Darunavir-based dual therapy of treatment-experienced HIV-infected patients: analysis from a national multicenter database

Rilpivirine plus cobicistat-boosted darunavir as a two-drug switch regimen in HIV-infected, virologically suppressed subjects on steady standard three-drug therapy: a randomized, controlled, non-inferiority trial (PROBE 2)

BACKGROUND

We explored the combination of rilpivirine plus cobicistat-boosted darunavir [a two-drug regimen (2DR)] when switching from standard triple combined ART.

METHODS

In this randomized, open-label, non-inferiority trial, participants had an HIV-RNA <50 copies/mL on a stable (>6 months) three-drug regimen. The primary endpoint was proportion with HIV-RNA <50 copies/mL at Week 24 (snapshot algorithm), with a -12% non-inferiority margin. ClinicalTrials.gov: NCT04064632.

RESULTS

One hundred and sixty patients were allocated (1:1) to 2DR or to continue current ART (CAR). At Week 24, 72 (90.0%) of participants with 2DR and 75 (93.8%) with CAR maintained HIV-RNA <50 copies/mL [difference -3.75% (95% CI = -11.63 to 5.63)], confirming non-inferiority. Non-inferiority was confirmed considering an HIV-RNA >50 copies/mL (0% for 2DR; 3.7% for CAR; 95% CI = -0.4 to 7.9). Four patients reported adverse events not leading to treatment discontinuation (one patient in the 2DR group and three patients in the CAR group); eight subjects discontinued therapy in the 2DR group and three in the CAR group. With 2DR, lipid serum concentrations increased, but differences were statistically significant only for tenofovir disoproxil fumarate-containing CAR and in 2DR patients receiving a pre-switch regimen including tenofovir disoproxil fumarate. Median bone stiffness decreased in the CAR group from 86.1 g/cm2 (IQR = 74-98) to 83.2 g/cm2 (IQR = 74-97) and increased in the 2DR group from 84.9 g/cm2 (IQR = 74-103) to 85.5 g/cm2 (IQR = 74-101). The reduction within the CAR group was significant (P = 0.043).

CONCLUSIONS

Once-daily rilpivirine plus cobicistat-boosted darunavir is an effective 2DR that combines a high virological efficacy with a potential to avoid major NRTI toxicities.

The effect of protease inhibitor-based dual antiretroviral regimens on CD4/CD8 ratio during the first year of therapy in ART-naïve patients with HIV-infection

OBJECTIVES

To assess the effect of protease inhibitor (PI)-based dual therapy on CD4/CD8 ratio during the first year of therapy in antiretroviral therapy (ART)-naïve patients using data from randomized controlled clinical trials.

METHODS

We pooled data from the GARDEL and ANDES studies, both randomized controlled clinical trials that recruited ART-naïve people living with HIV and randomly assigned them to receive PI-based dual therapy (DT) or triple therapy (TT) aiming to compare viral efficacy. We compared median CD4/CD8 ratios and the proportion of patients with CD4/CD8 ratio > 1 at 48 weeks after ART initiation in both treatment arms using the Mann-Whitney U-test and the χ² test. We performed subgroup analysis for patients > 50 years old, with baseline CD4 counts ≤ 200 cells/μL, viral load > 100 000 HIV RNA copies/mL, and ritonavir-boosted lopinavir-based therapy.

RESULTS

We analysed data from 571 patients: 292 on DT and 279 on TT. No differences were observed in CD4/CD8 ratio (0.632 vs. 0.617, P = 0.729) or in the proportion of patients with CD4/CD8 ratio > 1 (17.9% vs. 19.3%, P = 0.678) 48 weeks after ART initiation. Subgroup analysis showed no further differences.

CONCLUSION

The impact of PI-based DT regimens on the CD4/CD8 ratio during the first year of treatment for ART-naïve patients is similar to that of TT.

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.

Real-life study of dual therapy based on dolutegravir and ritonavir-boosted darunavir in HIV-1-infected treatment-experienced patients

BACKGROUND

Dual therapy based on dolutegravir and ritonavir-boosted darunavir (DTG/DRV/r) is a combination of well-known drugs with a high genetic barrier to HIV resistance.

METHOD

A retrospective analysis of all HIV-1 infected treatment-experienced patients who switched to DTG/DRV/r from May 2014 till March 2017 in 4 Polish centres-results of a 48-week treatment.

RESULTS

The study group consisted of 59 men and 17 women. Median baseline parameters were: age- 42.7 years, CD4 cells count- 560.5 cells/μl, CD4 cells nadir- 150 cells/μl, number of prior antiretroviral regimens- 3. The introduction of dual therapy was primarily due to virologic failure (30 patients), adverse events on previous regimens (17 patients) and therapy simplification (27 patients). At week 48 the treatment was continued in 70/76 of patients and the median CD4 cells count increased from 560.5 to 641.0 cells/μl. The therapy was discontinued in six patients (1 -virologic failure, 1 -decrease of estimated glomerular filtration rate (eGFR), 1 -myalgia, 3 -lost to follow-up). At week 48 six patients had detectable viremia, but only in one patient viremia was higher than 200 copies/ml. At week 48 the level of serum total cholesterol of the investigated subjects was statistically significantly higher than at the moment of dual therapy introduction (185.8 mg/dl vs. 174.8 mg/dl- p<0.05). However, in patients previously not treated with TDF, there were no changes in lipid parameters during therapy. Proteinuria was observed in 13.2% of patients before the switch to dual therapy and in 7.1% of patients at week 48.

CONCLUSIONS

The investigated dual therapy was effective and safe. The observed increase in lipid parameters only concerned the patients who had used a TDF-based regimen prior to analysed dual treatment.

Efficacy and safety of nucleoside-sparing regimen based on raltegravir and ritonavir-boosted darunavir in HIV-1-infected treatment-experienced patients

AIM

To assess the efficacy and tolerability of dual therapy containing raltegravir (RAL) and ritonavir boosted darunavir (DRV/r) in HIV-1-infected treatment-experienced patients.

METHOD

Retrospective analysis of 81 HIV-1-infected treatment-experienced patients (56 male and 25 female, 5 Polish centers) who switched to RAL/DRV/r.

RESULTS

The main reasons for the introduction of dual therapy were renal dysfunction (16/81 patients-19.8%) and virologic failure on previous regimens (15/81 patients-18.5%). At 48 weeks the treatment was continued in 58/81 (71.6% of patients). In three patients the therapy was discontinued because of virologic failure. However, no mutations to DRV or integrase inhibitors (InI) were detected. At 48 weeks of treatment CD4⁺ lymphocyte count increased statistically significantly (median 121 cells/μL) P < 0.005. The main reasons for the discontinuation of therapy were treatment simplification (11/23-47.8% patients), adverse events (7/23 patients 30.4%), virologic failure (3/23 patients 13.0%). All patients who switched to RAL/DRV/r therapy because of prior renal impairment were maintained on the treatment for 48 weeks. In this group, before the introduction of dual therapy eGFR (estimated glomerular filtration rate) <60 mL/min/1.72 m² was reported in nine patients and after 48 weeks in four patients (56.3% vs 25%) (P > 0.05). We found a statistically significant decrease in the prevalence of proteinuria or eGFR <60 mL/min/1.72 m² (93.8% vs 37.5%; P = 0.004 before and after the introduction of dual therapy, respectively).

CONCLUSIONS

Dual therapy was effective and safe for the vast majority of antiretroviral-experienced subjects. Such therapy can be recommended especially for patients with renal impairment or NRTIs intolerance.

Efficacy and tolerability of switching to a dual therapy with darunavir/ritonavir plus raltegravir in HIV-infected patients with HIV-1 RNA ≤50 cp/mL

BACKGROUND

Nucleos(t)ide reverse transcriptase inhibitors (NRTI) toxicity may represent a threat for long-term success of combined antiretroviral therapy. Some studies have suggested a possible improvement of NRTI-related toxicity after switching to NRTI-sparing regimens.

OBJECTIVES

We aimed to explore the efficacy and tolerability of switching to darunavir/ritonavir (DRV/r) plus raltegravir (RAL) while having a viral load (VL) ≤50 copies/mL in the clinical setting.

STUDY DESIGN

Treatment-experienced HIV 1-infected patients enrolled in the ICONA Foundation Study cohort were included if they switched their current regimen to DRV/r + RAL with a HIV-RNA ≤50 copies/mL. Different definitions of virological failure (VF) and treatment failure (TF) were employed. Kaplan-Meier curves and Cox regression models were performed to estimate time to event probability.

RESULTS

We included 72 HIV-infected patients, 22 (31%) of these were female, 31 (43%) men who have sex with men (MSM) amd 15 (21%) had hepatitis co-infections. Median age was 44 (IQR: 35-50) years amd CD4 count was 389 (IQR 283-606) cells/mmc. Median follow-up time for TF was 24 (IQR 9-31) months. Twenty-five discontinuations occurred (60% simplifications); only 2 (8%) were toxicity-driven (lipid elevations). The probability of VF (confirmed VL >50 copies/mL) was estimated at 7% [95% confidence interval (CI) 1-13%] by 12 and 9% (95% CI 2-16%) by 24 months. When considering TF, we found a probability of stop/intensification/single VL > 200 copies/mL of 13% (95% CI 1-17%) and 22% (95% CI 11-33%) by 12 and 24 months. Female gender (adjusted relative hazard, ARH = 0.10; 95% CI 0.01-0.74; p = 0.024) and older age (AHR = 0.50 per 10 years older; 95% CI 0.25-0.99; p = 0.045) were associated with a lower risk of TF. A previous PI failure was strongly associated with TF (AHR = 52.6, 95% CI 3.6-779; p = 0.004).

CONCLUSIONS

DRV/r + RAL is a valuable NRTI-sparing option, especially in female and older patients, with a relatively low risk of VF and good tolerability after 2 years since start in an ART-experienced population. However, previous PI-failure should be a limiting factor for this strategy.

NRTI Sparing Therapy in Virologically Controlled HIV-1 Infected Subjects: Results of a Controlled, Randomized Trial (Probe)

Dual treatments could help clinicians to avoid drawbacks and toxicities due to the nucleosidic backbone, while maintaining the efficacy and convenience of robust combination antiretroviral therapy (cART). We explored the combination of rilpivirine plus boosted darunavir (DRV) as an option when switching from standard cART in patients who are virologically suppressed. In this randomized, open-label, proof-of-concept, noninferiority trial, we recruited patients aged 18 years or older with chronic HIV-1 infection and on a stable, effective (>6 months) protease inhibitor-based cART including a nucleosidic backbone. The primary endpoint was noninferiority of the virological response between treatment groups, according to FDA snapshot approach. Sixty patients were randomly allocated to dual treatment with rilpivirine plus boosted DRV or to continue their ongoing triple treatment. Noninferiority was shown at the prespecified level of -12% both at 24 and 48 weeks. At week 24, 100% of patients in the dual arm presented a blood HIV-RNA level <50 copies per milliliter compared with 90.1% in the triple drug arm (difference 9.9%, 95% CI: -0.7 to 20.7), whereas, at 48 weeks, the same proportions were 96.7% and 93.4%, respectively (difference 3.3%, 95% CI: -7.15 to 13.5). The mean change in CD4 cell count from baseline was 6.0 cells per microliter (SD, 184) for dual treatment and 16.5 cells per microliter (SD, 142) for triple treatment. A relevant decrement in CD838HLADR cells was observed in both arms. The reduction was, however, significantly more pronounced in the dual-therapy arm. At week 48, the CD838HLADR cell count was 3.4% (SD, 2.2) in the dual-therapy arm and 5.2% (SD, 3.1) in the triple arm (P = 0.018). None of the patients developed severe adverse events nor had to stop treatment because of adverse events or presented grade 3-4 laboratory abnormalities. A greater reduction of bone stiffness (-2.25; SD, 7.1) was observed in patients randomized to continue triple therapy compared with patients switched to dual therapy (-0.32; SD, 8.8). Finally, baseline HIV-DNA content directly correlated with pre-cART viral load of patients (P = 0.021), but not with time on cART or time with HIV-RNA below 50 copies per milliliter. Independently of the study arm, patients with a n HIV-RNA level constantly above 3 copies per milliliter or showing viral blips had baseline HIV-DNA levels significantly higher (64,656 copies per 10 cells; SD, 93057) compared with patients who constantly presented a HIV-RNA level below the detection limit of 3 copies per milliliter (14,457 copies per 10 cells; SD, 14098) (P = 0.001). A rilpivirine-boosted plus ritonavir-boosted DRV therapy was not inferior over 48 weeks to a standard boosted protease inhibitor-based triple cART. The dual therapy did not negatively affect lipid profile and renal function and was more friendly on bone metabolism. This approach constitutes an alternative for patients experiencing nucleoside reverse transcriptase inhibitor-related toxicities.

Switching to boosted protease inhibitor plus a second antiretroviral drug (dual therapy) for treatment simplification: a multicenter observational study

BACKGROUND

Aim of the study was to assess predictors of discontinuation/toxicity of boosted PI-based (PI/r) dual therapy (DT).

METHODS

Observational, retrospective switch study in patients successfully treated with triple drugs regimen. Patients switched to PI/r based DT [darunavir (DRV/r), lopinavir (LPV/r) or atazanavir (ATV/r)] plus a second drug: [raltegravir (RAL), maraviroc (MVC) etravirine (ETR), lamivudine (3TC) or tenofovir (TDF)] between 2009 and 2014 were included. The effect of each drug as well as other clinical and virological cofactors over treatment discontinuation (TD) was assessed using survival analysis.

RESULTS

Overall, 376 patients were included with mean follow-up of 73 weeks. The most commonly used drugs in DT were DRV/r (63.0 %) and RAL (53.7 %). TD was observed in 77 (20,4 %) patients: 38 (10,1 %) virological failure, 35 (9,3 %) toxicity/intolerance (4 deaths) and 4 (1 %) interruptions for patients decision. At Cox Model, adjusted by demographic and laboratory variables, DRV/r and ATV/r significantly reduced the likelihood of TD and longer treatment was associated with lower risk, while low CD4 count at baseline and number of previous regimens with a higher risk. Moreover, RAL and 3TC use were significantly associated with lower TD by toxicity.

CONCLUSIONS

In our clinical practice experience, switching virologically suppressed patients to PI/r based DT showed adequate safety and efficacy, so that it may be used in selected patients with specific medical needs.

Darunavir/cobicistat for the treatment of HIV-1: a new era for compact drugs with high genetic barrier to resistance

INTRODUCTION

Cobicistat-boosted darunavir is a boosted protease inhibitor in a fixed-dose combination to be approved for the treatment of human immunodeficiency virus type1 infection. It contains darunavir, a well-known protease inhibitor with a good efficacy and safety profile, and the new pharmacokinetic enhancer cobicistat. The convenience of this combination in a single pill makes this compound easier to take, thus improving adherence.

AREAS COVERED

PubMed and www.clinicaltrials.gov were searched with the term "darunavir/cobicistat" for all clinical trials conducted up to date, as well as for those ongoing and to be opened in the near future as well as for pharmacology data. A review of abstracts from major infectious diseases (particularly those dedicated to human immunodeficiency disease) and pharmacology conferences from 2010 to 2015 was also conducted.

EXPERT OPINION

improving adherence, particularly by minimizing pill burden with convenient formulations (i.e., fixed-dose combination), is one of the major objectives of modern antiretroviral treatment of patients with human immunodeficiency virus disease. Cobicistat is an alternative agent to ritonavir for boosting plasma drug levels for several antiretrovirals. Darunavir co-administered with low-dose ritonavir, in combination with other antiretrovirals, is recommended in several guidelines for treatment of patients with human immunodeficiency disease. Darunavir/cobicistat fixed-dose combination allows for a once-daily treatment regimen with a reduced pill burden. This new co formulation makes this compound easier to take, thus improving adherence.