Background
Reducing the number of active compounds for lifelong HIV treatment is of interest, especially to reduce potential long-term side effects. The Rumba study is the first randomized clinical trial evaluating the impact on the viral reservoir, inflammation and metabolic parameters of switch from a 2nd generation integrase inhibitor (INSTI)-based triple ART regimen towards DTG/3TC vs. B/F/TAF. Results at 48 weeks confirm the effectiveness and safety of switch to DTG/3TC. Here, we quantified the mean change in inflammatory markers and immune cell counts between baseline and week 144 as an exploratory objective.
Methods
In this phase 4, prospective controlled switch trial, participants with HIV-1 RNA<50 copies/ml plasma at least 3 months on any stable 2nd generation INSTI-based triple ART were randomized 2:1 to switch to DTG/3TC (N=89) or to switch or stay on B/F/TAF (N=45). Plasma viraemia was quantified via the Cobas AmpliPrep-Cobas TaqMan HIV-1 test, D-dimers via immunoturbidimetry, cytokines via Meso Scale Discovery and immune cells via Sysmex/flow cytometry. Statistical analysis was performed with linear regression on log-transformed data, adjusted for baseline responses, CD4/CD8 ratio, smoking status and age.
Results
Baseline characteristics were well balanced between the treatment groups, except for peak viral load (Table 1). Data were available for 103 participants at W144 (73 DTG/3TC; 30 B/F/TAF), no discontinuation was reported due to virological failure. Virological success was high, with all participants having a viral load <50 copies/ml at W144.
The relative changes from baseline of inflammatory markers sCD14, sCD163, TNF-α, IL-8, IL-10, IL-21, CXCL-1, IP-10, VCAM-1, CRP and D-dimer did not differ between the treatment groups, both in the complete case and multiple imputation analyses. sCD14 decreased by 17% [CI 9-17%] in DTG/3TC and 10% [3-17%] in B/F/TAF. Furthermore, we observed no significant differences between the groups for CD4, CD8 and monocyte counts/µl whole blood.
Conclusions
The Rumba W144 data confirms that switch to DTG/3TC does not appear to have a negative impact with regard to viral suppression, inflammatory markers and immune cell counts. We did not observe significant differences in these exploratory outcomes between B/F/TAF and DTG/3TC.
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