HIV viral kinetics and T cell dynamics in antiretroviral naïve persons starting an integrase strand transfer inhibitor and protease inhibitor regimen

BACKGROUND

Nucleos(t)ide reverse transcriptase inhibitor (NRTI)-sparing regimens may potentially minimize antiretroviral (ART) toxicities, but demonstrate mixed efficacy and toxicity results. The impact of an integrase strand transfer inhibitor (INSTI) and protease inhibitor (PI) regimen on HIV viral dynamics and T cell kinetics remains underdescribed.

OBJECTIVE

To compare the effect of raltegravir + ritonavir boosted lopinavir (RAL + LPV/r) to efavirenz/tenofovir disoproxil fumarate/emtricitabine (EFV/TDF/FTC) on HIV kinetics and T cell dynamics.

METHODS

Fifty participants naïve to ART underwent HIV viral kinetic sampling evaluated using biexponential mixed effects modeling. A subset of 28 subjects (with complete viral suppression) underwent flow cytometry and evaluation of soluble markers of inflammation at weeks 0, 4, and 48 of ART.

RESULTS

RAL + LPV/r compared to EFV/TDF/FTC resulted in a prolonged first phase viral decay rate (18 vs. 13 days p < 0.01). From weeks 0 to 4, RAL + LPV/r was associated with a trend toward greater decreases in activated CD4⁺ T cells (-3.81 vs. -1.18 p = 0.09) and less decreases in activated effector memory CD4⁺ T cells (-0.63 vs. -2.69 p-0.07). These trends did not persist to week 48. No differences were noted at any time point for soluble markers of immune activation.

CONCLUSIONS

The prolonged first phase viral decay observed with RAL + LPV/r in persons starting ART did not result in differences in viral suppression at week 48. We also observed trends in declines in certain cellular markers of immune activation but it remains unclear if this could translate to long-term immunologic benefits in persons on an INSTI + PI.

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.