Sustained virological response was achieved by 1036 patients ( 50.5 % ) during the retrospective phase : 325 were genotypes 1/4 ( 34.1 % ) and 684 were genotypes 2/3 ( 67.2 % ) and by 800 patients ( 38.6 % ) during the prospective phase : 300 were genotypes 1/4 ( 28.4 % ) and 473 were genotypes 2/3 ( 51.5 % ) .