A potent inhibitor of HIV integrase (IC50 = 2.7 nM for HIV-1 integrase-catalyzed strand transfer in vitro); inhibits HIV-1 viral replication (EC50 = 0.51 nM) in PMBCs; CC50 values are 189 and 52 μM in unstimulated and stimulated PBMCs; prevents replication of several HIV-1 strains (EC50s = 0.36-2.1 nM) that are resistant to NRTIs, NNRTIs, and protease inhibitors and impairs their ability to infect CIP4 cells