Impact of antiretroviral regimens containing Integrase Inhibitors on achieving viral suppression at ultra-low levels compared to other ART strategies.

Background: Despite effective antiretroviral therapy (ART), residual low-level HIV viremia may persist. Integrase inhibitor (INSTI)-based regimens have become preferred treatments, but their impact on controlling residual viral replication remains unclear.

Objective: To evaluate the impact of integrase inhibitor-based regimens on achieving target not detected (TND) rates compared to other antiretroviral strategies.

Methods: This retrospective cohort study assessed 131 virologically suppressed people with HIV (PWH) categorized into 4 treatment groups: Group 1, treated with protease inhibitor (PI) or non-nucleoside reverse transcriptase inhibitor (NNRTI) based regimens (n = 30); Group 2, treated with INSTI-based regimens (n = 30); Group 3, initially treated with PI/NNRTI regimens who switched to INSTI-based therapy (n = 26); and Group 4, initially treated with INSTI triple therapy who switched to dual therapy (n = 30). The primary endpoint was the proportion of "target not detected" (TND) HIV-1 RNA measurements.

Results: INSTI-based regimens showed significantly higher TND rates compared to PI/NNRTI-therapies (difference: 18.5%, p < 0.001). Switching from PI/NNRTI to INSTI-based therapies increased TND rates from 52.6% to 92%. Multivariate analysis identified shorter time to viral suppression and absence of HCV co-infection as factors associated with higher TND rates. No significant differences were observed when switching from INSTI-based triple therapy to INSTI-based dual therapy.

Conclusion: INSTI-based regimens, whether triple or dual therapy, achieve better control of residual viremia compared to other treatment strategies. This improved virological control was maintained during follow-up and was independent of the number of drugs.