Drug-resistance development differs between HIV-1-infected patients failing first-line antiretroviral therapy containing nonnucleoside reverse transcriptase inhibitors with and without thymidine analogues

Impact of archived M184V/I mutation on the effectiveness of switch to co-formulated elvitegravir, cobicistat, emtricitabine and tenofovir alafenamide among virally suppressed people living with HIV

OBJECTIVES

Real-world experience regarding the effectiveness of co-formulated elvitegravir, cobicistat, emtricitabine and tenofovir alafenamide (EVG/C/FTC/TAF) as a switch regimen is sparse among people living with HIV (PLWH) harbouring the M184V/I mutation with or without thymidine analogue-associated mutations (TAMs).

METHODS

In this retrospective multicentre study, PLWH who were switched to EVG/C/FTC/TAF after having achieved viral suppression (plasma HIV RNA <200 copies/mL) for 6 months or longer were included. Patients with archived M184V/I mutation (case patients) were matched to controls without M184V/I mutation at a 1:4 ratio. Patients with a history of virological failure or resistance to elvitegravir were excluded. The primary endpoint was virological non-success (plasma HIV RNA ≥50 copies/mL) at Week 48 of switch using a modified FDA snapshot analysis.

RESULTS

Overall, 100 case patients with the M184V/I mutation were identified, including 6 (6.0%) with K65R and 13 (13.0%) with at least one TAM, and were matched to 400 controls in terms of gender, age (mean = 40.3 versus 39.7 years) and cumulative exposure duration to tenofovir disoproxil fumarate (median = 146 versus 143 weeks). At Week 48, the rate of virological non-success for the case patients and controls was 5.0% (5/100) and 3.3% (13/400), respectively (difference = 1.7%; 95% CI = -2.9%-6.3%), while the rate of virological success was 88.0% and 89.5% for the case patients and controls, respectively. The presence of the K65R mutation or TAMs was not associated with virological non-response.

CONCLUSIONS

Among virally suppressed PLWH, EVG/C/FTC/TAF is effective in maintaining viral suppression at Week 48 despite archived M184V/I mutation with or without TAMs.

Accumulation of HIV-1 Drug Resistance Mutations After First-Line Immunological Failure to Evaluate the Options of Recycling NRTI Drugs in Second-Line Treatment: A Study from South India

Lack of HIV-1 viral load monitoring in resource-limited settings leads to the development of HIV drug resistance mutations, although WHO recommends viral load testing for monitoring as this helps in preserving future treatment options and also avoid unnecessary switching to more expensive drugs. A total of 101 patients attaining first-line treatment failure (FTF) were followed until second-line treatment failure (STF) to study the rate of accumulation of thymidine analogue mutations (TAMs), their future drug options, and genetic evolution. The result shows that predominant nucleos(t)ide reverse transcriptase inhibitor (NRTI) mutations were M184V/I (87.3% in FTF and 79% in STF) followed by TAMs (53.4% in FTF and 54.5% in STF). The rate of accumulation of TAMs was higher for a patient with TAMI [0.015 TAM per person-month (TPPM)], TAMII (0.042 TPPM), and 1 (0.005 TPPM) or 2 TAMs (0.008 TPPM) compared with a patient with both TAMs and 3 or >3 TAMs. Future ART options show that >50% of the patients can be considered for choices to recycle NRTIs in the second-line, and third-line therapy. We conclude that the patients who initiated thymidine analogue-based first-line before 2010 can be very well opted for AZT- and TDF-based second-line regimen in the future.

Focus on Chirality of HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors

Chiral HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) are of great interest since one enantiomer is often more potent than the corresponding counterpart against the HIV-1 wild type (WT) and the HIV-1 drug resistant mutant strains. This review exemplifies the various studies made to investigate the effect of chirality on the antiretroviral activity of top HIV-1 NNRTI compounds, such as nevirapine (NVP), efavirenz (EFV), alkynyl- and alkenylquinazolinone DuPont compounds (DPC), diarylpyrimidine (DAPY), dihydroalkyloxybenzyloxopyrimidine (DABO), phenethylthiazolylthiourea (PETT), indolylarylsulfone (IAS), arylphosphoindole (API) and trifluoromethylated indole (TFMI) The chiral separation, the enantiosynthesis, along with the biological properties of these HIV-1 NNRTIs, are discussed.

Prevalence of K65R in patients treated with tenofovir disoproxil fumarate: recommendations based on the Frankfurt HIV Cohort Study Resistance Database (FHCS-RD)

Mutations in the genome of HIV-1 can compromise the success of antiretroviral treatments (ARTs) in HIV-1-infected individuals. The Frankfurt HIV Cohort Study Resistance Database (FHCS-RD) has previously documented a decline in the burden of resistance-associated mutations (RAMs) following the implementation of several new antiretroviral therapy regimens in 2007. In the current study, the annual burden of RAMs documented in the FHCS-RD in 2005-2013 was set in relation to the annual number of all cohort patients, drug regimens, available resistance tests, and prevalence for each RAM on relevant codons of reverse transcriptase (RT) and protease (PR) genes. A specific focus was put on the prevalence of the tenofovir disoproxil fumarate (TDF) signature mutation K65R in HIV-1 RT in relation to the application of TDF within ART. Between 2005 and 2012, a total of 4423 HIV genotyping data sets from 4509 patients were analysed. All mutations show a consistent decline, and the most impressive decrease was observed for thymidine analogue mutations (TAMs). The frequency of non-TAMs and PR mutations also decreased, but generally to a lower extent. The prevalence of K65R decreased from 2.6 % in 2005 to 0.2 % in 2012 despite increased use of TDF-containing ART. Both the improved strategic use of TDF in ARTs and generally more effective ART regimens may have resulted in decreasing RAM prevalences in FHCS-RD since 2007. These trends challenge the cost-effectiveness of resistance testing prior to failing ART.

Viral Escape in the Central Nervous System with Multidrug-Resistant Human Immunodeficiency Virus-1

In this study, we report the case of a patient infected with human immunodeficiency virus (HIV)-1 who developed ataxia and neurocognitive impairment due to viral escape within the central nervous system (CNS) with a multidrug-resistant HIV-1 despite long-term viral suppression in plasma. Antiretroviral therapy optimization with drugs with high CNS penetration led to viral suppression in the CSF, regression of ataxia, and improvement of neurocognitive symptoms.

Successful switch to rilpivirine/tenofovir/emtricitabine in HIV-1-infected patients with an isolated K103N mutation acquired during prior nonnucleoside reverse transcriptase inhibitor therapy

OBJECTIVES

Whether treatment-experienced HIV-1-infected patients with an acquired K103N mutation after failing nonnucleoside reverse transcriptase inhibitor (NNRTI) regimens can be treated with rilpivirine is unknown. The aim of this pilot study was to evaluate the efficacy of rilpivirine/tenofovir/emtricitabine in HIV-1-infected patients with an isolated K103N mutation.

METHODS

A prospective study was carried out in HIV-1-infected adults who acquired the K103N mutation on failing NNRTI regimens. No other mutations in reverse transcriptase were allowed. Patients had to be on second-line regimens with HIV-1 RNA < 200 copies/mL for ≥ 6 months. Exclusion criteria were: use of acid-reducing agents, insufficient caloric intake and impaired renal function. Of primary interest was virological success (HIV-1 RNA < 200 copies/mL) at weeks 6, 12, 24 and 48.

RESULTS

Of 1550 HIV-1-infected patients at the Erasmus Medical Center Rotterdam, we identified 10 HIV-1-infected patients with an isolated K103N mutation acquired after NNRTI failure. Five patients were not eligible for inclusion in the study, and two patients refused participation. Three African women (23-35 years of age) were included and were switched from boosted protease inhibitor-based second-line therapies to rilpvirine/tenofovir/emtricitabine. HIV-1 RNA was < 200 copies/mL at weeks 6, 12, 24 and 48 for all patients. No adverse events were observed. All patients had HIV-1 RNA < 200 copies/mL for 6-50 months prior to the switch.

CONCLUSIONS

This pilot study demonstrates the successful switch of HIV-1-infected patients who acquired an isolated K103N mutation during previous NNRTI therapy to rilpivirine/tenofovir/emtricitabine. In selected patients, single-tablet regimens are also becoming a valid treatment option for second-line HIV-1 therapy.