Study AI455-096 was a 48-week, randomised, double-blind study with Zerit (40 mg twice daily), in combination with lamivudine (150 mg twice daily) plus efavirenz (600 mg once daily), in 76 treatment-naive patients, with a median CD4 cell count of 261 cells/ mm3 (range 63 to 962 cells/ mm3) and a median plasma HIV-1 RNA of 4.63 log10 copies/ ml (range 3.0 to 5.9 log10 copies/ ml) at baseline.