When protocol Amendment 2 was released, there were patients who had already been randomized into the study. These patients were included in the trial prior to making changes to the eligibility criteria. Thus, the study contains 2 distinct cohorts. Cohort 1 contains those patients who had already been randomized, and had been deemed eligible based on the original inclusion/exclusion criteria, prior to Amendment 2. No new patients were randomized to Cohort 1. Cohort 2 contains patients who were randomized, having been found eligible based on the revised inclusion/exclusion criteria, after Amendment 2. Differences in the inclusion and exclusion criteria are indicated below.