The primary endpoint will be the PFS rate at 6 month, which is defined as the proportion of subjects alive, free of disease progression at 6 months. The treatment regimen would be considered of insufficient activity for further study in this population if PFS rate at 6 months is 50% or less, and the minimum required level of efficacy that would warrant further study with the proposed regimen is a 75% PFS rate at 6 months. The study design includes interim monitoring for futility using a predictive probability approach. We will stop the study early if given the information at the interim analysis, it is unlikely that the PFS rate at 6 months will be greater than 50% if the study continues to the end.