Information Bictegravir (GS-9883) is a novel, potent, once-daily, unboosted inhibitor ofHIV-1 integrase. Targets HIV-1 integrase In vitro Bictegravir exhibits potent and selective in vitro antiretroviral activity in both T-cell lines and primary human T lymphocytes, with 50% effective concentrations ranging from 1.5 to 2.4 nM and selectivity indices up to 8,700 relative to cytotoxicity. Bictegravir inhibits the strand transfer activity with an IC50 of 7.5 ± 0.3 nM. Relative to its inhibition of strand transfer activity, Bictegravir is a much weaker inhibitor of 3\'-processing activity of HIV-1 integrase, with an IC50 of 241 ± 51 nM. Bictegravir potently inhibits HIV-1 replication in both MT-2 and MT-4 cells with EC50s of 1.5 and 2.4 nM, respectively, and selectivity indices (50% cytotoxic concentration [CC50]/EC50) of ∼6,800 in MT-2 cells and ∼1,500 in MT-4 cells.