Of 328 patients who were assigned to a treatment group, 223 had a baseline HCV RNA level ≥400,000 IU/mL (84 C/C, 108 T/C, 31 T/T) and 105 had a baseline HCV RNA level <400,000 IU/mL (27 C/C, 60 T/C, 18 T/T). The rs12979860 genotype was determined for 97 of 150 (64.7%) patients with an RVR assigned to group D. The majority of these patients (60 [61.9%]) had the homozygous C/C genotype, and 37 individuals

carried the T allele (35 had the T/C genotype, 36.1%; 2 had the T/T genotype, PF-562271 mouse 2.1%). Of 97 patients with an RVR assigned to group D and with a known rs12979860 genotype, 93 (95.9%) achieved an EoT response, of whom four were lost to follow-up. Among the 89 patients with known end-of-follow-up results, 78 patients (87.6%) achieved an SVR and 11 (12.4%) relapsed. SVR rates exceeded 80%, regardless of rs12979860 genotype (Fig. 3A). Relapse rates were numerically lower in patients with the C/C genotype, but did not differ significantly from those in patients PF-6463922 cost carrying the T allele (T/C and T/T combined) overall (Fig. 3B). The results were similar when the analysis was restricted to genotype 1 patients (Fig. 3C,D). Only one of the 17 HCV genotype 4 patients with an RVR relapsed. This individual had the C/C genotype. Among individuals with the C/C genotype and baseline HCV RNA levels of <400,000 IU/mL and ≥400,000 IU/mL, respectively, 5.0% (1/20) and 13.9% (5/36) of patients relapsed. Among those patients with

T allele (T/C or T/T genotype) and baseline HCV RNA level <400,000 IU/mL the relapse rate was 11.5% (3/26). Only seven patients with T allele and a baseline HCV RNA level ≥400,000 IU/mL achieved an RVR: five achieved an SVR and two relapsed. The rs12979860 genotype was determined for 183 of 289 (63.3%) patients without an RVR who achieved an EVR at week 12 and were randomized to groups A or B. Fifty (27.3%) patients had the

homozygous C/C genotype and 133 individuals carried the T allele (99 [54.1%] had the T/C genotype, and 34 [18.6%] had the T/T genotype). The distribution of rs12979860 genotypes was similar in groups A and B (Fig. 1). Among patients with known rs12979860 genotypes in groups A and B, respectively, 82/93 (88.2%) and 63/90 (70.0%) achieved an EoT response, of whom 51/82 (62.2%) and 51/63 (81.0%) achieved an SVR, and 31/82 (37.8%) and 12/63 (19.0%) patients relapsed. SVR rates were numerically ID-8 higher in patients treated for 72 weeks regardless of rs12979860 genotype, although the positive impact of extended treatment was magnified in patients who carried a T allele (Fig. 4A). Relapse rates, the primary outcome in the original study, were numerically lower in patients treated for 72 weeks (20.0%, 95% confidence interval [CI] = 10.2-30.9) compared with 48 weeks (26.9%, 95% CI = 27.3-49.2; odds ratio [OR] = 2.58; 95% CI = 0.32-6.83), and were markedly lower in patients who carried a T allele (48 versus 72 weeks: 42.9%, 95% CI = 29.7-56.8 versus 18.8%, 95% CI = 8.9-32.