Lack of impact of protease inhibitor resistance-associated mutations on the outcome of HIV-1-infected patients switching to darunavir-based dual therapy

Background: Little is known about the impact of baseline resistance-associated mutations (RAMs) on the outcomes of alternative therapeutic strategies such as dual regimens. We assessed the efficacy of boosted darunavir plus raltegravir (DRV + RAL) dual regimen as a simplification strategy in virologically suppressed patients with protease inhibitors RAMs.Methods: Retrospective, multicentre study on the evolution of 228 heavily pretreated patients who switched to boosted DRV + RAL according to genotypic sensitivity score (GSS). Patients were classified as full susceptible (GSS = 2; n = 177), or with reduced darunavir susceptibility (GSS < 2; n = 51).Results: Median (range) number of prior antiretroviral regimens was 9 (6-14), with a median (range) of 2 (1-3), 4 (3-6), and 5 (2-9) major mutations to non-nucleoside reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors, and protease inhibitors, respectively. The median time of virological suppression before simplification was 49 months (IQR 39.8-63.5). Patients with reduced darunavir GSS showed a higher number of protease inhibitors-RAMs (9.3 vs 4.5, p < .01) and were suppressed for longer time (median, 61 months). At week 96, the rate of virological failure was low (two cases, 0.9%; 95% confidence interval, CI, 0.4-2.7%), and the efficacy, excluding non-virological reasons, was 96.8% (95%CI, 90.2-98.4%), without differences according to GSS or protease inhibitors-RAMs. Furthermore, significant improvements in CD4+ counts and CD4/CD8 ratio were observed (p < .01) in both groups.Conclusions: Treatment simplification to a dual regimen of boosted DRV + RAL after long-term virological suppression was not associated with a high risk of treatment failure, even in patients harbouring protease inhibitors-resistant HIV infection.

Effectiveness of Once/Day Dolutegravir Plus Boosted Darunavir as a Switch Strategy in Heavily Treated Patients with Human Immunodeficiency Virus

STUDY OBJECTIVE

Dual therapy with once/day dolutegravir (DTG) plus boosted darunavir (DRV/b) may be a suitable and effective strategy with a high genetic barrier to resistance in patients infected with human immunodeficiency virus (HIV). Our aim was to evaluate the effectiveness of DTG plus DRV/b (DTG+DRV/b) as a switch strategy in HIV-infected patients, irrespective of their history of virologic failure (VF).

DESIGN

Multicenter retrospective cohort study.

SETTING

Human immunodeficiency outpatient treatment clinics at three university hospitals in Spain.

PATIENTS

Fifty HIV-infected adults who had a stable antiretroviral treatment (ART) regimen and an undetectable viral load for at least 6 months, and whose ART was switched to once/day DTG+DRV/b between January 2015 and January 2018 were included in the analysis. Historical genotype at the time of VF was available in 44 patients.

MEASUREMENTS AND MAIN RESULTS

Patients were followed until VF or treatment discontinuation for any reason. The primary outcome was the percentage of patients with a viral load of 50 copies/mL or lower at the last follow-up visit. Secondary outcomes included changes in CD4⁺ cell count, lipid profile, and renal function. Of the 50 patients included, median time of viral suppression was 52 months (interquartile range [IQR] 18-103 mo) and nadir CD4⁺ 89 cells/mm³ (IQR 37-241 cells/mm³ ). Patients had a history of a median of 8 ART combinations (IQR 4-11 combinations) and 3 VFs (IQR 2-8 VFs). The historical genotypes from 44 patients showed 41 patients (93.2%) with nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) resistance-associated mutations (RAMs), 32 (72.7%) with nonnucleoside reverse transcriptase inhibitor (NNRTI) RAMs, and 12 (27.3%) with primary protease inhibitor (PI) RAMs; 7 (15.9%) had darunavir RAMs, and no patients had baseline integrase strand transfer inhibitor RAMs. Thirty-seven patients (84.1%) had resistance to at least two antiretroviral classes. After a median of 25 months (IQR 17-28 mo) of follow-up, 49 patients (98%) maintained a viral load of 50 copies/mL or lower, and 1 patient (2%) had VF. No new RAMs emerged at VF. At week 4, serum creatinine concentration increased a median of 0.12 mg/dl (0.03-0.23 mg/dl). At last visit, total cholesterol and low-density lipoprotein cholesterol levels increased by a median of 9 mg/dl (IQR -18 to 40 mg/dl) and 16 mg/dl (IQR -9 to 40 mg/dl), respectively, whereas CD4⁺ cell count remained stable (median +13 cell/mm³ ).

CONCLUSION

In this cohort of heavily treated HIV-infected patients with virologic suppression, switching to the combination of DTG+DRV/b was a convenient regimen that was highly effective and had good tolerability.

Effectiveness, Safety, and Tolerability of a Switch to Dual Therapy with Dolutegravir Plus Cobicistat-Boosted Darunavir in Treatment-Experienced Patients with Human Immunodeficiency Virus

BACKGROUND

Dual regimen with dolutegravir plus cobicistat-boosted darunavir (DTG/DRV/c) is reasonable alternative option for patients with existing resistance and/or intolerance to nucleoside reverse transcriptase inhibitors (NRTIs).

MATERIAL AND METHODS

All patients who switched to DTG/DRV/c among treatment-experienced patients with human immunodeficiency virus (HIV) in a tertiary university hospital were selected. We analyzed the effectiveness, safety, and tolerability based on serial laboratory data and clinical findings. The primary endpoint was defined as the proportion of patients with plasma HIV RNA below 50 copies/mL at week 48 after switch. Secondary endpoints included evaluation of safety and tolerability.

RESULTS

Thirty-one patients were retrospectively analyzed. The main reasons for the change to DTG/DRV/c were treatment failure in 13 patients (41.9%), simplification in 12 patients (38.7%), and adverse drug reaction in 6 patients (19.4%). Among the 13 patients who switched owing to treatment failure, the proportion of patients in whom the viral loads were suppressed to less than 50 copies/mL increased from 0% at baseline to 45% at 4 weeks, 50% at 12 weeks, 50% at 24 weeks, and 66.7% at 48 weeks. HIV virus levels decreased and CD4⁺ T cell counts increased during the follow-up period. In non-treatment failure patients (18 patients), the levels of viral suppression and CD4⁺ T cells were maintained. There were no significant differences in renal function, liver function, glucose levels, and lipid profile before and after regimen changes. The tolerability was very good: 30 patients (96.8%) tolerated the drugs well and only 1 patient discontinued owing to no improvement in renal insufficiency. Two patients (6.4%) in treatment failure group failed to reach viral suppression.

CONCLUSION

The use of DTG/DRV/c in HIV treatment-experienced patients appears to be a very good regimen for switch therapy that is effective and well tolerated, without significant adverse drug reaction.

Budget impact analysis of the simplification to atazanavir + ritonavir + lamivudine dual therapy of HIV-positive patients receiving atazanavir-based triple therapies in Italy starting from data of the Atlas-M trial

Background

This analysis aimed at evaluating the impact of a therapeutic strategy of treatment simplification of atazanavir (ATV)+ ritonavir (r) + lamivudine (3TC) in virologically suppressed patients receiving ATV+r+2 nucleoside reverse transcriptase inhibitors (NRTIs) on the budget of the Italian National Health Service (NHS).

Methods

A budget impact model with a 5-year time horizon was developed based on the clinical data of Atlas-M trial at 48 weeks (in terms of percentage of patients experiencing virologic failure and adverse events), from the Italian NHS perspective. A scenario in which the simplification strategy was not considered was compared with three scenarios in which, among a target population of 1,892 patients, different simplification strategies were taken into consideration in terms of percentage of patients simplified on a yearly basis among those eligible for simplification. The costs considered were direct medical costs related to antiretroviral drugs, adverse events management, and monitoring activities.

Results

The percentage of patients of the target population receiving ATV+r+3TC varies among the scenarios and is between 18.7% and 46.9% in year 1, increasing up to 56.3% and 84.4% in year 5. The antiretroviral treatment simplification strategy considered would lead to lower costs for the Italian NHS in a 5-year time horizon between −28.7 million € and −16.0 million €, with a reduction of costs between −22.1% (−3.6 million €) and −8.8% (−1.4 million €) in year 1 and up to −39.9% (−6.9 million €) and −26.6% (−4.6 million €) in year 5.

Conclusion

The therapy simplification for patients receiving ATV+r+2 NRTIs to ATV+r+3TC at a national level would lead to a reduction of direct medical costs over a 5-year period for the Italian NHS.

Impact of low-level viraemia on virological failure in HIV-1-infected patients with stable antiretroviral treatment

BACKGROUND

Low-level viraemia (LLV) occurs in 20-40% of patients achieving viral suppression with antiretroviral therapy (ART). The risk of virological failure (VF: confirmed HIV RNA >200 copies/ml) in these patients is still a matter of debate.

METHODS

This is a prospective cohort study in HIV-infected adults attending the HIV clinic of a tertiary care hospital in Spain. Patients with HIV RNA <25 copies/ml and stable ART for at least 6 months presenting LLV (defined as HIV RNA between 25-1,000 copies/ml) from January 2011 to January 2013 were included and followed until VF or end of follow-up in June 2014.

RESULTS

A total of 300 out of 1,733 (17.3%) patients with undetectable viraemia for 4.2 years showed LLV: 25-50 copies/ml in 167 (55.7%) patients, 51-200 copies/ml in 111 (37%) and 201-1,000 copies/ml in 22 (7.3%) cases. After a median follow-up of 2.6 years, 23 (7.7%) patients presented VF. No patient with a single or multiple unconfirmed LLV went on to develop VF. HIV RNA >200 copies/ml (HR 59.6; 95% CI 15.7, 227), ritonavir-boosted protease inhibtor (PI/r)-based dual therapy (HR 10.2; 95% CI 2.1, 49.8) and PI/r monotherapy (HR 7.9; 95% CI 1.4, 43.3) were associated with VF. Persistent LLV, defined as HIV RNA <200 copies/ml in at least three consecutive samples, for at least 12 weeks, was detected in 27 (1.6%) patients and 14 (51.9%) of those evolved to VF.

CONCLUSIONS

Nearly one-fifth of patients on suppressive ART showed LLV and 8% of them developed VF. HIV RNA >200 copies/ml was the strongest predictor of VF. Over half of patients with persistent viraemia <200 copies/ml showed VF.

Cerebrospinal fluid and plasma lopinavir concentrations and viral response in virologically suppressed patients switching to lopinavir/ritonavir monotherapy once daily

BACKGROUND

Lopinavir/ritonavir (LPV/r) monotherapy is used in selected virologically suppressed HIV-infected patients. Some would prefer a once-daily (OD) dose instead of the usual twice-daily dose to favour adherence. However, trough concentrations of the drug in blood and particularly in cerebrospinal fluid (CSF) may not be adequate to maintain viral suppression.

METHODS

Prospective, open-label pilot study to evaluate the efficacy and safety of LPV/r monotherapy OD. HIV-1-infected patients, virologically suppressed for at least 6 months were enrolled. HIV viral load (VL) was determined at baseline and at weeks 4, 8, 12, 16, 24, 36 and 48. Lumbar puncture was performed in a subgroup of patients to evaluate CSF VL and CSF LPV concentrations.

RESULTS

A total of 21 patients were included. At week 48, 85.7% (n=18) showed viral suppression (VL<40 copies/ml). Two patients had viral failure (9.5%) and a third was withdrawn from the study because of gastrointestinal symptoms. Nine patients were enrolled in the substudy. CSF VL was <40 copies/ml in all cases. Median (range) LPV concentration was 9.78 ng/ml (1.93-78.3) in CSF and 1,970 (154-16,700) ng/ml in plasma; the CSF/plasma ratio was 0.004 (0.001-0.186).

CONCLUSIONS

In this small pilot study, LPV/r monotherapy OD maintained plasma HIV RNA suppression at 48 weeks in most patients, with no cases of CSF viral escape. However, CSF LPV concentrations were close to the 50% inhibitory concentration threshold in several patients; hence, this intervention should be avoided in patients with advanced immune suppression and/or those individuals presenting with significant comorbidities such as hepatitis C coinfection.

Safety, efficacy and indications of prescription of maraviroc in clinical practice: Factors associated with clinical outcomes

Maraviroc is approved for treatment-experienced HIV+ adults in twice-daily administration. Limited data are available on safety, efficacy and use in routine clinical practice, outside of restrictive clinical trials. This retrospective multicenter (27 centers) study included 667 subjects starting a regimen with maraviroc. The primary endpoint was plasma HIV-RNA <50copies/mL and CD4(+) cell count change at 48 and 96weeks (FDA snapshot analysis). 94.4% had CCR5 tropism (58.3% Trofile™, 29.2% population genotype, and 12% genotyping proviral DNA). Half of the subjects received the drug in scenarios or dosages outside the initial approval. Maraviroc was prescribed for salvage in 346 (51.9%) individuals, as a switch strategy due to toxicity in 135 (38.7%), for immune discordance in 75 (11.2%), and for simplification in 48 (7.2%). After salvage therapy, 223 (64.5%) subjects had HIV-RNA <50copies/mL at 48weeks, and 178 (51.4%) at 96weeks. Darunavir/r was included in 224 (64.7%) subjects and associated with higher rates of virological and immunologic efficacy (p<0.001). In multivariate analysis MSM (OR 2.25; 95%CI 1.29-3.94) and baseline HIV-RNA <100,000copies/mL (OR 1.96; 1.06-3.70) were associated with virological suppression. An increase in CD4(+) counts was seen at 48 and 96weeks in subjects with immune discordance (p<0.001). Maraviroc was used once-daily in 142 (21.3%) subjects overall, and 68 (57.4%) in switch/simplification. No new safety signals were identified. Besides in salvage regimens, maraviroc was frequently used in switch due to toxicity, simplification, and immune discordance. The efficacy in salvage in clinical practice was higher than in phase III clinical trials, likely due to availability of new active drugs in the regimen. These results increase our understanding of the efficacy, safety, and conditions of prescription of maraviroc beyond the initial registrational trials and the early manufacturer pharmacovigilance programs.

Efficacy and safety of darunavir/ritonavir plus etravirine dual regimen in antiretroviral therapy-experienced patients: a multicenter clinical experience

OBJECTIVES

To assess the outcome of a dual regimen combining darunavir/ritonavir plus etravirine in a cohort of antiretroviral therapy (ART)-experienced patients.

METHODS

A retrospective analysis was performed on all ART-experienced patients starting a darunavir/ritonavir plus etravirine regimen at the 3 clinics. Patients were stratified according to HIV RNA detectability (≥ 40 copies/mL) at baseline. Two efficacy endpoints were evaluated by Kaplan-Meier and Cox multivariable models: virological failure (confirmed HIV RNA ≥ 40 copies/mL after 6 months) and therapeutic failure (including virological failure and treatment discontinuation for any reason).

RESULTS

Sixty-eight patients were included in the study. They had a median of 10.8 years on ART and 5 previous ART regimens; 61.3% showed primary protease inhibitor (PI) mutations and 70% showed previous non-nucleoside reverse transcriptase inhibitor (NNRTI) exposure. HIV RNA was detectable in 34 (50%) patients. The median observation period was 21 (interquartile range [IQR], 11.9-25.1) months. After 24 months, 75.1% of the patients were still on the study regimen and 88.8% remained free from virological failure. Although a higher therapeutic failure rate was reported in patients with detectable viremia at baseline, only the immunological status revealed an independent predictive role. No differences in virological failure were observed according to HIV RNA detectability at baseline; a higher number of previous ART regimens was the only predictor. Discontinuation due to adverse events occurred in 5.9%.

CONCLUSIONS

Darunavir/ritonavir plus etravirine regimen proved virological efficacy and safety in heavily pretreated patients with a high rate of virological success, even in patients who switched during virological failure.

Dolutegravir: clinical efficacy and role in HIV therapy

The human immunodeficiency virus type-1 (HIV-1) integrase enzyme has recently emerged as a primary alternative target to block viral replication, and integrase strand transfer inhibitors (INSTIs) are now considered an alternative 'third agent' class of antiretroviral (ARV) drugs. Dolutegravir is the first next-generation INSTI showing some novel and intriguing characteristics: it has a favorable pharmacokinetic profile with a prolonged intracellular halflife, rendering feasible a once daily dosing without the need for pharmacokinetic boosting. Secondly, it is largely metabolized via uridine diphosphate glucuronosyltransferase-1A1 with a minor component of cytochrome P450 isoforms, thus allowing a low grade of drug-drug interactions, so that its metabolic profile consents co-administration with the majority of the other ARV drugs without dose adjustments. Lastly, but no less important, virological studies have clearly demonstrated that dolutegravir has a significant activity against HIV-1 isolates showing raltegravir and/or elvitegravir associated resistance mutations. The attributes of once daily administration and the potential to treat INSTI-resistant viruses make dolutegravir an interesting and promising new agent in the treatment of both naïve and experienced HIV-1 subjects. In this review, the main concerns on dolutegravir efficacy are focused through the analysis of the currently available data from clinical studies in naïve and experienced patients, evaluating its possible place within the anti-HIV-1 drug armamentarium. The development of newer once daily, single tablet coformulations improved drug adherence and maximized the success of ARV therapy. Pharmacokinetic studies and dose-ranging trials suggested that dolutegravir is a good candidate for a single tablet regimen in one or more new coformulated pills that will be available in the near future.

Antiretroviral regimens sparing agents from the nucleoside(tide) reverse transcriptase inhibitor class: a review of the recent literature

The nucleoside(tide) reverse transcriptase inhibitors (NRTIs) have traditionally been an important 'back-bone' of an antiretroviral therapy (ART) regimen. However all agents have been associated with both short- and long-term toxicity. There have also been concerns regarding the efficacy and safety of a treatment sequencing strategy in which those with past exposure and/or resistance to one or more NRTIs are re-exposed to 'recycled' NRTIs in subsequent ART regimens. Newer, potent and possible safer, agents from various ART classes continue to become available. There has therefore been growing interest in evaluating NRTI-sparing regimens. In this review, we examined studies of NRTI-sparing regimens in adult HIV-positive patients with varying degrees of ART experience. We found that in treatment experienced patients currently on a failing regimen with detectable viral load, there now exists a robust evidence for the use of NRTI-sparing regimens including raltegravir with a boosted-protease inhibitor with or without a third agent. In those on a virologically suppressive regimen switching to a NRTI-sparing regimen or in those ART-naïve patients initiating an NRTI-sparing regimen, evidence is sparse and largely comes from small exploratory trials or observational studies. Overall, these studies suggest that caution needs to be exercised in carefully selecting the right candidate and agents, especially in the context of a dual-therapy regimen, to minimise the risks of virological failure. There is residual toxicity conferred by the ritonavir boost in protease-inhibitor containing NRTI-sparing regimens. Fully-powered studies are needed to explore the place of N (t)RTI-sparing regimens in the sequencing of ART. Additionally research is required to explore how to minimise the adverse effects associated with ritonavir-based pharmacoenhancement.

Long-term efficacy and safety of atazanavir/ritonavir treatment in a real-life cohort of treatment-experienced patients with HIV type 1 infection

Atazanavir-based regimens have established efficacy and safety in both antiretroviral (ARV)-naive and -experienced patients. However, data evaluating effectiveness beyond 2 years is sparse. Therefore, we assessed the long-term outcomes of ritonavir-boosted atazanavir (ATV/r)-containing regimens in ARV-experienced patients in a clinical setting in a noncomparative, retrospective, observational study collecting data from three European HIV databases on ARV-experienced adults with HIV-1 infection starting an ATV/r-based regimen. Data were extracted every 6 months (maximum follow-up 5 years). Primary outcome was the proportion of patients remaining on ATV/r by baseline HIV-1 RNA (<500 or ≥500 copies/ml). Secondary outcomes included time to virologic failure, reasons for discontinuation, and long-term safety profile. The duration of treatment and time to virologic failure were analyzed using the Kaplan-Meier method. Data were analyzed for 1,294 ARV-experienced patients (male 74%; mean ART exposure 5.7 years). After 3 years, 56% (95% CI: 52%, 60%) of patients with baseline HIV-1 RNA <500 copies/ml and 53% (95% CI: 49%, 58%) of those with HIV-1 RNA ≥500 copies/ml remained on ATV/r. After 3 years, 75% (95% CI: 69%, 80%) of patients with baseline HIV-1 RNA <50 copies/ml remained suppressed and 51% (95% CI: 47%, 55%) of those with baseline HIV-1 RNA ≥50 copies/ml achieved and maintained virologic suppression. Although adverse events (AEs) were the main known reason for discontinuation, no unexpected AEs were observed. In a real-life setting ATV/r-based regimens demonstrated sustained virologic suppression in ARV-experienced patients. After long-term therapy the majority of patients remained on treatment and no unexpected AEs were observed.