Table 1.

CYP17, growth inhibitory activities and androgen receptor binding of 5 and analogs.

Compound	CYP17 IC₅₀ (nM)^a	AR binding EC₅₀ (nM)^b		Cell growth inhibition GI₅₀ (μM)^c

		Wild-type (LAPC-4)	Mutant (T877A, LNCaP)	LNCaP	LAPC-4
5	47	405	1240	6.0	3.2
6	150	934	1600	8.0	16.0
8	120	2460	4340	7.0	19.0
15	^-	^-	^-	17.6	^-
18	^*	1100	1280	^-	^-
For comparison:
Casodex	^-	4300	971	^-	^-

IC₅₀ is the concentration of inhibitor required to inhibit the CYP17 enzyme activity by 50%, each in duplicate.

EC₅₀ is the concentration of compound required for a 50% displacement of [³H]R1881 from the androgen receptor.

GI₅₀ is the concentration of compound required to cause 50% growth inhibition of LNCaP or LAPC-4 cells.

Less than 30% inhibition at 500 nM.

= not determined.