Individuals who have virologic suppression of HIV with daily oral dolutegravir/abacavir/lamivudine (DTG/ABC/3TC) can be switched safely with or without an oral lead-in phase to monthly injectable cabotegravir plus rilpirivine (CAB/RPV) with comparable efficacy and safety, new data suggest.
Among 232 patients who had virologic suppression (HIV-1 RNA less than 50 copies/mL) following 100 weeks of therapy with DTG/ABC/3TC, the safety and tolerability of the long-acting CAB/RPV formulation was similar whether patients were immediately switched to it or transitioned over 1 month with an oral lead-in phase, reported Ronald D’Amico, MD, from ViiV Healthcare, and colleagues during the annual HIV Glasgow drug therapy meeting, which was held virtually this year because of the pandemic.
Virologic suppression rates 24 weeks after the switch were 99.1% for patients switched directly to the long-acting CAB/RPV and 93.4% for patients who had an oral lead-in; virologic data at this time point was not available for 7 patients (5.8%) in the oral lead-in arm vs 0% of patients in the direct-treatment group.
The investigators reported results of the extension phase of the FLAIR trial. In this study, 629 treatment-naive study participants started on DTG/ABC/3TC, and those who achieved viral suppression at 20 weeks, were then randomly assigned to continue with that regimen or to switch to long-acting CAB/RPV. Participants in the switch group began with a 30-day lead-in regimen of daily oral cabotegravir 30 mg plus rilpivirine 900 mg and then switched to monthly intramuscular injections.
In the current study, the investigators reported on the extension switch population. At week 100 of the study, patients initially assigned to DTG/ABC/3TC could opt to switch to intramuscular CAB/RPV either directly (111 patients) or with 1 month of oral CAB/RPV (121 patients).
At 24 weeks following the switch (study week 124), only one patient in each study arm had HIV-1 RNA of 50 copies/mL or greater, and as noted before 99% of patients in the direct-to-injection arm had maintained virologic suppression, as did 93% of patients in the oral lead-in group. One patient in the direct-to-injection arm had a confirmed virologic failure at week 112.
There was one grade 4 drug-related adverse event in the direct-to-injection group, a case of mixed cellularity Hodgkin lymphoma. Severe (grade 3) adverse events occurred in one patient in the direct arm, and five in the oral lead-in group.
Patients generally tolerated the long-acting injections well. Injection site reactions were the most common adverse events reported; most were mild or moderate in severity, the investigators reported.
Long-acting CAB/RPV is an investigational formulation. Last December, the US Food and Drug Administration denied approval to the formulation based on manufacturing and chemistry concerns, according to a company press release.
HIV Glasgow 2020 Virtual Conference: Abstract O414. October 5-8, 2020.
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