TMC310911 is a potent and orally active HIV type-1 (HIV-1) protease inhibitor with EC50 values ranged from 2.2 nM to 14.2 nM for wild-type HIV-1. TMC310911 has potent activity against a wide spectrum of recombinant HIV-1 isolates. TMC310911 has strong antiviral activity. IC50 & Target: EC50: 2.2-14.2 nM (Wild-type HIV-1)In Vitro: For a panel of 2,011 recombinant isolates with decreased susceptibility to at least one of the currently approved protease inhibitors (PIs), the FC in TMC310911 EC50 is ≤4 for 82% of isolates and ≤10 for 96% of isolates. The fold change (FC) in TMC310911 EC50 is ≤4 and ≤10 for 72% and 94% of isolates with decreased susceptibility to Darunavir, respectively. In vitro resistance selection (IVRS) performed with r13025, a multiple-PI-resistant recombinant isolate, and TMC310911 selected for mutations L10F, I47V, and L90M (FC in TMC310911 EC50 = 16). The TMC310911 EC50 values against HIV-1/LAI and HIV-2/ROD in MT4 cells with EC50 values of 14.2 nM and 2 nM, respectively, and HIV-1/LAI and HIV-1/SF2 in PBMCs with EC50 values of 2.2 nM and 2.3 nM, respectively, and HIV-1/BaL in M/M cells with an EC50 value of 13.9 nM. And the corresponding EC90 values ranged from 5.0 to 94.7 nM. The TMC310911 CC50 for MT4 cells is 9.9 μM.