Rilpivirine (R278474) hydrochloride is a potent and specific diarylpyrimidine (DAPY) non-nucleoside reverse transcriptase inhibitor ( NNRTI ). Rilpivirine hydrochloride has high antiviral activity against wild-type HIV ( EC 50 =0.4 nM) and mutant viruses ( EC 50 =0.1-2.0 nM). Rilpivirine hydrochloride has a high genetic barrier to resistance development of HIV In Vitro R278474 is active against wild-type HIV-1 (EC 50 =0.4 nM) and all single and double mutants tested (EC 50 =0.1-2.0 nM). R278474 (10-5000 nM; 30 d) does not observe the sign of wild-type HIV-1 breakthrough at 1 μM within 30 days. R278474 inhibits 81% of clinical isolates (about 1200 recombinant clinical isolates) at a 50% inhibitory concentration (EC 50 ) less than 1 nM, and inhibits 94% at EC 50 less than 10 nM. TMC278 shows subnanomolar EC 50 s against wild-type HIV-1 group M isolates (0.07-1.01 nM). MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo R278474 (10-160 mg/kg; p.o. for 1 month) does not produce abnormal effects in rat, apart from liver weight increase and species-specific thyroid hypertrophy, both at the higher dose levels . R278474 (i.v.) exhibits elimination half-life ranges from 4.4 h in rat to 31 h in dog, and exposure (AUC inf ) amounts to 3.1 μg?h/mL (4 mg/kg) in rat, 8.7 μg?h/mL (1.25 mg/kg) in dog, 1.4 μg?h/mL (1.25 mg/ kg) in monkey, and 44?μg h/mL (1.25 mg/kg) in rabbit . R278474 (p.o.) exhibits half-life ranges between 2.8 h in rat and 39 h in dog, and oral bioavailability of 32% and 31% in rat and dog . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Form:Solid IC50& Target:IC50: 20±10 μM (MMP), Ki: 1.5±0.27 nM (MMPs)