The Food and Drug Administration has approved a combination drug intended to treat HIV-1 infections – bictegravir, emtricitabine, tenofovir alafenamide – in virologically suppressed (HIV-1 RNA less than 50 copies/mL) adults who have no history of antiretroviral treatment or as a replacement for their current antiretroviral regimen.
The approval of the new combination drug (Biktarvy) was based on four active, randomized, controlled trials comprising three double-blind studies and one open label study. After 48 weeks of treatment in all trials, CD4+ cell count was evaluated to determine the efficacy of bictegravir, emtricitabine, tenofovir alafenamide, compared with other antiretroviral therapies.
In trial 1489, patients were randomized 1:1 to receive Biktarvy (n = 314) or ABC/DTG/3TC (abacavir 600 mg/dolutegravir 50 mg/lamivudine 300 mg) (n = 315). Trial 1490 was similar to trial 1489, with patients randomized 1:1 to receive either Biktarvy (n = 320) or DTG + FTC/TAF (dolutegravir + 50 mg, emtricitabine 200 mg/tenofovir alafenamide fumarate 25 mg) (n = 325). In trial 1489, the mean increase in CD4+ count after 48 weeks was 233 cells per mm3 and 229/mm3 in the Biktarvy and ABC/DTG/3TC groups, respectively. Similarly, counts in trial 1490 CD4+ after 48 weeks were 180/mm3 and 201/mm3 in the Biktarvy and DTG + FTC/TAF groups, respectively.
Trial 1844, another randomized trial, was composed of patients who switched to Biktarvy from their older treatment. Patients were randomized 1:1 to the new treatment (n = 282) or their previous antiretroviral regimen (n = 281).
Over 48 weeks, the mean change in CD4+ cell count was –31 cells per mm3 in subjects who switched to Biktarvy and 4/mm3 in subjects who stayed on ABC/DTG/3TC.
The open-label portion of the study, trial 1878, evaluated the safety and efficacy of switching from other retroviral treatments (n = 287) to Biktarvy (n = 290). The average change in CD4+ count after 48 weeks was 25 cells per mm3 who switched to Biktarvy and 0/mm3 who stayed on their previous regimens.
The new combination has received a boxed warning regarding the risk of severe acute exacerbations of hepatitis B that have been reported in patients coinfected with HIV-1 and HBV and have discontinued products containing emtricitabine (FTC) and/or tenofovir disoproxil fumarate (TDF) and may occur with discontinuation of Biktarvy. Such patients should be closely monitored for hepatic function with both clinical and laboratory follow-up for at least several months in patients if they discontinue Biktarvy. If appropriate, antihepatitis B therapy may be warranted.
The approved recommended dosage for bictegravir, emtricitabine, tenofovir alafenamide combination drug is one tablet daily with or without food. More information is available on the FDA website.