Recycling Tenofovir in Second-line Antiretroviral Treatment With Dolutegravir: Outcomes and Viral Load Trajectories to 72 weeks.

BACKGROUND: Recycling tenofovir and lamivudine/emtricitabine with dolutegravir (TLD) after failure of non-nucleoside transcriptase inhibitor first-line antiretroviral therapy is more tolerable and scalable than dolutegravir plus optimized nucleoside reverse transcriptase inhibitors. Studies have demonstrated TLD's efficacy as second line, but long-term follow-up is limited. METHODS: ARTIST is a single arm, prospective, interventional study conducted in Khayelitsha, South Africa, which switched 62 adults with 2 viral loads >1000 copies/mL from tenofovir, lamivudine/emtricitabine, and an non-nucleoside transcriptase inhibitor to TLD. We report efficacy to 72 weeks and, in a post hoc analysis, evaluated viral load trajectories of individuals with viremic episodes. RESULTS: Virologic suppression was 86% [95% confidence interval (CI) 74 to 93], 74% (95% CI: 61 to 84), and 75% (95% CI: 63 to 86) <50 copies/mL and 95%, 84%, and 77% <400 copies/mL at week 24, 48, and 72, respectively, with 89% (50/56) resistant (Stanford score ≥15) to tenofovir and/or lamivudine preswitch. No participants developed integrase-inhibitor resistance. Of the 20 participants not suppressed at week 24 and/or 48, 2 developed virologic failure, 1 switched regimen (adverse event), 2 were lost to follow-up, 1 missed the visit, 1 transferred out, 9 resuppressed <50 copies/mL with enhanced adherence counseling, and 4 remained viremic (3 with <200 copies/mL) at week 72. CONCLUSIONS: Recycling NRTIs with dolutegravir was effective for most participants to 72 weeks. Most with viremia did not develop virologic failure and subsequently suppressed with enhanced adherence counseling or continued to have low-level viremia. No integrase-inhibitor resistance was detected despite low-level viremia in a minority of participants.

Virologic efficacy of tenofovir, lamivudine and dolutegravir as second-line antiretroviral therapy in adults failing a tenofovir-based first-line regimen.

OBJECTIVE: Recycling tenofovir and lamivudine/emtricitabine (XTC) with dolutegravir would provide a more tolerable, affordable, and scalable second-line regimen than dolutegravir with an optimized nucleoside reverse transcriptase inhibitor (NRTI) backbone. We evaluated efficacy of tenofovir/lamivudine/dolutegravir (TLD) in patients failing first-line tenofovir/XTC/efavirenz or nevirapine. DESIGN: Single arm, prospective, interventional study. SETTING: Two primary care clinics in Khayelitsha, South Africa. PARTICIPANTS: Sixty adult patients with two viral loads greater than 1000 copies/ml. INTERVENTION: Participants were switched to TLD with additional dolutegravir (50 mg) for 2 weeks to overcome efavirenz induction. PRIMARY OUTCOME: Proportion achieving viral load less than 50 copies/ml at week 24 using the FDA snapshot algorithm. RESULTS: Baseline median CD4+ cell count was 248 cells/µl, viral load 10 580 copies/ml and 48 of 54 (89%) had resistance (Stanford score ≥15) to one or both of tenofovir and XTC. No participants were lost to follow-up. At week 24, 51 of 60 [85%, 95% confidence interval (CI) 73-93%] were virologically suppressed, six had viral load 50-100 copies/ml, one had viral load 100-1000 copies/ml, one no viral load in window, and one switched because of tenofovir-related adverse event. No integrase mutations were detected in the one participant meeting criteria for resistance testing. Virological suppression was achieved by 29 of 35 (83%, 95% CI 66-93%) with resistance to tenofovir and XTC, 11 of 13 (85%, 95% CI 55-98%) with resistance to XTC, and six of six (100%, 95% CI 54-100%) with resistance to neither. CONCLUSION: A high proportion of adults switching to second-line TLD achieved virologic suppression despite substantial baseline NRTI resistance and most not suppressed had low-level viraemia (≤100 copies/ml). This suggests recycling tenofovir and XTC with dolutegravir could provide an effective second-line option.

AntiRetroviral Therapy In Second-line: investigating Tenofovir-lamivudine-dolutegravir (ARTIST): protocol for a randomised controlled trial.

Background: Dolutegravir has superior efficacy and tolerability than lopinavir-ritonavir in second-line antiretroviral therapy after failure of a first-line non-nucleoside reverse transcriptase inhibitors-based regimen, when dolutegravir is accompanied by at least one fully active nucleoside reverse transcriptase inhibitor (NRTI). Resistance testing to select NRTIs is not feasible in low- and middle-income countries due to cost and limited laboratory capacity. Evidence suggests that recycling tenofovir plus lamivudine or emtricitabine backbone with dolutegravir could provide an effective second-line option. This study aims to determine the virologic efficacy of tenofovir-lamivudine-dolutegravir (TLD) with and without a lead-in supplementary dose of dolutegravir (to counteract the inducing effect of efavirenz) in patients failing a first-line regimen of tenofovir-emtricitabine-efavirenz (TEE). Methods: We will perform a parallel group, randomised (1:1), double blind, placebo-controlled, Phase II trial, comparing TLD fixed dose combination daily with a lead-in supplementary 50 mg dolutegravir dose versus matching placebo taken 12 hours later for the first 14 days, in patients failing a first-line TEE regimen. The trial will be set in two primary care clinics in Khayelitsha; a large, peri-urban informal settlement in Cape Town, South Africa. We will enrol 130 participants, with follow-up to 48 weeks. The primary endpoint is proportion achieving viral load <50 copies/mL at week 24 using a modified intention-to-treat analysis and the U.S. Food and Drug Administration snapshot algorithm. Secondary endpoints include virologic suppression at weeks 12 and 48, time to suppression, emergence of dolutegravir and new NRTI resistance mutations, safety, and tolerability. Discussion: Impaired viral fitness due to NRTI resistance mutations and dolutegravir's high barrier to resistance provide rationale for switching patients from a failing TEE regimen to TLD; however, clinical evidence regarding virologic efficacy is lacking. This study provides estimates of such a strategy's early virologic efficacy with and without a supplementary dolutegravir dosing. Registration: ClinicalTrials.gov NCT03991013 (19/06/2019).