CD161 is a potent, selective, and orally bioavailable BET bromodomain inhibitor (IC50s: 28.2 nM and 7.2 nM for BRD4 BD1 and BRD4 BD2) with good anticancer activity.

BRD4 BD2:7.2 nM, BRD4 BD1:28.2 nM

CD161 (NKR-P1A) (30-3000 nM; 1 hour) is very effective in inducing rapid down-regulation of c-Myc at as early as the 1 h time point and in a dose-dependent manner. CD161 has Kis of 8.2 nM and 1.4 nM for BRD4 BD1 and BRD4 BD2, respectively.

CD161 (5 mg/kg (iv), 25 mg/kg (po); 0-24 hours) has the t1/2 of 2.4 hours (iv) and 2.9 hours (po) for rat; the Cmax of 7333 ng/mL (po) for rat. CD161 (po; 20, 40 mg/kg/day; 45 days) achieves essentially complete tumor growth inhibition. The t1/2 of mice is 0.5 hours (iv) and 1.60 hours (po); the Cmax of mice is 983.1 ng/mL (po).