RTI RAMs, such as K65R, M184V or K103N and PI RAM V82A, were identified in < 20% of the population. Deep sequencing could be of greater value in detecting acquired resistance mutations early.

Diverse Human Immunodeficiency Virus-1 Drug Resistance Profiles at Screening for ACTG A5288: A Study of People Experiencing Virologic Failure on Second-line Antiretroviral Therapy in Resource-limited Settings

BACKGROUND

Human immunodeficiency virus (HIV) drug resistance profiles are needed to optimize individual patient management and to develop treatment guidelines. Resistance profiles are not well defined among individuals on failing second-line antiretroviral therapy (ART) in low- and middle-income countries (LMIC).

METHODS

Resistance genotypes were performed during screening for enrollment into a trial of third-line ART (AIDS Clinical Trials Group protocol 5288). Prior exposure to both nucleoside reverse transcriptase inhibitors (NRTIs) and non-NRTIs and confirmed virologic failure on a protease inhibitor-containing regimen were required. Associations of drug resistance with sex, age, treatment history, plasma HIV RNA, nadir CD4+T-cell count, HIV subtype, and country were investigated.

RESULTS

Plasma HIV genotypes were analyzed for 653 screened candidates; most had resistance (508 of 653; 78%) to 1 or more drugs. Genotypes from 133 (20%) showed resistance to at least 1 drug in a drug class, from 206 (32%) showed resistance to at least 1 drug in 2 drug classes, and from 169 (26%) showed resistance to at least 1 drug in all 3 commonly available drug classes. Susceptibility to at least 1 second-line regimen was preserved in 59%, as were susceptibility to etravirine (78%) and darunavir/ritonavir (97%). Susceptibility to a second-line regimen was significantly higher among women, younger individuals, those with higher nadir CD4+ T-cell counts, and those who had received lopinavir/ritonavir, but was lower among prior nevirapine recipients.

CONCLUSIONS

Highly divergent HIV drug resistance profiles were observed among candidates screened for third-line ART in LMIC, ranging from no resistance to resistance to 3 drug classes. These findings underscore the need for access to resistance testing and newer antiretrovirals for the optimal management of third-line ART in LMIC.

A retrospective descriptive investigation of adult patients receiving third-line antiretroviral therapy in the North West province, South Africa

Background

Greater access and prolonged exposure to ART may inevitably lead to more treatment failure and increase the need for third-line ART (TLART) in a resource-limited setting.

Objective

To describe characteristics and resistance patterns of adult patients initiated on TLART in three districts of the North West province.

Method

All-inclusive retrospective descriptive investigation. Demographics and clinical variables were recorded from adult patient health records (2002-2017) and analysed.

Results

21 Patients (17 females, 4 males) with median (IQR) age of 34 years (30.2-37.8) at HIV diagnosis and 45 years (39.5–47) at TLART initiation were included. Median duration (days) from HIV diagnosis to first-line ART initiation was 101 (37-367), treatment duration on first-line, second-line and between second-line failure and TLART initiation were: 1 269 (765–2 343); 1 512 (706-2096) and 71 (58-126) days respectively.

High-level resistance most prevalent were: nelfinavir/r (85.7%), indinavir/r (80.9%), lopinavir/r (76.2%), emtricitabine and lamivudine (95.2%), nevirapine (76.2%) and efavirenz (71.4%). Resistance to 3 major PI mutations in 95% of patients and cross resistance were documented extensively.

Conclusion

This study support the need for earlier resistance testing. It firstly reported on time duration post diagnosis on various ART regimens and secondly resistance patterns of adults before TLART was initiated in these districts.

Drug Resistance Mutations Against Protease, Reverse Transcriptase and Integrase Inhibitors in People Living With HIV-1 Receiving Boosted Protease Inhibitors in South Africa

The South African national combination antiretroviral therapy (cART) roll-out program started in 2006, with over 4.4 million people accessing treatment since it was first introduced. HIV-1 drug resistance can hamper the success of cART. This study determined the patterns of HIV-1 drug-resistance associated mutations (RAMs) in People Living with HIV-1 (PLHIV-1). Receiving first (for children below 3 years of age) and second-line (for adults) cART regimens in South Africa. During 2017 and 2018, 110 patients plasma samples were selected, 96 samples including those of 17 children and infants were successfully analyzed. All patients were receiving a boosted protease inhibitor (bPI) as part of their cART regimen. The viral sequences were analyzed for RAMs through genotypic resistance testing. We performed genotypic resistance testing (GRT) for Protease inhibitors (PIs), Reverse transcriptase inhibitors (RTIs) and Integrase strand transfer inhibitors (InSTIs). Viral sequences were subtyped using REGAv3 and COMET. Based on the PR/RT sequences, HIV-1 subtypes were classified as 95 (99%) HIV-1 subtype C (HIV-1C) while one sample as 02_AG. Integrase sequencing was successful for 89 sequences, and all the sequences were classified as HIV-1C (99%, 88/89) except one sequence classified CRF02_AG, as observed in PR/RT. Of the 96 PR/RT sequences analyzed, M184V/I (52/96; 54%) had the most frequent RAM nucleoside reverse transcriptase inhibitor (NRTI). The most frequent non-nucleoside reverse transcriptase inhibitor (NNRTI) RAM was K103N/S (40/96, 42%). Protease inhibitor (PI) RAMs M46I and V82A were present in 12 (13%) of the sequences analyzed. Among the InSTI major RAM two (2.2%) sequences have Y143R and T97A mutations while one sample had T66I. The accessory RAM E157Q was identified in two (2.2%). The data indicates that the majority of the patients failed on bPIs didn't have any mutation; therefore adherence could be major issue in these groups of individuals. We propose continued viral load monitoring for better management of infected PLHIV.

Zimbabwe's national third-line antiretroviral therapy program: Cohort description and treatment outcomes

Background

In 2015, Zimbabwe introduced third-line antiretroviral therapy (ART) through four designated treatment centers; three government clinics in Harare and Bulawayo, and Newlands Clinic (NC), operated by a private voluntary organization in Harare. We describe characteristics of patients receiving third line ART and analyzed treatment outcomes in this national programme as of 31 December 2018.

Methods

We described the population using proportions for categorical variables, and medians and interquartile ranges for continuous variables. Patients from NC, where data were more complete, were followed from the date of starting third-line ART until death, transfer, loss to follow up or 31 December 2018.

Results

A total of 209 patients had ever received third-line ART: 124 at NC and 85 from the three government clinics. HIV genotype results were available for 89 (72%) patients at NC and fourteen (16.5%) patients in the government clinics. Median duration of third line ART (years) in the government clinics was 2.3 (IQR:0.6–3.4), 1.3 (IQR: 0.7–1.7) and 1 (0.6–1.9). Of the 67 patients who received third line ART in the government clinics for at least six months, 53 (79%) had most recent viral load (VL) < 1000 copies/ml. Data on other treatment outcomes from government clinics were incomplete.

From NC: a total of 109 (88%) patients were still in care, 13 (10.5%) had died and 2 (1.5%) were transferred. Median duration of third-line ART was 1.4 years (IQR: 0.6–2.8). Among the 111 NC patients who had received third-line ART for at least 6 months, 83 (75%) had a VL <50 copies/ml and 106 (95.5%) had a VL <1000 copies/ml.

Conclusion

Our findings demonstrate that, with comprehensive care, patients failing second-line ART can achieve high rates of virological suppression on third-line regimens. There is need to decentralize the provision of third-line ART in Zimbabwe. More needs to be done to improve completeness of data in the government clinics.

Third-Line Antiretroviral Therapy Program in the South African Public Sector: Cohort Description and Virological Outcomes

Background:

The World Health Organization recommends that antiretroviral therapy (ART) programs in resource-limited settings develop third-line ART policies. South Africa developed a national third-line ART program for patients who have failed both first-line non-nucleoside reverse transcriptase inhibitor–based ART and second-line protease inhibitor (PI)-based ART. We report on this program.

Methods:

Third-line ART in South Africa is accessed through a national committee that assesses eligibility and makes individual regimen recommendations. Criteria for third-line include the following: ≥1 year on PI-based ART with virologic failure, despite adherence optimization, and genotypic antiretroviral resistance test showing PI resistance. We describe baseline characteristics and resistance patterns of this cohort and present longitudinal data on virological suppression rates.

Results:

Between August 2013 and July 2014, 144 patients were approved for third-line ART. Median age was 41 years [interquartile range (IQR): 19–47]; 60% were women (N = 85). Median CD4⁺ count and viral load were 172 (IQR: 128–351) and 14,759 (IQR: 314–90,378), respectively. About 2.8% started PI-based ART before 2004; 11.1% from 2004 to 2007; 31.3% from 2008 to 2011; and 6.3% from 2012 to 2014 (48.6% unknown start date). Of the 144 patients, 97% and 98% had resistance to lopinavir and atazanavir, respectively; 57% had resistance to darunavir. All were initiated on a regimen containing darunavir, with raltegravir in 101, and etravirine in 33. Among those with at least 1 viral load at least 6 months after third-line approval (n = 118), a large proportion (83%, n = 98) suppressed to <1000 copies per milliliter, and 79% (n = 93) to <400 copies per milliliter.

Conclusion:

A high proportion of third-line patients with follow-up viral loads are virologically suppressed.

A Clinical Prediction Rule for Protease Inhibitor Resistance in Patients Failing Second-Line Antiretroviral Therapy

BACKGROUND

Most adults with virological failure on second-line antiretroviral therapy (ART) in resource-limited settings have no major protease inhibitor (PI) resistance mutations. Therefore, empiric switches to third-line ART would waste resources. Genotypic antiretroviral resistance testing (GART) is expensive and has limited availability. A clinical prediction rule (CPR) for PI resistance could rationalize access to GART.

SETTING

A private sector ART cohort, South Africa.

METHODS

We identified adults with virologic failure on ritonavir-boosted lopinavir/atazanavir-based ART and GART. We constructed a multivariate logistic regression model including age, sex, PI duration, short-term adherence (using pharmacy claims), concomitant CYP3A4-inducing drugs, and viral load at time of GART. We selected variables for the CPR using a stepwise approach and internally validated the model by bootstrapping.

RESULTS

148/339 (44%) patients had PI resistance (defined as ≥ 1 major resistance mutation to current PI). The median age was 42 years (interquartile range 36-48), 212 (63%) were females, 308 (91%) were on lopinavir/ritonavir, and median PI duration was 2.6 years (interquartile range 1.6-4.7). Variables associated with PI resistance and included in the CPR were age {adjusted odds ratio (aOR) 1.96 (95% confidence interval [CI]: 1.42 to 2.70) for 10-year increase}, PI duration (aOR 1.14 [95% CI: 1.03 to 1.26] per year), and adherence (aOR 1.22 [95% CI: 1.12 to 1.33] per 10% increase). The CPR model had a c-statistic of 0.738 (95% CI: 0.686 to 0.791).

CONCLUSIONS

Older patients with high adherence and prolonged PI exposure are most likely to benefit from GART to guide selection of a third-line ART regimen. Our CPR to select patients for GART requires external validation before implementation.

Drug resistance and optimizing dolutegravir regimens for adolescents and young adults failing antiretroviral therapy

OBJECTIVES

The integrase strand inhibitor dolutegravir (DTG) combined with tenofovir and lamivudine (TLD) is a single tablet regimen recommended for 1st, 2nd and 3rd-line public health antiretroviral therapy (ART). We determined drug resistance mutations (DRMs) and evaluated the predictive efficacy of a TLD containing regimen for viremic adolescents and young adults in Harare, Zimbabwe.

METHODS

We sequenced plasma viral RNA from HIV-1-infected adolescents and young adults on 1st and 2nd-line ART with confirmed virologic failure (viral load >1000 copies/ml) and calculated total genotypic susceptibility scores to current 2nd, 3rd line and DTG regimens.

RESULTS

A total of 160 participants were genotyped; 112 (70%) on 1st line and 48 (30%) on 2nd line, median (interquartile range) age 18 (15-19) and duration of ART (interquartile range) was 6 (4-8) years. Major DRMs were present in 94 and 67% of 1st and 2nd-line failures, respectively (P < 0.001). Dual class resistance to nucleotide reverse transcriptase inhibitors and nonnucleotide reverse transcriptase inhibitors was detected in 96 (60%) of 1st-line failures; protease inhibitor DRMs were detected in a minority (10%) of 2nd-line failures. A total genotypic susceptibility score of 2 or less may risk protease inhibitor or DTG monotherapy in 11 and 42% of 1st-line failures switching to 2nd-line protease inhibitor and TLD respectively.

CONCLUSION

Among adolescents and young adults, current protease inhibitor-based 2nd-line therapies are poorly tolerated, more expensive and adherence is poor. In 1st-line failure, implementation of TLD for many adolescents and young adults on long-term ART may require additional active drug(s). Drug resistance surveillance and susceptibility scores may inform strategies for the implementation of TLD.

Third-line antiretroviral therapy in low-income and middle-income countries (ACTG A5288): a prospective strategy study

BACKGROUND

Antiretroviral therapy (ART) management is challenging for individuals in resource-limited settings presenting for third-line treatment because of complex resistance patterns, partly due to reduced access to viral load monitoring. We aimed to evaluate use of newer antiretroviral drugs and contemporary management approaches, including population-based sequencing, to select appropriate antiretrovirals, plasma viral load monitoring, and interventions to improve adherence in individuals presenting with second-line viral failure.

METHODS

A5288 was a phase 4, third-line ART strategy study done at 19 urban sites in ten countries that enrolled adult participants with confirmed plasma HIV-1 RNA (viral load) of 1000 copies per mL or more after more than 24 weeks of protease inhibitor-based second-line ART. The primary objective was to use antiretrovirals (raltegravir, etravirine, and ritonavir-boosted darunavir) and diagnostic monitoring technologies, including viral load, genotyping, and adherence support to achieve viral load suppression (defined as ≤200 copies per mL) in 65% or more of participants. ART history and real-time drug resistance genotypes were used to assign participants to one of four cohorts: cohort A (no lopinavir resistance) stayed on second-line ART and cohorts B (B1, best available nucleoside reverse transcriptase inhibitors [NRTIs] plus ritonavir-boosted darunavir plus raltegravir; B2, ritonavir-boosted darunavir plus raltegravir plus etravirine; B3, ritonavir-boosted darunavir, raltegravir, and either tenofovir plus emtricitabine or tenofovir plus lamivudine), C (ritonavir-boosted darunavir plus raltegravir plus tenofovir-emtricitabine or tenofovir plus lamivudine), and D (best available NRTIs plus ritonavir-boosted darunavir plus raltegravir) were defined by increasing levels of resistance and received appropriate regimens, including new antiretrovirals. Participants in Cohort B without detectable hepatitis B surface antigen were assigned by blocked randomisation to cohorts B1 and B2, and those with detectable hepatitis B surface antigen were assigned to cohort B3. The trial is registered with ClinicalTrials.gov, number NCT01641367.

FINDINGS

From Jan 10, 2013, to Sept 10, 2015, 545 participants were enrolled. 287 (53%) were assigned to cohort A, 74 (14%) to B1, 72 (13%) to B2, eight (1%) to B3, 70 (13%) to C, and 34 (6%) to D. Overall, 349 (64%, 95% CI 60-68) participants achieved viral suppression at week 48, with proportions varying from 125 (44%) of 287 in cohort A to 65 (88%) of 74 in cohort B1, 63 (88%) of 72 in B2, eight (100%) of eight in B3, 63 (90%) of 70 in C, and 25 (74%) of 34 in D. Participants in cohort A remained on their second-line protease inhibitor, and had the most participants with grade 3 or higher adverse events (147 [51%]).

INTERPRETATION

Targeted real-time genotyping to select third-line ART can appropriately allocate more costly antiretrovirals to those with greater levels of HIV drug resistance.

FUNDING

National Institutes of Health.

Brief Report: Assessing the Association Between Changing NRTIs When Initiating Second-Line ART and Treatment Outcomes

BACKGROUND

After first-line antiretroviral therapy failure, the importance of change in nucleoside reverse transcriptase inhibitor (NRTI) in second line is uncertain due to the high potency of protease inhibitors used in second line.

SETTING

We used clinical data from 6290 adult patients in South Africa and Zambia from the International Epidemiologic Databases to Evaluate AIDS (IeDEA) Southern Africa cohort.

METHODS

We included patients who initiated on standard first-line antiretroviral therapy and had evidence of first-line failure. We used propensity score-adjusted Cox proportional-hazards models to evaluate the impact of change in NRTI on second-line failure compared with remaining on the same NRTI in second line. In South Africa, where viral load monitoring was available, treatment failure was defined as 2 consecutive viral loads >1000 copies/mL. In Zambia, it was defined as 2 consecutive CD4 counts <100 cells/mm.

RESULTS

Among patients in South Africa initiated on zidovudine (AZT), the adjusted hazard ratio for second-line virologic failure was 0.25 (95% confidence interval: 0.11 to 0.57) for those switching to tenofovir (TDF) vs. remaining on AZT. Among patients in South Africa initiated on TDF, switching to AZT in second line was associated with reduced second-line failure (adjusted hazard ratio = 0.35 [95% confidence interval: 0.13 to 0.96]). In Zambia, where viral load monitoring was not available, results were less conclusive.

CONCLUSIONS

Changing NRTI in second line was associated with better clinical outcomes in South Africa. Additional clinical trial research regarding second-line NRTI choices for patients initiated on TDF or with contraindications to specific NRTIs is needed.

Research on the treatment effects and drug resistances of long-term second-line antiretroviral therapy among HIV-infected patients from Henan Province in China

Background

HIV/AIDS patients who fail to respond to first-line treatment protocols are switched to second-line ART. Identifying factors that influence effective second-line treatment can improve utilization of limited medical resources. We investigated the efficacy of long-term second-line anti-retroviral therapy (ART) after first-line virologic failure as well as the impact of non-nucleotide reverse transcriptase inhibitor (NNRTI), nucleotide reverse transcriptase inhibitor (NRTI), and protease inhibitor (PI) resistance mutations and medication adherence on ineffective viral suppression.

Methods

A total of 120 patients were evaluated at 6, 12, 18, 24, and 48 months after initiation of second-line ART; a paper questionnaire was administered via a face-to-face interview and venous blood samples were collected. CD4⁺ T cell count, viral load, and drug resistance genotypes were quantified.

Results

CD4⁺ T cell counts increased from 170 cells/μL (IQR 100–272) at baseline to 359 cells/μL (IQR 236–501) after 48 months of second-line treatment. Viral load (log₁₀) decreased from 4.58 copies/mL (IQR 3.96–5.17) to 1.00 copies/mL (IQR 1.00–3.15). After switching to second-line ART, nine patients newly acquired the NRTI drug-resistant mutation, M184 V/I. No major PI resistance mutations were detected. Logistical regression analysis indicated that medication adherence < 90% in the previous month was associated with ineffective viral suppression; baseline high/low/moderate level resistance to 3TC/TDF was protective towards effective viral suppression.

Conclusions

Long-term second line ART was effective in the Henan region of China. Drug resistance mutations to NRTIs were detected in patients receiving second-line ART, suggesting that drug resistance surveillance should be continued to prevent the spread of resistant strains. Patient medication adherence supervision and management should be strengthened to improve the efficacy of antiviral treatment.

Effectiveness of Protease Inhibitor/Nucleos(t)ide Reverse Transcriptase Inhibitor-Based Second-line Antiretroviral Therapy for the Treatment of Human Immunodeficiency Virus Type 1 Infection in Sub-Saharan Africa: A Systematic Review and Meta-analysis

Background

In sub-Saharan Africa, 25.5 million people are living with human immunodeficiency virus (HIV), representing 70% of the global total. The need for second-line antiretroviral therapy (ART) is projected to increase in the next decade in keeping with the expansion of treatment provision. Outcome data are required to inform policy.

Methods

We performed a systematic review and meta-analysis of studies reporting the virological outcomes of protease inhibitor (PI)-based second-line ART in sub-Saharan Africa. The primary outcome was virological suppression (HIV-1 RNA <400 copies/mL) after 48 and 96 weeks of treatment. The secondary outcome was the proportion of patients with PI resistance. Pooled aggregate data were analyzed using a DerSimonian-Laird random effects model.

Results

By intention-to-treat analysis, virological suppression occurred in 69.3% (95% confidence interval [CI], 58.2%-79.3%) of patients at week 48 (4558 participants, 14 studies), and in 61.5% (95% CI, 47.2%-74.9%) at week 96 (2145 participants, 8 studies). Preexisting resistance to nucleos(t)ide reverse transcriptase inhibitors (NRTIs) increased the likelihood of virological suppression. Major protease resistance mutations occurred in a median of 17% (interquartile range, 0-25%) of the virological failure population and increased with duration of second-line ART.

Conclusions

One-third of patients receiving PI-based second-line ART with continued NRTI use in sub-Saharan Africa did not achieve virological suppression, although among viremic patients, protease resistance was infrequent. Significant challenges remain in implementation of viral load monitoring. Optimizing definitions and strategies for management of second-line ART failure is a research priority.

Prospero Registration

CRD42016048985.

High quality of life, treatment tolerability, safety and efficacy in HIV patients switching from triple therapy to lopinavir/ritonavir monotherapy: A randomized clinical trial

Trial design

The QoLKAMON study evaluated quality of life, efficacy and treatment safety in HIV patients receiving lopinavir/ritonavir in monotherapy (MT) versus continuing combined antiretroviral triple treatment with a boosted protease inhibitor (TT).

Methods

This was a 24-week, open-label, multicentre study in virologically-suppressed HIV-infected participants (N = 225) with a 2:1 randomization: 146 patients who switched to MT were compared with 79 patients who remained on a TT regimen. The primary endpoint was change in patient-reported outcomes in quality of life as measured by the MOS-HIV and EQ-5D questionnaires. Secondary endpoints included treatment adherence, patient satisfaction, incidence of adverse events and differences in plasma HIV-1 RNA viral load (VL) and CD4 cell counts.

Results

Baseline quality of life, measured with the MOS-HIV score, was very good (overall score of 83 ± 10.5 in the MT arm and 82.3 ± 11.3 in the TT arm) and suffered no change during the study in any of the arms (at week 24, 83.5 ± 12.2 in MT arm and 81.9 ± 12.7 in TT arm), without statistically significant differences when compared. In regards to adherence to therapy and patient satisfaction, some aspects (number of doses forgotten in the last week and satisfaction of treatment measured with the CESTA score, dimension 1) improved significantly with MT. There were also no differences in the incidence and severity of adverse events, even though 22.8% of those in the MT arm switched their treatment when they were included in the study. Moreover, there was also no significant difference between the immunological and virological evolution of MT and TT. In the MT arm, the VL was always undetectable in 83% of patients (vs 90.7% in the TT arm) and there were only 6.7% of virological failures with VL > 50 copies/mL (vs 2.3% in the TT arm), without resistance mutations and with resuppression of VL after switching back to TT.

Conclusions

In a new clinical trial, monotherapy as a treatment simplification strategy in HIV-1 infected patients with sustained viral suppression has demonstrated quality of life, safety and efficacy profiles comparable to those of conventional triple therapy regimens.

HIV-1 Drug Resistance and Third-Line Therapy Outcomes in Patients Failing Second-Line Therapy in Zimbabwe

OBJECTIVES

To analyze the patterns and risk factors of HIV drug resistance mutations among patients failing second-line treatment and to describe early treatment responses to recommended third-line antiretroviral therapy (ART) in a national referral HIV clinic in Zimbabwe.

METHODS

Patients on boosted protease inhibitor (PI) regimens for more than 6 months with treatment failure confirmed by 2 viral load (VL) tests >1000 copies/mL were genotyped, and susceptibility to available antiretroviral drugs was estimated by the Stanford HIVdb program. Risk factors for major PI resistance were assessed by logistic regression. Third-line treatment was provided as Darunavir/r, Raltegravir, or Dolutegravir and Zidovudine, Abacavir Lamivudine, or Tenofovir.

RESULTS

Genotypes were performed on 86 patients who had good adherence to treatment. The median duration of first- and second-line ART was 3.8 years (interquartile range [IQR], 2.3-5.1) and 2.6 years (IQR, 1.6-4.9), respectively. The median HIV viral load and CD4 cell count were 65 210 copies/mL (IQR, 8728-208 920 copies/mL) and 201 cells/mm3 (IQR, 49-333 cells/mm3). Major PI resistance-associated mutations (RAMs) were demonstrated in 44 (51%) non-nucleoside reverse transcriptase inhibitor RAMs in 72 patients (83%) and nucleoside reverse transcriptase inhibitors RAMs in 62 patients (72%). PI resistance was associated with age >24 years (P = .003) and CD4 cell count <200 cells/mm3 (P = .007). In multivariable analysis, only age >24 years was significantly associated (adjusted odds ratio, 4.75; 95% confidence interval, 1.69-13.38; P = .003) with major PI mutations. Third-line DRV/r- and InSTI-based therapy achieved virologic suppression in 29/36 patients (81%) after 6 months.

CONCLUSIONS

The prevelance of PI mutations was high. Adolescents and young adults had a lower risk of acquiring major PI resistance mutations, possibly due to poor adherence to ART. Third-line treatment with a regimen of Darunavir/r, Raltegravir/Dolutegravir, and optimized nucleoside reverse transcriptase inhibitors was effective.

Multicentre analysis of second-line antiretroviral treatment in HIV-infected children: adolescents at high risk of failure

Introduction: The number of HIV-infected children and adolescents requiring second-line antiretroviral treatment (ART) is increasing in low- and middle-income countries (LMIC). However, the effectiveness of paediatric second-line ART and potential risk factors for virologic failure are poorly characterized. We performed an aggregate analysis of second-line ART outcomes for children and assessed the need for paediatric third-line ART.

Methods: We performed a multicentre analysis by systematically reviewing the literature to identify cohorts of children and adolescents receiving second-line ART in LMIC, contacting the corresponding study groups and including patient-level data on virologic and clinical outcomes. Kaplan–Meier survival estimates and Cox proportional hazard models were used to describe cumulative rates and predictors of virologic failure. Virologic failure was defined as two consecutive viral load measurements >1000 copies/ml after at least six months of second-line treatment.

Results: We included 12 cohorts representing 928 children on second-line protease inhibitor (PI)-based ART in 14 countries in Asia and sub-Saharan Africa. After 24 months, 16.4% (95% confidence interval (CI): 13.9–19.4) of children experienced virologic failure. Adolescents (10–18 years) had failure rates of 14.5 (95% CI 11.9–17.6) per 100 person-years compared to 4.5 (95% CI 3.4–5.8) for younger children (3–9 years). Risk factors for virologic failure were adolescence (adjusted hazard ratio [aHR] 3.93, p < 0.001) and short duration of first-line ART before treatment switch (aHR 0.64 and 0.53, p = 0.008, for 24–48 months and >48 months, respectively, compared to <24 months).

Conclusions: In LMIC, paediatric PI-based second-line ART was associated with relatively low virologic failure rates. However, adolescents showed exceptionally poor virologic outcomes in LMIC, and optimizing their HIV care requires urgent attention. In addition, 16% of children and adolescents failed PI-based treatment and will require integrase inhibitors to construct salvage regimens. These drugs are currently not available in LMIC.

Key Factors Influencing the Emergence of Human Immunodeficiency Virus Drug Resistance in Low- and Middle-Income Countries

The emergence and spread of human immunodeficiency virus (HIV) drug resistance from antiretroviral roll-out programs remain a threat to long-term control of the HIV-AIDS epidemic in low- and middle-income countries (LMICs). The patterns of drug resistance and factors driving emergence of resistance are complex and multifactorial. The key drivers of drug resistance in LMICs are reviewed here, and recommendations are made to limit their influence on antiretroviral therapy efficacy.

Virological Outcomes of Second-line Protease Inhibitor-Based Treatment for Human Immunodeficiency Virus Type 1 in a High-Prevalence Rural South African Setting: A Competing-Risks Prospective Cohort Analysis

Background

Second-line antiretroviral therapy (ART) based on ritonavir-boosted protease inhibitors (bPIs) represents the only available option after first-line failure for the majority of individuals living with human immunodeficiency virus (HIV) worldwide. Maximizing their effectiveness is imperative.

Methods

This cohort study was nested within the French National Agency for AIDS and Viral Hepatitis Research (ANRS) 12249 Treatment as Prevention (TasP) cluster-randomized trial in rural KwaZulu-Natal, South Africa. We prospectively investigated risk factors for virological failure (VF) of bPI-based ART in the combined study arms. VF was defined by a plasma viral load >1000 copies/mL ≥6 months after initiating bPI-based ART. Cumulative incidence of VF was estimated and competing risk regression was used to derive the subdistribution hazard ratio (SHR) of the associations between VF and patient clinical and demographic factors, taking into account death and loss to follow-up.

Results

One hundred one participants contributed 178.7 person-years of follow-up. Sixty-five percent were female; the median age was 37.4 years. Second-line ART regimens were based on ritonavir-boosted lopinavir, combined with zidovudine or tenofovir plus lamivudine or emtricitabine. The incidence of VF on second-line ART was 12.9 per 100 person-years (n = 23), and prevalence of VF at censoring was 17.8%. Thirteen of these 23 (56.5%) virologic failures resuppressed after a median of 8.0 months (interquartile range, 2.8-16.8 months) in this setting where viral load monitoring was available. Tuberculosis treatment was associated with VF (SHR, 11.50 [95% confidence interval, 3.92-33.74]; P < .001).

Conclusions

Second-line VF was frequent in this setting. Resuppression occurred in more than half of failures, highlighting the value of viral load monitoring of second-line ART. Tuberculosis was associated with VF; therefore, novel approaches to optimize the effectiveness of PI-based ART in high-tuberculosis-burden settings are needed.

Clinical Trials Registration

NCT01509508.

Treatment outcomes of over 1000 patients on second-line, protease inhibitor-based antiretroviral therapy from four public-sector HIV treatment facilities across Johannesburg, South Africa

Objectives

To report predictors of outcomes of second‐line ART for HIV treatment in a resource‐limited setting.

Methods

All adult ART‐naïve patients who initiated standard first‐line treatment between April 2004 and February 2012 at four public‐sector health facilities in Johannesburg, South Africa, experienced virologic failure and initiated standard second‐line therapy were included. We assessed predictors of attrition (death and loss to follow‐up [≥3 months late for a scheduled visit]) using Cox proportional hazards regression and predictors of virologic suppression (viral load <400 copies/ml ≥3 months after switch) using modified Poisson regression with robust error estimation at 1 year and ever after second‐line ART initiation.

Results

A total of 1236 patients switched to second‐line treatment in a median (IQR) of 1.9 (0.9‐4.6) months after first‐line virologic failure. Approximately 13% and 45% of patients were no longer in care at 1 year and at the end of follow‐up, respectively. Patients with low CD4 counts (<50 vs. ≥200, aHR: 1.85; 95% CI: 1.03–3.32) at second‐line switch were at greater risk for attrition by the end of follow‐up. About 75% of patients suppressed by 1 year, and 85% had ever suppressed by the end of follow‐up.

Conclusions

Patients with poor immune status at switch to second‐line ART were at greater risk of attrition and were less likely to suppress. Additional adherence support after switch may improve outcomes.

Prevalence of Antiretroviral Drug Resistance in Patients Who Are Not Responding to Protease Inhibitor-Based Treatment: Results From the First National Survey in South Africa

Limited data exist on human immunodeficiency virus type 1 (HIV-1) resistance in patients who are not responding to protease inhibitor (PI)-based regimens in resource-limited settings. This study assessed resistance profiles in adults across South Africa who were not responding to PI-based regimens. pol sequencing was undertaken and submitted to the Stanford HIV Drug Resistance Database. At least 1 major PI mutation was detected in 16.4% of 350 participants. A total of 53.4% showed intermediate resistance to darunavir/ritonavir, whereas high-level resistance was not observed. Only 5.2% and 32.8% of participants showed high-level and intermediate resistance to etravirine, respectively. Although the prevalence of major PI mutations was within previously reported ranges, most patients will likely experience virological suppression during receipt of currently available South African third-line regimens.

Human Immunodeficiency Virus-1 Sequence Changes and Drug Resistance Mutation Among Virologic Failures of Lopinavir/Ritonavir Monotherapy: AIDS Clinical Trials Group Protocol A5230

Background. The mechanism of virologic failure (VF) of lopinavir/ritonavir (LPV/r) monotherapy is not well understood. We assessed sequence changes in human immunodeficiency virus-1 reverse-transcriptase (RT) and protease (PR) regions.

Methods. Human immunodeficiency virus-1 pol sequences from 34 participants who failed second-line LPV/r monotherapy were obtained at study entry (SE) and VF. Sequence changes were evaluated using phylogenetic analysis and hamming distance.

Results. Human immunodeficiency virus-1 sequence change was higher over drug resistance mutation (DRM) sites (median genetic distance, 2.2%; Q1 to Q3, 2.1%–2.5%) from SE to VF compared with non-DRM sites (median genetic distance, 1.3%; Q1 to Q3, 1.0%–1.4%; P < .0001). Evolution over DRM sites was mainly driven by changes in the RT (median genetic distance, 2.7%; Q1 to Q3, 2.2%–3.2%) compared with PR (median genetic distance, 1.1%; Q1 to Q3, 0.0%–1.1%; P < .0001). Most RT DRMs present at SE were lost at VF. At VF, 19 (56%) and 26 (76%) were susceptible to efavirenz/nevirapine and etravirine (ETV)/rilpivirine (RPV), respectively, compared with 1 (3%) and 12 (35%) at SE. Participants who retained nonnucleoside reverse-transcriptase inhibitor (NNRTI) DRMs and those without evolution of LPV/r DRMs had significantly shorter time to VF.

Conclusions. The selection of LPV/r DRMs in participants with longer time to VF suggests better adherence and more selective pressure. Fading NNRTI mutations and an increase in genotypic susceptibility to ETV and RPV could allow for the reuse of NNRTI. Further studies are warranted to understand mechanisms of PR failure.

Protease Inhibitor Resistance in the First 3 Years of Second-Line Antiretroviral Therapy for HIV-1 in Sub-Saharan Africa

BACKGROUND

As antiretroviral therapy (ART) programs in sub-Saharan Africa mature, increasing numbers of persons with human immunodeficiency virus (HIV) infection will experience treatment failure, and require second- or third-line ART. Data on second-line failure and development of protease inhibitor (PI) resistance in sub-Saharan Africa are scarce.

METHODS

HIV-1-infected adults were included if they received >180 days of PI-based second-line ART. We assessed risk factors for having a detectable viral load (VL, ≥400 cps/mL) using Cox models. If VL was ≥1000 cps/mL, genotyping was performed.

RESULTS

Of 227 included participants, 14.6%, 15.2% and 11.1% had VLs ≥400 cps/mL at 12, 24, and 36 months, respectively. Risk factors for a detectable VL were as follows: exposure to nonstandard nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based (hazard ratio, 7.10; 95% confidence interval, 3.40-14.83; P < .001) or PI-based (7.59; 3.02-19.07; P = .001) first-line regimen compared with zidovudine/lamivudine/NNRTI, PI resistance at switch (6.69; 2.49-17.98; P < .001), and suboptimal adherence (3.05; 1.71-5.42; P = .025). Among participants with VLs ≥1000 cps/mL, 22 of 32 (69%) harbored drug resistance mutation(s), and 7 of 32 (22%) harbored PI resistance.

CONCLUSIONS

Although VL suppression rates were high, PI resistance was detected in 22% of participants with VLs ≥1000 cps/mL. To ensure long-term ART success, intensified support for adherence, VL and drug resistance testing, and third-line drugs will be necessary.

Random lopinavir concentrations predict resistance on lopinavir-based antiretroviral therapy

Considering that most patients who experience virological failure (VF) on lopinavir-based antiretroviral therapy (ART) fail due to poor adherence rather than resistance, an objective adherence measure could limit costs by rationalising the use of genotype antiretroviral resistance testing (GART) in countries with access to third-line ART. A cross-sectional study was conducted in a resource-limited setting at two large clinics in Kwazulu-Natal, South Africa, in patients experiencing VF (HIV-RNA > 1000 copies/mL) on lopinavir-based ART who had undergone GART. Associations between major protease inhibitor (PI) resistance mutations and random plasma lopinavir concentrations were explored. A total of 134 patients, including 31 children, were included in the analysis. The prevalence of patients with major PI resistance mutations was 20.9% (n = 28). A random lopinavir concentration above the recommended minimum trough of 1 µg/mL [adjusted odds ratio (aOR) = 5.81, 95% confidence interval (CI) 2.04-16.50; P = 0.001] and male sex (aOR = 3.19, 95% CI 1.22-8.33; P = 0.018) were predictive of the presence of at least one major PI resistance mutation. Random lopinavir concentrations of <1 µg/mL had a negative predictive value of 91% for major PI resistance mutations. Random lopinavir concentrations are strongly associated with the presence of major PI resistance mutations. Access to costly GART in patients experiencing VF on second-line ART could be restricted to patients with lopinavir concentrations above the recommended minimum trough of 1 µg/mL or, in areas where GART is unavailable, could be used as a criterion to empirically switch to third-line ART.

Contribution of Gag and Protease to HIV-1 Phenotypic Drug Resistance in Pediatric Patients Failing Protease Inhibitor-Based Therapy

Protease inhibitors (PIs) are used as a first-line regimen in HIV-1-infected children. Here we investigated the phenotypic consequences of amino acid changes in Gag and protease on lopinavir (LPV) and ritonavir (RTV) susceptibility among pediatric patients failing PI therapy. The Gag-protease from isolates from 20 HIV-1 subtype C-infected pediatric patients failing an LPV and/or RTV-based regimen was phenotyped using a nonreplicativein vitroassay. Changes in sensitivity to LPV and RTV relative to that of the matched baseline (pretherapy) sample were calculated. Gag and protease amino acid substitutions associated with PI failure were created in a reference clone by site-directed mutagenesis and assessed. Predicted phenotypes were determined using the Stanford drug resistance algorithm. Phenotypic resistance or reduced susceptibility to RTV and/or LPV was observed in isolates from 10 (50%) patients, all of whom had been treated with RTV. In most cases, this was associated with protease resistance mutations, but substitutions at Gag cleavage and noncleavage sites were also detected. Gag amino acid substitutions were also found in isolates from three patients with reduced drug susceptibilities who had wild-type protease. Site-directed mutagenesis confirmed that some amino acid changes in Gag contributed to PI resistance but only in the presence of major protease resistance-associated substitutions. The isolates from all patients who received LPV exclusively were phenotypically susceptible. Baseline isolates from the 20 patients showed a large (47-fold) range in the 50% effective concentration of LPV, which accounted for most of the discordance seen between the experimentally determined and the predicted phenotypes. Overall, the inclusion of thegaggene and the use of matched baseline samples provided a more comprehensive assessment of the effect of PI-induced amino acid changes on PI resistance. The lack of phenotypic resistance to LPV supports the continued use of this drug in pediatric patients.

Virological failure in patients with HIV-1 subtype C receiving antiretroviral therapy: an analysis of a prospective national cohort in Sweden

BACKGROUND

People with HIV-1 in low-income and middle-income countries increasingly need second-line regimens with boosted protease inhibitors. However, data are scarce for treatment response in patients with HIV-1 subtype C (HIV-1C), which is predominant in these regions. We aimed to examine factors associated with virological failure in patients in a standardised national health-care setting.

METHODS

We analysed data for participants in InfCare HIV, a prospective national cohort that includes more than 99% of people with HIV in Sweden. We extracted data for the cohort from the InfCare HIV database on Jan 14, 2015. Baseline was initiation of antiretroviral therapy. We used logistic regression to assess factors associated with primary virological failure (failure to suppress HIV-1 within 9 months) in patients with HIV-1B and HIV-1C and calculated odds ratios (OR) for failure. We also used Cox regression models to calculate hazard ratios (HR) for time-to-secondary virological failure (detectable viral load after initial virological suppression). We did homology-based molecular modelling to assess docking.

FINDINGS

We included 1077 patients with HIV-1B and 596 with HIV-1C. In multivariate regression analysis, pre-therapy higher viral load (OR 1·82, 95% CI 1·49-2·21; p<0·0001), subtype C infection (1·75, 1·06-2·88; p=0·028), and boosted protease inhibitor-based regimens (1·55, 1·45-2·11; p=0·004) were associated with increased risk of primary virological failure. Individuals with HIV-1C who were given therapy with boosted protease inhibitors had earlier time-to-secondary virological failure than did those with HIV-1B given similar regimens (adjusted HR 1·92, 95% CI 1·30-2·83; p=0·002). Molecular modelling suggested lower affinity for protease inhibitors to HIV-1C protease than to HIV-1B.

INTERPRETATION

Our findings suggest an increased risk of virological failure in patients with HIV-1C, especially in those on boosted protease inhibitor-based regimens. Future studies should further dissect the biochemical and viral mechanisms of resistance to protease inhibitors in patients with non-B subtypes of HIV-1, including clinical studies to assess the efficacy of boosted protease inhibitor-based regimens in low-income and middle income countries.

FUNDING

Karolinska Institutet Research Foundation, Swedish Research Council, Stockholm County Council, Swedish Physicians against AIDS, US National Institutes of Health, University of Missouri.

High prevalence of PI resistance in patients failing second-line ART in Vietnam

Background

There are limited data from resource-limited settings on antiretroviral resistance mutations that develop in patients failing second-line PI ART.

Methods

We performed a cross-sectional virological assessment of adults on second-line ART for ≥6 months between November 2006 and December 2011, followed by a prospective follow-up over 2 years of patients with virological failure (VF) at the Hospital for Tropical Diseases, Vietnam. VF was defined as HIV RNA concentrations ≥1000 copies/mL. Resistance mutations were identified by population sequencing of the pol gene and interpreted using the 2014 IAS-USA mutation list and the Stanford algorithm. Logistic regression modelling was performed to identify predictors of VF.

Results

Two hundred and thirty-one patients were enrolled in the study. The median age was 32 years; 81.0% were male, 95.7% were on a lopinavir/ritonavir-containing regimen and 22 (9.5%) patients had VF. Of the patients with VF, 14 (64%) carried at least one major protease mutation [median: 2 (IQR: 1–3)]; 13 (59%) had multiple protease mutations conferring intermediate- to high-level resistance to lopinavir/ritonavir. Mutations conferring cross-resistance to etravirine, rilpivirine, tipranavir and darunavir were identified in 55%, 55%, 45% and 27% of patients, respectively. Higher viral load, adherence <95% and previous indinavir use were independent predictors of VF. The 2 year outcomes of the patients maintained on lopinavir/ritonavir included: death, 7 (35%); worsening virological/immunological control, 6 (30%); and virological re-suppression, 5 (25%). Two patients were switched to raltegravir and darunavir/ritonavir with good HIV control.

Conclusions

High-prevalence PI resistance was associated with previous indinavir exposure. Darunavir plus an integrase inhibitor and lamivudine might be a promising third-line regimen in Vietnam.

Third-line antiretroviral therapy in Africa: effectiveness in a Southern African retrospective cohort study

BACKGROUND

An increasing number of patients in Africa are experiencing virologic failure on second-line antiretroviral therapy (ART) and those who develop resistance to protease inhibitors (PI) will require third-line ART, but no data on the outcomes of third-line are available from the region. We assessed the virologic outcomes and survival of patients started on salvage ART in a Southern African private sector disease management programme.

METHODS

Retrospective observational cohort study with linkage to the national death register. Adults (≥18 years) who started salvage ART between July 2007 and December 2011 were included. Salvage ART was defined by inclusion of darunavir or tipranavir in an ART regimen after having failed another PI. For Kaplan-Meier (KM) analysis, patients were followed up until event, or censored at death (only for virologic outcomes), leaving the programme, or April 2014.

RESULTS

152 patients were included. Subtype was known for 113 patients: 111 (98 %) were infected with subtype C. All 152 had a genotype resistance test demonstrating major PI resistance mutations. Salvage drugs included were: darunavir/ritonavir (n = 149), tipranavir/ritonavir (n = 3), raltegravir (n = 58), and etravirine (n = 8). Median follow-up was 2.5 years (IQR = 1.5-3.3). 82.9 % achieved a viral load ≤400 copies/ml and 71.1 % ≤50 copies/ml. By the end of the study 17 (11.2 %) of the patients had died. The KM estimate of cumulative survival was 87.2 % at 2000 days.

CONCLUSIONS

Virologic suppression was comparable to that demonstrated in clinical trials and observational studies of salvage ART drugs conducted in other regions. Few deaths occurred during short term follow-up. Third-line regimens for patients with multidrug resistant subtype C HIV in Africa are virologically and clinically effective.

Genetic Changes in HIV-1 Gag-Protease Associated with Protease Inhibitor-Based Therapy Failure in Pediatric Patients

Studies have shown a low frequency of HIV-1 protease drug resistance mutations in patients failing protease inhibitor (PI)-based therapy. Recent studies have identified mutations in Gag as an alternate pathway for PI drug resistance in subtype B viruses. We therefore genotyped the Gag and protease genes from 20 HIV-1 subtype C-infected pediatric patients failing a PI-based regimen. Major protease resistance mutations (M46I, I54V, and V82A) were identified in eight (40%) patients, as well as Gag cleavage site (CS) mutations (at codons 373, 374, 378, 428, 431, 449, 451, and 453) in nine (45%) patients. Four of these Gag CS mutations occurred in the absence of major protease mutations at PI failure. In addition, amino acid changes were noted at Gag non-CS with some predicted to be under HLA/KIR immune-mediated pressure and/or drug selection pressure. Changes in Gag during PI failure therefore warrant further investigation of the Gag gene and its role in PI failure in HIV-1 subtype C infection.

Short term adherence tool predicts failure on second line protease inhibitor-based antiretroviral therapy: an observational cohort study

Background

Most patients who experience virologic failure (VF) on second line antiretroviral therapy (ART) in low-middle income countries fail due to poor adherence rather than antiretroviral resistance. A simple adherence tool designed to detect VF would conserve resources by rationally limiting need for viral load (VL) testing and, in those countries with access to third line ART, the need for resistance testing.

Methods

We conducted an observational cohort study of patients who initiated second line ART at a clinic in Kwazulu-Natal, South Africa. Using clinical and pharmacy refill data extracted from the clinic’s electronic database, we determined risk factors for VF. Three different methods of calculating short term pharmacy refill adherence were evaluated and compared with long term adherence since second line initiation. We also explored the ability of differing durations of short term pharmacy refill to predict VF on second line ART.

Results

We included 274 patients with a median follow up of 27 months on second line ART. VF ranged between 3% and 16% within each six month interval after initiating second line ART. 243 patients with at least one VL after 4 months on second line were analysed in the statistical analysis. Pharmacy refill adherence assessed over shorter periods (4 to 6 months) predicted virologic suppression as well as pharmacy refill assessed over longer periods. The risk of VF fell 73% with each 10% increase in adherence measured from pharmacy refills over a 4 month period. Low CD4 count at second line ART initiation was a significant independent risk factor for VF.

Conclusion

Patients identified as poorly adherent by short term pharmacy refill are at risk for VF on second line ART. This pragmatic adherence tool could assist in identifying patients who require adherence interventions, and help rationalize use of VL monitoring and resistance testing among patients on second line ART.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0664-3) contains supplementary material, which is available to authorized users.

Effectiveness and cost-effectiveness of potential responses to future high levels of transmitted HIV drug resistance in antiretroviral drug-naive populations beginning treatment: modelling study and economic analysis

BACKGROUND

With continued roll-out of antiretroviral therapy (ART) in resource-limited settings, evidence is emerging of increasing levels of transmitted drug-resistant HIV. We aimed to compare the effectiveness and cost-effectiveness of different potential public health responses to substantial levels of transmitted drug resistance.

METHODS

We created a model of HIV transmission, progression, and the effects of ART, which accounted for resistance generation, transmission, and disappearance of resistance from majority virus in the absence of drug pressure. We simulated 5000 ART programmatic scenarios with different prevalence levels of detectable resistance in people starting ART in 2017 (t0) who had not previously been exposed to antiretroviral drugs. We used the model to predict cost-effectiveness of various potential changes in policy triggered by different prevalence levels of resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) measured in the population starting ART.

FINDINGS

Individual-level resistance testing before ART initiation was not generally a cost-effective option, irrespective of the cost-effectiveness threshold. At a cost-effectiveness threshold of US$500 per quality-adjusted life-year (QALY), no change in policy was cost effective (ie, no change in policy would involve paying less than $500 per QALY gained), irrespective of the prevalence of pretreatment NNRTI resistance, because of the increased cost of the policy alternatives. At thresholds of $1000 or higher, and with the prevalence of pretreatment NNRTI resistance greater than 10%, a policy to measure viral load 6 months after ART initiation became cost effective. The policy option to change the standard first-line treatment to a boosted protease inhibitor regimen became cost effective at a prevalence of NNRTI resistance higher than 15%, for cost-effectiveness thresholds greater than $2000.

INTERPRETATION

Cost-effectiveness of potential policies to adopt in response to different levels of pretreatment HIV drug resistance depends on competing budgetary claims, reflected in the cost-effectiveness threshold. Results from our model will help inform WHO recommendations on monitoring of HIV drug resistance in people starting ART.

FUNDING

WHO (with funds provided by the Bill & Melinda Gates Foundation), CHAIN (European Commission).

Antiretroviral therapy and efficacy after virologic failure on first-line boosted protease inhibitor regimens

BACKGROUND

Virologic failure (VF) on a first-line ritonavir-boosted protease inhibitor (PI/r) regimen is associated with low rates of resistance, but optimal management after failure is unknown.

METHODS

The analysis included participants in randomized trials who experienced VF on a first-line regimen of PI/r plus 2 nucleoside reverse transcriptase inhibitors (NRTIs) and had at least 24 weeks of follow-up after VF. Antiretroviral management and virologic suppression (human immunodeficiency virus type 1 [HIV-1] RNA <400 copies/mL) after VF were assessed.

RESULTS

Of 209 participants, only 1 participant had major PI-associated treatment-emergent mutations at first-line VF. The most common treatment approach after VF (66%) was to continue the same regimen. The virologic suppression rate 24 weeks after VF was 64% for these participants, compared with 72% for those who changed regimens (P = .19). Participants remaining on the same regimen had lower NRTI resistance rates (11% vs 30%; P = .003) and higher CD4(+) cell counts (median, 275 vs 213 cells/µL; P = .005) at VF than those who changed. Among participants remaining on their first-line regimen, factors at or before VF significantly associated with subsequent virologic suppression were achieving HIV-1 RNA <400 copies/mL before VF (odds ratio [OR], 3.39 [95% confidence interval {CI}, 1.32-8.73]) and lower HIV-1 RNA at VF (OR for <10 000 vs ≥10 000 copies/mL, 3.35 [95% CI, 1.40-8.01]). Better adherence after VF was also associated with subsequent suppression (OR for <100% vs 100%, 0.38 [95% CI, .15-.97]). For participants who changed regimens, achieving HIV-1 RNA <400 copies/mL before VF also predicted subsequent suppression.

CONCLUSIONS

For participants failing first-line PI/r with no or limited drug resistance, remaining on the same regimen is a reasonable approach. Improving adherence is important to subsequent treatment success.

Implementing HIV-1 genotypic resistance testing in antiretroviral therapy programs in Africa: needs, opportunities, and challenges

Tremendous progress has been made with the scale-up of antiretroviral therapy in Africa, with an estimated seven million people now receiving antiretroviral therapy in the region. The long-term success of antiretroviral therapy programs depends on appropriate strategies to deal with potential threats, one of which is the emergence and spread of antiretroviral drug resistance. Whilst public health surveillance forms the mainstay of the World Health Organization approach to antiretroviral drug resistance, there is likely to be increasing demand for access to drug resistance testing as programs mature and as HIV clinical management becomes more complex. African-owned research initiatives have helped to develop affordable resistance testing appropriate for use in the region, and have developed delivery models for resistance testing at different levels of the public health system. Some upper-middle-income countries such as Botswana and South Africa have introduced drug resistance testing for selected patient groups to guide clinical management. The scale-up of resistance testing will require substantial expansion of clinical and laboratory capacity in the region, but the expertise and resources exist in Africa to support this. The long-term population health impact and cost-effectiveness of resistance testing in the region will also require further investigation.

Accumulation of protease mutations among patients failing second-line antiretroviral therapy and response to salvage therapy in Nigeria

BACKGROUND

To date, antiretroviral therapy (ART) guidelines and programs in resource-limited settings (RLS) have focused on 1(st)- and 2(nd)-line (2 L) therapy. As programs approach a decade of implementation, policy regarding access to 3(rd)-line (3 L) ART is needed. We aimed to examine the impact of maintaining patients on failing 2 L ART on the accumulation of protease (PR) mutations.

METHODS AND FINDINGS

From 2004-2011, the Harvard/APIN PEPFAR Program provided ART to >100,000 people in Nigeria. Genotypic resistance testing was performed on a subset of patients experiencing 2 L failure, defined as 2 consecutive viral loads (VL)>1000 copies/mL after ≥6 months on 2 L. Of 6714 patients who received protease inhibitor (PI)-based ART, 673 (10.0%) met virologic failure criteria. Genotypes were performed on 61 samples. Patients on non-suppressive 2 L therapy for <12 months prior to genotyping had a median of 2 (IQR: 0-5) International AIDS Society (IAS) PR mutations compared with 5 (IQR: 0-6) among patients failing for >24 months. Patients developed a median of 0.6 (IQR: 0-1.4) IAS PR mutations per 6 months on failing 2 L therapy. In 38% of failing patients no PR mutations were present. For patients failing >24 months, high- or intermediate-level resistance to lopinavir and atazanavir was present in 63%, with 5% to darunavir.

CONCLUSIONS

This is the first report assessing the impact of duration of non-suppressive 2 L therapy on the accumulation of PR resistance in a RLS. This information provides insight into the resistance cost of failing to switch non-suppressive 2 L regimens and highlights the issue of 3 L access.

Emergence of HIV drug resistance during first- and second-line antiretroviral therapy in resource-limited settings

INTRODUCTION

Antiretroviral therapy (ART) in resource-limited settings has expanded in the last decade, reaching >8 million individuals and reducing AIDS mortality and morbidity. Continued success of ART programs will require understanding the emergence of HIV drug resistance patterns among individuals in whom treatment has failed and managing ART from both an individual and public health perspective. We review data on the emergence of HIV drug resistance among individuals in whom first-line therapy has failed and clinical and resistance outcomes of those receiving second-line therapy in resource-limited settings.

RESULTS

Resistance surveys among patients initiating first-line nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based therapy suggest that 76%-90% of living patients achieve HIV RNA suppression by 12 months after ART initiation. Among patients with detectable HIV RNA at 12 months, HIV drug resistance, primarily due to M184V and NNRTI mutations, has been identified in 60%-72%, although the antiretroviral activity of proposed second-line regimens has been preserved. Complex mutation patterns, including thymidine-analog mutations, K65R, and multinucleoside mutations, are prevalent among cases of treatment failure identified by clinical or immunologic methods. Approximately 22% of patients receiving second-line therapy do not achieve HIV RNA suppression by 6 months, with poor adherence, rather than HIV drug resistance, driving most failures. Major protease inhibitor resistance at the time of second-line failure ranges from 0% to 50%, but studies are limited.

CONCLUSIONS

Resistance of HIV to first-line therapy is predictable at 12 months when evaluated by means of HIV RNA monitoring and, when detected, largely preserves second-line therapy options. Optimizing adherence, performing resistance surveillance, and improving treatment monitoring are critical for long-term prevention of drug resistance.

Trends in Genotypic HIV-1 Antiretroviral Resistance between 2006 and 2012 in South African Patients Receiving First- and Second-Line Antiretroviral Treatment Regimens

Objectives

South Africa’s national antiretroviral (ARV) treatment program expanded in 2010 to include the nucleoside reverse transcriptase (RT) inhibitors (NRTI) tenofovir (TDF) for adults and abacavir (ABC) for children. We investigated the associated changes in genotypic drug resistance patterns in patients with first-line ARV treatment failure since the introduction of these drugs, and protease inhibitor (PI) resistance patterns in patients who received ritonavir-boosted lopinavir (LPV/r)-containing therapy.

Methods

We analysed ARV treatment histories and HIV-1 RT and protease mutations in plasma samples submitted to the Tygerberg Academic Hospital National Health Service Laboratory.

Results

Between 2006 and 2012, 1,667 plasma samples from 1,416 ARV-treated patients, including 588 children and infants, were submitted for genotypic resistance testing. Compared with 720 recipients of a d4T or AZT-containing first-line regimen, the 153 recipients of a TDF-containing first-line regimen were more likely to have the RT mutations K65R (46% vs 4.0%; p<0.001), Y115F (10% vs. 0.6%; p<0.001), L74VI (8.5% vs. 1.8%; p<0.001), and K70EGQ (7.8% vs. 0.4%) and recipients of an ABC-containing first-line regimen were more likely to have K65R (17% vs 4.0%; p<0.001), Y115F (30% vs 0.6%; p<0.001), and L74VI (56% vs 1.8%; p<0.001). Among the 490 LPV/r recipients, 55 (11%) had ≥1 LPV-resistance mutations including 45 (9.6%) with intermediate or high-level LPV resistance. Low (20 patients) and intermediate (3 patients) darunavir (DRV) cross resistance was present in 23 (4.6%) patients.

Conclusions

Among patients experiencing virological failure on a first-line regimen containing two NRTI plus one NNRTI, the use of TDF in adults and ABC in children was associated with an increase in four major non- thymidine analogue mutations. In a minority of patients, LPV/r-use was associated with intermediate or high-level LPV resistance with predominantly low-level DRV cross-resistance.

A pragmatic approach to HIV-1 drug resistance determination in resource-limited settings by use of a novel genotyping assay targeting the reverse transcriptase-encoding region only

In resource-limited settings (RLS), reverse transcriptase (RT) inhibitors form the backbone of first-line treatment regimens. We have developed a simplified HIV-1 drug resistance genotyping assay targeting the region of RT harboring all major RT inhibitor resistance mutation positions, thus providing all relevant susceptibility data for first-line failures, coupled with minimal cost and labor. The assay comprises a one-step RT-PCR amplification reaction, followed by sequencing using one forward and one reverse primer, generating double-stranded coverage of RT amino acids (aa) 41 to 238. The assay was optimized for all major HIV-1 group M subtypes in plasma and dried blood spot (DBS) samples using a panel of reference viruses for HIV-1 subtypes A to D, F to H, and circulating recombinant form 01_AE (CRF01_AE) and applied to 212 clinical plasma samples and 25 DBS samples from HIV-1-infected individuals from Africa and Europe. The assay was subsequently transferred to Uganda and applied locally on clinical plasma samples. All major HIV-1 subtypes could be detected with an analytical sensitivity of 5.00E+3 RNA copies/ml for plasma and DBS. Application of the assay on 212 clinical samples from African subjects comprising subtypes A to D, F to H (rare), CRF01_AE, and CRF02_AG at a viral load (VL) range of 6.71E+2 to 1.00E+7 (median, 1.48E+5) RNA copies/ml was 94.8% (n = 201) successful. Application on clinical samples in Uganda demonstrated a comparable success rate. Genotyping of clinical DBS samples, all subtype C with a VL range of 1.02E+3 to 4.49E+5 (median, 1.42E+4) RNA copies/ml, was 84.0% successful. The described assay greatly reduces hands-on time and the costs required for genotyping and is ideal for use in RLS, as demonstrated in a reference laboratory in Uganda and its successful application on DBS samples.

HIV-1 genetic diversity and drug resistance among Senegalese patients in the public health system

In this study, we investigated the prevalence of human immunodeficiency virus type 1 (HIV-1) drug resistance mutations and genetic variability among Senegalese patients undergoing highly active antiretroviral therapy (ART) in the public health system. We conducted a cross-sectional study of 72 patients with suspected therapeutic failure. HIV-1 genotyping was performed with Viroseq HIV-1 Genotyping System v2.0 or the procedure developed by the ANRS AC11 resistance study group, and a phylogenetic analysis was performed. The median follow-up visit was at 40 (range, 12 to 123) months, and the median viral load was 4.67 (range, 3.13 to 6.94) log(10) copies/ml. The first-line therapeutic regimen was nucleoside reverse transcriptase inhibitors (NRTIs) plus efavirenz (EFV) or NRTIs plus nevirapine (NVP) (54/72 patients; 75%), and the second-line therapy was NRTIs plus a protease inhibitor (PI/r) (18/72; 25%). Fifty-five patients (55/72; 76.39%) had at least one drug resistance mutation. The drug resistance rates were 72.22 and 88.89% for the first-line and second-line ARTs, respectively. In NRTI mutations, thymidine analog mutations (TAMs) were found in 50.79% and the M184V mutation was found in 34.92% of the samples. For non-NRTI resistance, we noted a predominance of the K103N mutation (46.27%). For PI/r, several cases of mutations were found with a predominance of M46I and L76V/F at 24% each. The phylogenetic analysis revealed CRF02_AG as the predominant circulating recombinant form (43/72; 59.72%). We found a high prevalence of resistance mutations and a high rate of TAMs among Senegalese patients in the public health system. These findings emphasize the need to improve virological monitoring in resource-limited settings.

Second-line antiretroviral therapy: long-term outcomes in South Africa

BACKGROUND

Currently, boosted protease inhibitor-containing regimens are the only option after first-line regimen failure available for patients in most resource-limited settings, yet little is known about long-term adherence and outcomes.

METHODS

We enrolled patients with virologic failure (VF) who initiated lopinavir/ritonavir-containing second-line antiretroviral therapy (ART). Medication possession ratios were calculated using pharmacy refill dates. Factors associated with 12-month second-line virologic suppression [viral load (VL) <50 copies/mL] and adherence were determined.

RESULTS

One hundred six patients (median CD4 count and VL at failure: 153 cells/mm(3) and 28,548 copies/mL, respectively) were enrolled. Adherence improved after second-line ART switch (median adherence 6 months prior, 67%; median adherence during initial 6 months of second-line ART, 100%; P = 0.001). Higher levels of adherence during second-line ART was associated with virologic suppression at month 12 of ART (odds ratio 2.5 per 10% adherence increase, 95% CI 1.3 to 4.8, P = 0.01). Time to virologic suppression was most rapid among patients with 91%-100% adherence compared with patients with 80%-90% and <80% adherence (log rank test, P = 0.01). VF during 24 months of second-line ART was moderate (month 12: 25%, n = 32/126; month 18: 21%, n = 23/112; and month 24: 25%, n = 25/99).

CONCLUSIONS

The switch to second-line ART in South Africa was associated with an improvement in adherence, however, a moderate ongoing rate of VF--among approximately 25% of patients receiving second-line ART patients at each follow-up interval--was a cause for concern. Adherence level was associated with second-line ART virologic outcome, helping explain why some patients achieved virologic suppression after switch and others did not.

Tenofovir in second-line ART in Zambia and South Africa: collaborative analysis of cohort studies

OBJECTIVES

Tenofovir (TDF) is increasingly used in second-line antiretroviral treatment (ART) in sub-Saharan Africa. We compared outcomes of second-line ART containing and not containing TDF in cohort studies from Zambia and the Republic of South Africa (RSA).

METHODS

Patients aged 16 years and older starting protease-inhibitor-based second-line ART in Zambia (1 cohort) and RSA (5 cohorts) were included. We compared mortality, immunological failure (all cohorts), and virological failure (RSA only) between patients receiving and not receiving TDF. Competing risk models and Cox models adjusted for age, sex, CD4 count, time on first-line ART, and calendar year were used to analyze mortality and treatment failure, respectively. Hazard ratios (HRs) were combined in fixed-effects meta-analysis.

FINDINGS

1687 patients from Zambia and 1556 patients from RSA, including 1350 (80.0%) and 206 (13.2%) patients starting TDF, were followed over 4471 person-years. Patients on TDF were more likely to have started second-line ART in recent years and had slightly higher baseline CD4 counts than patients not on TDF. Overall, 127 patients died, 532 were lost to follow-up, and 240 patients developed immunological failure. In RSA, 94 patients had virologic failure. Combined HRs comparing TDF with other regimens were 0.60 (95% confidence interval [CI]: 0.41 to 0.87) for immunologic failure and 0.63 (0.38-1.05) for mortality. The HR for virologic failure in RSA was 0.28 (0.09-0.90).

CONCLUSIONS

In this observational study, patients on TDF-containing second-line ART were less likely to develop treatment failure than patients on other regimens. TDF seems to be an effective component of second-line ART in southern Africa.

The clinical and economic impact of genotype testing at first-line antiretroviral therapy failure for HIV-infected patients in South Africa

BACKGROUND

In resource-limited settings, genotype testing at virologic failure on first-line antiretroviral therapy (ART) may identify patients with wild-type (WT) virus. After adherence counseling, these patients may safely and effectively continue first-line ART, thereby delaying more expensive second-line ART.

METHODS

We used the Cost-Effectiveness of Preventing AIDS Complications International model of human immunodeficiency virus (HIV) disease to simulate a South African cohort of HIV-infected adults at first-line ART failure. Two strategies were examined: no genotype vs genotype, assuming availability of protease inhibitor-based second-line ART. Model inputs at first-line ART failure were mean age 38 years, mean CD4 173/µL, and WT virus prevalence 20%; genotype cost was $300 per test and delay to results, 3 months. Outcomes included life expectancy, per-person costs (2010 US dollars), and incremental cost-effectiveness ratios (dollars per years of life saved [YLS]).

RESULTS

No genotype had a projected life expectancy of 106.1 months, which with genotype increased to 108.3 months. Per-person discounted lifetime costs were $16 360 and $16 540, respectively. Compared to no genotype, genotype was very cost-effective, by international guidance, at $900/YLS. The cost-effectiveness of genotype was sensitive to prevalence of WT virus (very cost-effective when prevalence ≥ 12%), CD4 at first-line ART failure, and ART efficacy. Genotype-associated delays in care ≥ 5 months decreased survival and made no genotype the preferred strategy. When the test cost was <$100, genotype became cost-saving.

CONCLUSIONS

Genotype resistance testing at first-line ART failure is very cost-effective in South Africa. The cost-effectiveness of this strategy will depend on prevalence of WT virus and timely response to genotype results.

Rates and predictors of failure of first-line antiretroviral therapy and switch to second-line ART in South Africa

OBJECTIVES

To measure rates and predictors of virologic failure and switch to second-line antiretroviral therapy (ART) in South Africa.

DESIGN

: Observational cohort study.

METHODS

We included ART-naive adult patients initiated on public sector ART (January 2000 to July 2008) at 5 sites in South Africa who completed ≥6 months of follow-up. We estimated cumulative risk of virologic failure (viral load ≥400 copies/mL with confirmation above varying thresholds) and switching to second-line ART.

RESULTS

Nineteen thousand six hundred forty-five patients (29,935 person-years) had a median of 1.3 years of study follow-up (1.8 years on ART) and a median CD4 count of 93 (IQR: 39-155) cells per microliter at ART initiation. About 9.9% (4.5 per 100 person-years) failed ART in median 16 (IQR: 12-23) months since ART initiation, with median 2.7 months (IQR: 1.6-4.7) months between first elevated and confirmatory viral loads. By survival analysis, using a confirmatory threshold of 400 copies per milliliter, 16.9% [95% confidence interval (CI): 15.4% to 18.6%] failed by 5 years on ART, but only 7.8% (95% CI: 6.6% to 9.3%) using a threshold of 10,000. CD4 <25 versus 100-199 (adjusted HR: 1.60; 95% CI: 1.37 to 1.87), ART initiation viral load ≥1,000,000 versus <10,000, (1.32; 0.91 to 1.93), and 2+ gaps in care versus 0 (95% CI: 7.25; 4.95 to 10.6) were predictive of failure. Overall, 10.1% (95% CI: 9.0% to 11.4%) switched to second-line by 5 years on ART. Lower CD4 at failure and higher rate of CD4 decline were predictive of switch (decline 100% to 51% versus 25% to -25%, adjusted HR: 1.96; 95% CI: 1.35 to 2.85).

CONCLUSIONS

In resource-limited settings with viral load monitoring, virologic failure rates are highly sensitive to thresholds for confirmation. Despite clear guidelines there is considerable variability in switching failing patients, partially in response to immunologic status and postfailure evolution.

HIV treatment and care in resource-constrained environments: challenges for the next decade

Many successes have been achieved in HIV care in low- and middle-income countries (LMIC): increased number of HIV-infected individuals receiving antiretroviral treatment (ART), wide decentralization, reduction in morbidity and mortality and accessibility to cheapest drugs. However, these successes should not hide existing failures and difficulties. In this paper, we underline several key challenges. First, ensure long-term financing, increase available resources, in order to meet the increasing needs, and redistribute the overall budget in a concerted way amongst donors. Second, increase ART coverage and treat the many eligible patients who have not yet started ART. Competition amongst countries is expected to become a strong driving force in encouraging the least efficient to join better performing countries. Third, decrease early mortality on ART, by improving access to prevention, case-finding and treatment of tuberculosis and invasive bacterial diseases and by getting people to start ART much earlier. Fourth, move on from WHO 2006 to WHO 2010 guidelines. Raising the cut-off point for starting ART to 350 CD4/mm³ needs changing paradigm, adopting opt-out approach, facilitating pro-active testing, facilitating task shifting and increasing staff recruitments. Phasing out stavudine needs acting for a drastic reduction in the costs of other drugs. Scaling up routine viral load needs a mobilization for lower prices of reagents and equipments, as well as efforts in relation to point-of-care automation and to maintenance. The latter is a key step to boost the utilization of second-line regimens, which are currently dramatically under prescribed. Finally, other challenges are to reduce lost-to-follow-up rates; manage lifelong treatment and care for long-term morbidity, including drug toxicity, residual AIDS and HIV-non-AIDS morbidity and aging-related morbidity; and be able to face unforeseen events such as socio-political and military crisis. An old African proverb states that the growth of a deep-rooted tree cannot be stopped. Our tree is well rooted in existing field experience and is, therefore, expected to grow. In order for us to let it grow, long-term cost-effectiveness approach and life-saving evidence-based programming should replace short-term budgeting approach.

Lopinavir/ritonavir monotherapy after virologic failure of first-line antiretroviral therapy in resource-limited settings

OBJECTIVE

To evaluate virologic response rates of lopinavir/ritonavir (LPV/r) monotherapy as second-line antiretroviral treatment (ART) among adults in resource-limited settings (RLSs).

DESIGN

An open-label pilot study of LPV/r monotherapy in participants on first-line nonnucleoside reverse transcriptase inhibitor three-drug combination ART with plasma HIV-1 RNA 1000-200 000  copies/ml.

METHODS

Participants were recruited from five sites in Africa and Asia within the AIDS Clinical Trials Group (ACTG) network. All participants received LPV/r 400/100  mg twice daily. The primary endpoint was remaining on LPV/r monotherapy without virologic failure at week 24. Participants with virologic failure were offered addition of emtricitabine and tenofovir (FTC/TDF) to LPV/r.

RESULTS

Mutations associated with drug resistance were encountered in nearly all individuals screened for the study. One hundred and twenty-three participants were enrolled, and 122 completed 24 weeks on study. A high proportion remained on LPV/r monotherapy without virologic failure at 24 weeks (87%). Archived samples with HIV-1 RNA levels less than 400  copies/ml at week 24 (n=102) underwent ultrasensitive assay. Of these individuals, 62 had levels less than 40  copies/ml and 30 had levels 40-200  copies/ml. Fifteen individuals experienced virologic failure, among whom 11 had resistance assessed and two had emergent protease inhibitor mutations. Thirteen individuals with virologic failure added FTC/TDF and one individual added FTC/TDF without virologic failure. At study week 48, 11 of 14 adding FTC/TDF had HIV-1 RNA levels less than 400  copies/ml.

CONCLUSION

In this pilot study conducted in diverse RLS, LPV/r monotherapy as second-line ART demonstrated promising activity.

Genotype assays and third-line ART in resource-limited settings: a simulation and cost-effectiveness analysis of a planned clinical trial

OBJECTIVES

To project the clinical and economic outcomes of a genotype assay for selection of third-line antiretroviral therapy (ART) in resource-limited settings, as per the planned international A5288 trial (MULTI-OCTAVE).

METHODS

We used the Cost-effectiveness of Preventing AIDS Complications (CEPAC)-International Model to compare three strategies for patients who have failed second-line ART in South Africa: sustained second-line: no genotype assay, all patients remain on second-line ART; A5288: genotype to determine the resistance profile and assign an appropriate regimen; or population-based third-line: no genotype, all patients switch to a potent third-line regimen. Model inputs are from published data in South Africa. Resistance profiles, ART regimens, and efficacy data were those used for trial planning.

RESULTS

Projected life expectancy for sustained second-line, A5288, and population-based third-line are 61.1, 103.8, and 104.2 months. Compared to sustained second-line ($12 ,460), per person lifetime costs increase for the A5288 ($39, 250) and population-based ($44, 120) strategies. The incremental cost-effectiveness ratio of A5288, compared to sustained second-line, is $7500/year of life saved (YLS), and for population-based third-line, compared to A5288, is $154 ,500/YLS. In the A5288 strategy, very late presentation to care, coupled with lengthy delays to obtain the genotype, dramatically reduces 5-year survival, making the population-based third-line strategy more attractive.

CONCLUSIONS

We project that, whereas the public health approach to third-line therapy is unaffordable, genotype assays and third-line ART in resource-limited settings will increase survival and be cost-effective compared to the population-based approach, supporting the value of an efficacy study.

Second-line antiretroviral therapy in a workplace and community-based treatment programme in South Africa: determinants of virological outcome

Background: As antiretroviral treatment (ART) programmes in resource-limited settings mature, more patients are experiencing virological failure. Without resistance testing, deciding who should switch to second-line ART can be difficult. The consequences for second-line outcomes are unclear. In a workplace- and community-based multi-site programme, with 6-monthly virological monitoring, we describe outcomes and predictors of viral suppression on second-line, protease inhibitor-based ART.

Methods: We used prospectively collected clinic data from patients commencing first-line ART between 1/1/03 and 31/12/08 to construct a study cohort of patients switched to second-line ART in the presence of a viral load (VL) ≥400 copies/ml. Predictors of VL<400 copies/ml within 15 months of switch were assessed using modified Poisson regression to estimate risk ratios.

Results: 205 workplace patients (91.7% male; median age 43 yrs) and 212 community patients (38.7% male; median age 36 yrs) switched regimens. At switch compared to community patients, workplace patients had a longer duration of viraemia, higher VL, lower CD4 count, and higher reported non-adherence on first-line ART. Non-adherence was the reported reason for switching in a higher proportion of workplace patients. Following switch, 48.3% (workplace) and 72.0% (community) achieved VL<400, with non-adherence (17.9% vs. 1.4%) and virological rebound (35.6% vs. 13.2% with available measures) reported more commonly in the workplace programme. In adjusted analysis of the workplace programme, lower switch VL and younger age were associated with VL<400. In the community programme, shorter duration of viraemia, higher CD4 count and transfers into programme on ART were associated with VL<400.

Conclusion: High levels of viral suppression on second-line ART can be, but are not always, achieved in multi-site treatment programmes with both individual- and programme-level factors influencing outcomes. Strategies to support both healthcare workers and patients during this switch period need to be evaluated; sub-optimal adherence, particularly in the workplace programme must be addressed.

Virologic failure of protease inhibitor-based second-line antiretroviral therapy without resistance in a large HIV treatment program in South Africa

BACKGROUND

We investigated the prevalence of wild-type virus (no major drug resistance) and drug resistance mutations at second-line antiretroviral treatment (ART) failure in a large HIV treatment program in South Africa.

METHODOLOGY/ PRINCIPAL FINDINGS

HIV-infected patients ≥ 15 years of age who had failed protease inhibitor (PI)-based second-line ART (2 consecutive HIV RNA tests >1000 copies/ml on lopinavir/ritonavir, didanosine, and zidovudine) were identified retrospectively. Patients with virologic failure were continued on second-line ART. Genotypic testing for drug resistance was performed on frozen plasma samples obtained closest to and after the date of laboratory confirmed second-line ART failure. Of 322 HIV-infected patients on second-line ART, 43 were adults with confirmed virologic failure, and 33 had available plasma for viral sequencing. HIV-1 RNA subtype C predominated (n = 32, 97%). Mean duration on ART (SD) prior to initiation of second-line ART was 23 (17) months, and time from second-line ART initiation to failure was 10 (9) months. Plasma samples were obtained 7(9) months from confirmed failure. At second-line failure, 22 patients (67%) had wild-type virus. There was no major resistance to PIs found. Eleven of 33 patients had a second plasma sample taken 8 (5.5) months after the first. Median HIV-1 RNA and the genotypic resistance profile were unchanged.

CONCLUSIONS/ SIGNIFICANCE

Most patients who failed second-line ART had wild-type virus. We did not observe evolution of resistance despite continuation of PI-based ART after failure. Interventions that successfully improve adherence could allow patients to continue to benefit from second-line ART therapy even after initial failure.