Efficacy of etravirine combined with darunavir or other ritonavir-boosted protease inhibitors in HIV-1-infected patients: an observational study using pooled European cohort data

Cohort Profile: A European Multidisciplinary Network for the Fight against HIV Drug Resistance (EuResist Network)

The EuResist cohort was established in 2006 with the purpose of developing a clinical decision-support tool predicting the most effective antiretroviral therapy (ART) for persons living with HIV (PLWH), based on their clinical and virological data. Further to continuous extensive data collection from several European countries, the EuResist cohort later widened its activity to the more general area of antiretroviral treatment resistance with a focus on virus evolution. The EuResist cohort has retrospectively enrolled PLWH, both treatment-naïve and treatment-experienced, under clinical follow-up from 1998, in nine national cohorts across Europe and beyond, and this article is an overview of its achievement. A clinically oriented treatment-response prediction system was released and made available online in 2008. Clinical and virological data have been collected from more than one hundred thousand PLWH, allowing for a number of studies on the response to treatment, selection and spread of resistance-associated mutations and the circulation of viral subtypes. Drawing from its interdisciplinary vocation, EuResist will continue to investigate clinical response to antiretroviral treatment against HIV and monitor the development and circulation of HIV drug resistance in clinical settings, along with the development of novel drugs and the introduction of new treatment strategies. The support of artificial intelligence in these activities is essential.

The HIV-1 reverse transcriptase E138A natural polymorphism decreases the genetic barrier to resistance to etravirine in vitro

OBJECTIVES

The HIV-1 reverse transcriptase (RT) natural polymorphism E138A is included among the mutations with a minor impact on response to etravirine. However, the interpretation of E138A on etravirine susceptibility is not consistent across different genotypic resistance algorithms. The aim of the study was to investigate the effect of E138A on the genetic barrier to resistance to etravirine in vitro.

METHODS

A panel of 20 clinically derived recombinant viruses (10 with WT 138E and 10 with 138A, all without any other resistance mutation) were cultured in the presence of increasing etravirine concentrations and analysed for genotypic changes at virus breakthrough. Parallel experiments were conducted with 138E/A/G/K/Q NL4-3-based clones.

RESULTS

In the NL4-3 background, codon 138 changes increased etravirine resistance in the following order: Q > K > A > G > E. The 138A viruses were less susceptible to etravirine compared with the 138E viruses [median (IQR) fold change, 1.8 (1.5-2.8) versus 1.3 (0.8-1.8); P = 0.026], overcame etravirine pressure earlier [HR (95% CI) for viral outgrowth with 138A, 5.48 (2.95-28.24); P < 0.001] and grew at higher drug concentrations [median (IQR), 1350 (1350-1350) versus 0 (0-1350) nM; P = 0.005]. A variety of etravirine resistance-related mutations and changes in the RT connection and RNase H domains accumulated without any consistent pattern depending on baseline codon 138.

CONCLUSIONS

E138A can contribute to reduced response to etravirine through a decreased genetic barrier to resistance. In vitro drug resistance selection is a valuable complement to define the full potential of low-level resistance mutations.

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.

Impact of etravirine on hospitalization rate between 2005 and 2011 among heavily treated HIV-1-infected individuals on failing regimens

Background

Etravirine (ETR), a non-nucleoside reverse transcriptase inhibitor (NNRTI) available in France since 2006, is indicated for antiretroviral-experienced HIV-infected adults, in combination with a ritonavir-boosted protease inhibitor (PI). To assess its clinical impact in routine care, we compared hospitalization rates according to ETR + PI prescription or not, among heavily treated HIV-1 infected individuals on failing regimens between 2005 and 2011.

Methods

From the French Hospital Database on HIV (ANRS CO4), we selected heavily treated individuals (prior exposure to at least 2 nucleoside reverse transcriptase inhibitor (NRTI), 2PI and 1 NNRTI) with viral load (VL) > 50 copies/mL who started a new antiretroviral (ARV) regimen between 2005 and 2011. Using an intention-to-continue-treatment approach, hospitalization rates were calculated for the individuals who received ETR + PI, during the months after initiating ETR + PI (ETR + PI) or for the individuals who received ETR + PI, in the months before ETR + PI initiation and for the individuals who never received ETR + PI (no ETR + PI). hospitalization from an AIDS-defining cause and hospitalization from a non-AIDS defining cause rates were also calculated. Poisson regression models were used to compare the incidences between the two groups, with adjustment for potential confounders.

Results

Of 3884 patients who met the inclusion criteria, 838 (21.6%) received ETR + PI. During 13,986 person-years (P-Y) of follow-up, there were 2484 hospitalizations in 956 individuals. The hospitalization rates per 1000 P-Y were 169.0 among individuals exposed to ETR + PI and 179.3 among those not exposed to ETR + PI. After adjustment, the respective hospitalization rates were 148.8 and 186.7 per 1000 P-Y, with an estimated relative risk of 0.80 (95%CI: 0.71–0.90), AIDS hospitalization rates were 11.5 and 22.7 per 1000 P-Y, with an estimated relative risk of 0.51(95%CI: 0.39–0.66) and non-AIDS hospitalization rates were 139.5 and 152.2 per 1000 P-Y, with an estimated relative risk of 0.92 (95%CI: 0.80–1.05).

Conclusions

Between 2005 and 2011, access to ETR + PI was associated with a 20% reduction in the hospitalization rate among heavily treated HIV-1-infected individuals. This reduction was mainly due to a reduction in the AIDS hospitalization rate.

Etravirine combined with antiretrovirals other than darunavir/ritonavir for HIV-1-infected, treatment-experienced adults: Week 48 results of a phase IV trial

Objective:

VIOLIN (TMC125IFD3002; NCT01422330) evaluated the safety, tolerability, and pharmacokinetics of etravirine with antiretrovirals other than darunavir/ritonavir in HIV-1-infected patients.

Methods:

In a 48-week, phase IV, single-arm, multicenter study, patients on prior antiretroviral therapy (⩾8 weeks) who needed to change regimen for virologic failure (viral load ⩾ 500 copies/mL) or simplification/adverse events (viral load < 50 copies/mL) received etravirine 200 mg bid with ⩾1 other active antiretroviral, excluding darunavir/ritonavir or only nucleoside/tide reverse transcriptase inhibitors.

Results:

Of 211 treated patients, 73% (n = 155) had baseline viral load ⩾ 50 copies/mL and 27% (n = 56) had baseline viral load < 50 copies/mL. Protease inhibitors were the most common background antiretrovirals (83%). Diarrhea was the most frequent adverse event (17%). Serious adverse events (no rash) occurred in 5% of patients; none were etravirine related. Overall, median etravirine AUC_12h was 5390 ng h/mL and C_0h was 353 ng/mL (N = 199). Week 48 virologic response rates (viral load < 50 copies/mL; Food and Drug Administration Snapshot algorithm) were 48% (74/155) (baseline viral load ⩾ 50 copies/mL) and 75% (42/56) (baseline viral load < 50 copies/mL). Virologic failure rates were 42% and 13%, respectively. The most frequently emerging etravirine resistance-associated mutations in virologic failures were Y181C, E138A, and M230L. Virologic response rates for patients with baseline viral load ⩾ 50 copies/mL were 38% (30/79) (non-adherent) versus 64% (44/69) (adherent subset).

Conclusion:

Etravirine 200 mg bid in combination with antiretrovirals other than darunavir/ritonavir was well tolerated in the studied treatment-experienced HIV-1-infected population. The overall etravirine safety and tolerability profile and pharmacokinetics (specifically in those patients who were adherent) were similar to those previously observed for etravirine in HIV-1-infected adults. The relatively high level of non-adherence, also observed in the pharmacokinetic assessments, negatively impacted virologic response, especially in patients with ⩾50 copies/mL at baseline.

Long-term clinical experience with darunavir (2007-2015) in a large cohort of HIV-infected patients in Spain

The clinical experience with the protease inhibitor darunavir/ritonavir (DRV/r) was retrospectively evaluated in a cohort of 173 HIV+ patients who initiated antiretroviral treatment including DRV/r (period 2007-2015). The 43.2% had a CD4 nadir ≤100 cells/mm³ , 64.1% were treatment-experienced, and 36.5% had failed to >3 lines of antiretroviral therapy. Nonetheless, the rate of virological suppression (HIV-RNA <50 copies/ml) in naïve patients was 63%, 66.7%, and 63.6% at 48, 96, and 144 weeks, respectively. The rate of virological suppression in treatment-experienced patients was 62.7%, 78.7%, and 79.1% at 48, 96, and 144 weeks, respectively. No differences were observed according to the immunovirological status neither dosage of DRV/r. Most of them (82.6%) maintained DRV/r treatment. Causes for DRV/r discontinuation were mainly gastrointestinal and cutaneous adverse events (10.5%), switch to simplification treatment strategies (3.5%) and virological failure (1.7%). These findings demonstrate the prolonged efficacy and tolerability of DRV/r even in multi-treated HIV+ patients with an unfavorable immunovirological status. J. Med. Virol. 88:2125-2131, 2016. © 2016 Wiley Periodicals, Inc.

Long-term efficacy and safety of etravirine-containing regimens in a real-life cohort of treatment-experienced HIV-1-infected patients

OBJECTIVES

Etravirine (ETR) was approved in France in September 2008 and is used in combination with a boosted protease inhibitor (bPI) and other anti-retrovirals (ART) in HIV-infected pre-treated patients. This study aimed to report in a real-life setting the efficacy and tolerability of ETR-based regimens and factors associated with virological response.

METHODS

The study population included all treatment-experienced patients who initiated an ETR-based regimen between September 2008 and July 2013 from the French Dat'AIDS cohort. Analyses were performed in ART-experienced patients starting ETR after virological failure (VF) or as a maintenance therapy (MT), with or without bPI.

RESULTS

A total of 2006 patients (VF, n = 1014 (51%); MT, n = 992 (49%)) were included. At M12, the proportion of patients with HIV RNA < 50 copies/ml was 71.7% (72.0% and 71.1% with or without bPI) in the VF group and 90.5% (85.0% and 92.3% with or without bPI) in the MT group, without significant differences regarding the use of bPI. ETR was discontinued in 8.8% of patients for adverse events in 23.9% of cases (21.5% in VF, 29.5% in MT), treatment failure in 15.2% (16.2% in VF, 7.4% in MT) or simplification in 5.4% (4.6% in VF, 7.4% in MT). In the VF group, factors associated with virological response were a longer duration of HIV infection (OR = 2.7; p < 0.001) and baseline HIV RNA < 5 log10 copies/mL (OR = 2.1; p = 0.002).

CONCLUSION

This study shows that in ART-experienced patients ETR is well tolerated with a high efficacy when combined with other active drugs, even when the regimen does not include a bPI.