48-week viral suppression rates in people with HIV starting long-acting CAB/RPV with initial viremia

Background: We previously demonstrated at the Ward 86 HIV clinic in San Francisco that long-acting cabotegravir/rilpivirine (LA-CAB/RPV) can rapidly lead to viral suppression (VS) in people with HIV (PWH) with viremia due to adherence challenges. We now evaluate VS durability in this population.

Methods: We conducted a retrospective cohort study of PWH who started LA-CAB/RPV with viremia (HIV RNA viral load [VL]≥50 copies/mL) before December 2022. Our primary outcome was VS (VL<50 copies/mL) with LA-CAB/RPV persistence (not discontinued or late by >14 days) at 48 weeks, using the closest VL to 48+/-8 weeks. We also describe viral failure (VF), defined as <2-log VL decline at 4 weeks or VL≥200 copies/mL after initial VS with emergent CAB- or RPV-associated resistance mutations; and overall 48-week VS including those switched to alternative ART.

Results: Fifty nine PWH initiated LA-CAB/RPV with viremia and were included in analysis; 49% had CD4<200 cells/µL and median baseline VL was 42,900 copies/mL (Q1-Q3 5,272-139,038). At 48 weeks, 47 met the primary outcome of VS with LA-CAB/RPV persistence (80%; 95%CI 67-89%). Five had VF with resistance (three with RPV-associated mutations, two with CAB and RPV-associated mutations) and one was lost-to-follow-up. At week 48, two of those with VF were suppressed on alternative regimens (lenacapavir+BIC/TAF/FTC and CAB+lenacapavir). Overall week 48 VS on either LA-CAB/RPV or alternative ART was 92% (54/59).

Conclusions: In PWH initiating LA-CAB/RPV with initial viremia, 48-week VS (<50 copies/mL) was 92%. Long-acting ART can be an important tool for improving VS among patients who face adherence challenges to oral ART.