Abstract
SOLAR (NCT04542070; registered 2020-09-09) is a Phase 3b study that demonstrated the noninferior virological efficacy of switching to cabotegravir + rilpivirine long-acting (CAB + RPV LA) dosed every 2 months vs. continuing daily oral bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) over 12 months. Participants were randomised (2:1) to switch to CAB + RPV LA or to continue BIC/FTC/TAF. Patient-reported endpoints included treatment preference, treatment satisfaction (12-item HIV Treatment Satisfaction Questionnaire status version), acceptability of injections (Perception of Injection questionnaire [acceptability domain]) and three single-item questions exploring psychological challenges related to HIV treatment (fear of disclosure, adherence-related anxiety and reminder of HIV status). Of 670 participants, 447 participants switched to CAB + RPV LA and 223 continued BIC/FTC/TAF. Overall, 18% were female, median age was 37 years and 31% were non-White. At Month 12, CAB + RPV LA significantly improved treatment satisfaction vs. BIC/FTC/TAF (mean [95% confidence interval (CI)] change: + 3.36 [2.59, 4.13] vs. -1.59 [-2.71, -0.47]; p < 0.001). At Month 12, a higher proportion of CAB + RPV LA arm participants reported improvements across the psychological challenges related to HIV treatment questions compared with BIC/FTC/TAF participants. Participants indicating ≥ 1 psychological challenge at baseline experienced a statistically significant and clinically meaningful improvement in treatment satisfaction after 12 months of CAB + RPV LA vs. continuing BIC/FTC/TAF (adjusted difference [95% CI]: 7.96 [5.65, 10.26]; p < 0.001). Most (90%, 382/425) questionnaire respondents preferred CAB + RPV LA vs. BIC/FTC/TAF (5%, 21/425). Switching to CAB + RPV LA was associated with significantly improved treatment satisfaction and relief from the fear of disclosure, anxiety surrounding adherence and reminder of HIV status.