Predictors of Post-switch Viremia in People With HIV on Injectable Cabotegravir/Rilpivirine.

BACKGROUND

Predictors of virologic failure in those receiving long-acting injectable (LAI) cabotegravir/rilpivirine (CAB/RPV) have been evaluated; however, factors associated with low-level viremia, including blips and persistent low-level viremia (pLLV), are not well-described.

METHODS

A retrospective cohort study was performed using data from April 2021 through December 2022. Inclusion criteria included treatment with CAB/RPV for at least 3 months, availability of pre- and postswitch HIV RNA values, HIV RNA value of <200 copies/mL (cpm) at the time of switch to CAB/RPV, and at least 1 postswitch HIV RNA collected >21 days after the start of CAB/RPV. Outcomes included incidence of HIV RNA ≥20, ≥50, and ≥200 cpm after switch and factors associated with detectable HIV RNA after switch.

RESULTS

The median duration of follow-up among 144 participants was 287 days. After switching to CAB/RPV, occurrences of at least 1 HIV RNA ≥20, ≥50, and ≥200 cpm after switch were 34.7%, 15.3%, and 2.8%, respectively. Those with pLLV before switch were significantly more likely to have detectable HIV RNA after switch [hazard ratio 24.39 (8.71-68.34)], and 44.4% of those with pLLV before switch continued with pLLV after switch to LAI CAB/RPV. Body mass index, late injection, and monthly versus every two-month dosing were not associated with detectable viremia after switch.

CONCLUSIONS

Despite virologic suppression at the time of switch and the perceived adherence benefits, participants still experienced blips or pLLV after switch to LAI CAB/RPV. Having detectable HIV RNA on oral therapy before switch was associated with detectable HIV RNA after switching.