Switching from a protease inhibitor-based regimen to a dolutegravir-based regimen: a randomized clinical trial to determine the effect on peripheral blood and ileum biopsies from ART-suppressed HIV-infected individuals.

Background: Optimization of combination antiretroviral therapy (cART) can impact the HIV reservoir. We evaluated the effect on the HIV reservoir in peripheral blood and ileum biopsies of switching from boosted protease inhibitor (PI)-based therapy to dolutegravir (DTG)-based therapy.

Methods: INDOOR is a phase IV open-label clinical trial that randomly included 42 HIV-1-infected individuals on effective cART: 20 who switched from boosted PI-based to DTG-based cART (switch group), and 22 who remained in boosted PI-based regimens (control group). We analyzed blood and ileum biopsies to quantify episomal, total, and integrated HIV-DNA, cell-associated HIV-RNA, residual plasma viremia, T-cell subsets, cell activation, and inflammation markers.

Results: There were no related adverse events or treatment discontinuations due to drug intolerance. The HIV reservoir was consistently larger in ileal than in peripheral CD4 + T cells in both groups (p<0.01). Residual viremia in plasma decreased in the switch group (p=0.03). However, we did not observe significant longitudinal changes in low-level viral replication, total and integrated HIV reservoir, HIV transcription, T-cell maturation subsets, immunoactivation markers, inflammatory soluble proteins, or cellular markers of latently infected cells.

Conclusions: The INDOOR study is the first evaluation of changes in HIV reservoir size in ileum biopsies and in peripheral blood in individuals switched from boosted PI- to DTG-based cART. Although this switch was safe and well tolerated, it had no impact on a large array of immunological and inflammatory markers or on HIV reservoir markers in peripheral or in ileal CD4 + T cells.

Clinical Trials Registration: EudraCT no. 2014-004331-39.