SAN DIEGO – The proportion of viral failure was lower in people living with HIV who took dolutegravir (DTG), compared with patients on other integrase strand transfer inhibitor (INSTI) regimens, according to a study presented at ID Week 2017, an infectious diseases meeting.
Investigators studied records of 6,636 HIV patients who started regimens between August 2013 and August 2016, gathered from the Center for Aids Research (CFAR) Network of Integrated Clinical Systems. The information was collected from eight centers across the United States.
Patients were split among three ART regimen groups: dolutegravir based, other INSTI based, and darunavir (DRV) based. Among the 6,636 people living with HIV studied, those using a DTG-based regimen were less than half as likely to exhibit viral failure as were those in the DRV-based group (hazard ratio, 0.41; 95% confidence interval, 0.37-0.86), according to Heidi Crane, MD, MPH, associate director of CFAR Clinical Epidemiology and Health Services Research at the University of Washington, Seattle.
In a comparison of DTG-based therapy compared to other INSTI-based therapies, patients in the DTG groups showed significantly lower risk for viral failure in a crude hazard ratio (HR, 0.57; 95% CI, 0.46-0.70), although, when adjusted, the investigators found the odds did not hold the same level of significance, despite still being at a lower risk (adjusted HR, 0.82; 95% CI, 0.65-1.03).
In a sensitivity analysis of ART-naive patients, investigators found that patients taking DTG regimens were at nearly one-third the risk of viral failure, compared with those taking a darunavir-based regimen (adjusted HR, 0.32; 95% CI, 0.14-0.75). However, when comparing DTG with other INSTI therapies among the ART-naive population, there was no significant difference reported, Dr. Crane said in.
Investigators found this difference significant when comparing DTG with DRV and DTG with other INSTIs to be a trend across all testing models, according to Dr. Crane.
“In the various sensitivity models, the association for dolutegravir versus other integrase inhibitors ranged from 0.8 to 0.98 depending on censoring, sometimes significant and sometimes not,” said Dr. Crane. “In contrast, the hazard ratio for the dolutegravir versus the darunavir regimens ranged from 0.4 to 0.5, depending on censoring definitions, and we could not break that binding.”
The changing levels of significance are becuase of the different definitions of censoring for end of follow-up, according to Dr. Crane.
In addition to improved viral failure rates, patients taking DRV-based regimens had a higher proportion of patients lost to follow-up (20%), compared with those assigned DTG regimens (5%), which Dr. Crane hypothesized could be a result of the difference in time on the market between the two drugs.
This study was limited to studying only those patients receiving treatment after 2013,
Funding was provided by ViiV and the National Institutes of Health, which funds the CFAR Network of Integrated Clinical Systems.
SOURCE: Nance R et al. .