Viremic events uncommon in patients with HIV on 3-drug ART regimen BIC/FTC/TAF

To evaluate viremic trends associated with the use of BIC/FTC/TAF, researchers in the United Kingdom and Spain conducted a post hoc analysis among patients with HIV infection. The analysis comprised patient data captured from 8 randomized controlled phase 3/3b trials (ClinicalTrials.gov Identifiers: NCT02607930, NCT02607956, NCT02603120, NCT02603107, NCT03110380, NCT03631732, NCT03405935, NCT02881320). Adult patients (N=2801) who initiated the 3-drug ART regimen had their HIV-1 viral load measured at baseline, in 4-week intervals until week 12, and every 12 weeks thereafter through the end of the study. The researchers monitored patients for viremic events, defined as any HIV-1 RNA measurement at or above 50 copies/mL.

A total of 411 viremic events occurred among the study population during the analysis. In patients with (n=290) and without (n=2511) a viremic event recorded, the median ages were 36 (IQR, 25-50) and 44 (IQR, 32-54) years (P =.0010), 82.4% and 82.3% were men, 49.1% and 39.4% were Black (P <.0001), and 50.0% and 19.1% were treatment-naive (P <.0001), respectively.

Of patients who experienced viremia, 75.5% had a single event, 16.9% had 2 events, and 7.6% had 3 or more events. The median time to first viremic event was 254 days.

Further analysis of patients who experienced viremia indicated most (86.2%) subsequently achieved resuppression. The rate resuppression was 95.1% after the exclusion of nonevaluable events and 97.1% in the subset of patients (n=145) who were naive to treatment. Overall, the median HIV-1 RNA level at the time of viremia was 2.25 log₁₀ copies/mL, with resuppression occurring after a median of 22 days.

In regard to preexisting primary resistance substitutions among patients who experienced viremia, the most common were K103N/S (n=28), E138A/G/K/Q/R (n=16), M184I/V (n=14), and G190A/E/Q/S (n=11).

Of 13 patients who experienced persistent viremia (median duration, 72 days), the majority (69.2%) exhibited viral loads at or above 200 copies/mL. Most patients with persistent viremia discontinued BIC/FTC/TAF due to lack of efficacy (n=3), personal decision (n=4), or loss to follow-up (n=4).

The researchers observed significantly increased rates of high-level treatment adherence (<85%) among patients with vs without a viremic event recorded during the study period (10.0% vs 4.2%; P =.0003).

Results of sensitivity analyses that used HIV-1 RNA levels of 200 copies/mL or greater and 1000 copies/mL or greater to define a viremic event were similar to those observed in the primary analysis.

Limitations of this analysis include the lack of a control group, the exploratory post hoc design, and the shorter follow-up time after resuppression in virologically suppressed vs treatment-naive patients.

According to the researchers, “Future research is needed to ascertain whether low-level viremia is associated with virologic failure over a longer follow-up period.”

Disclosure: This study was supported by Gilead Sciences, Inc., and multiple study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

By Jessica Nye, PhD

References:

Pozniak A, Orkin C, Yazdanpanah Y, et al. Efficacy of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) after a viremic event: a pooled analysis of studies in people with HIV. Infect Dis Ther. Published online April 15, 2025. doi:10.1007/s40121-025-01153-y