Investigators at each centre randomly assigned patients ( @:@ ; block size of four ; stratified by time to suppression -LSB- < @ year or > @ year -RSB- and nadir CD@ cell count -LSB- < @ cells per L or > @ cells per L -RSB- ; computer-generated random sequence ) to continue triple treatment or switch to dual treatment ( oral lopinavir @ mg and oral ritonavir @ mg twice daily plus oral lamivudine @ mg once daily ) .