Background:
We previously demonstrated that initiation of long-acting cabotegravir/rilpivirine (LA-CAB/RPV) in people with HIV (PWH) with an unsuppressed HIV viral load (VL) at the Ward 86 clinic in San Francisco can rapidly lead to viral suppression (VS). We now seek to evaluate the durability of VS in this population.
Methods:
We conducted a retrospective cohort study of PWH who started LA-CAB/RPV before 7/17/2023, focusing on those with HIV VL ≥50 copies/mL at initiation. Our primary outcome was VS (VL <50 copies/mL) and LA-CAB/RPV persistence (not discontinued or late by >14 days) at 24 weeks, using the closest VL to 24+/-8 weeks. We considered missing 24-week VL as 1) unsuppressed (primary analysis); and 2) suppressed if evidence of VS before and after the outcome window (sensitivity analysis). We also describe viral failure (VF), defined as <2-log viral load decline at 4 weeks or VL ≥200 copies/mL after initial VS with emergent CAB- or RPV-associated resistance mutations; discontinuations; and overall VS at week 24 including those who switched to oral ART.
Results:
Among 243 PWH initiating LA-CAB/RPV, 88 (36%) had baseline VL ≥50 copies/mL and 60 had ≥32 weeks of follow-up time to assess the primary outcome (88% cisgender men, 47% age ≥50, 40% white, 28% Latino/a, 25% Black, 47% with housing instability, 43% using stimulants). At 24 weeks, 51 (85%) had VS, 4 had VL ≥50 copies/mL and 5 had missing VL data (table). Forty-nine met the primary outcome of LA-CAB/RPV persistence and VS (82%; 95%CI 69-90%), with this estimate rising to 85% (52/60) using imputed VLs in sensitivity analysis. Of the four with VL ≥50 copies/mL at week 24, two had VF with resistance (RT E138K, INSTI R263K; RT L100I, Y181I) and two had slow viral decay without resistance. After week 24, both patients with VF later attained VS on alternative regimens (lenacapavir(LEN)+BIC/TAF/FTC and CAB+LEN). Four other patients discontinued LA-CAB/RPV before week 24: two had VS on oral ART at week 24, one had VS after switch to oral ART but missing week 24 VL, and one was off ART and lost to follow-up due to psychosis. Week 24 VS on either LA-CAB/RPV or oral ART using imputed VL data was 92% (55/60).
Conclusions:
In those initiating LA-CAB/RPV without viral suppression, 24-week VS estimates were at least 85%. Long-acting ART can be an important tool for improving VS among patients who face adherence challenges to oral ART.
