Table 2.

ARV microbicides in preclinical development

Category	Mechanism of action	Compound	Stage of development
Nonnucleoside reverse transcriptase inhibitors	Bind to a hydrophobic pocket within reverse transcriptase to block DNA polymerization	UC-781	Development has been discontinued
		IQP-0528	Preclinical
Entry inhibitors
CCR5 antagonists	Bind to CCR5 to inhibit binding of coreceptor to gp120, preventing virus entry into cells	RANTES analogues	Preclinical
		L860167	Preclinical
gp120 inhibitors	Bind to gp120 to prevent binding of virus to cells	Cyanovirin-N	Preclinical
		Griffithsin	Preclinical
		BMS-599793	Preclinical
mAbs	Bind to a range of different targets on viral gp120 or gp41, or to cellular receptors (eg, CD4, CCR5, CXCR4) to prevent entry of HIV into cells	b12	Preclinical
		MAPP66	Preclinical
D-peptide	Targets gp41 pocket	PIE12-Trimer	Preclinical [49]
Retrocyclin	Binds to heptad repeat 2 (HR2) region of gp41	RC-101	Preclinical [50]

CCR5 chemokine (C–C) motif receptor 5, CXCR4 chemokine (C–X–C motif) receptor 4, mAbs monoclonal antibodies, RANTES regulated upon activation, normal T-cell expressed and secreted