Galeterone

2 years -80 in solvent

Injection s.c. twice daily

LNCaP and LAPC4

Dissolved in DMSO, final concentrations ca.20 uM

Prepared at 17.2 mg/mL in a 0.3% solution of hydroxypropyl cellulose in saline

Galeterone is effective at preventing binding of [3H]-R1881 to the mutant LNCaP AR (T877A) with IC50 of 845 nM. Galeterone inhibits the DHT-induced proliferation of LNCaP and LAPC4 cells in a dose-dependent manner with IC50 of 6 uM and 3.2 uM, respectively. [1] Galeterone also inhibits the binding of [3H]-R1881 to the T575A mutant AR in PC3 cells with IC50 of 454 nM. Galeterone potently inhibits the proliferation of LNCaP and LAPC4 cells in the absence of DHT stimulation with IC50 of 2.6 uM and 4 uM, respectively. Furthermore, Galeterone treatment increases the degradation rate of the AR in a dose-dependent manner. [2] Galeterone potently inhibits the growth of the androgen-independent cell lines PC-3 and DU-145 in a dose-dependent manner with GI50 of 7.82 uM and 7.55 uM, respectively. Galeterone induces the endoplasmic reticulum stress response resulting in down-regulation of cyclin D1 protein expression and cyclin E2 mRNA. [3] Galeterone effectively inhibits proliferation of HP-LNCaP and C4-2B cell lines with IC50 of 2.9 uM and 9.7 uM, respectively. Galeterone treatment at 1 uM effectively inhibits androgen receptor activation in LNCaP cells (50%) and HP-LNCaP cells (70%). Galeterone decreases activation of the androgen receptor in both LNCaP cells and HP-LNCaP cells with IC50 of 1 uM and 411 nM, respectively, and down-regulates androgen receptor protein expression by 50% after 24 hour of treatment. [4] Galeterone reduces AR protein and mRNA expression, antagonizes AR-dependent promoter activation induced by androgen, and significantly reduces the phospho-4EBP1 levels. [6]

7 days

Cells are seeded in 24 well multi-well plates. Cells are treated with the increasing concentration of Galeterone in steroid free medium with or without 1 nM DHT (LNCaP), or 10 nM DHT (LAPC4) and allowed to grow for 7 days. The number of viable cells is compared by MTT assay (LAPC4) or XTT assay (LNCaP) on the 7th day.

Galeterone (TOK-001) is a selective CYP17 inhibitor and androgen receptor (AR) antagonist with IC50 of 300 nM and 384 nM, respectively, and is a potent inhibitor of human prostate tumor growth. Phase 2.