An NNRTI (Kis = 2.93 and 3.85-56.5 nM for wild-type and mutant HIV-1 RTs, respectively); inhibits wild-type and mutant HIV-1 viral replication in MT-4 human T lymphoid cells (IC95s = 1.5-1,500 nM); prevents RNA plus-strand initiation (IC50 = 17 nM); reduces HIV-1 cDNA in spleen of HIV-1-challenged HIV-susceptible transgenic rats,