The current standard of care for HIV treatment is a three-drug regimen consisting of two nucleoside reverse transcriptase inhibitors (NRTIs) combined with an integrase strand transfer inhibitor (INSTI) or a protease inhibitor (PI). Darunavir boosted with ritonavir (DRV/r) is the only preferred PI in the US DHHS HIV Treatment Guidelines, but little is known about its effectiveness when combined with abacavir (ABC) and lamivudine (3TC). This study compared the effectiveness of ABC/3TC when used with DRV/r to ABC/3TC when used with other boosted PIs (PI/r) in a treatment-experienced HIV-infected population.
Treatment-experienced HIV-infected patients initiating their first regimen containing ABC and 3TC in combination with any PI in the year 2005 or later were selected from the Observational Pharmaco-Epidemiology Research & Analysis (OPERA) cohort, a prospective observational cohort reflecting routine medical care. Viral load measurements taken during follow-up were compared between patients taking ABC/3TC+DRV/r and ABC/3TC+ non-DRV PI/r. Multivariable logistic regression models were fit to assess the association between regimen exposure and viral load suppression.
A total of 141 patients initiating ABC/3TC+DRV/r and 511 patients initiating ABC/3TC+non-DRV PI/r were included in the analysis. After adjusting for factors associated with baseline health (CD4, viral load), the DRV/r and non-DRV PI/r regimens showed equivalent effectiveness while being treated with the regimen of interest [adjusted odds ratio (95% confidence interval): 0.91 (0.54, 1.51)]. Patients in both treatment groups also showed similar reductions in viral load [median (interquartile range (IQR)) DRV/r vs. non-DRV/r PIs: -28 (-671, 0) vs. -23 (-341, 0) copies/mL; p=0.43) and gains in CD4 cell counts [median (IQR) DRV/r vs. non-DRV/r PIs: 105 (21, 249) vs. 124 (18, 273) cells/mm3; p=0.60] during the same period.
Patients with poorer health indicators at baseline may be more likely to initiate ABC/3TC with DRV/r than ABC/3TC with other PIs. Patients on ABC/3TC+DRV/r appear to experience similar treatment benefit to patients taking ABC/3TC with other PIs in terms of absolute reductions in viral load.
Janssen Pharmaceuticals: Investigator and Scientific Advisor , Consulting fee and Research support
F. Carpio, None
R. Hsu, ViiV Healthcare: Investigator , Scientific Advisor and Speaker's Bureau , Consulting fee , Research support and Speaker honorarium
Janssen Pharmaceuticals: Scientific Advisor and Speaker's Bureau , Consulting fee and Speaker honorarium
E. Dejesus, ViiV Healthcare: Consultant and Investigator , Consulting fee and Research support
Janssen Pharmaceuticals: Consultant , Investigator and Speaker's Bureau , Consulting fee , Research support and Speaker honorarium
G. Pierone, ViiV Healthcare: Investigator , Research support
Janssen Pharmaceuticals: Investigator , Research support
C. Henegar, ViiV: Investigator , Research support
E. Brouwer, None
J. Fusco, ViiV Healthcare: Investigator , Research support
G. Fusco, ViiV Healthcare: Investigator , Research support
M. Wohlfeiler, ViiV: Investigator and Scientific Advisor , Consulting fee and Research support