²¹¹At-CD38 therapy in subcutaneous MM models. Mice bearing subcutaneous OPM-2^Luc xenografts were treated on day 0 with 30 or 45 µCi ²¹¹At-CD38 or ²¹¹At-Ab⁻ (isotype control); n = 8 to 9 mice per group. Tumor dimensions were monitored 3 times weekly and mice euthanized when tumor volumes met IACUC requirements. (A) Tumor progression for untreated controls and 45-µCi groups; error bars = 1 SEM. (B) Kaplan-Meier survival curves. The 45-µCi ²¹¹At-CD38 treatment increased median survival relative to untreated (P < .0001) and to 45-µCi ²¹¹At-Ab⁻ treated mice (P = .0005). The 30-µCi groups are not shown for visual clarity; data are described in “Results.”