Comparative risk of failure of ABC/3TC or TDF/FTC based first-line regimens in patients with a high viral load

Virologic Outcomes Among People Living With Human Immunodeficiency Virus With High Pretherapy Viral Load Burden Initiating on Common Core Agents

Background

People living with human immunodeficiency virus (PLWH) initiating antiretroviral therapy (ART) with viral loads (VLs) ≥100 000 copies/mL are less likely to achieve virologic success, but few studies have characterized real-world treatment outcomes.

Methods

ART-naive PLWH with VLs ≥100 000 copies/mL initiating dolutegravir (DTG), elvitegravir (EVG), raltegravir (RAL), or darunavir (DRV) between 12 August 2013 and 31 July 2017 were identified from the OPERA database. Virologic failure was defined as (i) 2 consecutive VLs ≥200 copies/mL after 36 weeks of ART; (ii) 1 VL ≥200 copies/mL with core agent discontinuation after 36 weeks; (iii) 2 consecutive VLs ≥200 copies/mL after suppression (≤50 copies/mL) before 36 weeks; or (iv) 1 VL ≥200 copies/mL with discontinuation after suppression before 36 weeks. Cox modeling estimated the association between regimen and virologic failure.

Results

There were 2038 ART-naive patients with high VL who initiated DTG (36%), EVG (46%), DRV (16%), or RAL (2%). Median follow-up was 18.1 (interquartile range, 12.4–28.9) months. EVG and DTG initiators were similar at baseline, but RAL initiators were older and more likely to be female with low CD4 cell counts while DRV initiators differed notably on factors associated with treatment failure. Virologic failure was experienced by 9.2% DTG, 13.2% EVG, 18.4% RAL, and 18.8% DRV initiators. Compared to DTG, the adjusted hazard ratio (95% confidence interval) was 1.46 (1.05–2.03) for EVG, 2.24 (1.50–3.34) for DRV, and 4.13 (1.85–9.24) for RAL.

Conclusions

ART-naive PLWH with high VLs initiating on DTG were significantly less likely to experience virologic failure compared to EVG, RAL, and DRV initiators.

Antiretroviral therapy-naïve people living with HIV (PLWH) initiating therapy with viral loads ≥100,000 copies/mL varied markedly at baseline. In adjusted models, PLWH initiating dolutegravir-based regimens were less likely to experience virologic failure as compared to elvitegravir, raltegravir and darunavir initiators.

Cascade of care and factors associated with virological suppression among HIV-positive persons linked to care in the Test and Keep in Care (TAK) project

Introduction

Early treatment remains the most effective HIV prevention strategy; poor linkage to care after HIV diagnosis may compromise this benefit. We sought to better understand patient characteristics and their association with virological suppression (VS) following cART initiation.

Methods

The TAK project collects pre-linkage to care and clinical data on patients diagnosed with HIV in voluntary testing facilities in central Poland. Data collected for persons diagnosed in 2010–2013 were linked with HIV clinic records. Individuals linked to care who commenced cART were followed from until the earliest of first VS (HIV RNA < 50 copies/ml), last visit, death or 6 January 2016. Cox-proportional hazard models were used to identify factors associated with first viral suppression.

Results

232 persons were HIV positive, 144 (62%, 95% CI 55, 68%) linked to care, 116 (81% of those linked to care, 95% CI 73, 87%) started cART during follow up, of which 113 (97%, 95% CI 93, 99%) achieved VS. Non-PI based regimen (for integrase inhibitors aHR: 5.03: 1.90, 13.32) and HLA B5701-positive (aHR: 3.97: 1.33, 11.85) were associated with higher chance of VS. Unknown syphilis status (aHR: 0.27: 0.13, 0.57) and higher HIV RNA (aHR a tenfold increase: 0.56: 0.42, 0.75) remained associated with lower chance of VS.

Conclusions

Although a low proportion of persons were linked to care, almost all those linked to care started cART and achieved rapid VS. The high rates of VS were irrespective of prior HIV-associated risk behaviours. Linkage to care remains the highest priority in prevention strategies in central Poland.

Candidates for inclusion in a universal antiretroviral regimen: are lamivudine and emtricitabine interchangeable?

PURPOSE OF REVIEW

Lamivudine (3TC) and emtricitabine (FTC) are the most widely used antiretroviral medications worldwide and are considered by the WHO to be interchangeable. This article reviews evidence supporting interchangeability of 3TC and FTC and considerations for future use.

RECENT FINDINGS

Three randomized trials have directly compared the safety and efficacy of 3TC and FTC against identical backbone regimens. Each of these trials reported a nonsignificant difference in virological suppression, and when results were pooled the overall difference was nonsignificant (relative risk 1.03, 95% confidence interval 0.96-1.10). These findings of equivalence are further supported by indirect evidence from nine randomized trials comparing 3TC and FTC against a similar backbone regimen of two different nucleoside reverse transcriptase inhibitors (relative risk of virological suppression 0.99, 95% confidence interval 0.96-1.01). Data from observational studies is mixed. Overall, reported differences between 3TC and FTC in observational studies are often associated with differences in the baseline characteristics of the treatment groups, notably with respect to immunological and virological status, comorbidity, substance misuse, and pill burden.

SUMMARY

The totality of evidence to date, from pharmacological data to observational studies to direct and indirect comparisons in randomized trials, suggests that 3TC and FTC can be considered to be therapeutically interchangeable and that if there are any differences, these are likely to be very small and not of major clinical importance.