Anastrozole(ZD1033) is a potent and highly selective aromatase (CYP19) inhibitor (IC50 = 15 nM) that has no discernible effect on adrenocorticoid hormone synthesis.
IC50 value: 15 nM [1]
Target: Aromatase
in vitro: Anastrozole has high intrinsic potency in vitro and inhibits human placental aromatase with an IC50 of 15 nM. Anastrozole it is 200 times as potent as AG, twice as potent as 4-OHA and one third as potent as fadrozole [1]. Anastrozole inhibits aromatase by binding competitively to the hem group of the CYP unit of the enzyme thereby reducing estrogen biosynthesis in the periphery and the breast. Anastrozole has little or no effect on other steroid hormones [2].
in vivo: Anastrozole elicits maximal activity in vivo in rats (inhibition of ovulation and androstenedione-induced uterine hypertrophy) and monkeys (lowering of plasma oestradiol) at 0.1 mg/kg p.o. At 30 times this dose, anastrozole does not elevate plasma 11-deoxycorticosterone in monkeys, and at 100 times this dose, does not affect plasma aldosterone levels or Na+/K+ excretion in rats, plasma K+ concentrations in dogs, or cause adrenal hypertrophy in rats or dogs [1]. ZD1033 was extensively metabolized in animals after oral administration; the metabolites were excreted predominantly in urine. The elimination half-life of ZD1033 in humans ranged from 30 to 60 hours 

Abiraterone   Abiraterone (CB-7598) is a potent steroidal cytochrome P450 17alpha-hydroxylase-17,20-lyase (CYP17) inhibitor with an IC50 at 4 nM. Abiraterone is used in treatment of prostate cancer.

IC50 value:
Target: CYP17
Abiraterone, a potent suppressor of cytochrome P450 17 α-hydroxysteroid dehydrogenase-mediated androgen production, has heralded a new era in the hormonal treatment of men with metastatic CRPC. Abiraterone acetate is associated with hypokalaemia, hypertension, and fluid retention or oedema, secondary to its mechanism of action, and with cardiac adverse events and hepatotoxicity; however, in the phase III studies the incidences of the most frequently reported grade 3 or 4 adverse events of special interest were relatively low.