Apricitabine is a deoxycytidine analogue. It is structurally related to lamivudine where the positions of the oxygen and the sulfur are essentially reversed. Even though apricitabine is a little less potent in vitro compared to some other NRTIs, it maintains its activity against a broad spectrum of HIV-1 variants with NRTI resistance mutations. Apricitabine is in the final stage of clinical development for the treatment of NRTI-experienced patients.