Weight Gain in Persons with HIV Switched from Efavirenz-based to Integrase Strand Transfer Inhibitor-based Regimens

BACKGROUND:With the introduction of integrase strand transfer inhibitor (INSTI)-based antiretroviral therapy (ART), persons living with HIV have a potent new treatment option. Recently, providers at our large treatment clinic noted weight gain in several patients switched from efavirenz/tenofovir disoproxil fumarate/emtricitabine (EFV/TDF/FTC) to dolutegravir/abacavir/lamivudine (DTG/ABC/3TC). In this study, we evaluated weight change in patients with sustained virologic suppression switched from EFV/TDF/FTC to an INSTI-containing regimen. METHODS:We performed a retrospective observational cohort study among adults on EFV/TDF/FTC for at least two years who had virologic suppression. We assessed weight change over 18 months in patients who switched from EFV/TDF/FTC to an INSTI-containing regimen or a protease inhibitor (PI)-containing regimen versus those on EFV/TDF/FTC over the same period. In a sub-group analysis, we compared patients switched to DTG/ABC/3TC versus raltegravir- or elvitegravir-containing regimens. RESULTS:A total of 495 patients were included136 switched from EVF/TDF/FTC to an INSTIcontaining regimen and 34 switched to a PI-containing regimen. Patients switched to an INSTIcontaining regimen gained an average of 2.9 kg at 18 months compared to 0.9 kg among those continued on EFV/TDF/FTC (p=0.003), while those switched to a PI regimen gained 0.7 kg (p=0.81). Among INSTI regimens, those switched to DTG/ABC/3TC gained the most weight at 18 months (5.3 kg, p=0.001 compared to EFV/TDF/FTC). CONCLUSION:Adults living with HIV with viral suppression gained significantly more weight after switching from daily, fixed dose EFV/TDF/FTC to an INSTI-based regimen compared to those remaining on EFV/TDF/FTC. This weight gain was greatest among patients switching to DTG/ABC/3TC.