Efficacy and safety of switching to long-acting cabotegravir + rilpivirine versus continuing bictegravir/emtricitabine/tenofovir alafenamide in Japanese participants: 12-month results from the phase 3b randomized SOLAR trial

In the phase 3b SOLAR study, switching to long-acting cabotegravir + rilpivirine (CAB+RPV LA) administered every 2 months (Q2M) was non-inferior to continuing daily oral bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF). We present a post hoc analysis of Japanese participants. SOLAR is a randomized (2:1), open-label, multicenter, non-inferiority study of virologically suppressed participants switching to CAB+RPV LA Q2M (with or without oral lead-in) versus continuing BIC/FTC/TAF. The primary endpoint was HIV-1 RNA ≥50 copies/mL at Month 12 (Snapshot algorithm). Of 670 participants (modified intention-to-treat–exposed population), 20 were from Japan (LA, n = 14; BIC/FTC/TAF, n = 6). At Month 12, no participants in either Japanese group had HIV-1 RNA ≥50 copies/mL; 86 % (12/14; 2 participants withdrew) versus 100 % (6/6) had HIV-1 RNA <50 copies/mL in the LA versus BIC/FTC/TAF groups; none had confirmed virologic failure. Withdrawals were due to a non–drug-related adverse event (AE; acute hepatitis B) and a physician decision. Excluding injection site reactions, drug-related AE rates were higher in the LA group (36 % vs 17 %; all grade 1 or 2). No drug-related serious AEs were reported. Injection site reactions were common (100 % [13/13] of LA participants); all were grade 1 or 2; none led to withdrawal; median duration was 4 days. Mean treatment satisfaction scores improved from baseline to Month 12 in the LA versus BIC/FTC/TAF Japanese groups (+6.25 vs + 0.33 on a 66-point scale). Though limited, these data suggest switching to CAB+RPV LA from BIC/FTC/TAF was well tolerated in Japanese participants, with comparable efficacy and improved treatment satisfaction.

ClinicalTrials.gov; NCT04542070 (https://www.clinicaltrials.gov/study/NCT04542070).