B/F/TAF safe, effective in adults with high HIV-1 RNA, low CD4 count

Adults with a high baseline HIV-1 RNA or low CD4 count may benefit from initial treatment with bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF), which has been shown to be safe and efficacious over 5 years of follow-up in a study presented at the ID Week 2022 Virtual Conference.

“People with HIV (PWH) who are initiated on guidelines-recommended first-line integrase strand transfer inhibitor-based antiretroviral therapy routinely achieve rapid virologic suppression,” said the researchers led by Dr Moti Ramgopal, medical director of Midway Specialty Care Center in Florida, US.

“[H]owever, those with a high baseline HIV-1 RNA and/or low CD4 count may be more challenging to manage in the short- and long-term,” they added.

Ramgopal and colleagues analysed results from two studies that assessed B/F/TAF as initial treatment stratified by baseline HIV-1 RNA and/or CD4 count to further describe the long-term outcomes over 5 years in select subgroups.

In the two studies, adults with HIV were randomly assigned to receive blinded initial treatment with B/F/TAF compared with dolutegravir (DTG)/abacavir/lamivudine (study 1489) or DTG+F/TAF (study 1490) for 144 weeks, followed by an optional switch to open-label B/F/TAF for 96 weeks.

The team of Ramgopal then presented the virologic response (HIV-1 RNA <50 c/mL, missing=excluded and missing=failure) and treatment-related adverse events (AEs) from a pooled analysis of participants initially randomized to B/F/TAF with baseline HIV-1 RNA 100,000‒400,000 copies/mL, HIV-1 RNA >400,000 copies/mL, and/or CD4 count <200 cells/µL through week 240.

A total of 634 adults (median age 32 years, 89 percent men) were originally randomized to B/F/TAF and included in the present analysis. Of these, 33 percent were of Black/African descent and 24 percent were Hispanic/LatinX. [IDWeek 2022, abstract 1251]

At baseline, 80 participants presented with a CD4 count <200 cells/µL and 119 with HIV-1 RNA >100,000 copies/mL. In the latter subgroup, 20 PWH had HIV-1 RNA >400,000 copies/mL.

At week 240, the low CD4 count and/or high HIV-1 RNA subgroups demonstrated high virologic suppression. In addition, none of the participants in the final resistance analysis showed virologic resistance to any component of B/F/TAF.

The most common treatment-related AEs across subgroups were nausea, headache, and diarrhoea. No serious AEs were recorded. However, one participant in the low CD4 count subgroup discontinued treatment due to an AE; no individual in the HIV-1 RNA subgroup ceased treatment.

“These outcomes provide additional evidence that B/F/TAF is an effective and durable regimen for a broad range of PWH, including those with advanced disease,” the researchers said.

These findings were also consistent with those of an earlier study involving 86 older adults with HIV in five European countries. Results showed that switching to B/F/TAF was effective and well tolerated in virologically suppressed adults aged ≥65 years over 48 weeks. [Infect Dis Ther 2021;10:775-788]

Rates of virologic suppression at weeks 24 and 48 were 97.7 percent and 90.7 percent, respectively. None of the participants had HIV-1 RNA ≥50 copies/ml, and all of them (100 percent) had virologic suppression by missing=excluded analysis at both time points. [Infect Dis Ther 2021;10:775-788]