Kaplan-Meier survival plot of MET-1–bearing NOD/SCID mice. The groups (11-12 mice/group) included those receiving intravenous PBS, 4 weekly doses of 4 mg/kg (100 μg/mouse) daclizumab, a single dose of 12 μCi (0.444 MBq) ²¹¹At-7G7/B6, a single dose of 12 μCi (0.444 MBq) ²¹¹At-11F11, and the combination of 4 mg/kg of 4-week daclizumab and a single dose of 12 μCi (0.444 MBq) ²¹¹At-7G7/B6. Survival in the treated groups was followed out to 94 days. The group receiving 4-week daclizumab, the group receiving a single dose of 12 μCi (0.444 MBq) ²¹¹At-7G7/B6, and the group receiving a 4-week combination of 4 mg/kg daclizumab with a single dose of 12 μCi (0.444 MBq) ²¹¹At-7G7/B6 had significantly prolonged survivals when compared with the PBS group or with the control group receiving the single dose of 12 μCi (0.444 MBq) ²¹¹At-11F11 (P < .001). The combination treatment of tumor-bearing mice with a single dose of 12 μCi (0.444 MBq) ²¹¹At-7G7/B6 and daclizumab for 4 weeks significantly prolonged the survival of the group when compared with the group that received 4-week daclizumab or the group that received a single dose of 12 μCi (0.444 MBq) ²¹¹At-7G7/B6 (P < .05).