Week 124 results of the randomized, open-label, Phase 3 FLAIR study evaluating long-acting cabotegravir + rilpivirine for treatment in adults with HIV-1 infection (ITT-E population)


BACKGROUND: Long-acting (LA) intramuscular injections of cabotegravir (CAB) and rilpivirine (RPV) have been developed as an alternative to daily oral dosing for HIV-1. The Phase 3 FLAIR study (NCT02938520) demonstrated noninferiority of switching virologically suppressed participants from daily oral dolutegravir/abacavir/lamivudine (DTG/ABC/3TC) to monthly CAB+RPV LA through Week (W) 48 and W96. Results for participants who received CAB+RPV for 124 weeks are presented.
METHODS: In the Maintenance Phase (W0'100), participants were randomized (1:1) to continue DTG/ABC/3TC or switch to monthly CAB+RPV LA after initially receiving a '¥4-week oral lead-in of CAB+RPV. At W100, participants receiving DTG/ABC/3TC could switch to CAB+RPV LA or withdraw. The primary endpoint was the proportion of participants with plasma HIV-1 RNA '¥50 copies/mL at W48 (FDA Snapshot algorithm). W124 endpoints included proportion of participants with HIV-1 RNA '¥50 and <50 copies/mL, confirmed virologic failure (CVF; two consecutive viral loads '¥200 copies/mL), and safety and tolerability.
RESULTS: Overall, 283 participants received '¥1 dose of CAB+RPV; median (range) age was 34.0 (19'68) years, 22% were female (sex at birth), and 76% were white. At W124, 14 (4.9%) participants had HIV-1 RNA '¥50 copies/mL, with 227 (80.2%) maintaining suppression (HIV'1 RNA <50 copies/mL). Through W124, 5 (1.8%) participants met CVF, one additional participant since W96 (Table). Injection site reactions (ISRs) were the most common drug-related adverse event (AE); most were Grade 1 or 2 (99.5%). The proportion of participants with ISRs decreased over time (W4: 72%; W48: 23%; W96: 19%; W124: 18%). Serious AEs and AEs leading to withdrawal occurred in 12% (one drug related) and 5% of participants, respectively, through 124 weeks.

CONCLUSIONS: At W124, monthly CAB+RPV LA maintained virologic suppression in most participants; the safety and tolerability profile was consistent with prior W48/W96 results. These results demonstrate the durability of CAB+RPV LA as a well-tolerated, effective maintenance therapy.