Simplifying ARV Therapy in the Setting of Resistance

HIV treatment simplification is typically indicated for virologically suppressed patients with no baseline resistance-associated mutations (RAMs) or prior virologic failure (VF) to the simplification regimen. Simplification can occur to minimize pill burden, toxicities, drug-drug interactions, or costs. As most studies for treatment simplification excluded patients with baseline RAMs or prior VF, this review is aimed to critically analyze data regarding treatment simplification in treatment-experienced patients.

Antiretroviral (ARV) regimens containing three-, two-, and one-drug(s) have been scarcely studied to assess virologic efficacy in treatment-experienced patients. Three-drug regimens with the most data and highest efficacy are with integrase strand transfer inhibitors (INSTIs). Regimens including dolutegravir (DTG) and bictegravir have been shown to maintain efficacy in patients with certain baseline RAMs. Dual therapy regimens include the use of DTG plus either lamivudine (3TC), rilpivirine (RPV), or other ARVs. None of these studies evaluated patients with baseline DTG resistance. Baseline RAMs to 3TC were not a predictor of VF in patients on DTG/3TC. Efficacy was seen with DTG/RPV; however, studies showed high rates of discontinuation. DTG plus boosted-protease inhibitors were studied in smaller but promising studies. Two small studies assessed the use of monotherapy with boosted darunavir or DTG, both showing virologic efficacy. Currently, three- and two-drug ARV regimens may be considered in this population with most studies evaluating the use of DTG and bictegravir without baseline INSTI RAMs. Future studies should include heavily treatment-experienced patients with a variety of baseline RAMs and a larger sample size.