NEW ORLEANS, LA—Combined daily dolutegravir (DTV, 50mg) and rilpivirine (RPV, 25mg) is safe for HIV-infected patients previously treated with other regimens, according to findings from a small observational retrospective study reported at IDWeek 2016.

The findings “suggest that this combination is both safe and well tolerated in patients who had experienced adverse events to previous ART,” reported Christopher Saling, MD, of the Department of Internal Medicine, St. Michael’s Medical Center, in Newark, NJ, and coauthors, in a poster presentation. “Also DTV+RPV seem very efficacious in suppressing HIV VL [viral load] in those with prior resistance.”

A larger study is required to confirm the long-term efficacy and safety of the regimen, the authors cautioned.

DTV+RPV is under study as a maintenance regimen in a Phase 3 trial. The presentation described patients who had been switched to DTV+RPV “for reasons other than simplification or maintenance.”

The study was conducted in an inner-city HIV clinic serving 1,232 HIV patients. A review identified 14 patients who had taken DTV+RPV following failure of a prior regimen. Virologic failure was defined as a confirmed detectable viral load in patients who were previously <20 copies/mL, undetectable on ART. Reasons for the switch included adverse events/resistance among 29% of patients, virologic failure among 14% of patients, and adverse events for 57% of patients. 

“Prior to the switch to DTV+RPV, 4 regimens were NNRTI-based, 5 contained protease inhibitors, 6 contained integrase inhibitors, and 11 had a regimen with a two-NRTI backbone,” the authors noted. “Half of the patients had developed resistance to their previous regimens, with four patients having 2 class-resistance and 3 [were] resistant only to NRTIs. Nine patients had intolerance to their prior regimens.”

As of May 1, 2016, patients had a combined total of 599-week of VL<20 copies/mL on DTV+RPV,” they reported. Overall, DTV+RPV seem effective in suppressing HIV VL in these patients with no signs of resistance to DTV and RPV.