By Ethan Covey

A mixed-dose combination of bictegravir, emtricitabine and tenofovir has demonstrated noninferiority in a recently completed phase 3 trial in HIV-positive patients.

The regimen, which is produced by Gilead Sciences, was found to be safe, well tolerated and noninferior to coformulated dolutegravir, abacavir and lamivudine (Triumeq, Viiv Healthcare) (Lancet 2017 Aug 31. [Epub ahead of print]).

“Physicians continue to look for treatment regimens with simple, convenient dosing that can sustain virologic suppression with a safety profile that is appropriate for most HIV patients,” said Joel Gallant, MD, MPH, the medical director of specialty services at Southwest CARE Center, in Santa Fe, N.M., and the lead author of the study.

Bictegravir, which is a novel, potent integrase strand transfer inhibitor (INSTI), features a high in vitro barrier to resistance and a low potential for drug–drug interactions, according to Dr. Gallant.

The randomized, double-blind, placebo-controlled trial studied HIV-1–infected adults (age ≥18 years) at 122 outpatient centers in nine countries in North America, Europe and Latin America. The participants were all previously untreated; were HLA-B*5701–negative; did not have hepatitis B infection; showed sensitivity to emtricitabine, tenofovir, lamivudine and abacavir; and had an estimated glomerular filtration rate of 50 mL/min or greater. Each individual was randomly assigned to receive coformulated bictegravir 50 mg, emtricitabine 200 mg and tenofovir alafenamide 25 mg, or coformulated dolutegravir 50 mg, abacavir 600 mg and lamivudine 300 mg, with matching placebo, once daily for 144 weeks.

Of the 631 participants, 92% of those in the bictegravir group achieved virologic suppression at 48 weeks. In the dolutegravir, abacavir and lamivudine group, 93% of patients achieved the same result. Additionally, adverse events were similar between groups, and none of the individuals developed treatment-related resistance to any study drug.

“Combinations of an integrase inhibitor plus a dual-NRTI backbone have become a standard of care for initial treatment of HIV,” Dr. Gallant added. “The investigational regimen of BIC/FTC/TAF has been well tolerated with low rates of discontinuations due to adverse events, a high barrier to resistance and few drug interactions.”

The authors also noted that since the BIC/FTC/TAF regimen doesn’t require testing for HLA B*5701, and provides guideline-recommended treatment for individuals coinfected with HIV and hepatitis B, it may prove beneficial for rapid administration of therapy in the clinical setting.