For each of these three comparisons, the difference in responder rate and associated 95% confidence interval was determined. Once the optimum TBV dose was identified, a test of noninferior efficacy was performed by comparing the proportions of responders at TW12 in the MLN0128 ic50 optimal TBV and RBV treatment arms. Chi-squared or the Fisher’s exact test compared anemia rates between the TBV and RBV groups with a 95% confidence interval. Secondary efficacy measures included the SVR defined as HCV RNA <100 copies/mL (39 IU/mL) and/or at least a 2-log decrease from baseline at TW4, TW24, TW48 and FW4 and FW12 and relapse rates at FW4, FW12, and
FW24. Secondary safety measures included the comparison of incidence of treatment-emergent adverse events. Subgroup analysis by HCV RNA levels at baseline, body weight, age, sex, race, and baseline fibrosis were performed using the trend test and the Fisher’s exact test for the primary endpoint. In addition, the Cochran-Mantel-Haenszel check details procedure, with the
Breslow-Day test was used to examine the homogeneity of treatment effect across strata. The investigators and the sponsor managed the data for this study. The sponsor completed the statistical analysis. The authors had access to the clinical study report and have either written or provided intellectual input to the manuscript. A total of 278 patients were randomized at 51 U.S. centers between March 2007 and October 2008. A total of 86 (41%) of patients in the TBV arms and 25 (36%) in the RBV arm completed treatment and follow-up. Overall, 122 (59%) patients withdrew prematurely
in the TBV arms compared to 45 (64%) in the RBV group. The most commonly cited reasons for premature withdrawal were lack of response (29%) and adverse events (20%). Figure 1 shows the disposition of patients during treatment. Baseline characteristics across the four treatment groups were similar (Table 1). The majority of patients were male (61%) with a mean weight of 82.1 kg and mean age of 49 years. African American or Latino patients accounted for 30% of the study medchemexpress population and 81% had high viral load defined as >400,000 IU/mL at baseline. The proportions of patients in the ITT population with an EVR, the primary endpoint of this study, were comparable between all groups with no statistical difference versus RBV. EVR was achieved in 64.2% (43 of 67) in the 20 mg/kg group, 57.1% (40 of 70) in the 25 mg/kg group, 54.4% (37 of 68) of the 30 mg/kg group and 51.4% (36 of 70) in the RBV group. Virologic response for TW4, 12, 24, and 48 as well as SVR are shown in Table 2. The proportion of patients with undetectable HCV RNA at every time point was similar between the TBV and RBV groups. Although responder rates were numerically lower at TW12 in the TBV 30 mg/kg group and somewhat higher at TW24 and TW48 in the TBV 20 mg/kg group, they were not significantly different for any of the TBV doses compared with RBV.