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.

Single-center experience evaluating and initiating people with HIV on long-acting cabotegravir/rilpivirine.

OBJECTIVE: To describe our experience evaluating and initiating individuals on long-acting injectable (LAI) cabotegravir/rilpivirine (CAB/RPV) and evaluate factors associated with starting LAI CAB/RPV and reasons for not starting. DESIGN: We conducted a retrospective single-center study at the UC San Diego Owen Clinic. METHODS: We included all individuals who expressed interest in treatment with LAI CAB/RPV between April 2021 and June 2022 who had a definitive decision made on starting LAI CAB/RPV. RESULTS: In total, 383 individuals were included with 201 (52.5%) initiating LAI CAB/RPV. Those who initiated LAI CAB/RPV were younger ( P  = 0.02) and were more likely to be on a two-drug regimen or first-generation integrase inhibitor regimen and less likely to be on a protease inhibitor or multiclass regimen. The most common reasons for not starting LAI CAB/RPV were inconsistent clinic attendance or difficulty being contacted and patient choice not to start. Of those who had a proviral DNA resistance test as workup for LAI CAB/RPV ( n  = 135), 18.5% had a resistance mutation identified that may have impacted the activity of LAI CAB/RPV. CONCLUSION: Despite novel challenges over half of our cohort initiated LAI CAB/RPV. Evaluating for potential non-nucleoside reverse transcriptase inhibitor resistance is an important part of the workup for LAI CAB/RPV and proviral DNA resistance testing can be an additional tool to identify potential resistance.

Prevalence, predictors, and outcomes of early adherence after starting or changing antiretroviral therapy.

The objectives of this research were to assess prevalence and predictors of early antiretroviral therapy adherence using multiple indicators and to estimate effects of early adherence on subsequent HIV viral load and CD4+ lymphocyte responses. Study subjects were adults with HIV infection referred to an antiretroviral therapy-monitoring clinic for initiation or change in therapy between March 1998 and June 1999. The design was a prospective observational cohort involving baseline interview followed by 30 days of electronic adherence monitoring (MEMS), 30-day interview, and follow-up viral load at 1, 3, and 6 months. Adherence indicators included MEMS therapeutic coverage, observed/expected cap openings, and self-reported adherence assessed at 30 days. Of 235 consenting patients, 60 (26%) failed to complete 30 days of electronic monitoring (noncompleters). At 6 months, mean change from baseline plasma viral load was inferior among noncompleters (0.5 log vs. 1.7 log). Predictors of adherence, varying by adherence metric, included: gender, race, prior antiretroviral therapy experience, substance abuse, prior adherence behavior, health beliefs, and pharmacist prediction of adherence. Self-reported adherence was more sensitive in predicting viral load responses than MEMS-based measures and identified poor adherence at earlier time points. Approximately a quarter of consenting patients were unable to complete 30 days of MEMS monitoring, and early drop out was a poor prognostic sign. Predictors of adherence varied depending upon how adherence was measured. Differences in virologic response between patients with optimal or poor adherence may not emerge until several months after regimen change or initiation. Structured assessment of self-reported adherence is an inexpensive and useful tool to assist clinicians in monitoring adherence.