Antiretroviral Activity of Emtricitabine, a Potent Nucleoside Reverse Transcriptase Inhibitor

Several studies have been conducted to determine the relative potency of emtricitabine in human lymphoblastoid T-cell lines (MT-4, CEM, or HT4-6C) acutely infected with a standardized infectious dose of a laboratory-adapted strain of HIV-1 (HIV-1 IIIB or HIV-1 LAV ) or HIV-2 (HIV-2 ZY ) Against laboratoryadapted strains of HIV-1, the EC 50 ranges were 0.009-0.5 M (emtricitabine), 0.005-0.06 M (zidovudine), 0.07-3.2 M (lamivudine), 8.5-16.0 M (didanosine) and 0.03-0.05 M (zalcitabine) (Table Emtricitabine consistently exhibited up to 10-fold greater activity than lamivudine against all viruses tested in all T-cell lines.