Accumulation of HIV-1 drug resistance after continued virological failure on first-line ART in adults and children in sub-Saharan Africa

Objectives Limited availability of viral load (VL) monitoring in HIV treatment programmes in sub-Saharan Africa can delay switching to second-line ART, leading to the accumulation of drug resistance mutations (DRMs). The objective of this study was to evaluate the accumulation of resistance to reverse transcriptase inhibitors after continued virological failure on first-line ART, among adults and children in sub-Saharan Africa. Methods HIV-1-positive adults and children on an NNRTI-based first-line ART were included. Retrospective VL and, if VL ≥1000 copies/mL, pol genotypic testing was performed. Among participants with continued virological failure (≥2 VL ≥1000 copies/mL), drug resistance was evaluated. Results At first virological failure, DRM(s) were detected in 87% of participants: K103N (38.7%), G190A (21.8%), Y181C (20.2%), V106M (8.4%), K101E (8.4%), any E138 (7.6%) and V108I (7.6%) associated with NNRTIs, and M184V (69.7%), any thymidine analogue mutation (9.2%), K65R (5.9%) and K70R (5.0%) associated with NRTIs. New DRMs accumulated with an average rate of 1.45 (SD 2.07) DRM per year; 0.62 (SD 1.11) NNRTI DRMs and 0.84 (SD 1.38) NRTI DRMs per year, respectively. The predicted susceptibility declined significantly after continued virological failure for all reverse transcriptase inhibitors (all P < 0.001). Acquired drug resistance patterns were similar in adults and children. Conclusions Patterns of drug resistance after virological failure on first-line ART are similar in adults and children in sub-Saharan Africa. Improved VL monitoring to prevent accumulation of mutations, and new drug classes to construct fully active regimens, are required

Previous antiretroviral drug use compromises standard first-line HIV therapy and is mediated through drug-resistance

In ART programs in sub-Saharan Africa, a growing proportion of HIV-infected persons initiating first-line antiretroviral therapy (ART) have a history of prior antiretroviral drug use (PAU). We assessed the effect of PAU on the risk of pre-treatment drug resistance (PDR) and virological failure (VF) in a multicountry cohort of HIV-infected adults initiated on a standard non-nucleoside reverse transcriptase inhibitor (NNRTI)-based first-line ART. Multivariate logistic regression was used to assess the associations between PAU, PDR and VF (defined as viral load ≥400 cps/mL). Causal mediation analysis was used to assess the proportion of the effect of PAU on VF that could be eliminated by intervening on PDR. Of 2737 participants, 122 (4.5%) had a history of PAU. Participants with PAU had a 7.2-fold (95% CI 4.4-11.7) risk of carrying PDR and a 3.1-fold (95% CI 1.6-6.1) increased risk of VF, compared to antiretroviral-naïve participants. Controlling for PDR would eliminate nearly half the effect of PAU on the risk of VF. Patients with a history of PAU are at increased risk of ART failure, which is to a large extent attributable to PDR. These findings support the recent WHO recommendations for use of differentiated, non-NNRTI-based empiric first-line therapy in patients with PAU

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

© 2017 Boerma R S et al; licensee International AIDS Society. 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 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

Accumulation of HIV-1 drug resistance after continued virological failure on first-line ART in adults and children in sub-Saharan Africa

Objectives Limited availability of viral load (VL) monitoring in HIV treatment programmes in sub-Saharan Africa can delay switching to second-line ART, leading to the accumulation of drug resistance mutations (DRMs). The objective of this study was to evaluate the accumulation of resistance to reverse transcriptase inhibitors after continued virological failure on first-line ART, among adults and children in sub-Saharan Africa. Methods HIV-1-positive adults and children on an NNRTI-based first-line ART were included. Retrospective VL and, if VL ≥1000 copies/mL, pol genotypic testing was performed. Among participants with continued virological failure (≥2 VL ≥1000 copies/mL), drug resistance was evaluated. Results At first virological failure, DRM(s) were detected in 87% of participants: K103N (38.7%), G190A (21.8%), Y181C (20.2%), V106M (8.4%), K101E (8.4%), any E138 (7.6%) and V108I (7.6%) associated with NNRTIs, and M184V (69.7%), any thymidine analogue mutation (9.2%), K65R (5.9%) and K70R (5.0%) associated with NRTIs. New DRMs accumulated with an average rate of 1.45 (SD 2.07) DRM per year; 0.62 (SD 1.11) NNRTI DRMs and 0.84 (SD 1.38) NRTI DRMs per year, respectively. The predicted susceptibility declined significantly after continued virological failure for all reverse transcriptase inhibitors (all P  Conclusions Patterns of drug resistance after virological failure on first-line ART are similar in adults and children in sub-Saharan Africa. Improved VL monitoring to prevent accumulation of mutations, and new drug classes to construct fully active regimens, are required

Previous antiretroviral drug use compromises standard first-line HIV therapy and is mediated through drug-resistance

In ART programs in sub-Saharan Africa, a growing proportion of HIV-infected persons initiating first-line antiretroviral therapy (ART) have a history of prior antiretroviral drug use (PAU). We assessed the effect of PAU on the risk of pre-treatment drug resistance (PDR) and virological failure (VF) in a multicountry cohort of HIV-infected adults initiated on a standard non-nucleoside reverse transcriptase inhibitor (NNRTI)-based first-line ART. Multivariate logistic regression was used to assess the associations between PAU, PDR and VF (defined as viral load ≥400 cps/mL). Causal mediation analysis was used to assess the proportion of the effect of PAU on VF that could be eliminated by intervening on PDR. Of 2737 participants, 122 (4.5%) had a history of PAU. Participants with PAU had a 7.2-fold (95% CI 4.4-11.7) risk of carrying PDR and a 3.1-fold (95% CI 1.6-6.1) increased risk of VF, compared to antiretroviral-naïve participants. Controlling for PDR would eliminate nearly half the effect of PAU on the risk of VF. Patients with a history of PAU are at increased risk of ART failure, which is to a large extent attributable to PDR. These findings support the recent WHO recommendations for use of differentiated, non-NNRTI-based empiric first-line therapy in patients with PAU

The relative contributions of HIV drug resistance, nonadherence and low-level viremia to viremic episodes on antiretroviral therapy in sub-Saharan Africa

Introduction: To achieve viral suppression among more than 90% of people on antiretroviral therapy (ART), improved understanding is warranted of the modifiable causes of HIV viremic episodes. We assessed the relative contributions of drug-resistance, nonadherence and low-level viremia (LLV) (viral load 50–999 cps/ml) on viremic episodes in sub-Saharan Africa. Methods: In a multicountry adult cohort initiating nonnucleoside reverse transcriptase inhibitor-based first-line ART, viremic episodes (viral load ≥1000 cps/ml) were classified as first, viral nonsuppression at 12 months; second, virological rebound at 24 months (after initial viral suppression at 12 months); third, failure to achieve viral resuppression at 24 months (after viremic episode at 12 months). We used adjusted odds ratios from multivariable logistic regression to estimate attributable fractions for each risk factor. Results: Of 2737 cohort participants, 1935 had data on pretreatment drug resistance (PDR) and at least 1 viral load outcome. Viral nonsuppression episodes [173/1935 (8.9%)] were attributable to nonadherence in 30% (35% in men vs. 24% in women) and to PDR to nonnucleoside reverse transcriptase inhibitors in 10% (15% in women vs. 6% in men). Notably, at contemporary PDR prevalences of 10–25%, PDR would explain 13–30% of viral nonsuppression. Virological rebound episodes [96/1515 (6.3%)] were mostly attributable to LLV (29%) and nonadherence (14%), and only rarely to PDR (1.1%). Failures to achieve viral resuppression [66/81 (81.5%)] were mostly attributable to the presence of acquired drug resistance (34%) and only rarely to nonadherence (2.4%). Conclusion: Effective adherence interventions could substantially reduce viral nonsuppression (especially in men) and virological rebound (especially during LLV), but would have limited effect on improving viral resuppression. Alternative ART regimens could circumvent PDR and acquired resistance.</p

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 &gt;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 &lt; .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 &lt; .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

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