Among African American patients with HIV infection, virologic suppression was maintained during treatment with bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF), regardless of pre-existing resistance, viral blips, or suboptimal adherence, according to research presented at the IDWeek, held virtually from September 29 to October 3, 2021.

Researchers used data obtained from a phase 3 multicenter study to assess resistance, viral blips, adherence, and virologic outcomes at week 72 among patients treated with B/F/TAF. Patients with resistance to either non-nucleotide reverse transcriptase inhibitors (NNRTI), protease inhibitors (PI), or certain NRTIs were included in the study. In addition, patients with M184V/I mutations and those with 1 to 2 thymidine analog mutations also met the inclusion criteria. Historical genotypes and retrospective baseline proviral DNA genotyping determined pre-existing resistance, and pill counts were used to calculate adherence rates. Viral blips were defined as transient HIV-1 RNA viral loads that were greater than or equal to 50 copies/mL.

Among a total of 489 patients included in the study, all had switched to treatment with B/F/TAF and had 1 or more post-switch HIV-1 RNA viral load measurement(s) available at the time of enrollment. Of patients included in the study, baseline genotypic data were available for 96% (n=468) of those with protease/reverse transcriptase mutations and 93% (n=453) of those with integrase-type mutations.


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Of 468 patients with protease/reverse transcriptase mutations, 68 (15%) had pre-existing resistance to NRTIs, 50 (11%) had resistance to M184V/I mutations, 36 (8%) had 1 or more thymidine analog mutations, 101 (22%) had NNRTI resistance, and 61 (13%) had PI resistance.

At week 72, HIV viral loads of less than 50 copies/mL were measured in 99% of patients at their last study visit. In regard to viral blips, the mean frequency was 1% per timepoint and no association was found between viral blips and occurrence of virologic failure. Medication adherence rates were less than 95% in 112 patients, of whom 110 had less than 50 copies/mL on measurement of HIV viral load at their last study visit. Of note, the researchers found that all patients with medication adherence rates of less than 80% (n=15) also had viral load measurements of less than 50 copies/mL at last visit. In addition, none of the included patients developed treatment emergent resistance to B/F/TAF or discontinued the medication regimen due to lack of efficacy.

“Continued HIV [virologic] suppression and absence of treatment-emergent resistance demonstrate the efficacy of B/F/TAF in African Americans regardless of adherence or pre-existing resistance to NNRTIs, PIs, or non-tenofovir NRTIs,” the researchers concluded.

Disclosure: Some author(s) declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Andreatta K, D’Antoni ML, Chang S, et al. High efficacy of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) in african american adults with HIV including those with preexisting resistance, viral blips, and suboptimal adherence. Presented at: IDWeek; September 29 to October 3, 2021. Poster 629.

This article was updated on October 18th, 2021, to correct errors that were included in the original version. Updates to the article include revised quantities of thymidine analog mutations that met the inclusion criteria, HIV viral load measurements, and medication adherence rates.