Table 1.

Novel agents targeting the AR axis in late-stage development for castration-resistant prostate cancer

	Agent	Phase	Population	Notes	References/clinicaltrials.gov
AR antagonist
	ARN-509	III	Non-metastatic CRPC	SPARTAN. Randomized, double- blinded, placebo controlled	Rathkopf 2013 (Rathkopf et al. 2013b)/ NCT01946204 (recruiting)
	ODM-201	III	Non-metastatic CRPC	ARAMIS. Randomized, double- blinded, placebo controlled	Fizazi 2014 (Fizazi et al. 2014)/ NCT02200614 (recruiting)
	Enzalutamide	III	Non-metastatic CRPC	PROSPER. Randomized, double- blinded, placebo controlled	NCT02003924 (recruiting)
	EPI-001	Pre- clinical	CRPC	Small-molecule inhibitor of the AR NTD	Andersen 2010 (Andersen et al. 2010) Myung 2013 (Myung et al. 2013)
Biosynthesis inhibitor
	Galeterone (TOK-001)	II	CRPC	ARMOR2, Mechanisms of action: CYP17A1 inhibitor, AR antagonist and may enhance AR degradation	NCT01709734 (recruiting)
	VT-464	I/II	CRPC	Potent inhibitor of CYP17,20-lyase	NCT02012920 (recruiting)
Targeting the AR carrier molecule
	AT13387	I/II	CRPC, post- abiraterone	Resorcinol inhibitor	Shapiro 2014 (Shapiro et al. 2014)/NCT01685268 (active, not recruiting)
	Apatorsen (OGX-427)	II	mCRPC with concurrent AA and prednisone use	Antisense inhibitor of HSP27. Preliminary data from NCT01120470 showed promising results	NCT01681433(recruiting)
Targeting the AR and PI3K/Akt/mTOR pathways
	GDC-0068	II	CRPC, post- docetaxel	AKT inhibitor, with and without AA	NCT01485861(recruiting)
Combination trials
	Enzalutamide plus AA	III	mCRPC	Randomized (enzalutamide plus AA vs. enzalutamide alone)	NCT01949337 (recruiting)

AR, androgen receptor; CRPC, castration-resistant prostate cancer; NTD, N-terminal domain; mCRPC, metastatic castration-resistant prostate cancer; AA, abiraterone acetate; HSP, heat shock protein; PI3K, phosphatidylinositol 3-kinase; mTOR, mammalian target of rapamycin.