 |
|
|
| |
Restarting bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) after virologic rebound: a pooled analysis of studies in people with HIV-1
|
| |
| |
Maintaining B/F/TAF After Rebound Resuppresses HIV in 80% in Trials
EACS 2023, October 18-21, 2023, Warsaw
Mark Mascolini
Four in 5 people with 1 or more virologic rebounds of 1000 copies or more while taking bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) in a clinical trial regained a viral load below 50 copies while continuing the 3-in-1 once-daily pill, according to pooled analysis of 9 phase 3 randomized trials [1]. No resistance mutations emerged while people had a detectable viral load during B/F/TAF therapy.
Because data on B/F/TAF in people with a detectable viral load are scanty, researchers involved in trials of this popular combination pooled data from 9 phase 3 trials of B/F/TAF in people 18 or older with no documented resistance to emtricitabine or TAF, a viral load below 50 copies for at least 3 months before screening (in B/F/TAF switch studies), and taking a stable antiretroviral regimen for at least 3 months before screening (in B/F/TAF switch studies).
In 3 trials participants took B/F/TAF as their first regimen, and in 6 trials they took it after another regimen had controlled HIV. For this analysis researchers defined virologic rebound as 1 or more viral loads at or above 1000 copies after a viral load below 50 copies, indicating spotty adherence. Resuppression meant a viral load below 50 copies after rebound to 1000 copies or higher.
The pooled study included 96 people with virologic rebound while taking B/F/TAF and 3672 with no rebound. The proportion of previously untreated people was greater in the rebound group than the no-rebound group (55.2% vs 18.8%, P < 0.0001). Compared with the no-rebound group, the rebound group had a higher proportion of blacks (53.1% vs 35.1%) and a lower proportion of whites (35.4% vs 51.1%) (P < 0.0001) but a similar proportion of Hispanics (21.9% and 18.0%). When starting B/F/TAF, a lower proportion of rebounders than nonrebounders had a viral load below 50 copies (41.7% vs 80.0%, P = 0.005). Rebounders did not differ from nonrebounders in proportions of women and men.
The researchers counted 110 rebounds in 96 of 3772 trial participants (2.5%) taking B/F/TAF. Before treatment with B/F/TAF in rebounders, 1 had an integrase inhibitor resistance mutation, 6 had a nucleoside/nucleotide mutation, 2 had a protease inhibitor mutation, and 20 had a nonnucleoside mutation.
Among the 110 rebound events, 91 (83%) were followed by virologic suppression below 50 copies with B/F/TAF. If the researchers excluded nonevaluable virologic rebounds, resuppression followed rebound in 91 of 98 cases (93%). Among 96 people who had a rebound on B/F/TAF, 77 (80%) regained a viral load below 50 copies after their last rebound while continuing B/F/TAF. When the research team excluded nonevaluable rebounds on B/F/TAF, 77 of 84 people (92%) achieved virologic resuppression while maintaining those antiretrovirals.
Median time to virologic rebound for these 110 rebounds was 273 days (interquartile range [IQR] 148 to 503), median time from rebound to resuppression stood at 23 days (IQR 19 to 38), and median duration of a detectable load in 7 rebounders who ultimately stopped B/F/TAF was 30 days (IQR 14 to 87). Median viral load in rebounds reached 6840 copies (IQR 2120 to 22,200). No resistance mutations emerged during rebounds while taking B/F/TAF.
A significantly higher proportion of people with versus without rebound had less than 85% adherence to study drugs (18% vs 4%, P < 0.0001).
The researchers believe these findings indicate that "continuation of B/F/TAF treatment is effective in achieving HIV-1 resuppression following virologic rebound."
Reference
1. Pozniak A, Orkin C, Maggiolo F, et al. Restarting bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) after virologic rebound: a pooled analysis of studies in people with HIV-1. EACS 2023, October 18-21, 2023, Warsaw. Abstract eP.A.086.
|
| |
|
|
|
|
|
