Coadministration of voriconazole (300 mg twice daily) and bictegravir (75 mg single dose) increased bictegravir AUC by 61% (due to inhibition of CYP3A) but had no significant effect on Cmax. No dose adjustment is required upon co-administration.

Coadministration of voriconazole (300 mg twice daily) and bictegravir (75 mg single dose) increased bictegravir Cmax and AUC by 9% and 61%.

The antiviral activity, safety, and pharmacokinetics of short-term monotherapy with bictegravir was evaluated in a phase 1b, randomized, double-blinded, adaptive, sequential cohort, placebo-controlled study. HIV-infected adults not taking antiretroviral therapy were randomized to receive BIC (5, 25, 50, or 100 mg) or placebo once daily for 10 days. Steady-state plasma exposure was approximately dose-proportional up to a 100 mg dose. Bictegravir AUCs on day 10 were 87538 ng.h/ml in the 50 mg group and 178.902 ng.h/ml in the 100 mg group. Bictegravir was safe and well tolerated at all dose levels.

The efficacy and safety of bictegravir coformulated with emtricitabine and tenofovir alafenamide as a fixed-dose combination versus coformulated dolutegravir, abacavir, and lamivudine was assessed in a double-blind, multicentre, active-controlled, randomised controlled non-inferiority trial. 631 participants were randomly assigned to receive coformulated bictegravir, emtricitabine, and tenofovir alafenamide (n=316) or coformulated dolutegravir, abacavir, and lamivudine (n=315), of whom 314 and 315 patients, respectively, received at least one dose of study drug. At 48 weeks, coformulated bictegravir, emtricitabine, and tenofovir alafenamide achieved virological suppression in 92% of previously untreated adults and was non-inferior to coformulated dolutegravir, abacavir, and lamivudine, with no treatment-emergent resistance. Bictegravir, emtricitabine, and tenofovir alafenamide was safe and well tolerated with better gastrointestinal tolerability than dolutegravir, abacavir, and lamivudine

In a randomised, double-blind, multicentre, placebo-controlled, non-inferiority trial, HIV-infected adults were randomly assigned to receive oral fixed-dose combination bictegravir 50 mg, emtricitabine 200 mg, and tenofovir alafenamide 25 mg (n=320)or dolutegravir 50 mg with coformulated emtricitabine 200 mg and tenofovir alafenamide 25 mg, with matching placebo (n-325), once a day for 144 weeks. The fixed-dose combination of bictegravir, emtricitabine, and tenofovir alafenamide was safe and well tolerated compared with the dolutegravir regimen. Incidence and severity of adverse events were similar between groups, and few participants discontinued treatment due to adverse events (5 [2%] of 320 in the bictegravir group and 1 [<1%] 325 in the dolutegravir group).