Switching to B/F/TAF maintains high viral suppression in elderly with HIV

Switching to a single-tablet regimen of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) maintains virologic suppression over 72 weeks in older people living with HIV (PLWH), according to a study presented at the HIV Glasgow 2020 Congress.

“As the age of PLWH increases, studies are needed to assess the safety and efficacy of antiretroviral therapy [ART] in this population. Older individuals are at increased risk of comorbidities and polypharmacy, so ensuring the safety and tolerability of ART in older PLWH is critical,” said the researchers.

B/F/TAF is a single-tablet regimen that has few drug-drug interactions and a high barrier to resistance. Being in small tablet size with no food restrictions for dosing, this combination regimen presents a convenient potential option, in particular for the elderly PLWH, the researchers pointed out.

The phase IIIb, international, open-label study enrolled 86 PLWH aged ≥65 years (median age 69 years, 13 percent female) who were virologically suppressed (defined as HIV-1 RNA <50 copies/mL). They were originally receiving either elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) or a tenofovir disoproxil fumarate (TDF)-based regimen and were switched to B/F/TAF. Majority of them were on E/C/F/TAF (92 percent) at baseline. [HIV Glasgow 2020, abstract P038]

At 72 weeks after switching, eighty participants (93 percent) continued to maintain high rates of virologic suppression. The remaining six participants (7 percent) did not have virologic data within the study window, of which four were due to treatment discontinuation. Even so, the last available HIV-1 RNA was <50 copies/mL for the four who had discontinued due to adverse events (AEs).

After excluding those with no data available, the rate of virologic suppression was 100 percent at week 72 in missing-data imputation analysis. The CD4 cell count changed by a median of 53 cells/mm³ (interquartile range, −49 to 120) from baseline.

No virologic failures were reported after switching, nor was there any emergent resistance.

In terms of safety profile, there were four AEs leading to premature discontinuation of study drug: one due to a grade 2 abdominal discomfort which was considered to be drug-related, another due to alcohol withdrawal, one because of benzodiazepine withdrawal, and the fourth was suicide. Grade 3–4 drug-related AEs occurred in 2 percent of the participants, but there were no serious AEs deemed to be drug-related.

For laboratory-related AEs, seven reported were of grade 3 and one was of grade 4, the latter being hyperkalaemia. There were no discontinuations due to bone, renal or hepatic AEs. 

“Through week 72, high rates of virologic suppression were maintained in PLWH who switched to B/F/TAF,” the researchers concluded.

“The safety and efficacy data support the switch to B/F/TAF in virologically suppressed HIV-infected individuals aged ≥65 years,” they added.