Aliskiren hemifumarate(CGP 60536 hemifumarate) is a direct renin inhibitor with IC50 of 1.5 nM. IC50 value: 1.5 nM [1] Target: renin in vitro: Aliskiren hemifumarate appears to bind to both the hydrophobic S1/S3-binding pocket and to a large, distinct subpocket that extends from the S3-binding site towards the hydrophobic core of renin. Oral bioavailability of Aliskiren hemifumarate is 2.4% in rats, 16% in marmosets and about 2.5% in humans [2]. in vivo: Aliskiren hemifumarate (< 10 mg/kg, oral) inhibits plasma renin activity and lowers blood pressure in sodium-depleted marmosets[3].Once-daily oral treatment with Aliskiren hemifumarate lowers blood pressure effectively, with a safety and tolerability profile, in patients with mild-to-moderate hypertension[4].