Table 2.

Novel agents targeting the AR axis in late-stage development for breast cancer

	Agent	Phase	Population	Notes	References/clinicaltrial.gov
AR antagonistz
	Bicalutamide	II	AR+ mTNBC	(Gucalp et al. 2013)	NCT00468715 (active, not recruiting)
	Enzalutamide (MDV3100)	II	AR+ mTNBC		NCT01889238 (active, not recruiting)
Biosynthesis inhibitor
	Abiraterone acetate	I/II	ER+ or AR+ mBCa, post- menopausal		NCT00755885 (recruiting)
	Abiraterone acetate	II	AR+ TNBC, molecular apocrine		NCT01842321 (recruiting)
	Orteronel (TAK-700)	Ib	HR+ mBCa	(prostate) (Dreicer et al. 2014)	NCT01808040 (recruiting)
	Orteronel (TAK-700)	II	HR+ mBCa		NCT01990209 (recruiting)
Targeting the AR carrier molecule
	Ganetespib (STA-9090)	II	mBCa	Small molecule Hsp90 inhibitor	NCT01273896 (completed results pending)
	Ganetespib (STA-9090)	II	mBCa (TNBC, ER+, HER2+)	Small molecule Hsp90 inhibitor	NCT01677455 (active, not recruiting)
Selective AR modulators (SARMs)
	Enobosarm (GTx-024)	II	mBCa		NCT01616758 (active, not recruiting)
Combination trials
	Trastuzumab + enzalutamide	II	mBCa, AR+,HER2+		NCT02091960 (recruiting)
	Fulvestrant + enzalutamide	II	ER+AR+ mBCa		NCT01597193 (recruiting)
	Exemestane + abiraterone	II	mBCa, ER+	(O'Shaughnessy et al. 2014)	NCT01381874 (active, not recruiting)

AR, androgen receptor; mTNBC, metastatic triple-negative breast cancer; ER, estrogen receptor; mBCa, metastatic breast cancer; TNBC, triple-negative breast cancer; HR, hormone receptor; hsp, heat shock protein.