There are many long-term HIV-infected patients with multi-drug resistance. These individuals usually require “salvage” therapy to maintain viral suppression. In recent years, fewer patients are failing first-line INSTI-based regimens, and thus there are few clinical trials of salvage therapy. This study from Italy included 130 subjects of who were switched from 42 different ART regimens to just dolutegravir (DTG) plus boosted darunavir (bDRV). Reasons for switching included simplification (45%), virologic failure (30%), or toxicity (16%). At baseline, 118 of the patients had resistance from one to five different drug classes. There was not resistance testing available for the other 12. Eighty-one had been on bDRV at baseline and one on DTG. All participants who were taking DRV with ritonavir were switched to co-formulated DRV/cobicistat between weeks 48 and 60. At 96 weeks on treatment with DTG/bDRV, only two patients had a viral load > 50 copies. Twenty-three had detectable viremia of 1-49 copies/mL, and 101 had NO detectable virus. Median increase in CD4 count was 54 (3.2%) from baseline although this was not a statistically significant change. Other safety and metabolic parameters including lipids and renal function either remained stable or improved during the 96-week time period.

Author’s Commentary: This data is reassuring for patients who may have broad NRTI resistance, transmitted resistance or intolerance to this class of HIV medications. There are several other studies supporting this combination of a boosted PI and INSTI. I have used this for a few patients in my clinical practice. A PubMed search revealed at least three other published studies showing the effectiveness of this 2-drug combination in treatment-experienced patients.