Kaplan-Meier estimates of OS of patients dichotomized by tumor burden changes at the 8 weeks as the landmark time point. Of 85 patients who were eligible for the 8-week landmark analysis, 66 patients whose tumor burden stayed below the baseline burden (< 0% increase) during the first 8 weeks of therapy had longer OS compared with 19 patients who had ≥ 0% increase in tumor burden by 8 weeks of therapy (median OS: 30.7 v 16.2 months, HR = 0.44, P = .01). HR, hazard ratio; OS, overall survival.